Was the universe made for life? - AlwaysAsking.com - AlwaysAsking.com Podcast

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Amy (00:00):
You're listening to the always asking.com podcast. This

(00:04):
is episode number seven.
Today's question was theuniverse made for life?
over the last century,physicists and cosmologists made
a series of disturbingdiscoveries of cosmic
coincidences. They found thatparameters of nature and
physical law are seen speciallycrafted to make life possible.

(00:28):
What are the implications ofthis? Are we just very lucky?
Was the universe designed? Ordoes it imply the existence of
other universes and today wewill review the data and
theories to find answers tothese questions. Enjoy

Brian (00:46):
was the universe made for life? In other words, were
physical laws and constants ofnature somehow chosen to allow
for complex life? In the past 65years, science has gradually
revealed a shocking lesson byevery right you shouldn't be
alive, none of us should. It wasonly too easy for something to

(01:08):
have gone wrong. For instance,had gravity been a little
stronger, or had carbon beenslightly different, or had
neutrinos not existed. In allcases, the result is disaster. A
dead universe devoid ofchemistry, life and
consciousness. Yet somehow,through incredible luck, divine

(01:29):
intervention, or otherwise, wedodged every bullet who enjoy a
universe with life. Amongpossible universes, ours is
among the rare few where life ofany kind is possible. And
against all odds, the universeis a place where life is
possible. To what can we ascribethis great fortune? How can it

(01:51):
be explained? as, quote? whatreally interests me is whether
God could have created the worldany differently? In other words,
whether the requirements oflogical simplicity admits a
margin of freedom. And quote,Albert Einstein,
why is the universe the way itis? Could it have been any other

(02:15):
way? First clues. In the pastcentury, cosmologists and
particle physicists developed anearly complete understanding of
our world and cosmos. Ourcurrent understanding now covers
a range from the astronomicalscales of superclusters, down to
the subatomic scales of quarks.
between the 1960s and 1980s,cosmologists developed a model

(02:38):
of the history and initialconditions of the universe known
as the lambda CDM model, whichis also known as the standard
model of cosmology. The lambdaCDM model has recently been
confirmed by satelliteobservations, including
observations made by the COBE wmap, and Planck satellites.
Likewise, between the 1950s and1970s, particle physicists

(03:02):
developed a model that describesfundamental forces of nature and
all known elementary particles.
It is called the Standard Modelof particle physics. Aside from
describing known particles, thismodel predicted particles that
have never been seen. Forinstance, it predicted the Higgs

(03:24):
boson. The Large Hadron Colliderat CERN, detected the Higgs
boson in 20 1248 years after itwas predicted, earning Peter
Higgs and Francois Engler the2013 Nobel Prize in Physics. But
these new theories also disturbphysicists and cosmologists, the

(03:44):
more they came to understand theparticulars of our universe, the
properties of particles, thestrength of the forces, the
initial conditions of the BigBang, the more they realized we
shouldn't even be here. Quote,as we look out into the universe
and identify the many accidentsof physics and astronomy that
have worked together to ourbenefit, it almost seems as if

(04:07):
the universe must in some sensehave known we were coming and
quote, Freeman Dyson in energyin the universe 1971.
A perfect balancein the 1960s cosmology
transition from a loose set ofunconfirmed speculations into a
hard science backed byobservation. In this emerging

(04:28):
field, cosmologists found acoincidence that couldn't be
brushed off as mere luck, itdemanded explanation. In 1948,
Ralph alpha and Robert Hermanwere the first to predict that
if the Big Bang happened, spaceshould be filled with a uniform
radiation emanating from alldirections in the sky, a
primordial heat remaining fromthe earliest moments of the

(04:51):
universe. At the time, there wasno technology to detect this
radiation alpha Herman'sprediction soon fell into
obscurity and was forgotten. 16years later, the chairman of
physics at Princeton, RobertDeke rediscovered this
prediction. With his colleagues,Jim Peebles and David Wilkinson,

(05:12):
they plans to build a deviceable to detect this radiation.
They could thereby confirm ordisprove the Big Bang. But as
fate had it, they were beaten tothe punch by two radio
astronomers Arno Penzias andRobert Wilson of Bell Labs. In
1964, Penzias and Wilson spent afrustrating year trying to

(05:35):
isolate the source of a signalinterfering with their
observations to no avail. amutual friend suggested that
they reach out to Robert Dick,who was a short drive away from
their facility in Holmdel, NewJersey. Penzias and Wilson
called dick who was in hisoffice with people's and
Wilkinson. After hearing thedetails of this interference

(05:57):
signal from the Bell Labs,researchers, Dick turned to his
colleagues and said, well, boys,we've been scooped. The
Princeton team drove to the BellLabs facility to hear the signal
for themselves. The signal hadall the right characteristics.
Its temperature, distribution,consistency, directionality, and

(06:18):
intensity all matched perfectlywith predictions of The Big Bang
Theory. They listen to a cosmichum of radiation that had been
traveling through space forbillions of years, the universe
had a beginning. It was one ofthe greatest scientific
discoveries of the 20th century,it earned Penzias and Wilson,

(06:39):
the 1978 Nobel Prize in Physics.
But this wasn't the end of thestory. In 1969, Dick recognized
an unsettling consequence of theBig Bang and the expansion of
the universe, it is highlyunstable. Have the density of
the universe been slightlygreater, the universe would have

(07:01):
collapsed billions of years ago,long before life formed, have
the density been slightly less,the universe would have expanded
too fast for galaxies and starsto form. It was as though the
universe sat on a knife's edge.
Had it not been so balanced, itwould have fallen to either side
and we wouldn't be here. Why theuniverse is density is perfectly

(07:23):
balanced is known as theflatness problem. Since
according to general relativity,a perfect balance implies that
spatial curvature is zero, flat,and modern observations confirm
space is flat to within theprecision of our measurement
abilities within 1%. Due to theunstable nature of the balance,
it implies that earlier, thebalance was even greater.

(07:47):
calculations reveal that if thecurvature is below 1%, today,
then one second after the BigBang, it would have been 10 to
the power of 15 times less. Thesituation is analogous to
rolling a bowling ball down thelanes so long the ball could
roll for billions of years. Ifwe find the ball drifted less

(08:08):
than 1% from center afterrolling for billions of years,
it suggests the ball must havebeen even closer to center when
it started.
Quote,if the rate of expansion one
second after the Big Bang hadbeen smaller, by even one part
in 100,000 million million, itwould have relapsed before it
reached its present size. On theother hand, if it had been

(08:31):
greater by a part in a million,the universe would have expanded
too rapidly for stars andplanets to form. And quote,
Stephen Hawking in a briefhistory of time 1996 edition, it
appears as though we are thewinners of a cosmic lottery,
have there been just slightlymore mass, then the universe

(08:54):
would have collapsed billions ofyears ago, had there been
slightly less, there would be nogalaxies, stars, planets or
humans, there'd be no time forany structures to condense out
of a rapidly expandinginterstellar gas. Our universe
is a Goldilocks universe wherethe density is just right, and
monkeying with physics. As longas human beings have looked up

(09:19):
at the night sky, we've wonderedwhat the stars were and what
makes them shine. But despitewondering for hundreds of
thousands of years, only in thelast 80 have we come to
understand how and why the starsshine. In 1920, Arthur Eddington
speculated that fusion ofhydrogen into helium powered the
stars, but it wasn't until 1939that Hans Beth did the math to

(09:44):
prove it, earning Beth the 1967Nobel Prize in Physics. The only
chemical elements produced inthe Big Bang were hydrogen and
helium along with trace amountsof lithium and beryllium. It was
believed that stars couldaccount for the production of
the 88 other naturally occurringelements, the elements we know

(10:05):
and love, which form our bodiesand are necessary for our
existence. These include carbon,nitrogen, oxygen, sodium, ion,
and so on. But there was aproblem. In 1939, it was
discovered that there is nostable element with an atomic

(10:25):
mass of five. This is known asthe mass five roadblock. Like a
staircase missing a step, itprevented heavier elements from
being built up adding onehydrogen nucleus at a time.
Instead, the process will holdit helium for a helium atom with
two protons and two neutrons,and perhaps two helium atoms

(10:47):
could fuse to make berylliumeight, and thereby jump over the
missing fifth step. But thisdidn't work either. In 1932,
john cockcroft and Ernest Waltonfound that beryllium eight is
unstable, it lasts for less thana thousandth of a trillionth of
a second of their work on themthe 1951 Nobel Prize in Physics

(11:10):
for transmuting the elementsrealizing the long held dream of
alchemists there are no stableelements with a mass number of
five or eight. In the words ofWilliam Fowler, the mass gaps at
five and eight spelled the Doomof gamers hopes that all nuclear
species could be produced in theBig Bang one unit of mass at a

(11:31):
time. So yet another step wasmissing. With no known mechanism
to get over the hurdle of themass five and mass age
roadblocks, there was noexplanation for how elements
necessary to life came to be.
This problem led thecosmologists Fred Hoyle in 1953,

(11:52):
to make what's described as themost outrageous prediction ever
made in science, pilesoutrageous prediction was the
existence of a yet undiscoveredexcited energy state of the
carbon 12 nucleus, which hadsomehow been missed by all the
particle physicists in theworld. If this state existed, it
would allow the triple alphaprocess the simultaneous

(12:14):
collision of three helium fournuclei to yield carbon 12. If
carbon could be made this way,the mass five and mass age
roadblocks could be cleared, andthen other heavier elements
could be built one hydrogen orhelium nucleus at a time.
Without this state, carbon wouldbe many millions of times rarer,

(12:34):
and we wouldn't be here. SoHoyle reasoned, this state of
carbon must exist. In 1953, piletraveled from Cambridge, England
to visit William Fowler'sNuclear Physics Lab at Caltech.
Pile asked that Fowler's lab dothe experiments to check for
this state of the carbon 12nucleus, which he predicted

(12:56):
should be at an energy level of7.6 8 million electron volts.
Quote,I was very skeptical that this
steady state cosmologists, thistheorist should ask questions
about the carbon 12 nucleus pilejust insisted, remember, we
didn't know him all that well.
Here was this funny little manwho thought that we should stop

(13:18):
all this important work that wewere doing otherwise and look
for this state, and we kind ofgave him the brush off. And
quote, William Fowler ininterview 1973 but Hoyle
succeeded in convincing a juniorphysicist at the lab Ward
whaling to check for it. Fivemonths later, pile received

(13:41):
word, whaling confirmed theexistence of the excited state
of carbon 12. And it was almostexactly where Heil predicted
that 7.65 5 million electronvolts. foils prediction is
remarkable because he usedastrophysics, the physics of
stars to find unknown propertiesin nuclear physics, the physics

(14:02):
of atoms and then nuclei, followwas an instant convert, quote.
So it was really quite a tour deforce that a man who walked into
the lab predicted the existenceof an excited state of a
nucleus. And when theappropriate experiment was
performed, it was found and nonuclear theorists starting from

(14:24):
basic nuclear theory could dothat then, nor can they really
do it now. So hoyles predictionwas a very striking one. And
quote, William Fowler ininterview 1973 his father took a
year off from his post atCaltech to work with Hoyle in
Cambridge. Together with twoastronomers, Margaret and

(14:48):
Jeffrey Burbidge, they workedout a complete theory of element
formation, showing how everyelement is produced and
explaining the relativeabundances of the elements as
found in nature. And their workwas revolution. And it made a
name for the author's. For thiswork. Fowler received the Nobel
Prize in Physics in 1983. poil,however, did not share in the

(15:12):
prize creating controversy. Inany event, no one denied the
significance of theiraccomplishment. With their 1957
paper, humanity finally had anunderstanding of where all the
matter which makes up our world,our food, our shelter, our very
bodies came from the innermostdepths of long dead stars. This

(15:35):
is what Carl Sagan meant when hesaid we are star stuff
harvesting starlight quote, Weare literally the ashes of long
dead stars. If you're lessromantic, we are the nuclear
waste from the fuel that madethose stars shine and quote. So
Martin Reese in what we stilldon't know, why are we here

(15:58):
2004. And so the world as weknow it is to the carbon 12
nucleus having this chanceproperty, like the delicate
balance of the density of theuniverse, the existence of this
state hangs in a delicatebalance. As it happens, the
energy level of this state is at7.655 mega electron volts, have

(16:23):
the energy level of this statebeing less than 7.596 mega
electron volts or greater than7.716 mega electron volts, there
will be almost no carbon in theuniverse. The minor miracle of
the carbon 12 nucleus havingthis excited state and it being
in exactly the right range didnot go unnoticed.

(16:44):
Quote,some super calculating intellect
must have designed theproperties of the carbon atom.
Otherwise the chance of myfinding such an atom through the
blind forces of nature would beutterly miniscule. A common
sense interpretation of thefacts suggests that a super
intellect has monkeyed withphysics, as well as with
chemistry and biology, and thatthere are no blind forces worth
speaking about in nature. Thenumbers one calculates from the

(17:07):
facts into me so overwhelming asto put this conclusion almost
beyond question. And quote, FredHoyle in the universe past and
present reflections 1982. Thebalancing of the Universes
density and the fortune of thecarbon 12 excited state with
just the first of many cosmiccoincidences, the more

(17:30):
scientists probe the innerworkings of the universe, the
more lucky coincidences theyfound, with each one evidence
gathered to support the ideathat the laws of physics are
finely tuned to permit theemergence of complexity. And
with that complexity, life,cosmic coincidences, and the
expansion rate of the universeand the existence of the excited

(17:55):
state for the carbon 12 nucleusare due to fundamental physical
forces. For instance, theexpansion rate of the universe
is governed by the strength ofgravity and the energy of the
vacuum. Likewise, the excitedstate of carbon 12 is determined
by electromagnetic and nuclearforces. So far, particle

(18:16):
physicists have identified 25dimensionless constants in the
standard model, whilecosmologists have identified
five others in a universe wherethese fundamental constants have
different values is just asmathematically and logically
consistent as our own. Theyrepresent other universes among

(18:36):
the set of possible universes.
Accordingly, these constants areconsidered free parameters of
the 30 known fundamentalphysical constants, very few of
them can change to anysignificant degree without
leading to a barren universe.
For instance, universe is ofonly hydrogen universes with no

(18:57):
aggregations of matter, oruniverses of only black holes.
Let's review the fragility ofour universe two tweaks to these
constants, chemistry and life.
Our universe has a richchemistry, the 92 naturally
occurring chemical elements cancombine in a nearly unlimited

(19:20):
number of ways. Atoms assembleinto molecules that encode
digital information and can evenself arrange into structures
that reproduce themselves inthree minutes after the Big
Bang. The only elements in theuniverse were hydrogen and
helium, in the universe remainthis way for hundreds of
millions of years. A thin hazeof light gas. it's doubtful that

(19:45):
any life could arise in auniverse with only these
elements of helium is chemicallyinert, and by itself, hydrogen
can only make dihydrogen.
Without chemistry, the universewould be lifeless. Fortunately,
the fusion in stars gave us 90other elements, and with them
new ways to combine, react andgenerate complexity. of the 92

(20:08):
stable chemical elements 60 canbe found in your body, and of
those around 30 are believed toplay a biological role in humans
as the King of the elements.
Some elements are more importantthan others when it comes to

(20:28):
supporting life. Of those carbonis the most special. For its
unique role in chemistry,carbons been called the king of
the elements of carbon is theonly element that can link up
for other atoms and also formunlimited chains made of links
with itself. Carbon is thereforethe glue that binds large and

(20:51):
complex molecules together.
Nearly every molecule with morethan five atoms contains carbon.
And this includes essentiallyall bio molecules,
carbohydrates, fats, proteins,RNA, DNA, amino acids, cell
walls, hormones, andneurotransmitters. Without
carbon, there could be no lifeas we know it, there could be no

(21:15):
life based on molecules. Sincecomplex molecules are impossible
without the glue of carbon tohold them together. That carbon
exists at all is due to themiracle of the oil state, which
depends on properties of nuclearand electromagnetic forces in a
desert universe. After hydrogenand helium, oxygen is the most

(21:38):
abundant element in theuniverse. by mass, it makes up
89% of the oceans, and 50% ofEarth's crust even makes up the
majority of your weight. Forevery 100 pounds, someone weighs
65 pounds Oxygen. Oxygen isimportant to life for its

(22:01):
reactivity. It reacts with everyelement except for fluorine and
the noble gases. without oxygen,there could be no h2 Oh, and the
whole universe would be adesert. And we owe our existence
not only to the presence ofoxygen in the universe, but to
the availability of oxygenoutside the cause of stars. All

(22:22):
oxygen came from the cause ofmassive stars. When these stars
exhausted their fuel, theircause collapsed under their own
weight. These cores are roughlythe size of our moon that have
the mass of our Sun.
Accordingly, their gravitationalfield is 200 billion times

(22:44):
stronger than Earth gravity.
It's so strong that in fallingmatter reaches a quarter of the
speed of light by the time ithits the center. In 10 seconds
10% of the stars mass isconverted into energy, and the
result is a type two supernova,also known as a core collapse
supernova. The stars outerlayers falling in would create a

(23:06):
black hole and lock away alloxygen forever. Except this
doesn't happen. In the lastmoments of collapse,
interactions by the weak nuclearforce trigger a bounce that
blows away the outer layers ofthe star. Have the weak force
been stronger, this bounce wouldhappen too early. If it had been
weaker, then the bounce wouldhappen too late. In both cases,

(23:30):
the result is a disaster. Theentire star, along with all of
its oxygen would fall into ablack hole and never be seen
again. without oxygen chemistryis crippled. There would be no
water, acids, bases, sugars,carbohydrates, fats, proteins,
alcohols, nor any respiration,combustion or photosynthesis as

(23:55):
we know them. Our lives areindebted to yet another precise
balance. This time, it is abalance of the seemingly
inconsequential weak nuclearforce.
Quote,every breath you take contains
atoms forged in the blisteringfurnaces deep inside stars.
Every flower you pick containsatoms blasted into space by

(24:19):
stellar explosions that blazedbrighter than a billion suns.
And quote, Marcus Chan in themagic furnace, the search for
the origins of atoms 2001.
Particle Physics and life. Thechemical properties of elements

(24:39):
are set by properties of smallerparts called particles. These
include protons, neutrons, andelectrons in the nucleus of the
atom is made of nucleons protonsand neutrons, while the outer
shell of the atom is composed ofelectrons. nucleons are
themselves made of morefundamental particles called

(25:01):
quarks. The Standard Modelcontains 17 known elementary
particles, and nearly everyparticle in the Standard Model
of particle physics has toexist, or else we would not be
here. Moreover, in most cases,the properties of each particle
such as its mass have to be justso a world of electrons and

(25:26):
electrons being so small andlike may seem remote and
abstract, but the world we knowis primarily the world of
electrons. The light we see isemitted by electrons. Sounds we
hear are carried by electronsbouncing off each other, and
tastes and smells we experienceare caused by chemical reactions

(25:46):
driven by electrons. Every timewe touch something, we feel the
repulsion of that thingselectrons. Every chemical
reaction is activity betweenelectrons. Accordingly, the
properties of elements, thecompounds, they can form, their
level of reactivity, all of itis determined by the properties

(26:07):
of electrons. If the mass orcharge of electrons are
different values, all ofchemistry would change. For
example, if electrons wereheavier, atoms would be smaller
and bonds would require moreenergy. If electrons were too
heavy, there would be nochemical bonding at all. If

(26:27):
electrons were much lighterbonds would be too weak to form
stable molecules like proteinsand DNA, visible and infrared
light would become ionizingradiation, and they would be as
harmful as x rays and uvr. To usnow, our own body heat would
damage our DNA. Luckily for us,electrons weigh just enough to

(26:50):
yield a stable but not sterilechemistry. Quote, the laws of
science, as we know them, atpresent contain many fundamental
numbers, like the size of theelectric charge of the electron,
and the ratio of the masses ofthe proton and the electron. The
remarkable fact is that thevalues of these numbers seem to

(27:11):
have been very finely adjustedto make possible the development
of life. For example, if theelectric charge of the electron
had been only slightly differentstars either would have been
unable to burn hydrogen andhelium, or else they would not
have exploded. And quote,Stephen Hawking in a brief
history of time 1988 A starlessuniverse, electrons are very

(27:38):
light compared to the protonsand neutrons. The protons mass m
sub p is 1,836.15 times the massof an electron m sub e, and the
neutrons mass m sub n is1,838.68 times the mass of an
electron m sub e. in a ton ofcoal, the electrons contribute

(28:03):
little more than half a pound.
We've seen how electron weightis of critical importance to
chemistry. But so to our massesof other particles, it was
important that one, protons andneutrons be close in weight to
yet different mass by more thanone electron, three, and also

(28:29):
that neutrons be heavier thanprotons. As it happens, all
three of these conditions holdtrue. had any of them not been
met, we end up with a universedevoid of life in particle
physics provides no explanationfor why neutrons are heavier
than protons rather than theother way around. Except if

(28:49):
protons were heavier, therecould be no lifelike us. A free
neutron is a neutron not part ofan atomic nucleus. Free neutrons
are unstable. They have a meanlifetime of about 15 minutes.
Left alone, a free neutron willdecay into a proton and
electron. Such decay is possiblebecause neutrons weigh more than

(29:14):
a proton and electron puttogether had instead, protons
weighed more than neutrons wouldbe stable and protons would be
unstable. A free proton wouldthen be able to decay into a
neutron and a positron. But mostof the hydrogen in the universe
has a nucleus that is nothingbut a free proton. If protons

(29:36):
were unstable, then hydrogen isunstable. Little hydrogen would
survive today, there would be nostars as we know them, only
neutron stars and black holes.
properties of subatomicparticles at the smallest scales
determine the course of eventsof the universe at the largest
scales. If neutrons weighed everso slightly less There would be

(29:58):
no stars. It was also necessarythat neutrons be unstable, had
protons and neutrons weighed thesame or been within one
electrons weight, then bothnucleons would be stable, and
they would have equal numbers ofprotons and neutrons in the
first minutes following the BigBang. Again, the result is

(30:19):
disaster. With equal numbers,each proton could pair with a
neutron to form hydrogen tohydrogen to rapidly reacts to
form helium four, there would beno more hydrogen of any kind in
the universe. No fuels are powerstars like our Sun, no water, no
organic chemistry, no life. In auniverse without atoms and

(30:45):
photons are particles of lightand carriers of the
electromagnetic force. photonsare the reason the sun warms you
like magnets repel electronsbinds to nuclei to make atoms
and why your eyes can see. Alaser beam consists of photons,
so to our old gamma rays, xrays, ultraviolet light, visible

(31:09):
light, infrared, microwaves andradio waves. Of all known
particles, only two aremassless. One is the glue and
the other is the photon. It wasnecessary for life in the
universe that photons bemassless Have they not been,
there would be no atoms. Virtualphotons carry the electrostatic

(31:35):
and magnetic forces. Becausephotons are massless virtual
photons can act over anydistance. If on the other hand,
photons had mass, then virtualphotons could only act over
short ranges on the order of thesize of a nucleus. There would
then be no attraction orrepulsion by electrons and

(31:57):
nothing to bind them to atoms.
There would be no chemistry onlyplasma ghosts to the rescue very
to kilometer under a mountain inJapan 13,000 electronic eyes
vigil over a tank of ultra purewater. This is the Super camio

(32:17):
cans detector at the kameokaObservatory in Japan. Each eye
is 20 inches wide and sensitiveenough to detect single photons
as they wait. In total darknessshielded from radiation by the
mountain submerged in 20 Olympicsized swimming pools of water
and the eyes wait patiently fora flash of light to appear in

(32:40):
the water. If they're lucky,this happens maybe once every
100 minutes. But what couldcause a flash of light out of
total darkness ghost particles.
The flashes are due to a tinyparticle known as the neutrino.
neutrinos are so small andlight, it takes half a million
of them to equal the weight ofone electron. Further, they have

(33:01):
no electric charge and so canpass straight through normal
matter. Even whole mountains. Awall of LED one light year thick
would only block half of them.
Quote,neutrinos are really pretty
strange particles when you getdown to it. They're almost
nothing at all, because theyhave almost no mass and no

(33:24):
electric charge. They're justlittle wisps of almost nothing.
And quote, john Conway and PBSinterview 2011. The infrequency
of neutrino detection at thekameoka Observatory is not
because neutrinos are rare,neutrinos are everywhere. Each

(33:45):
second 100 billion neutrinospass through the tip of your
thumb. On Earth, most neutrinoscome from the core of the sun.
About 2% of the sun's energy isradiated away is neutrinos. To
neutrinos The earth istransparent, that day or night,

(34:05):
they pass through us unnoticed.
This is earns neutrinos thenickname of ghost particles.
This is why neutrinos are sohard to detect only once every
few hours is a neutrino stoppedby the massive water tank in
kameoka. But on February24 1987, something strange

(34:31):
happened. It had not happenedbefore nor has it happened since
in the span of 10 seconds, thekameoka Observatory registered
12 separate flashes, it was nota problem with the equipment at
the same time, and on the otherside of the world. The IMD
detector in Ohio also saw aflurry of flashes in their

(34:52):
neutrino detector during thosesame 10 seconds. Something
somewhere released an incredibleburst of neutrinos. As it turned
out, the source of this neutrinoburst was something far away and
long ago, the death of a starbeyond the galaxy. These
neutrino labs were the first todetect the explosion. And

(35:15):
astronomers wouldn't notice theevent until several hours later.
Today, a network of neutrinolabs now former supernova early
warning system in 2002,Masatoshi Koshiba, who directed
the neutrino experiments, andRaymond Davis Jr, who built the
first neutrino detector sharethe Nobel Prize in Physics for

(35:38):
the detection of theseneutrinos. Given their ghostly
nature, it would be easy towrite off neutrinos as playing
no important role in theuniverse and having no relevance
to life. But we owe ourexistence to the tiny neutrino.
It is the neutrino that rescuesoxygen and other vital elements

(35:59):
from disappearing into thecollapsing core of a dying star.
During a core collapse, 100times more energy is released in
10 seconds than our sun willemit in her 10 billion year
life. Around 99% of this energyis released as neutrinos, only a
ghost particle could escape fromthe core and reach the outer

(36:21):
layers of the collapsing star.
There they deposit a little oftheir energy, giving the outer
layers enough of a push to blowthe star apart and save elements
like oxygen from otherwisecertain doom. There would be no
oxygen, no water, and likely nolife if it weren't for the
neutrino and the role it playsduring the deaths of these
giants.

(36:44):
Quote,a very interesting question to
me is, is the universe morecomplicated than it needs to be
to have us here? In other words,is there anything in the
universe which is just here toamuse physicists, and it's
happened again, and again thatthere was something which seemed
like it was just a frivolitylike that, where later we've

(37:04):
realized that, in fact, no, ifit weren't for that little
thing, we wouldn't be here. I'mnot convinced, actually, that we
have anything in this universewhich is completely unnecessary
to life. And quote, Max Tegmarkand what we still don't know why
are we here 2004 fundamentalforces and life there are just

(37:27):
four fundamental forces innature. One, electromagnetism,
two, gravity, three, the weaknuclear force and for the strong
nuclear force, these forcesdrive all movement and every

(37:50):
physical interaction. In each ofthem. Scientists have noticed an
inexplicable balancing act ofelectromagnetism, and the
greatest damn mystery inphysics. The movement of the
compasses needle is driven bythe electromagnetic force. The
strength of the electromagneticforce is determined by a

(38:12):
dimensionless constant calledthe fine structure constant
alpha. Alpha equals 0.00729351,approximately one over 137 due
to alpha having a value of oneover 137, the speed of an
electron in a hydrogen atom isone 137 the speed of light. It

(38:34):
also sets the fraction ofelectrons that emit light when
they strike phosphorescentscreens at one 100 and 37th.
Determining such fundamentalproperties as the speed of
electrons in atoms means alphadetermines how large atoms are,
which in turn determines whatmolecules are even possible. A

(38:54):
different alpha would changeproperties like the melting
point of water and the stabilityof atomic nuclei. Physicists
calculated that had alphadiffered from its current value
by just 4%. The carbon 12excited energy level would not
be in the right place, therewould be almost no carbon in the

(39:15):
universe if alpha were one over131, or one over 144.
Quote,it has been a mystery ever since
it was discovered more than 50years ago, and all good
theoretical physicists put thisnumber up on their wall and
worry about it. Immediately, youwould like to know where this

(39:35):
number for a coupling comesfrom? Is it related to pi or
perhaps to the base of naturallogarithms? Nobody knows. It's
one of the greatest damnmysteries of physics, a magic
number that comes to us with nounderstanding by man. You might
say the hand of God wrote thatnumber. And we don't know how he
pushed his pencil. We know whatkind of Dance to do

(39:59):
experimentally to measure thisnumber very accurately, but we
don't know what kind of dance todo on the computer to make this
number come out without puttingit in secretly, and quote,
Richard Fineman in QED thestrange theory of light and
matter 1985 gravity and thelives and deaths of stars, the

(40:21):
gravitational force between anapple and the earth pulls both
together. The strength ofgravity is determined by a
dimensionless constant calledthe gravitational coupling
constant, alpha sub G, alpha subG equals 5.907 times 10 to the
power of minus 39. It isstriking how small alpha sub G

(40:46):
is. The smallness of alpha sub gmeans gravity is exceptionally
feeble compared to the otherforces so much weaker. It's an
unsolved mystery of physicscalled the hierarchy problem. If
alpha sub g were larger, you andeverything else in the universe
would weigh more. Conversely, ifalpha sub g was smaller,

(41:07):
everything would weigh less. Butif gravity was so weak, we
wouldn't be here. In 1947, thephysicist Pascal Jordan noticed
a strange coincidence, hedescribed it in his book The
origin of the stars. Thecoincidence he noticed was that
the mass of the Sun issuspiciously close to the weight

(41:29):
of a proton divided by alpha subg to the power of three over
two. And, in fact, the mass ofnearly every star is within a
factor of 10. From this number,there is a reason for this, the
electrostatic repulsion betweentwo protons is about 10 to the
power of 36 times stronger thantheir gravitational attraction.

(41:50):
and, accordingly, once you havearound 10 to the power of 36,
times three halves, or 10, tothe power of 54 protons in one
place, as in a star, thegravitational attraction between
the star and the proton beginsto eclipse the strength of two
protons repulsion, sparkingfusion. But should the mass of a
compact object increase muchpast this level, the star

(42:14):
becomes unstable and will eitherblow itself apart or collapse
into a neutron star or blackhole at the Chandra Sacre limit.
The reason stars are so big isbecause gravity is so weak. If
gravity was stronger, everythingminiature rises, planets,
mountains, animals, even theobservable universe need to

(42:35):
shrink to not collapse undertheir weight. And see why are
things the size that they arein. A stronger gravity not only
decreases the stars size, butalso its life expectancy. A
smaller style leaks heat morequickly. If gravity were 10
times stronger, and equivalentlyhot star would live just one

(42:57):
10th of the time. So if alphasub g had 37 zeros rather than
38 after its decimal point, astar like our Sun would live not
10 billion years, but 1 billionshort lived stars Doom complex
life, it took billions of yearsfor multicellular life to appear
on Earth, the chance for life toappear at all only diminishes as

(43:21):
alpha sub g increases. Thecosmologists Martin Reese
described the astrophysics of ahypothetical universe where
alpha sub G is a million timesstronger than it is, quote,
he would leak more quickly fromthese mini stars. In this
hypothetical strong gravityworld, stellar lifetimes would

(43:44):
be a million times shorter.
Instead of living for 10 billionyears, a typical star would live
for about 10,000 years, many sunwould burn faster and would have
exhausted its energy before eventhe first steps in organic
evolution had got underway. Andquote, so Martin Reese in just
six numbers 1999. Life owes itsexistence to weak gravity. But

(44:10):
we should also be grateful thatalpha sub g isn't zero or
negative. And this leads todisaster of another kind. with
zero or negative gravity, nogalaxies, stars or planets form,
there would be no place for lifeTo begin, for there would be no
places at all, the weak nuclearforce and the biggest

(44:33):
explosions. The weak force isultimately responsible for the
eerie glow surrounding nuclearreactors. The weak nuclear force
causes particle decay, the decayrate is set by a dimensionless
constant called the weak forcecoupling constant alpha sub W.
Alpha sub W is approximately0.000001 or two tend to the

(44:56):
power of minus six. Unstableparticles such as neutrons
muons, and pi ions spontaneouslyconvert or decay into other
particles. For example, invaderdecay and neutron decays into a
proton, electron and neutrino isa larger alpha sub w shortens

(45:20):
the lives of unstable particlesand accelerates radioactive
decay. But altering alpha sub whas other consequences. The
value of alpha sub w causes thebiggest explosions in the
universe. The biggest manmadeexplosion was the 50 mega tons
are bomba, and it had a yield of50 million tons of TNT. Its

(45:43):
mushroom cloud rose to 42 milesreaching the edge of space at
five times the height ofEverest. Yet this explosion is
pitiful next to the biggestexplosions known as the biggest
explosions in the universe, ourcore collapse supernovae, they
release the energy of 10 to thepower of 28 Tsar bombs, if each

(46:06):
sandgren equal to billions ourbombs, and if every grain of
sand on earth speeches explodedat once, that would approach the
power of a core collapsesupernova.
Quote,the neutrino luminosity of a
core collapse supernova brieflyexceeds the light output of all
the stars of the observableuniverse. And quote, Cray Hogan

(46:28):
and why the universe is just so1999.
As we've seen, these mostpowerful explosions depend on
the most ghostly of particlesthe neutrino, but the explosions
also depend on the neutrinohaving the right amount of

(46:49):
ghostliness ever so rarely, aneutrino interacts with a
particle through the weaknuclear force. For instance, a
neutrino might interact with anelectron and give it enough
energy to knock it away from itsatom. This electron, if
traveling fast enough, creates ashockwave of light, the optical

(47:10):
equivalent of a sonic boom knownas the cheering cough effect.
The effect is named for Pawelcheering cough, who first
noticed it in 1934, earning hima share of the 1958 Nobel Prize
in Physics. This effect isresponsible for the flashes of
like neutrino detectors lookfor, and also the blue glow seen

(47:30):
inside nuclear reactors. Sinceneutrinos feel the weak nuclear
force, the value of alpha sub wdetermines the ease at which
neutrinos interact with regularmatter. It sets the neutrinos
level of ghostliness. Recentmodels show that alpha sub w
been less than half its currentvalue, neutrinos would leave the

(47:52):
collapsing core too quickly toforestall the collapse.
Conversely, add alpha sub wbeing more than five times its
current value, then neutrinoswould be trapped in the core for
too long. Again, they would beunable to prevent the collapse
of the star. Recent computersimulations reveal how the

(48:12):
largest explosions in theuniverse are caused by otherwise
on assuming particles. Corecollapse supernovae are the
source of all free oxygen in theuniverse. Every Breath You Take
and drop of water you sipcontains oxygen from these stars
blown into space by neutrinos.
If alpha sub w had been a littlebigger or smaller, elements

(48:35):
necessary for life would stayforever trapped in the remnants
of giant stars. Accordingly,life as we know it depends on
alpha sub w being close to0.000001. The strong nuclear
force and sticky nuclear armsand the strong nuclear force
reveals its power whenever atomssplit or fuse. The strong

(48:58):
nuclear force is the glue thatholds the atomic nuclei
together. The stickiness of thisglue is determined by a
dimensionless constant call thestrong force coupling constant
alpha sub s. Alpha sub s isapproximately one of the four
fundamental forces alpha sub sis the strongest. It is 137

(49:21):
times stronger than theelectromagnetic force and a
million times stronger than theweak nuclear force. Unlike
electromagnetism, and gravity,the strong force is range
limited, it can only be felt upto a few feet photometers away.
A larger alpha sub s makesfusion easier and fishing

(49:44):
harder. With a smaller alpha subs, the reverse happens. We are
lucky alpha sub s is much largerthan alpha. If it weren't, the
strong force wouldn't be able toovercome the electrostatic
reaction. have protons andnuclei of atoms wouldn't stay
together at all. In such auniverse, the only possible atom

(50:05):
is hydrogen. Accordingly, if thestrong force weren't so strong,
we wouldn't be here. In yourbody, only about 1% of your
weight comes from the weight ofyour constituent particles, and
the other 99% comes from thebinding energy of the strong
nuclear force. And the reasonthere are about 100 chemical

(50:28):
elements is due to the fact thatthe strong force is about 100
times stronger than theelectromagnetic force. But it is
a delicate balance, the strongforce must not be too strong,
had alpha sub has been 3.7%.
Stronger, fusion would be tooeasy. All hydrogen would have

(50:51):
fused into helium in the firstminutes after the Big Bang,
there would be no water, noorganic compounds, nor fuel for
stars like our Sun. Yet, ifalpha sub s were 11%, weaker,
hydrogen two wouldn't be stable.
Hydrogen two plays a necessaryrole in fusion of stars like our
Sun. So with a slightly weaker,strong force, again, our sun

(51:16):
doesn't shine. A more recentanalysis has placed even tighter
constraints on alpha sub s,given the details of how carbon
and oxygen are produced in thecause of stars. Quote, even with
a change of 0.4%, in thestrength of the nuclear nuclear
force, carbon based life appearsto be impossible, since all the

(51:39):
stars then would produce eitheralmost solely carbon or oxygen,
but could not produce bothelements
and quote, Luke a bombs in thefine tuning of the universe for
intelligent life 2011. Why doesalpha sub s have the value it

(51:59):
does? No one can say. All weknow is that if it didn't, there
would be no one here tospeculate about it. cosmology
life, we've seen how particlephysics operating at the
smallest scales of reality islittered with coincidences that
make life possible. But particlephysicists are not alone in

(52:22):
mystifying themselves withdiscoveries of this kind of
cosmologists studying thelargest scales of reality. And
the origins of the universe havefound that had the initial
conditions not been just right,none of us would be here.
infinitely intelligent babiesand spacetime dimensionality are

(52:43):
University is marked by havingthree dimensions of space,
height, width, depth, and onedimension of time. Under
Einstein's relativity, space andtime merge into a unified whole
called space time. Since thereare three dimensions of space
and one of time, physicistssometimes refer to this as a

(53:04):
three plus one spacetime. Seewhat is time, even the number
and character of dimensionsappear significant to life. In a
two dimensional space likeflatland, topological
constraints make certain vitalstructures difficult or
impossible to form. 2d spaceimposes limits on complexity,

(53:26):
for example, digestive tract catcreatures in half. Furthermore,
nerve cells neurons, and bloodvessels can't cross without
intersecting difficulties ofanother kind appear when the
number of spatial dimensionsincreases beyond three, with
four rather than threedimensions of space, Newton's

(53:48):
inverse square law becomes aninverse cube law. In space with
greater than or equal to fourdimensions, orbits are unstable.
Planets either crash into theirstars or drift away. Electron
orbits also become unstable. In1997, the cosmologists Max
Tegmark was the first to noticeand describe the apparent

(54:12):
necessity of three plus onespacetime to life. Quote, with
more or less than one timedimension, the partial
differential equations of naturewould lack the hyperbolicity
property that enables observersto make predictions. In a space
with more than three dimensions,there can be no traditional
atoms and perhaps no stablestructures in that space with

(54:35):
less than three dimensionsallows no gravitational force
and may be too simple and barrento contain observers. And,
quote, Max Tegmark in on thedimensionality of spacetime 1997
spacetime falls into the oneplace where life is possible.

(54:56):
Quote, this leaves three spatialdata I mentioned in one time
dimension as the only viableoption. In other words, an
infinitely intelligent babycould in principle before making
any observations at all,calculate from first principles
that there's a level twomultiverse with different
combinations of space and timedimensions, and that three plus

(55:19):
one is the only optionsupporting life. Paraphrasing
Descartes, it could then thinkkognito, ergo three space
dimensions and one timedimension before opening its
eyes for the first time andverifying its predictions. And
quote, Max Tegmark in ourmathematical universe 2014

(55:42):
dark matter and the cosmic web.
cosmologists suspect thereexists a particle even more
ghostly than the neutrino. Whileneutrinos can feel both gravity
and the weak force, particles ofdark matter are thought to only
respond to gravity. There aremany theories for what Dark
Matter could be. Examplesinclude axions, sterile

(56:04):
neutrinos, and wimps. And so farall have eluded direct
detection. If Dark Matter onlyinteracts through gravity, it
would be invisible, even to suchsensitive detectors as the Super
kamioka. And for all that ispresently known, dark matter
particles could be everywhere,and many might be streaming

(56:26):
through Earth and our bodiesright now. But if they are, we
wouldn't have the slightestclue. The rotational speeds of
stars within galaxies providedhints of Dark Matters presence.
In 1884, Lord Kelvin analyzedthe speeds of stars orbiting the
galaxy, he found that starsmoved so fast that they should

(56:49):
fly off, there wasn't enoughgravity from visible matter to
keep them in orbit. This ledKelvin to speculate that most
matter is in dim or dark stars.
current models suggest that bymass, dark matter makes up 84.5%
of all the matter in theuniverse, regular matter is less

(57:10):
common. Modern detection effortshave mostly ruled out large
aggregations of regular matter,such as black holes, rogue
planets, and brown dwarfs ascandidates for this missing
mass. This finding has led mostphysicists to look to a yet
undiscovered particle or familyof particles as responsible.

(57:32):
Dark Matter may be invisible,but that doesn't mean it's
unimportant. On the contrary,dark matter appears necessary to
our existence. Detailed computersimulations of the universe
reveal the critical role DarkMatter plays in the formation of
galaxies, stars, and life.
Gravity caused dark matter tocoalesce in filaments, or

(57:53):
tendrils, forming a great cosmicweb. This web is the scaffolding
for the structures of theuniverse is a regular matter,
which makes up galaxies andgalaxy clusters clumped along
the filaments of this web.
Quote,I worked on trying to make
universes without dark matter ina computer, and they were always

(58:14):
a disaster. They just neverworked. So a universe without
dark matter is just a faileduniverse. It's a pretty boring,
barren place. Galaxies justdon't form. And if galaxies
don't form, stars don't form.
And if stars don't form,presumably people don't form. It

(58:38):
was only when we got the rightchemistry, you know, the right
mix of dark matter and ordinarymatter that we suddenly came up
with replica universes that forall intents and purposes look
just like the real thing. Andquote, Carlos Franklin, what we
still don't know. Why are wehere 2004. Galaxy like objects

(59:00):
only appear in computersimulations having the right mix
of dark matter. Without darkmatter, and also the right ratio
of dark matter to ordinarymatter. Our universe would be a
boring, barren place, universalhomogeneity and unwelcome stars
in the 1964 detection ofmicrowaves by Arno Penzias and

(59:23):
Robert Wilson helped establishthe Big Bang in terrestrial
measurements showed the signalhad an equal intensity coming
from every direction in the sky.
But according to cosmologicaltheories, the signals shouldn't
be uniform, there needed to besome density variations, or else
gravity wouldn't have caused anyclumping into galaxies at all.

(59:43):
It took satellite basedmeasurements to give sufficient
precision. The measurementspainted a picture of the mottled
nature of the CMB. The cosmicmicrowave background or CMB, is
a map of the oldest radiation inthe universe as it appears
across the sky. project leadersbehind these satellite

(01:00:05):
measurements, George Smoot andjohn Mather received the 2006
Nobel Prize in Physics. In thewords of the prize committee,
the measurements marked theinception of cosmology as a
precise science of thetemperature of space across the
night sky is nearly but notperfectly uniform. It varies by
approximately two parts in100,000. This has been termed

(01:00:30):
the homogeneity constant Q, Q isapproximately 0.00002, or two
times 10 to the power of minusfive. The variations in
temperature are due to densityvariations in the early
universe. Over time, thesedensity differences became

(01:00:52):
magnified through gravity to seeall the large scale structures
we see today, the web of darkmatter, galaxy super clusters
and galaxies themselves. We arevery fortunate that Q is two
parts in 100,000, rather than in10,000, or 1 million. In either
case, we probably wouldn't behere. Q determines the size and

(01:01:12):
densities of galaxies, orreduced q leads to small and
sparsely populated galaxies.
Such galaxies wouldn't have thegravity to keep and recycle the
heavy elements bequeathed byprevious generations of stars.
If key were much smaller,galaxies wouldn't form at all. A

(01:01:36):
larger queue is no better. Hadqueue been larger galaxies
become so densely populated thatstars often pass near each
other. These unwelcome guestscause havoc for planets, they
can permanently alter planetaryorbits even cause planets to be
ejected from their star system.
This would be a disaster for anylife developing on such worlds.

(01:01:58):
If q were even bigger, say onepart in 1000, then there would
be no stars or galaxies, onlymonster black holes that quickly
swallow all matter in theuniverse. And, again, there will
be no chance for life as we knowit. Fortunately, with q equals
two times 10 to the power ofminus five, our universe is

(01:02:20):
neither too lumpy nor toosmooth. It's just right. The
stars are close enough to reuseelements from previous
generations, but not so close.
They run into each other, thecosmological constant, and
Einstein's greatest blunder isthe strength of the force that

(01:02:41):
drives the expansion of theuniverse is determined by a
number called the cosmologicalconstant lambda.
Lambda is approximately 2.888times 10 to the power of minus
122. Lambda is incredibly small,it has 120 zeros after the

(01:03:02):
decimal point, and then a twolambda is referred to by many
names such as Quintessence, darkenergy, vacuum energy, zero
point energy, anti gravity, andthe fifth force. Regardless of
what we call it, all names referto the same phenomenon that the
universe is expansion is notslowing but accelerating. In

(01:03:25):
1917, in an effort to explainhow the universe could be static
and eternal, the prevailingbelief at the time without
gravitationally collapsing,Einstein introduced lambda as a
parameter to his equations ofgeneral relativity. Quote, the
system of equations allows areadily suggested extension
which is compatible with therelativity postulate and is

(01:03:48):
perfectly analogous to theextension of Parsons equation.
For on the left hand side of theequation, we had the fundamental
tensor g sub UV multiplied by auniversal constant negative
lambda at present unknownwithout destroying the general
covariance, this field equationwith lambda sufficiently small

(01:04:08):
is in any case also compatiblewith the facts of experience
derived from the solar system.
And quote, Albert Einstein incosmological considerations in
the general theory of relativity1917 but observations by vesto
Slifer and later by Edwin Hubbleand Milton humus and suggested
the universe was not static butdynamic. In 1922, Alexander

(01:04:32):
Friedman showed that theequations of general relativity
could account for and describean expanding universe in a final
blow. Arthur Eddington whoironically proved Einstein right
in 1919. By performing the firsttest of general relativity prove
Einstein's static cosmologicalmodel wrong in 1930. Eddington

(01:04:54):
showed that a static universe isunstable and therefore could Not
be eternal. Einstein was quickto change his mind. He said new
observations by Hubble andhumans and concerning the
redshift of light in distantNebula we make the presumptions
near that the general structureof the universe is not static.
He added, the redshift of thedistant nebulae have smashed my

(01:05:18):
old construction like a hammerblow. According to George
gameau, Einstein said, theintroduction of the cosmological
term was the biggest blunder heever made in his life, and
Einstein likely considered as ablunder not for being wrong, but
because he missed anopportunity. And Einstein not
tried to prove a static universeand instead looked at what his

(01:05:40):
own equations implied. He mighthave predicted a dynamic
universe before observationalresults came in. Einstein could
have scooped Hubble, the idea ofa cosmological constant was
abandoned. But in 1980, it madea return with the theory of
cosmic inflation and cosmicinflation fill gaps in the Big

(01:06:01):
Bang. It explained where all thematter and energy came from, why
the universe is expanding, andwhy the density of the universe
rests on a knife edge. See whatcaused the Big Bang. All
inflation needed to get startedwas for the energy of the vacuum
to be nonzero. If vacuum energyis nonzero, space expands on its

(01:06:24):
own, exactly in the way that acosmological constant predicts.
Quote, the repulsive gravityassociated with the false vacuum
is just what Hubble ordered. Itis exactly the kind of force
needed to propel the universeinto a pattern of motion in
which any two particles aremoving apart with a velocity

(01:06:45):
proportional to theirseparation. And, quote, Alan
Guth in eternal inflation andits implications 2007
inflation provided an answer toone fine tuning question. It
answered Why is the density ofthe universe so close to the

(01:07:06):
critical density, but in doingso, inflation reintroduced
lambda, and the value of lambdahighlighted a fine tuning
coincidence so extreme that it'sconsidered one of the greatest
unsolved mysteries in physics.
JOHN Wheeler and Richard Finemanestimated that there ought to be
enough vacuum energy in thespace of a light bulb to boil

(01:07:27):
the Earth's oceans. According toquantum field theory, we expect
the inherent energy of thevacuum to be 10 to the power of
113 joules per cubic meter. Thattype two supernova, by
comparison is just 10 to thepower of 46 joules. But when
cosmologists measured thevacuums energy, they found it to

(01:07:48):
be pitifully weak1,000,000,000th of a joule per
cubic meter. In this case,theory and experiment disagreed
by a factor of 10 to the powerof 122. This error is described
as the worst theoreticalprediction in the history of
physics. The question of whythis prediction was so bad is

(01:08:09):
called the cosmological constantproblem, or the vacuum
catastrophe. It remains one ofthe great Unsolved Mysteries of
physics. But there is at leastone reason why vacuum energy is
so low, you probably guessed hadit not been as small as it is,
life could not exist. In 1987,before lambda was measured,

(01:08:33):
Steven Weinberg predicted thatlamda must be nonzero positive
and smaller than 10 to the powerof minus 120. Weinberg reason
that had lambda be negative, theuniverse would have
gravitationally collapsedbillions of years ago, had
instead lambda been slightlylarger than it is, say around 10
to the power of minus 119. Thenthe universe would expand too

(01:08:56):
quickly for galaxies, stars orplanets to form. In 1998. Two
teams of astronomers studyingdistant supernovae confirmed
Weinberg's prediction, and theyfound that the expansion rate of
the universe was not slowingdown, but accelerating. The
observed rate of acceleratedexpansion places lambda 2.888

(01:09:19):
times 10 to the power of minus122. This was exactly in the
range Steven Weinberg hadpredicted 11 years earlier. For
ediscovery Saul Perlmutter, Adamrecent Brian Schubert received
the 2011 Nobel Prize in Physics80 years after introducing it,

(01:09:40):
Einstein's cosmological constantwas vindicated. The only
difference is lambda is not at avalue that keeps the static
universe but instead is slightlylarger, and so it drives an
expansion of vacuum energyappears in the Casimir effect
and Vander Waals forces. Theseforces allow geckos to climb

(01:10:01):
walls and colloidal solutionslike mayonnaise to hold together
despite being a mix of oil andwater. The same energy that
holds Mayo together pushes thegalaxies apart. But the
probability of lambda having thevalue it does this so low that
it was inconceivable tophysicists, there appears to be
no reason it should be so small,aside from the fact that a

(01:10:25):
miniscule lambda is necessaryfor there to be any complex
structures or life in thisuniverse.
Quote,the fine tunings, how fine tunes
are they, most of them are 1%sort of things. In other words,
if things are 1%, different,everything gets bad. And the
physicist could say, maybe thoseare just luck. On the other

(01:10:49):
hand, this cosmological constantis tuned to one part in 10, to
the power of 120 120 decimalplaces. Nobody thinks that's
accidental. That is not areasonable idea that something
is tuned to 120 decimal placesjust by accident. That's the

(01:11:10):
most extreme example of finetuning. And quote, Leonard
Susskind in what we still don'tknow, are we real? In 2004? How
lucky were we? We've seen thenear misses good fortunes, and
happy accidents that conspiredto make life possible in this

(01:11:32):
universe. Life requires complexstructures. complex structures
require large aggregations ofmatter, and many ways to
organize it. And this requires arich chemistry. And in this
universe, a rich chemistryrequires stars and stars need
the right kind of particles withthe right masses, a balance of

(01:11:55):
the forces and precisely setinitial conditions for the
universe. What are the oddseverything would work out just
right? How likely would it havebeen to get a life sustaining
universe if the fundamentalconstants of nature were chosen
at random, the right particles,without the right particles of

(01:12:15):
the right masses, we don't havea chemistry. chemical properties
depend on three parameters. Theproton mass m sub p of the
electron, proton mass ratio,beta, and the fine structure
constant alpha. If the electronmass were 50% less stars would

(01:12:37):
be too dim. If 250% more, therewould be no hydrogen. If the
proton mass was 0.1% less, therewould be only hydrogen. If 0.2%
more, there would be onlyneutrons. If the photon had a
mass, there would be no atoms.

(01:13:01):
If the neutrino didn't exist,there would be no free oxygen.
In the graph depicting ourisland of habitability within
the possibility space of twoparameters, beta and alpha.
Constraints preventing lifeappear in the shaded regions of
life is possible in the unshadedarea. If a grand unified theory

(01:13:24):
is true, alpha must fall betweenthe two vertical lines. The
dashed line shows universeswhere stars are hot enough to
emit light with enough energy totrigger chemical reactions. For
example, photosynthesis. acrossthe range of every possibility,
our universe occupies a positionon the dashed line and the

(01:13:44):
unshaded region marked by plus,quote,
virtually no physical parameterscan be changed by large amounts
without causing radicalqualitative changes to the
physical world. And quote, MaxTegmark in his the theory of
everything, nearly the ultimateensemble theory in 1998,

(01:14:08):
balanced forces to get the rightphysics having the right
structures of the smallestscales of atomic nuclei, and the
largest scales of stars andgalaxies, the four forces have
to have a finely tuned balance.
If electromagnetism were 4%,less or 4% more, there'd be
almost no carbon. If gravity wasnon positive, there would be no

(01:14:31):
structures. If it were not lessthan 10 to the power of minus
36, there would be no long livedstars. If the weak force were
50% less, or five times more,there would be no rebound of a
core collapse, and hence nooxygen. If the strong force were
11% less stars wouldn't shine.

(01:14:55):
If 3.7% more there would be nohydrogen In the graph depicting
our island of habitabilitywithin the possibility space of
two parameters, alpha sub s andalpha life is possible in the
unshaded area. If a grandunified theory is true, alpha
must fall between the twovertical lines. If alpha sub s

(01:15:19):
was slightly stronger, we runinto the proton disaster, nuclei
of two protons become stable andthere would be no hydrogen.
Moving to the right, repulsionbetween protons becomes too
strong. As a result, carbon andall heavier elements become
unstable. Moving below thehorizontal line prevents

(01:15:40):
deuterium from forming, whichhas a key role in stellar fusion
stars like our Sun would notshine across the range of
possibilities, our universe,it's squished between all these
bounds, occupying a spot markedby the black square. Quote, if
any one of the numbers weredifferent, even to the tiniest

(01:16:02):
degree, there would be no stars,no complex elements, no life,
and, quote, Martin Reese preciseinitial conditions. A few
cosmological parameters have noimpact on biology or chemistry.
We can therefore consider themindependently tuned from other

(01:16:23):
constants of nature likeparticle masses and force
strengths. These independentcosmological parameters are the
density of dark matter zita subc, the homogeneity constant Q,
and the cosmological constantlambda. These parameters drive

(01:16:45):
the formation of galaxies, starsand planets. If spacial
dimensionality were less thanthree things would be too
simple. If more than three,there are no stable orbits, if
Dark Matter density were 50%less, there would be no
galaxies. If 20 times more,there would be no stars. If

(01:17:09):
density fluctuations were lessthan 10 to the power of minus
six, there would be nostructures, if less than 10 to
the power of minus four starswould be too close. If the
cosmological constant werenegative, the universe would
have collapsed. If it were morethan 10 to the power of minus
120, there would be nostructures. In the graph

(01:17:33):
depicting our island ofhabitability within the
possibility space of twoparameters queue and total
matter densities eater life ispossible in the unshaded region.
If the density q was slightlygreater galaxies would be too
dense and dangerous to lifebearing planets. If q or much

(01:17:53):
less galaxies wouldn't be ableto condense out of intergalactic
gas. Moving to the right, if thedark matter density is too high,
stars can't fragment out of thegas within galaxies. across the
range of all possibilities, ouruniverse sits comfortably
between these two extremesoccupying the spot marked by the

(01:18:14):
star. Quote, it seems clear thatthere are relatively few ranges
of values for the numbers thatwould allow for development of
any form of intelligent life.
And quote, Stephen Hawkingbetween order and chaos of life,
or more generally, complexitywalks a narrow line between a

(01:18:36):
suffocating simplicity and anuntameable chaos. On the side of
simplicity, we have universeswithout structure, a universe
that's nothing but a diffuse gasdevoid of galaxies, stars, and
planets. There are universeslacking heavy elements, chemical
bonding by atoms capable oflinking into large and complex

(01:18:58):
bio molecules. On the side ofchaos, we have universes lacking
stability. stars that live fastand die young galaxies swarmed
by black holes and planetsplagued by passing stars,
asteroid bombardment, and nearbygamma ray bursts and supernovae.
There are universes wherechemical bonds form and break

(01:19:19):
too easily, and where allsunlight is ionizing.
Fortunately for us, ours is auniverse that occupies a happy
medium between simplicity andchaos. Here interesting things
happen. But things are stableenough to reliably encode and
copy information, a universalrequirement for life or anything

(01:19:40):
that reproduces of the doesn'talso have knobs of particle
physics and cosmology we'vereviewed every one of them
happens to be tuned to aposition that makes life
possible. Quote, to some of us,it looks like we have to live
with the idea that the constantsof Nature, the laws of nature,
everything that we know aboutsomehow was influenced by our

(01:20:03):
own existence. And quote,Leonard Susskind in what we
still don't know, are we real2004 counting our luck. How
lucky should we count ourselvesare the odds of a life
supporting universe modestlysmall, like one in 10 are

(01:20:25):
incredibly small like one in100,000,000,001 way to estimate
this is to consider thepossibility space for each of
the fundamental constants ofnature, and then look to see
what fraction of that range iscompatible with life. For life
to be possible required not justone coincidence, but many of
each of the constants had tofall in a life compatible range.

(01:20:49):
had anyone been off, it wouldhave sterilized the universe. If
there are 12 fundamentalconstants important to life,
then the fraction of lifesupporting universes having our
laws of physics could becalculated as the volume of the
12 dimensional space compatiblewith life divided by the total
12 dimensional space of possiblevalues. But 12 dimensional

(01:21:12):
spaces are hard to imagine andeven more difficult to depict on
paper. Alternatively, we candepict this as six two
dimensional areas and considerjust two constants at a time.
For example, we might take anytwo constants, the weak force
versus the strong force, space,dimensions versus time

(01:21:35):
dimensions, electron mass versusproton mass, and so on, and
graph six areas. Each area formsa dartboard whose Bullseye is
the life friendly range. If theconstants of nature were chosen
randomly, then getting a lifefriendly universe is equivalent
to throwing a dart at a randomspot at each of the six areas

(01:21:56):
and having it hit the bull's eyeall six times. If the average
area of the bull's eyes is 10%of the total, then the odds of
hitting it six times in a rowfor a random throws one in a
million. If the area of thebullseye is 1% of the board, the
odds fall to one in a trillion.

(01:22:17):
For a typical dartboard, thearea of the bullseye is just one
1296 of the board. The odds ofhitting six Bull's eyes in six
random throws are one in 4.7million trillion so lowers to
have never happened in thehistory of darts. But how big
are the bull's eyes in the caseof fundamental constants? How

(01:22:41):
big are the boards, knowing bothis necessary to compute the
exact odds of a life friendlyuniverse in dartboards of the
fundamental constants of nature,the bullseye marks a life
friendly range. In the graphs oflife friendly regions, the life
compatible areas represent anarrow fraction of the

(01:23:02):
possibility space. This suggeststhat across the range of all
possible values, combinationssupporting life are few and far
between.
Quote,of course, there might be other
forms of intelligent life notdreamed of even by writers of
science fiction that did notrequire the light of a star like
the Sun or the heavier chemicalelements that are made in stars

(01:23:24):
and are flung back into spacewhen the stars explode.
Nevertheless, it seems clearthat there are relatively few
ranges of values for the numbersthat would allow the development
of any form of intelligent lifeand quote, Stephen Hawking in a
brief history of time 1988 butcalculating the exact

(01:23:47):
probability of life iscomplicated. In most cases,
science lacks an understandingof the possible ranges different
constants might take and howlikely different values are.
This makes quantifying the exactlikelihood of life difficult,
but there is one constant whoserange and likelihood are both
known. Further, it can beconsidered independently from

(01:24:10):
the other constant. It plays norole in determining nuclear
physics, chemistry or biology isthe finest tuning in the
dartboards of the fundamentalconstants. Some Bull's eyes are
smaller than others, we mightsay these parameters are more
finely tuned, greater precisionwas required to set those

(01:24:32):
parameters. Among all the knownfundamental constants, one of
them is the most finely tuned ofall, this finest tuning is
lambda, and the cosmologicalconstant lambda is understood to
be the inherent energy of thevacuum. According to quantum
field theory, the vacuum is acollection of overlapping

(01:24:54):
particle fields with one fieldfor each kind of particle
Particles then can be understoodas vibrations in their
respective field. Each of thefew dozen particle fields
contribute some amount ofenergy, which can be positive or
negative towards the energy ofthe vacuum. What's remarkable is
that when all of theseindependent field energies are

(01:25:17):
summed, they cancel out to 120decimal places, the value of
lambda zero, a decimal point,followed by 120 zeros. And then
finally 2888. for there to beany structures, complexity, or
life in this universe, it wasnecessary for lamda to be so

(01:25:38):
small, but how likely was it toquote, their smallness with
respect to the Planck scale isnot understood and is considered
as unnatural in relativisticquantum field theory, because it
seems to require precisecancellations among much larger
contributions. If thesecancellations happen for no

(01:25:58):
fundamental reason, they areunlikely in the sense that
something random order onenumbers gives 10 to the power of
minus 120 with a probability ofabout 10 to the power of minus
120. End quote. authors ofdirect anthropic bound on the
week scale from supernovaexplosions 2019.

(01:26:23):
To get a feeling for howunlikely such an occurrence is,
imagine we had an infinitelysided die. That is, rather than
a standard six sided die, we hadone with infinitely many sides a
sphere. On this die, we candenote each of the infinite
values existing between minusone and plus one, we might do

(01:26:43):
this by having bakhtin of minusone white denote plus one, and
every shade of gray between themarking the continuous range,
and having the magnitude of thevacuum energy be less than 10 to
the power of minus 120 isequivalent to rolling this
spherical die a few dozen times.
And after adding the numbers,finding the magnitude of the
result is less than one in 10 tothe power of 120. This is

(01:27:06):
extraordinarily unlikely. To putit in context, consider that the
odds of winning a NationalLottery are about one in 100
million, or one in 10 to thepower of eight, and one in 10 to
the power of 120 represents theequivalent odds to winning a
National Lottery 15 times in arow. We definitely are winners

(01:27:28):
in a cosmic lottery. Could itall be a coincidence? At a
certain point, luck becomesimplausible as an explanation.
If the same person won aNational Lottery 15 times in a
row, we would look to otheranswers besides me luck to
explain it. Perhaps someonerigged the game. Or perhaps the

(01:27:51):
person used their winnings tocontinue buying up all possible
tickets. It is a mystery thatdemands an explanation of the
extraordinary odds we overcameto win the right to exist seem
to be telling us somethingimportant about existence and
reality. But what why theuniverse is made for life. So

(01:28:12):
Martin Reese is professor ofcosmology and astrophysics at
the University of Cambridge,Master of Trinity College,
former president of the RoyalSociety and the current
Astronomer Royal. Reese hasspent much of his life on the
question of why the universe issuited for life. He authored one
of the first papers on thesubject, wrote a book on it, and

(01:28:35):
even hosted a television showexploring the topic. In his
book, just six numbers, Reesedescribes three known answers to
the question of why the universeis finely tuned for life.
coincidence,we're just incredibly lucky, and
there is no explanation orreason to Providence. Our

(01:28:57):
universe was designed, chosen orcreated to allow life
multiverse. There are manyuniverses most are barren, but
some permit life. Let's considerthe implications for each of
these answers. As a coincidence,however small it may be, there

(01:29:21):
is a chance that there is asingle universe neither designed
nor one of many, which justhappens to have physical laws
and constants that are lifepermitting. Perhaps things are
not so hopeless for life as weestimated. It might be that life
finds a way in a large fractionof possible universes. If so,

(01:29:41):
then we shouldn't be sosurprised. But there are reasons
to doubt this. Life requires aspecial environment. Life must
be capable of maintaining,repairing, copying, and mutating
its information. patterns of theenvironment must allow life to

(01:30:01):
arise and self assemble and alsoself replicate. Across possible
environments, few appear tosupport both needs. Most seem to
miss the necessary balancebetween simplicity and chaos. If
the environment is too simple,there's no hope of getting self
arising self replicating forms.

(01:30:25):
If the environment is toochaotic, there's no hope of
preserving information acrossgenerations. JOHN von Neumann
created the first selfreplicating machine. It was
designed to operate within acellular automaton, a specially
crafted environment having itsown set of rules, ie its own
laws of physics. But in the setof possible cellular automata,

(01:30:49):
only a small fraction has theright balance of complexity and
stability to support selfreplication. Quote, it seems
plausible that even in the spaceof cellular automata, the set of
laws that permit the emergenceand persistence of complexity is
a very small subset of allpossible laws. The point is that

(01:31:10):
however many ways there are ofbeing interesting, there are
vastly many more ways of beingtrivially simple or utterly
chaotic. And quote, Luke a bombsin the fine tuning of the
universe for intelligent life2011. as Richard Dawkins put it,
however, many ways there may beof being alive, it is certain

(01:31:32):
that there are vastly more waysof being dead. Even in a life
friendly universe like ours, wefind ourselves in a very special
place. Most of the universe isintergalactic space, a cold,
dark void, having just onehydrogen atom per cubic meter in

(01:31:52):
our environment is some 10 tothe power of 30 times denser
than average. As Max Tegmarknoted only a thousandth of a
trillionth of a trillionth of atrillionth of our universe lies
within a kilometre of aplanetary surface. itself
doubtful life could arise in thenear vacuum of intergalactic
space, nor is it likely to existin the hot cause of planets or

(01:32:15):
stars. Most of our universes inhospitable life can't always
find a way that Earth is aloneEden, trillions of miles sit
between her and the nearestplausibly hospitable locations.
Kepler 22 B, which may haveliquid water is 6000 trillion

(01:32:37):
kilometers away. The rarity oflife in the universe speaks to
how uncommon life may be acrossthe set of possible universes.
Even where life is known to bepossible, it appears to be
exceedingly rare to see Are wealone. the sensitivity of life
to the smallest changes in thefundamental constants further

(01:32:58):
suggests it takes a rare mix ofparticles, forces and initial
conditions working together tomake a universe with life.
Quote, it is logically possiblethat parameters determined
uniquely by abstract theoreticalprinciples just happen to
exhibit all the apparent finetunings required to produce by a
lucky coincidence, a universecontaining complex structures,

(01:33:22):
but that I think, really strainscredulity. And quote, Frank will
check in physics today 2006.
But if incredible luck is notthe answer, then someone or
something must have set thingsup just right, Providence.

(01:33:43):
Divine Providence is anotherpossible answer to the mystery.
This is the belief that theuniverse was designed and
created with intention, perhapsto be interesting to support the
existence of intelligent life.
Fred Hoyle, who had been alifelong atheist, was led by his
discovery of the carbon 12excited state to believe in a

(01:34:04):
super calculating intellect whomust have designed the
properties of the carbon atom.
In this, he is not alone. ArnoPenzias, who discovered the
cosmic Hammer of the Big Bangsaid astronomy leads us to a
unique event, a universe whichwas created out of nothing one
with a very delicate balanceneeded to provide exactly the

(01:34:26):
conditions required to permitlife and one which has an
underlying one might saysupernatural plan. Quote, a life
giving factor lies at the centerof the whole machinery and
design of the world. And quote,john Archibald Wheeler in
foreword to the anthropiccosmological principle 1986. If

(01:34:51):
there is one universe with oneset of laws, divine providence
is a natural conclusion. So manybullets were dodged in the many
fine tuning meanings that it allbeing a coincidence doesn't hold
water. While some physicistswere open to this possibility,
most were unsettled by it. Finetunings suggest a fine tuner.

(01:35:13):
But once a day it is invoked aspart of an explanation. Further
scientific progress holds, asany line of inquiry can be
answered with it was God's plan.
Quote, this is a dislike ofmixing religion into physics. I
think they were somewhat afraidthat if it was admitted that the
reason the world is the way itis, has to do with our own

(01:35:33):
existence, that that could behijacked by the creationists by
the intelligent designers. Andof course, what they would say
is yes, we always told you sothere is a benevolent somebody
Way up high in the universe whocreated the universe exactly so
that we could live. I thinkphysicists shrank at the idea of
getting involved in such things.

(01:35:57):
And quote, Leonard Susskind inwhat we still don't know, are we
real in 2004. About the claimthat creation or a creator is
unscientific is now in doubt. Intoday's scientists have already
wet their toes in the area ofcreating universes, they do so

(01:36:19):
in highly detailed computersimulations. simulation is
indispensable to today'sscientists. It enables them to
create, experiment with andexplore cosmic evolution. It
allows us to see inside thecause of collapsing stars and
understand the physics ofalternate universes with

(01:36:40):
different constants or initialconditions. The cosmologists
Alan Guth, even thinks it ispossible in principle to create
and split off an entire newphysical universe in the
laboratory. Quote, the odd thingis that you might even be able
to start a new universe usingenergy equivalent to just a few
pounds of matter, provided youcould find some way to compress

(01:37:04):
it to a density of about 10 tothe 75th power grams per cubic
centimeter, and provided youcould trigger the thing
inflation would do the rest issuch an achievement is obviously
far beyond our technology, butsome advanced civilization in
the distant future might aswell, you never know. For all we

(01:37:24):
know, our own universe may havestarted in someone's basement.
And quote, Alan Guth inphysicist aims to create a
universe literally 1987.
If our universe is the result ofsuch an experiment, or if it
exists as a simulation performedby a higher being or species,

(01:37:46):
then our universe is lifefriendly because of the
providence of our Creator. Theparticular constants and laws
would have been chosen withintention to see, are we living
in a computer simulation? And isit possible to create new
universes? But even if this isthe case, the mystery still

(01:38:06):
remains. How did the simulatoror universe creator come to be?
If the creator arose throughnatural processes, the universe
hosting the creator would alsohave to have been finely tuned.
It pushes the question back onestep, but does not ultimately
answer it. Though we cannot ruleout Providence as an

(01:38:28):
explanation. This solutionraises as many questions as it
answers. Scientists wanting toprogress on the mystery of fine
tuning Salta, naturalisticexplanation of multiverse, if we
are not exceedingly lucky, andif our universe was not
designed, there is onealternative, many, perhaps even

(01:38:49):
an infinite number of universesexist, there will be life in
some and not in others. Quote,we imagined our universe to be
unique, but it is one of animmense number, perhaps an
infinite number of equallyvalid, equally independent,
equally isolated universes.
There will be life in some andnot in others. In this view, the

(01:39:11):
observable universe is just anewly formed backwater of a much
vaster, infinitely old andwholly unobservable cosmos. If
something like this is right,even our residual pride palette
as it must be of living in theonly universe is denied to us.
And quote, Carl Sagan in paleblue dot 1994. Under the

(01:39:34):
multiverse explanation, ouruniverse is just one of a much
larger set of other equally realuniverses, and each of these
universes may be ruled bydifferent physics, different
forces, constants, particletypes, dimensionality, and so
on. Most universes won't haverules of the kinds necessary for

(01:39:58):
Life, they will be empty, and noone will be there to appreciate
the splendor how many otheruniverses might there be? While
we have no way to know the exactnumber of extent universes, it's
possible to estimate theminimum. It is equivalent to
asking how many lottery ticketsare needed to have a good chance

(01:40:20):
of winning the answer more thanthe inverse of the likelihood
that a single ticket is awinner. So if the odds
particular one in 100 million,you need around 100 million
tickets for a high chance ofwinning. Next use this same
logic to consider how manyuniverses are needed to make up
for the unlikelihood of lambdafalling in a life friendly range

(01:40:42):
whose improbability was on theorder of one in 10 to the power
of 120. Quote, Weinberg'sapproach for explaining the
cosmological constant only worksif we're part of a multiverse in
which there are a huge number ofdifferent universes, their
cosmological constants must fillout some 10 to the power of 124

(01:41:02):
distinct values. Only with thatmany different universes Is
there a high likelihood thatthere's one with a cosmological
constant that matches ours, andquote, Brian Greene in the
hidden reality 2011 this number10 to the power of 124 is far

(01:41:22):
greater than the number of atomsin the observable universe
estimated to be 10 to the powerof 80. Where does all this stuff
come from? Is the multiversetheory even scientific when we
cannot observe or interact withthese other universes? As Paul
Davis said, invoking an infinityof unseen universes to explain

(01:41:45):
the unusual features of the onewe do see is just as ad hoc as
invoking an unseen creator. Butas Max Tegmark points out, the
idea of parallel universes isnot a theory, but a prediction
made by several existingtheories, which are themselves
testable and falsifiable andthus, scientific. Examples
include cosmic inflation, whichsuggests eternal inflation, a

(01:42:13):
reality populated with anexponentially growing number of
big bangs, with new universesperpetually created for all time
in string theory,which suggests a string theory
landscape having at least 10 tothe power of 500 unique sets of
physical laws with differentparticle types and fundamental

(01:42:34):
constants in quantum mechanics,whose Schrodinger equation taken
at face value implies unseenparallel worlds, a quantum
multiverse with branchesconstantly diverging from our
own to explore allpossibilities, and see, does
everything that can happenactually happen. independent of

(01:42:57):
the search for answers to finetuning, various fields of
science are increasinglypointing in the direction of
many universes, a multiverse in1996, Tegmark went one step
further. In his mathematicaluniverse hypothesis, he put
forward the idea that theequations of string theory may

(01:43:18):
not be the only equations thatcan define universes. According
to his radical idea, equationsof string theory represent just
one of an infinite number ofself consistent physical
equations, and all consistentsets of equations correspond to
physically real universes. Seehow big is the universe? And why

(01:43:39):
does anything exist? But how doparallel universes explain why
this universe is made for life?
The anthropic principle, theexistence of other universes, by
itself does not explain why theuniverse we are in is finely
tuned to support life. To getthere we need one extra

(01:44:03):
ingredient the anthropicprinciple. This term was coined
by Brandon Carter in his 1974paper detailing the coincidences
in cosmology, but the ideapredates this quote, my
Princeton colleague, Robert Dekeexpressed it this way, what good
is a universe without somebodyaround to look at it? And quote,

(01:44:28):
john Archibald Wheeler in fromthe Big Bang to the Big Crunch
2004 all the places where lifeis possible may be few and far
between. But wherever lifeexists, it is only found in
places where it is possible forlife to exist. And this applies
whether it is in a life possibleuniverse on a hospitable planet,

(01:44:51):
or by a pool of water in a vastdesert. The anthropic principle
is the self evident truth thatlife only finds itself in places
compatible with its existence.
And therefore, it's no surprisewe find ourselves in a universe
having a rare combination oflife friendly laws, so long as
the number of universes is largeenough, quote, The analogy here

(01:45:12):
is of a ready made clothes shop.
If there is a large stock ofclothing, you're not surprised
to find a suit that fits. Ifthere are many universes, each
governed by a different set ofnumbers, there will be one where
there is a particular set ofnumbers suitable to life. We are

(01:45:34):
in that one, end quote. SoMartin riesen, why is their life
in 2000? solving the fine tuningmystery? we've considered three
possible answers to the mysteryof why the universe is made for
life. Which one is right? Howcould we ever tell? Here we can

(01:45:58):
apply a technique known asBayesian inference? First, we
divide the decision into threeanswers that are mutually
exclusive. at most one is trueand collectively exhaustive. At
least one is true. coincidence,there is one universe not
designed for life. Providence,there is one universe design for

(01:46:21):
life. In the multiverse, thereis not one universe. When framed
in this way, there is zerouncertainty whether one of the
answers is true. The onlyuncertainties which one is true.
If we were to divide up ourcertainty as to which answer is
correct, then if we areconsistent, the sum of the

(01:46:42):
certainty across the answersmust add to 100%. And we all
know this intuitively, when youhear there is a 30% chance of
rain tomorrow, you can inferthat there is a 70% chance that
it will not rain tomorrow,raining and not raining are
mutually exclusive as they can'tboth happen. raining and not

(01:47:04):
raining are also collectivelyexhaustive, as at least one of
those possibilities must occur.
We can use this method to narrowdown an answer. Is there one
universe not designed for life?
before considering any evidence,we might equally divide our
level of certainty across thethree possible answers.

(01:47:26):
Coincidence 33.33%? Providence33.33% multiverse 33.33% We
could also group answers up anyway we like, for instance,

(01:47:46):
coincidence 33.33%, Providenceor multiverse 66.67% or
equivalently? coincidence.
33.33% is not coincidence.
66.67%. According to the rulesof Bayesian inference, anytime

(01:48:13):
new evidence is taken intoconsideration, we must update
our certainty accordingly. Sayyou originally assumed even ants
of rain, you would begin with50% certainty it would rain and
the 50% chance it would notrain. But upon learning new
evidence, you revise yourcertainty. If you hear there's

(01:48:35):
not a cloud in the sky, yourcertainty might shift from a 50%
certainty of rain to a 5%certainty of rain and 95%
certainty of no rain. Similarly,evidence of fine tuning acts
like learning there's not acloud in the sky. It forces us
to revise downwards our initialcertainty in the answer that

(01:48:56):
there is one universe which isnot designed for life. If fine
tuning evidence causes us torevise our certainty in the
coincidence answer from 33% to1%. Then our confidence in not
coincidence or equivalentlyProvidence or multiverse rises
to 99% of coincidence 1% ofProvidence or multiverse 99% of

(01:49:23):
the lower the probability ofcoincidence, the more certain we
are that Providence ormultiverse is true, since all
must add up to 100% of finetuning evidence suggests that
the odds of coincidence may bein the neighborhood of one in 10
to the power of 120 or less.
This means we can withoverwhelming certainty, rule out
coincidence as the answer. Thisleaves two possibilities and we

(01:49:47):
can conclude with overwhelmingcertainty that either Providence
or multiverse is correct.
And, quotemost sets of values will give
rise to universes that Althoughthey might be very beautiful,
would contain the one able towonder if that beauty one can
take this either as evidence ofa divine purpose in creation and

(01:50:07):
the choice of the laws ofscience or as support for the
strong anthropic principle. Andquote, Stephen Hawking in a
brief history of time 1988 isthere one universe design for
life? If there is only oneuniverse, and we rule out
coincidence, that leaves onealternative Providence, the

(01:50:31):
universe was made for life.
Quote, anthropic fine tuning istoo remarkable to be dismissed
as just a happy accident. Andquote, john polkinghorne in
science and theology 1998. Ifit's not a coincidence that life

(01:50:53):
is possible, then there had tohave been a tuner be the
simulator, universe creator,super calculating intellect,
intelligent designer, or deity.
Its purposes led it to choosefrom among the many
possibilities, one set ofphysical laws where life is
possible. But concludingProvidence as an answer requires
the assumption that there isonly one universe, ruling out

(01:51:15):
coincidence can bring us towardscertainty in either Providence
or multiverse. But it can't tellus which of these two remaining
answers is right. Is there notone universe? Once coincidences
ruled out as an answer, we cansay? Either one, there is a
designer or two, there is amultiverse. Could there really

(01:51:41):
be more to reality than we cansee? Are there other universes
with different laws, constants,particles and properties? We
cannot see everything thatexists. Given the finite speed
of light, we are not even in aposition to see all of our
universe. Though we are not in aposition to survey all of

(01:52:04):
reality, nature has provided ushints of cosmic inflation,
string theory, and fine tuningall suggest our universe is part
of a vast and variegatedreality. Quote, the most
important scientific revolutionsall include, as their only
common feature, the dethronelint of human arrogance from one

(01:52:25):
pedestal after another ofprevious convictions about our
centrality in the cosmos, andquote, Stephen Jay Gould, but
should have asked possiblyinfinite reality exist. This
leads us back to the notion of acreator, an entity able to
design and make universes.

(01:52:48):
According to Martin Reese, ouruniverse may be far from optimal
in terms of its potential forcomplexity. If so, then there
exists within the multiversesome universes having a greater
capacity for complexity,computation and intelligence
than our own. Quote, we canimagine universes that might be

(01:53:09):
more propitious. These, ofcourse would be potential
realities far beyond the powersof our brains to conceive. But
we can't assume in this granderCosmos that there couldn't be
other universes displaying morecomplexity than ours. We know
that over a few decades,computers have evolved from
being able to simulate only verysimple patterns to being able to
create virtual worlds as itwere, with quite a lot of detail

(01:53:31):
in them. And if that trend wereto continue, then we can imagine
computers which will be able tosimulate worlds perhaps even as
complicated as the one we thinkwe're living in and quote, so
Martin Reese, in what we stilldon't know, are we real? 2004

(01:53:52):
final thoughts?
Was the universe made for life?
This one question threadstogether humanity's desire to
understand its origin and placein the cosmos, and to know
whether we were created withintention and purpose or through
blind luck and happenstance.
reaching a point of progress onthis question took the

(01:54:13):
combination of some of thegreatest scientific discoveries
of the past century. But wecannot say with confidence that
life of any kind is rare andprecious. Life's Rarity speaks
to the existence of somethingbeyond what we can observe a
reality that transcends thisuniverse, a reality which is

(01:54:34):
potentially infinite andcontains all possibilities. If
not coincidence, is the answer,Providence or multiverse? To our
surprise, we find thatregardless of which answer is
right, both lead to the sameplace a belief in something
greater than ourselves. IfProvidence is the answer, then

(01:54:54):
we get a creator outright. Ifmultiverse is the answer, then
we get an A Infinite realitycontaining universe is greater
than our own with beings greaterthan ourselves. Such beings
would be in a position wherethey could create other
universes, either directly orvia computer simulation, thereby
becoming the source of DivineProvidence to those beings they

(01:55:16):
create. The Infinite andcomprehensive reality of the
multiverse might even containall things. The hypothetically
omniscience mind of God likewisecontains all things, or at least
knowledge of all things. Isthere a difference between the
two? might they be the samething? See, Does God Exist? As

(01:55:41):
the philosopher JJC smartreminds us if we postulate God
in addition to the createduniverse, we increase the
complexity of our hypothesis. Wehave all the complexity of the
universe itself. And we have Inaddition, the at least equal
complexity of God. But smarttempered his statement, adding
if the theist can show theatheist that postulating God

(01:56:03):
actually reduces the complexityof one's total worldview, then
the atheist should be a theist,so it may be with the belief in
an infinite reality.

Amy (01:56:16):
This has been another episode presented by always
asking.com where we ask the bigquestions. Thanks for listening

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