September 22, 2025 • 35 mins
In this episode of SpaceTime, we tackle the mysteries of the cosmos with a new mathematical model of the universe and ponder the age-old question: are we alone in the universe?
New Model of the Universe
Scientists have unveiled a groundbreaking mathematical model aimed at simplifying our understanding of the universe's evolution over the past 13.8 billion years. This innovative research, based on data from the Dark Energy Spectroscopic Instrument (DESI), offers fresh insights into the cosmic web's structure, revealing how dark energy influences cosmic expansion. Lead author Leonardo Gianni from the University of Queensland discusses how this model challenges existing paradigms and provides a clearer picture of the universe's complex behaviour, including the impact of voids and collapsing regions of matter.
Are We Alone?
A new study presented at the European Planetary Science Congress raises intriguing questions about the existence of intelligent alien civilizations. Researchers estimate that the nearest technological society in our galaxy could be over 33,000 light years away, with conditions on their home planets potentially mirroring those of Earth. The study highlights the challenges of sustaining advanced life and the long timelines required for such civilizations to coexist with humanity.
Partial Solar Eclipse
Today, a partial solar eclipse graced the skies over New Zealand, the South Pacific, and parts of Australia and Antarctica. As the Moon passed between the Earth and the Sun, observers witnessed a stunning celestial display with up to 70% of the Sun's face obscured. This remarkable event serves as a reminder of the intricate dance of celestial bodies that shape our night sky.
www.spacetimewithstuartgary.com
✍️ Episode References
Physical Review Letters
https://journals.aps.org/prl/
European Planetary Science Congress
https://www.epsc2025.eu/
Become a supporter of this podcast: https://www.spreaker.com/podcast/spacetime-space-astronomy--2458531/support.
New Model of the Universe
Are We Alone?
Partial Solar Eclipse
New Model of the UniverseAre We Alone?Partial Solar Eclipse
New Model of the Universe
Scientists have unveiled a groundbreaking mathematical model aimed at simplifying our understanding of the universe's evolution over the past 13.8 billion years. This innovative research, based on data from the Dark Energy Spectroscopic Instrument (DESI), offers fresh insights into the cosmic web's structure, revealing how dark energy influences cosmic expansion. Lead author Leonardo Gianni from the University of Queensland discusses how this model challenges existing paradigms and provides a clearer picture of the universe's complex behaviour, including the impact of voids and collapsing regions of matter.
Are We Alone?
A new study presented at the European Planetary Science Congress raises intriguing questions about the existence of intelligent alien civilizations. Researchers estimate that the nearest technological society in our galaxy could be over 33,000 light years away, with conditions on their home planets potentially mirroring those of Earth. The study highlights the challenges of sustaining advanced life and the long timelines required for such civilizations to coexist with humanity.
Partial Solar Eclipse
Today, a partial solar eclipse graced the skies over New Zealand, the South Pacific, and parts of Australia and Antarctica. As the Moon passed between the Earth and the Sun, observers witnessed a stunning celestial display with up to 70% of the Sun's face obscured. This remarkable event serves as a reminder of the intricate dance of celestial bodies that shape our night sky.
www.spacetimewithstuartgary.com
✍️ Episode References
Physical Review Letters
https://journals.aps.org/prl/
European Planetary Science Congress
https://www.epsc2025.eu/
Become a supporter of this podcast: https://www.spreaker.com/podcast/spacetime-space-astronomy--2458531/support.
New Model of the Universe
Are We Alone?
Partial Solar Eclipse
New Model of the UniverseAre We Alone?Partial Solar Eclipse
Mark as Played
Transcript
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Speaker 1 (00:00):
This is Spacetime Series twenty eight, episode one hundred and fourteen,
for broadcast on the twenty second of September twenty twenty five.
Coming up on Space Time, a new model to explain
the cosmos, one of those ultimate questions of science and humanity?
Are we alone in the universe? And a partial solar
eclipse darkens the skies of the South Pacific. All that
(00:23):
and more coming up on space Time.
Speaker 2 (00:27):
Welcome to space Time with Stuart Gary.
Speaker 1 (00:46):
Scientists have developed a new mathematical model of the universe,
one which attempts to explain its evolution over the past
thirteen point eight billion years in a more simplistic manner.
The new research reported in the journal Physical Review Letters.
It's based on data from DESI, the Dark Energy Spectroscopic Instrument,
which is measurements of the universe up to eleven billion years.
(01:08):
The large scale structure of the universe is sort of
like a giant cosmic web, comprising strands and filaments of galaxies,
galaxy clusters, and superclusters wrapped around the outskirts of vast
near empty voids. The author's work tries for the first
time to explain collapsing regions of matter and expanding voids.
(01:29):
The stati's lead author, Leonardo Jiani from the University of Queensland,
says it's dark energy which remains the key factor in
cosmic evolution. Dark energy is a measurement showing not just
that the universe is expanding, but that its rate of
expansion is actually accelerating. It originally began as a sort
of fudge factor called the cosmological constant, invented by Albert Einstein,
(01:52):
whose field theories showed that the universe was in fact expanding.
The problem is Einstein lived at a time when it
was generally accepted that the universe was actually in a
steady state which always remained generally the same on cosmic scales.
So to try and explain the expansion his equations were showing,
Einstein invented his cosmological constant in order to artificially adjust
(02:13):
the figures and return the universe into a steady state
as it should be. However, years later, observations by Edwin
Hubble proved that the universe really was expanding. That forced
Einstein to remove his cosmological constant, which he later described
as his biggest mistake. Then, in the nineteen nineties, observations
of supernovae showed that the universe wasn't just expanding, but
(02:37):
that rate of expansion was actually increasing, and so Einstein's
cosmological constant was back, but this time under the new
term of dark energy. Dark because no one really knew
exactly what it was, some sort of anti gravity or
vacuum energies the best they could come up with. Then
along came David Wheelchair from the University of Canterbury, who
(02:57):
challenged the status quo in the early two thousand. They
used improved analysis of supernova light to show that the
universe is expanding in a more varied, a more lumpier way.
Woolche's work supports a timescape model of cosmic expansion, one
which doesn't have the need for dark energy, because the
differences in stretching light aren't the result of an accelerating universe,
(03:19):
but instead a consequence of how science calibrates time and distance.
Timescape takes into account the fact that time itself slows
down around mass, and so an ideal clock in the
empty space of a vast void would take faster than
what the same clock would inside a galaxy. In fact,
the model suggests that a clock in the Milky Way
(03:41):
would be about thirty five percent slower than the same
clock at an average position in a large cosmic void,
and that means billions more years would have passed inside
a void compared to inside galaxy, and this would in
turn allow more expansion of space, making it seem like
the expansion is getting faster when such vast, empty voids
(04:02):
grow to dominate the universe. Wulci said he's finding show
that science doesn't need dark energy to explain why the
universe appears to be expanding at an ever accelerating rate.
He says dark energy is simply a misidentification of variations
in the kinetic energy of expansion, which is not uniform
in the universe as lumpy as the one we actually
(04:23):
live in, and that's where the new work of Jihanni
comes in. His research shows dark energy is real, but
maybe not as strong as some have suggested. Johnny's new
model can change the way physicists and cosmologists look at
the universe. He points out that the standard model mapping
the universe from the Big Bang right through to now
as matter particles of the same size not interacting with
(04:46):
each other, but in reality, astronomers can see there are
stars in black holes, galaxy clusters, and empty regions constantly
interacting through it. Forces such as gravity not accounted for
but the standard model. Johnny says, for the past third years,
scientists have tried to explain what's happening as this complex
universe expands, and there been plenty of exotic attempt set solutions.
(05:08):
You see, astronomers know that voids and collapsing regions exist,
but according to Janni, they didn't really know how to
compute their impact on the measurements, and he says his
model gives them a recipe to compute that figure without
the need for any new physics. This new framework uses
simple mathematical terms to describe how the emergence of complex
(05:29):
structures in the universe affects cosmological measurements. Janni and colleagues
set out to identify the minimum size avoid needs to
be in order to impact the measurements, as well as
the minimum size of galaxy. Customers have independent data sets,
including the DESI. Data were plotted against an x and
y axis chart showing the minimum sizes of the collapsing
(05:50):
and expanding regions of space which can impact cosmological measurements. Now,
the standard model of the universe should see all of
these data set contours overlap, but at one end of
the graph, where the sizes of the expanding and contracting
regions would be too large for them to exist, But
instead they overlap in a different region, and that indicates
(06:11):
that the large voids of space may well be responsible
for the anomalous behavior observed in the data. Yanni says
the new model also helps address two of the biggest
problems in modern cosmology, Hubble tension and the evidence for
dynamical dark energy. Hubble tension is a discrepancy between two
methods currently used to calculate the universe's rate of expansion,
(06:32):
known as the Hubble constant. Well Dynamical dark energy is
a theory that says energy is not constant, but changing
or weakening over time. The Hubble constant is an expansion
rate of roughly seventy kilometas per second per mega parsek,
with a level of uncertainty of around five kilometis per
second per mega parsek, a mega parsek being three point
(06:53):
twenty six million light years. But you see that figure
depends on how you're measuring the brightness of type one
ac supernovae still are explosions marking the deaths of specific
types of stars, which are all roughly the same mass
when they die, and so explode with roughly the same
level of luminosity. These can therefore be used as standard
(07:13):
candles to determine distance through the inverse square lore. It's
like looking at a row of street lights down a
road and being able to tell how far away each
light is by how bright it appears to be. The
alternative method involves observing the cosmic microwave background radiation, the
left overheat generated three hundred and eighty thousand years after
the Big Bang, when the universe's primordial quark gluon plasma
(07:36):
cooled enough for the first atoms to form, and you
can observe this cosmic microwave background radiation today, three point
eight billion years later as the white noise static you
get between stations on old analog radio and TV sets.
Of course, today that primordial superintense heat has now cooled
to just two point seven degrees above absolute zero, and
(07:59):
this is where hubble tension arises, because these two different
measurement methods have viewed its slightly different values, creating a
crisis in cosmology, Jenny says, if you try to assume
that dark energy is weakening, and then you try to
infer how fast the universe is expanding from that data,
you get even lower measurements for the rate of expansion
of the universe, solutions to one problem creating another. In
(08:22):
his model, any weakening of energy is just a detailed
accounting of what the universe looks like today. It behaves
as if it were weakening, but may not be weakening
at all, Jenny says, Essentially, when asked if the complexity
of the universe were showing up in the desert data,
the results shows that it was, and his study can
explain those observations.
Speaker 3 (08:44):
It's a new model, but what I think it's very
relevant is that it doesn't really require much new physics,
so it's nothing revolutionary in terms of our understanding of
nature the universe. Say, the main point is that our
previous model, our previous understand cosmology and evolution of the
universe as well, was based on the fact that the
universe looks the same everywhere, and it's basically describing all
(09:08):
the matter in the universe as if they were thus
practicles that do not interact between each other and this
description on sufficiently or let's a very large scale to
the side of the universe wise is working very well. However,
the precision of our measurements and experiments become so large,
or become so good that we actually start to see
(09:31):
some hint that this model could not be valid anymore.
And what I did, essentially is trying to give up
description to take into account the fact that the universe
is not made by you know, identical marbles everywhere, but
from you know, structures that can vary between large filaments
(09:51):
and clusters of galaxies, and that masters two very large
voids that expand faster than the rest. So you in
a few words, my mathematical model is trying to quantify
how many of these structures that are out there and
giving to each of them some energy so that I
can estimate how much their presence is outed in the
(10:12):
evolution of the universe.
Speaker 1 (10:13):
Understanding they true structure the universe and our place in
it is really important for how we observe the universe
and how we measure it.
Speaker 3 (10:20):
Yeah, percasely, also because you know, all these structures were
not existing back when the universe was very young, so
they actually evolved with time, just like us, and we
happen to appear in one for more of these complex
web of structures. When I say one or more, I
mean that it's quite hard to distinguish if we live
in underdense environment or over dense environment. Given our measurements,
(10:42):
we of course have things. But in order to understand
our cosmic environment, our local, our place in the universe.
If I can be the dramatic, we need a lot
of data and very sophisticated noise. And the data becoming
available only now our future.
Speaker 1 (10:58):
Will the universe span forever into a cosmic deep phraeze,
Will that expansion slow down and become a steady state,
or will gravity eventually take over from dark energy and
we see the universe begin to collapse again into another
big crunch, which could result in another Big Bang, then
another big crunch. I mean this is determining the ultimate
fate of the universe.
Speaker 3 (11:19):
Yeah, and that all the options that you gave so
far are basically all available given our current understanding, we
of course have a hint about what the nature of
that energy is. And according to these what I can
tell you is that seems like the universe will expand
forever even if that energy is weakening or this is
at least the latest evidence from some data called but
(11:44):
an echocoustical solution, it seems.
Speaker 1 (11:46):
Like it sure waves in the early universe.
Speaker 3 (11:48):
Yes, exactly. Yeah, Like if you look at the distribution
of galaxies in the universe, this is not random. It's
sechally describing a very complex and nice pattum in which
galaxies tend to for structures, tend to agglomerate in certain
spots and to elute in others, reflecting somehow the initial
conditions of the universe. So if to make a metaphor,
(12:11):
imagine you ared at a pond, then you throw a
bunch of frogs in the pond in the water, you
will see sound water waves in the metaphor, and where
the crest of the waves merge together, that's where you
would expect another excess, another flow of water. It's the
same with galaxies. We start with these initial conditions, which
is like you know, a painting or an initial setting
of where the matter is distributed more or less the
(12:33):
same agreew but with small situations, and then this wave propagates,
and when they propagate, they tend to agglumerate. Galaxies in
their intersection points, so again it's not a random pattern.
From the structure of the pattern, by trying to measure it,
we can understand more about what the energy content of
the universe, So how much that can it be? Is around?
Much matter is around? It's very cool, and you know
(12:55):
this dise cosmogical probe is but the only acoustic oscillation
is has been known for years now. But for the
very first time, we have really enough observation of galaxies.
I'm talking about a millions of galaxies that we can
use to put on a very significant sample and statistic.
So this is very exciting and it's why it's amazing
(13:16):
to be on the job right now.
Speaker 1 (13:18):
For me, Does our position within the cosmic web play
an important role? In other words, if the local galactic
group that's the Milky Way Andromata Triangular and all the
satellite galaxies around us, if this local galactic group we're
in is in one of these filaments, we would have
a different understanding of the universe compared to what we
would see or what we would experience if we're in
(13:41):
the middle of one of these vast voids. Does that
play a role in our understanding of dark matter and
dark energy.
Speaker 3 (13:47):
It surely does. So if I can be very simplistic,
let's imagine that that work environment, our cosmic neighborhood, let's see,
is like a work gloss. This is outing slightly our
perception of what's outside the glass. Of course, lights travel
propagate within, and so it's slightly affected reflected and our
(14:09):
cosmological inference. So what we learn about the universe needs
to keep account of this water glass around us, which
is unavoidable. Now, if you know the properties of the glass,
you can kind of keep that into account and try
to correct your measurements so that you're obtaining a closer
description of the universal side. However, understand the glass itself
(14:29):
is a very interesting field of research. So let's say
that with the water glass is very thick, like we
live in an overdanced region of the universe. Then light
will be struggling reaching gas, and this will make us
experience a universe that seems to expand slightly faster outside.
(14:51):
And the opposite is true in the case of underdanced class.
So if we live in avoid now, the truth is
that is, if we live been avoid, it's quite unlikely
that we are saved because by definition, voids should have
less galaxies, so it would be a statistical fluctuations on
an unlikely scenario. And also from what we know by
(15:13):
reconstructing the velocity field of galaxies in the local universe,
we kind of believe that we are part of our supercluster.
The supercluster can be identified with an object called Lanyakia,
which is this massive supercluster of containing hundreds of thousands
of galaxies, or even a larger supercluster called Shaftli the
(15:33):
Safti concentration. So let's say that these hints seems indicate
that we actually belong to our overdense region of the universe,
if that makes sense.
Speaker 1 (15:44):
See that's interesting because just last week we had a
paper come out suggesting that the density in our region
of the universe is actually lower than the average. So
we're getting these conflicting figures. Depends on the observations you're making,
I guess.
Speaker 3 (15:58):
Exactly depends really are on because logical probe using and
the fact that there is seemingly not a simple answer
to this question kind of reflects why it's so important
that we keep trustesting our models and our analysis. I
should say that historically this local underdance region has been
advocated and exploited in the past because it was proposed
(16:19):
early in the two thousand as an alternative to the
existance of that Kennedy that chemopy is a beautiful resource
that we have to explain a lot of problems or
a lot of seemingly inconsistent observations that become not inconsistent
when you introduce their.
Speaker 1 (16:34):
Charity is Will Chair from the University of Canterbury.
Speaker 3 (16:38):
Yeah, for example, the Timescape model from David Wature. But
I'm talking even earlier than that, like back really in
the early two thousand, before the Timescape model was our
people had this model called Hpbull bubble in which they
were explaining or we were trying to explain the apparent
accelerated expansion of the universe with us living in a
(16:58):
local void so like a bubble in the otherwise on
much units and is isotropic universe. And of course these
type of models, including the one you mentioned from the
which became very popular because they provide a very physical
explanation to something that is a bit uncomfortable. That kind
of is a bit uncomfortable from a theoretical point of
view because it challenges kind of the physics that we
(17:19):
experience so every day. So this Underdanse model became very popular,
and in my short life as an academic roughly ten years,
I saw them coming up over and over again several times.
To my understanding, it's all about the scales you are
trying to consider. If you consider, if you restrict yourself
only to certain scales, you might find evidence of a void,
(17:42):
But if you shorten your window or enlarge it, you
can find presence of classes. Because it's a very complicated structure,
and the name of the game is usually distancing, but
actually getting distances right in the universe is very hard
because unfortunately we cannot feel the inter as you know
of in the galactic side, even if we try so,
(18:02):
we have to struggle with understanding these distances in a
good way. My personal take is that I would not
confidently say neither of the two ind that we live
inside avoid or needed that we live inside the film.
But from a gambling perspective, it's more likely that we
live in a filament if you ask. Also, I ever
(18:22):
work on like AKM, this big large supercluster of galaxies,
and what I found is actually that it is compatible,
like our data are compatible with the local in falling region.
If you interpret these velocities of galaxy as due to
the fact that there is a center of gravity towards
which they're falling.
Speaker 1 (18:41):
So with energy existing but awakening that I guess all
birds well for a big phrase ultimate fight for the universe,
but not a big rip.
Speaker 3 (18:50):
Yes, you are clearly talking about singularities, in cosmological singularities,
So big freeze would be something like the universe. It's expanding,
but instead of accelerating exponentially, since that energies weakening, the
break of expansion is not fascillating a start, and so
everything will be put faster apart from everything else and
(19:11):
we end up you know, cold and kind of boarding universe,
which at least is a perspective. It's very relaxing to
me compared to a bigree where I look in collact
exponentially and even the distance between atom.
Speaker 1 (19:25):
Is exponentially ripped apart, very uncareful.
Speaker 3 (19:31):
Yeah, this is a bit more uncomfortable to me.
Speaker 1 (19:33):
Or at least away.
Speaker 3 (19:35):
You know, I'm confident that it would be not my
personal problem. It's more of a philosophical approach if you want.
But what is really important for me to stress out
is that all these data speaking about weakening of the
energies or evidence against the standard model are basically a
strong evidence that science works very well.
Speaker 1 (19:57):
That's doctor Leonards Jenny from the Universe of Queensland, and
this is space time still to come, we ask one
of those ultimate questions of science and humanity? Are we
alone in the universe? And today Planet Earth experienced a
partial solar eclipse, a celestial spectacle visible across New Zealand,
the South Pacific, a sliver of the Australian Pacific coast
(20:20):
and across much of Antarctica. All that and more still
to come on space time. Well after that deep dive
(20:42):
in cosmology we used to open the show, now might
be a good time to ask one of those ultimate
questions of science and humanity? Are we alone in the universe?
And that's where a new study comes in. Reminds me
a bit of that line from H. G. Wells War
of the World's The chances of anything coming from Mars
are a million to one, and the new study warns
(21:04):
that the chances of intelligent alien civilizations existing in our
galaxy aren't really much better. A report presented at the
European Planetary Science Congress in Helsinki provides new speculation on
the likelihood of another earthlike society existing in our small
corner of the universe. The studies authors Manuel Chef and
Helmet Lemma Earth from the Austrian Academy of Sciences, say
(21:26):
the nearest technological civilization in the Milky Way, according to
their calculations, would probably be at least thirty three thousand
light years away, and that such a society would need
to have survived for at least two hundred and eighty
thousand years potentially millions of years, in order to coexist
with us. At the same time, they argue that just
like Planet Earth, their home planet would need to have
(21:47):
an active plate tectonic system in order to regulate carbon
dioxide and maintain a long term biosphere, without which its
atmosphere could become either depleted or toxic. Earth's atmosphere comprises
seventy eight percent nitrogen, twenty one percent oxygen, and trace
amounts of other gases, including cab dioxide levels which currently
sit at zero point zero four two percent, although that
(22:10):
number is increasing every day. Sheriff and Lamour estimate that
Earth will lose sufficient atmospheric cabda oxide for photosynthesis within
the next two hundred million to a billion years, regardless
of any greenhouse effect. They say their modeling suggests that
planets with ten percent carbon dioxide could support biasphes for
approximately four point two billion years. Well one percent atmospheric
(22:32):
cab dioxide would allow up to three point one billion
years of habitability. Even so, such a world would, just
like the Earth, still need at least eighteen percent oxygen
in order to support complex animal life as we know it,
and that would be essential for any advanced civilization to
use fire, not just for warmth and cooking, but also
for metal working in industry, a prerequisite for technology. Now,
(22:54):
it took four point six billion years of planetary evolution
for humans to reach that level of technic logical advancement.
You ought to say, any civilization on a high commdark
side planet would also need to endure at least two
hundred and eighty thousand years in order to overlap with
humanity now. In order to live and say a Star
Trek style universe, a galaxy with malible civilizations existing simultaneously,
(23:17):
it would, according to the authors, require a societal lifespan
exceeding ten million years compared to Homo sapiens mere three
hundred to three hundred and fifty thousand years based on
the fossil record. Shrefin Lammas say that if extraterrestrial intelligence
does exist out there, it's likely to be far older
than us me humans. They also speculate that the closest
(23:37):
advanced civilization would be on the fast side of our galaxy,
which I guess will be in star Trek terms the
delta or gamma quadrants. So you can forget worrying about
the Klingon, Zindi or Cardassians and be far more concerned
about the Borg Kason and Foundest dominion. This is space
time still to come. A partial solar eclipse darkens the
(23:59):
Sun Guys, and later in the Science report a bit
of good news with the ozone hole over Antarctica being
a bit smaller now than what it was in recent years.
All that and more still to come on space time.
(24:27):
Lad at Earth experienced a partial solar eclipse today. The
celestial spectacle was visible across New Zealand, the South Pacific,
a sliver of the Australian Pacific coast, and across much
of Antarctica. Partial solar eclipses happened when the new Moon
moves between the Sun and the Earth, obscuring a good
portion of our local star. You see, Usually, the Moon's
(24:47):
orbit around the Earth passes a little above or a
little below the apparent track of the Sun across the sky.
And because the orbits of both the Moon and the
Earth are elliptical rather than perfectly circular, their distance from
each other and the Sun also varies. But roughly once
every eighteen months or so, the celestial mechanics time out
just so right that everything's in alignment. The result is
(25:10):
a solar eclipse, or in this case, a partial solar eclipse.
The southernmost parts of New Zealand South Island, including Christchurch,
Dunedin and Invicago, were the best places to see the eclipse,
which took place as the sun was rising in the morning.
The people there saw up to around seventy percent of
the Sun's face eclipsed by the moon in the early dawn,
(25:30):
forming a crescent as it rose. The moon then slowly
moved across the Sun, blocking out more and more of
its light over the next hour. As for Australia, only
observers on the very tip of the East coast saw
the Sun be partially eclipsed as it rose above the
horizon this morning. The celestial event began at three point
thirty in the morning Australian Eastern Standard time, with the
(25:52):
partial reaching its maximum between five forty one and five
forty three in the morning before ending at seven point
fifty four. Today's event came just two weeks after a
total lunar eclipse, which saw parts of Australia, Europe, Africa,
and Asia experience earth shadow obscuring the full Moon, turning
it blood red. That entire spectacle evolved over five hours,
(26:14):
starting with the first dusky bite of the Moon, and
totality lasting a total one hour and twenty two minutes.
The Sun will put on an even better display next year,
when its shadow crosses both polar regions of Earth. A
ring of fire annual eclipse will cut across Antarctica in February.
That's when the Moon's just a little bit too far
away from the Earth for a total solar eclipse. But
(26:35):
then a total solar eclipse will occur over the Arctic
in August, providing a spectacular show not just for anyone
at the North Pole, but also for people in Greenland,
Iceland and Spain. The next total solar eclipse in Australia
will be on July the twenty second, twenty twenty eight,
with a path of totality crossing the Western Australian Kimberley
Coast and then passing through the Northern Territory, southwestern Queensland
(26:57):
and New South Wales before reaching the South Pacifica coast
at Sydney at two o'clock in the afternoon. This is
space time, and time now to take a brief look
(27:22):
at some of the other stories making US and science
this week with a science report. A new study warns
that boys who are exposed to passive smoking as a
child could go on to have kids of their own
with impaired lung function. The findings, reported in the General Thorax,
found that a dad's childhood passive smoking could put his
kids at risk, and that risk is further heightened those
(27:44):
kids are childhood passive smokers themselves. The authors say that
the study highlights the intergenerational harms of smoking. They urge
fathers to intercept this harmful legacy by avoiding lighting up
anywhere near their children. Bit of good news now, Earth's
protective ozone layer is healing and the ozone hole in
twenty twenty four was smaller than it has been in
(28:06):
recent years. The findings in a new study by the
World Meteorological Organization indicate that the low level of ozone
depletion last year was in part due to naturally occurring
yide fluctuations. However, the report also found that the long
term positive trend reflected the success of international action, with
only China going against the trend, showing continued high levels
(28:29):
of chlorofluorocarbon emissions compared to previous years. Total stratospheric ozone
cover was higher over much of the globe, and the
depth of the Adarctic ozone hole in twenty twenty four,
which appears over Antarctica every southern hemisphere spring, was below
the nineteen ninety to twenty twenty average. Chlorofluorocarbons are chemicals
that destroy the Earth's protective stratospheric ozone layer. They do
(28:52):
this by releasing chlorine atoms when exposed to ultraviolet light,
creating an ozone hole and allowing harmful UVB radiation to
reach the planet's surface. Or once used in refrigerants and aerosopropellants,
the production of most CFC's has now been phased out
under the Montreal Protocols. Israel has started using the first
(29:14):
fully operational directed energy weapon, the Ion Beam. The new
anti missile aser defense shield will eventually replace existing interceptor
missiles like Arrow and Iron Dome, as well as the
Patriot Atti missile missile. The idef's announcement follows the deployment
back in June of a scaled down version of the
Ion Beam platform, which is so far successfully shot down
(29:34):
some forty drones fired at Israel by Hesbala terrorists financed
by the Islamic Republic of Iran. The new, more powerful
Ion Beam M batteries shoot out not only drones but
also missiles, rockets and mortars, and at longer ranges, potentially
even shortly after they're launched. Current IDEF plants call for
three variants of the energy weapon. The light ten kilowa
(29:57):
laser beam, which is already in operation and used by
ground forces short wrench targets. The new version is the
Ion M variant, which fires a two hundred and fifty
millimeter fifty killer what beam which can be mounted on
trucks and fired while mobile. And there's also a full
size directed energy weapon version which can fire a four
hundred and fifty millimeter one hundred killer what laser beam. Well,
(30:20):
it seems flat earthers have found a new way to
try and con weak minded people into believing their claims.
Their latest spiel involves offering money to anyone who can
prove the Earth is round, but they're not allowed to
use science, mathematics, or even photos from space. These unfair
conditions make it virtually impossible to prove the Earth is round,
and so it allows the pseudo scientific community the falsely
(30:43):
clam of victory. However, as Tim Mendem from Austrange Skeptics explains,
one man tried and the matter eventually wound up in
court with contract law rather than science being the eventual winner.
Speaker 4 (30:55):
This is a fellow a flat Earth proponent name then Garcia,
who put out a challenge five thousand dollars for anyone
who could provide real world proof that the Earth is
a sphere. Now, his criteria for this You couldn't use
scientific instruments, you couldn't use satellite imagery, you couldn't use
math based geodetic measurements or traditional astronomical observations. So you think,
(31:18):
what else do we have, and he was offering this
five thousand dollars, so someone took it up. The contract
said that you have to use the Ptolemaic measurement, which
is the curvature of the Earth, which is eight inches
per mile square, which is actually not correct.
Speaker 1 (31:34):
Egypt.
Speaker 4 (31:34):
I know he was in Egypt, but this actual figure,
it's not exactly accurate apparently. So what's happening is that
this guy has a challenge out here for someone to
prove this measurement system which is not exactly accurate, without
using any other sort of scientific equipment. Now someone did it.
They claim they did it, that he didn't pay up.
So the person who's supposed that you know, that approved
(31:56):
the Earth was round, took the flat earth. The court
or the court knocked it out. No, no, you can't
get your five thousand bucks. And a lot of people saying,
you know who are science based, saying, hey, O a second,
this guy is saying the Earth is flat, and in
the court of law you're saying it is. The thing
is that what the judge wasn't saying the Earth is flat.
He also wasn't saying it is around.
Speaker 1 (32:13):
What he was saying is that contract.
Speaker 4 (32:14):
It's the legal contract, and you didn't comply with the
ridiculous elements of this legal contract. So it's in the.
Speaker 1 (32:20):
Templications for you guys that skeptics, because you have a
very substantial reward for anyone who can prove science. Yeah.
Speaker 4 (32:29):
Yeah, we've been one hundred thousand dollars under scientific conditions
that there are greed conditions. The skeptics don't set the rules.
It's that the conditions are agreed by both sides.
Speaker 3 (32:36):
Right.
Speaker 4 (32:37):
It's not like I'm going to set up this thing
and you have to do it, right. This is is
that they let's find out a way to test this
particular claim the flat earth is a bit different because
it's not their specific claim of stunning skill that they have.
You're going to have both science have to agree with
the fair test beforehand. Otherwise the test doesn't go ahead
for our one hundred thousand dollars talents. And we've had
people apply for it, and we've tested people and so
(32:58):
sign no one's been able to prove that they can
do the things they say they can do. But this
particular thing I'm proving, the flat Earth's very similar thing
to what happened in the eighteen hundreds with fellow name
Alfred Russell Wallace, who was one of the developers of
the theory of evolution, who was also scientist in many
different areas. And someone else stood up this thing proved
the Earth is the sphere. And he went and did
an experiment on a canal, posts and all sorts of things,
(33:20):
and proved quite definitively that the Earth was curved. And
then the guy said, no, One'm not going to pay you.
So they took in the court and went on and
on and not Wallace said, not paying more money for
the court than he would ever have got for the
challenge amounts. So this is very well, then it is
the principle. Yet but in this particular case there was
a money principle, not not not the scientific principle. So
people are disappointed that in a court of law the
(33:41):
flat earth theory was not thrown out as ridiculous. And
the story goes is that the law was not looking
at the science, but also wasn't necessarily looking at how
reasonable the conditions were. It's just that the challenge that
did not comply with the unreasonable conditions, So that would
then be used to say the court of law, yeah,
they didn knock that flat Earth, but clearly said for
the contract scientific Unfortunately.
Speaker 1 (34:02):
That's timidum from Australian Skeptics, and that's the show for now.
(34:23):
Spacetime is available every Monday, Wednesday and Friday through Apple Podcasts, iTunes, Stitcher,
Google podcast, pocker Casts, Spotify, Acast, Amazon Music, Bytes dot com, SoundCloud, YouTube,
your favorite podcast download provider, and from space Time with
Stuart Gary dot com. Space Time's also broadcast through the
(34:44):
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(35:07):
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Speaker 2 (35:15):
You've been listening to space Time with Stuart Gary. This
has been another quality podcast production from bytes dot com
This is Spacetime Series twenty eight, episode one hundred and fourteen,
for broadcast on the twenty second of September twenty twenty five.
Coming up on Space Time, a new model to explain
the cosmos, one of those ultimate questions of science and humanity?
Are we alone in the universe? And a partial solar
eclipse darkens the skies of the South Pacific. All that
(00:23):
and more coming up on space Time.
Speaker 2 (00:27):
Welcome to space Time with Stuart Gary.
Speaker 1 (00:46):
Scientists have developed a new mathematical model of the universe,
one which attempts to explain its evolution over the past
thirteen point eight billion years in a more simplistic manner.
The new research reported in the journal Physical Review Letters.
It's based on data from DESI, the Dark Energy Spectroscopic Instrument,
which is measurements of the universe up to eleven billion years.
(01:08):
The large scale structure of the universe is sort of
like a giant cosmic web, comprising strands and filaments of galaxies,
galaxy clusters, and superclusters wrapped around the outskirts of vast
near empty voids. The author's work tries for the first
time to explain collapsing regions of matter and expanding voids.
(01:29):
The stati's lead author, Leonardo Jiani from the University of Queensland,
says it's dark energy which remains the key factor in
cosmic evolution. Dark energy is a measurement showing not just
that the universe is expanding, but that its rate of
expansion is actually accelerating. It originally began as a sort
of fudge factor called the cosmological constant, invented by Albert Einstein,
(01:52):
whose field theories showed that the universe was in fact expanding.
The problem is Einstein lived at a time when it
was generally accepted that the universe was actually in a
steady state which always remained generally the same on cosmic scales.
So to try and explain the expansion his equations were showing,
Einstein invented his cosmological constant in order to artificially adjust
(02:13):
the figures and return the universe into a steady state
as it should be. However, years later, observations by Edwin
Hubble proved that the universe really was expanding. That forced
Einstein to remove his cosmological constant, which he later described
as his biggest mistake. Then, in the nineteen nineties, observations
of supernovae showed that the universe wasn't just expanding, but
(02:37):
that rate of expansion was actually increasing, and so Einstein's
cosmological constant was back, but this time under the new
term of dark energy. Dark because no one really knew
exactly what it was, some sort of anti gravity or
vacuum energies the best they could come up with. Then
along came David Wheelchair from the University of Canterbury, who
(02:57):
challenged the status quo in the early two thousand. They
used improved analysis of supernova light to show that the
universe is expanding in a more varied, a more lumpier way.
Woolche's work supports a timescape model of cosmic expansion, one
which doesn't have the need for dark energy, because the
differences in stretching light aren't the result of an accelerating universe,
(03:19):
but instead a consequence of how science calibrates time and distance.
Timescape takes into account the fact that time itself slows
down around mass, and so an ideal clock in the
empty space of a vast void would take faster than
what the same clock would inside a galaxy. In fact,
the model suggests that a clock in the Milky Way
(03:41):
would be about thirty five percent slower than the same
clock at an average position in a large cosmic void,
and that means billions more years would have passed inside
a void compared to inside galaxy, and this would in
turn allow more expansion of space, making it seem like
the expansion is getting faster when such vast, empty voids
(04:02):
grow to dominate the universe. Wulci said he's finding show
that science doesn't need dark energy to explain why the
universe appears to be expanding at an ever accelerating rate.
He says dark energy is simply a misidentification of variations
in the kinetic energy of expansion, which is not uniform
in the universe as lumpy as the one we actually
(04:23):
live in, and that's where the new work of Jihanni
comes in. His research shows dark energy is real, but
maybe not as strong as some have suggested. Johnny's new
model can change the way physicists and cosmologists look at
the universe. He points out that the standard model mapping
the universe from the Big Bang right through to now
as matter particles of the same size not interacting with
(04:46):
each other, but in reality, astronomers can see there are
stars in black holes, galaxy clusters, and empty regions constantly
interacting through it. Forces such as gravity not accounted for
but the standard model. Johnny says, for the past third years,
scientists have tried to explain what's happening as this complex
universe expands, and there been plenty of exotic attempt set solutions.
(05:08):
You see, astronomers know that voids and collapsing regions exist,
but according to Janni, they didn't really know how to
compute their impact on the measurements, and he says his
model gives them a recipe to compute that figure without
the need for any new physics. This new framework uses
simple mathematical terms to describe how the emergence of complex
(05:29):
structures in the universe affects cosmological measurements. Janni and colleagues
set out to identify the minimum size avoid needs to
be in order to impact the measurements, as well as
the minimum size of galaxy. Customers have independent data sets,
including the DESI. Data were plotted against an x and
y axis chart showing the minimum sizes of the collapsing
(05:50):
and expanding regions of space which can impact cosmological measurements. Now,
the standard model of the universe should see all of
these data set contours overlap, but at one end of
the graph, where the sizes of the expanding and contracting
regions would be too large for them to exist, But
instead they overlap in a different region, and that indicates
(06:11):
that the large voids of space may well be responsible
for the anomalous behavior observed in the data. Yanni says
the new model also helps address two of the biggest
problems in modern cosmology, Hubble tension and the evidence for
dynamical dark energy. Hubble tension is a discrepancy between two
methods currently used to calculate the universe's rate of expansion,
(06:32):
known as the Hubble constant. Well Dynamical dark energy is
a theory that says energy is not constant, but changing
or weakening over time. The Hubble constant is an expansion
rate of roughly seventy kilometas per second per mega parsek,
with a level of uncertainty of around five kilometis per
second per mega parsek, a mega parsek being three point
(06:53):
twenty six million light years. But you see that figure
depends on how you're measuring the brightness of type one
ac supernovae still are explosions marking the deaths of specific
types of stars, which are all roughly the same mass
when they die, and so explode with roughly the same
level of luminosity. These can therefore be used as standard
(07:13):
candles to determine distance through the inverse square lore. It's
like looking at a row of street lights down a
road and being able to tell how far away each
light is by how bright it appears to be. The
alternative method involves observing the cosmic microwave background radiation, the
left overheat generated three hundred and eighty thousand years after
the Big Bang, when the universe's primordial quark gluon plasma
(07:36):
cooled enough for the first atoms to form, and you
can observe this cosmic microwave background radiation today, three point
eight billion years later as the white noise static you
get between stations on old analog radio and TV sets.
Of course, today that primordial superintense heat has now cooled
to just two point seven degrees above absolute zero, and
(07:59):
this is where hubble tension arises, because these two different
measurement methods have viewed its slightly different values, creating a
crisis in cosmology, Jenny says, if you try to assume
that dark energy is weakening, and then you try to
infer how fast the universe is expanding from that data,
you get even lower measurements for the rate of expansion
of the universe, solutions to one problem creating another. In
(08:22):
his model, any weakening of energy is just a detailed
accounting of what the universe looks like today. It behaves
as if it were weakening, but may not be weakening
at all, Jenny says, Essentially, when asked if the complexity
of the universe were showing up in the desert data,
the results shows that it was, and his study can
explain those observations.
Speaker 3 (08:44):
It's a new model, but what I think it's very
relevant is that it doesn't really require much new physics,
so it's nothing revolutionary in terms of our understanding of
nature the universe. Say, the main point is that our
previous model, our previous understand cosmology and evolution of the
universe as well, was based on the fact that the
universe looks the same everywhere, and it's basically describing all
(09:08):
the matter in the universe as if they were thus
practicles that do not interact between each other and this
description on sufficiently or let's a very large scale to
the side of the universe wise is working very well. However,
the precision of our measurements and experiments become so large,
or become so good that we actually start to see
(09:31):
some hint that this model could not be valid anymore.
And what I did, essentially is trying to give up
description to take into account the fact that the universe
is not made by you know, identical marbles everywhere, but
from you know, structures that can vary between large filaments
(09:51):
and clusters of galaxies, and that masters two very large
voids that expand faster than the rest. So you in
a few words, my mathematical model is trying to quantify
how many of these structures that are out there and
giving to each of them some energy so that I
can estimate how much their presence is outed in the
(10:12):
evolution of the universe.
Speaker 1 (10:13):
Understanding they true structure the universe and our place in
it is really important for how we observe the universe
and how we measure it.
Speaker 3 (10:20):
Yeah, percasely, also because you know, all these structures were
not existing back when the universe was very young, so
they actually evolved with time, just like us, and we
happen to appear in one for more of these complex
web of structures. When I say one or more, I
mean that it's quite hard to distinguish if we live
in underdense environment or over dense environment. Given our measurements,
(10:42):
we of course have things. But in order to understand
our cosmic environment, our local, our place in the universe.
If I can be the dramatic, we need a lot
of data and very sophisticated noise. And the data becoming
available only now our future.
Speaker 1 (10:58):
Will the universe span forever into a cosmic deep phraeze,
Will that expansion slow down and become a steady state,
or will gravity eventually take over from dark energy and
we see the universe begin to collapse again into another
big crunch, which could result in another Big Bang, then
another big crunch. I mean this is determining the ultimate
fate of the universe.
Speaker 3 (11:19):
Yeah, and that all the options that you gave so
far are basically all available given our current understanding, we
of course have a hint about what the nature of
that energy is. And according to these what I can
tell you is that seems like the universe will expand
forever even if that energy is weakening or this is
at least the latest evidence from some data called but
(11:44):
an echocoustical solution, it seems.
Speaker 1 (11:46):
Like it sure waves in the early universe.
Speaker 3 (11:48):
Yes, exactly. Yeah, Like if you look at the distribution
of galaxies in the universe, this is not random. It's
sechally describing a very complex and nice pattum in which
galaxies tend to for structures, tend to agglomerate in certain
spots and to elute in others, reflecting somehow the initial
conditions of the universe. So if to make a metaphor,
(12:11):
imagine you ared at a pond, then you throw a
bunch of frogs in the pond in the water, you
will see sound water waves in the metaphor, and where
the crest of the waves merge together, that's where you
would expect another excess, another flow of water. It's the
same with galaxies. We start with these initial conditions, which
is like you know, a painting or an initial setting
of where the matter is distributed more or less the
(12:33):
same agreew but with small situations, and then this wave propagates,
and when they propagate, they tend to agglumerate. Galaxies in
their intersection points, so again it's not a random pattern.
From the structure of the pattern, by trying to measure it,
we can understand more about what the energy content of
the universe, So how much that can it be? Is around?
Much matter is around? It's very cool, and you know
(12:55):
this dise cosmogical probe is but the only acoustic oscillation
is has been known for years now. But for the
very first time, we have really enough observation of galaxies.
I'm talking about a millions of galaxies that we can
use to put on a very significant sample and statistic.
So this is very exciting and it's why it's amazing
(13:16):
to be on the job right now.
Speaker 1 (13:18):
For me, Does our position within the cosmic web play
an important role? In other words, if the local galactic
group that's the Milky Way Andromata Triangular and all the
satellite galaxies around us, if this local galactic group we're
in is in one of these filaments, we would have
a different understanding of the universe compared to what we
would see or what we would experience if we're in
(13:41):
the middle of one of these vast voids. Does that
play a role in our understanding of dark matter and
dark energy.
Speaker 3 (13:47):
It surely does. So if I can be very simplistic,
let's imagine that that work environment, our cosmic neighborhood, let's see,
is like a work gloss. This is outing slightly our
perception of what's outside the glass. Of course, lights travel
propagate within, and so it's slightly affected reflected and our
(14:09):
cosmological inference. So what we learn about the universe needs
to keep account of this water glass around us, which
is unavoidable. Now, if you know the properties of the glass,
you can kind of keep that into account and try
to correct your measurements so that you're obtaining a closer
description of the universal side. However, understand the glass itself
(14:29):
is a very interesting field of research. So let's say
that with the water glass is very thick, like we
live in an overdanced region of the universe. Then light
will be struggling reaching gas, and this will make us
experience a universe that seems to expand slightly faster outside.
(14:51):
And the opposite is true in the case of underdanced class.
So if we live in avoid now, the truth is
that is, if we live been avoid, it's quite unlikely
that we are saved because by definition, voids should have
less galaxies, so it would be a statistical fluctuations on
an unlikely scenario. And also from what we know by
(15:13):
reconstructing the velocity field of galaxies in the local universe,
we kind of believe that we are part of our supercluster.
The supercluster can be identified with an object called Lanyakia,
which is this massive supercluster of containing hundreds of thousands
of galaxies, or even a larger supercluster called Shaftli the
(15:33):
Safti concentration. So let's say that these hints seems indicate
that we actually belong to our overdense region of the universe,
if that makes sense.
Speaker 1 (15:44):
See that's interesting because just last week we had a
paper come out suggesting that the density in our region
of the universe is actually lower than the average. So
we're getting these conflicting figures. Depends on the observations you're making,
I guess.
Speaker 3 (15:58):
Exactly depends really are on because logical probe using and
the fact that there is seemingly not a simple answer
to this question kind of reflects why it's so important
that we keep trustesting our models and our analysis. I
should say that historically this local underdance region has been
advocated and exploited in the past because it was proposed
(16:19):
early in the two thousand as an alternative to the
existance of that Kennedy that chemopy is a beautiful resource
that we have to explain a lot of problems or
a lot of seemingly inconsistent observations that become not inconsistent
when you introduce their.
Speaker 1 (16:34):
Charity is Will Chair from the University of Canterbury.
Speaker 3 (16:38):
Yeah, for example, the Timescape model from David Wature. But
I'm talking even earlier than that, like back really in
the early two thousand, before the Timescape model was our
people had this model called Hpbull bubble in which they
were explaining or we were trying to explain the apparent
accelerated expansion of the universe with us living in a
(16:58):
local void so like a bubble in the otherwise on
much units and is isotropic universe. And of course these
type of models, including the one you mentioned from the
which became very popular because they provide a very physical
explanation to something that is a bit uncomfortable. That kind
of is a bit uncomfortable from a theoretical point of
view because it challenges kind of the physics that we
(17:19):
experience so every day. So this Underdanse model became very popular,
and in my short life as an academic roughly ten years,
I saw them coming up over and over again several times.
To my understanding, it's all about the scales you are
trying to consider. If you consider, if you restrict yourself
only to certain scales, you might find evidence of a void,
(17:42):
But if you shorten your window or enlarge it, you
can find presence of classes. Because it's a very complicated structure,
and the name of the game is usually distancing, but
actually getting distances right in the universe is very hard
because unfortunately we cannot feel the inter as you know
of in the galactic side, even if we try so,
(18:02):
we have to struggle with understanding these distances in a
good way. My personal take is that I would not
confidently say neither of the two ind that we live
inside avoid or needed that we live inside the film.
But from a gambling perspective, it's more likely that we
live in a filament if you ask. Also, I ever
(18:22):
work on like AKM, this big large supercluster of galaxies,
and what I found is actually that it is compatible,
like our data are compatible with the local in falling region.
If you interpret these velocities of galaxy as due to
the fact that there is a center of gravity towards
which they're falling.
Speaker 1 (18:41):
So with energy existing but awakening that I guess all
birds well for a big phrase ultimate fight for the universe,
but not a big rip.
Speaker 3 (18:50):
Yes, you are clearly talking about singularities, in cosmological singularities,
So big freeze would be something like the universe. It's expanding,
but instead of accelerating exponentially, since that energies weakening, the
break of expansion is not fascillating a start, and so
everything will be put faster apart from everything else and
(19:11):
we end up you know, cold and kind of boarding universe,
which at least is a perspective. It's very relaxing to
me compared to a bigree where I look in collact
exponentially and even the distance between atom.
Speaker 1 (19:25):
Is exponentially ripped apart, very uncareful.
Speaker 3 (19:31):
Yeah, this is a bit more uncomfortable to me.
Speaker 1 (19:33):
Or at least away.
Speaker 3 (19:35):
You know, I'm confident that it would be not my
personal problem. It's more of a philosophical approach if you want.
But what is really important for me to stress out
is that all these data speaking about weakening of the
energies or evidence against the standard model are basically a
strong evidence that science works very well.
Speaker 1 (19:57):
That's doctor Leonards Jenny from the Universe of Queensland, and
this is space time still to come, we ask one
of those ultimate questions of science and humanity? Are we
alone in the universe? And today Planet Earth experienced a
partial solar eclipse, a celestial spectacle visible across New Zealand,
the South Pacific, a sliver of the Australian Pacific coast
(20:20):
and across much of Antarctica. All that and more still
to come on space time. Well after that deep dive
(20:42):
in cosmology we used to open the show, now might
be a good time to ask one of those ultimate
questions of science and humanity? Are we alone in the universe?
And that's where a new study comes in. Reminds me
a bit of that line from H. G. Wells War
of the World's The chances of anything coming from Mars
are a million to one, and the new study warns
(21:04):
that the chances of intelligent alien civilizations existing in our
galaxy aren't really much better. A report presented at the
European Planetary Science Congress in Helsinki provides new speculation on
the likelihood of another earthlike society existing in our small
corner of the universe. The studies authors Manuel Chef and
Helmet Lemma Earth from the Austrian Academy of Sciences, say
(21:26):
the nearest technological civilization in the Milky Way, according to
their calculations, would probably be at least thirty three thousand
light years away, and that such a society would need
to have survived for at least two hundred and eighty
thousand years potentially millions of years, in order to coexist
with us. At the same time, they argue that just
like Planet Earth, their home planet would need to have
(21:47):
an active plate tectonic system in order to regulate carbon
dioxide and maintain a long term biosphere, without which its
atmosphere could become either depleted or toxic. Earth's atmosphere comprises
seventy eight percent nitrogen, twenty one percent oxygen, and trace
amounts of other gases, including cab dioxide levels which currently
sit at zero point zero four two percent, although that
(22:10):
number is increasing every day. Sheriff and Lamour estimate that
Earth will lose sufficient atmospheric cabda oxide for photosynthesis within
the next two hundred million to a billion years, regardless
of any greenhouse effect. They say their modeling suggests that
planets with ten percent carbon dioxide could support biasphes for
approximately four point two billion years. Well one percent atmospheric
(22:32):
cab dioxide would allow up to three point one billion
years of habitability. Even so, such a world would, just
like the Earth, still need at least eighteen percent oxygen
in order to support complex animal life as we know it,
and that would be essential for any advanced civilization to
use fire, not just for warmth and cooking, but also
for metal working in industry, a prerequisite for technology. Now,
(22:54):
it took four point six billion years of planetary evolution
for humans to reach that level of technic logical advancement.
You ought to say, any civilization on a high commdark
side planet would also need to endure at least two
hundred and eighty thousand years in order to overlap with
humanity now. In order to live and say a Star
Trek style universe, a galaxy with malible civilizations existing simultaneously,
(23:17):
it would, according to the authors, require a societal lifespan
exceeding ten million years compared to Homo sapiens mere three
hundred to three hundred and fifty thousand years based on
the fossil record. Shrefin Lammas say that if extraterrestrial intelligence
does exist out there, it's likely to be far older
than us me humans. They also speculate that the closest
(23:37):
advanced civilization would be on the fast side of our galaxy,
which I guess will be in star Trek terms the
delta or gamma quadrants. So you can forget worrying about
the Klingon, Zindi or Cardassians and be far more concerned
about the Borg Kason and Foundest dominion. This is space
time still to come. A partial solar eclipse darkens the
(23:59):
Sun Guys, and later in the Science report a bit
of good news with the ozone hole over Antarctica being
a bit smaller now than what it was in recent years.
All that and more still to come on space time.
(24:27):
Lad at Earth experienced a partial solar eclipse today. The
celestial spectacle was visible across New Zealand, the South Pacific,
a sliver of the Australian Pacific coast, and across much
of Antarctica. Partial solar eclipses happened when the new Moon
moves between the Sun and the Earth, obscuring a good
portion of our local star. You see, Usually, the Moon's
(24:47):
orbit around the Earth passes a little above or a
little below the apparent track of the Sun across the sky.
And because the orbits of both the Moon and the
Earth are elliptical rather than perfectly circular, their distance from
each other and the Sun also varies. But roughly once
every eighteen months or so, the celestial mechanics time out
just so right that everything's in alignment. The result is
(25:10):
a solar eclipse, or in this case, a partial solar eclipse.
The southernmost parts of New Zealand South Island, including Christchurch,
Dunedin and Invicago, were the best places to see the eclipse,
which took place as the sun was rising in the morning.
The people there saw up to around seventy percent of
the Sun's face eclipsed by the moon in the early dawn,
(25:30):
forming a crescent as it rose. The moon then slowly
moved across the Sun, blocking out more and more of
its light over the next hour. As for Australia, only
observers on the very tip of the East coast saw
the Sun be partially eclipsed as it rose above the
horizon this morning. The celestial event began at three point
thirty in the morning Australian Eastern Standard time, with the
(25:52):
partial reaching its maximum between five forty one and five
forty three in the morning before ending at seven point
fifty four. Today's event came just two weeks after a
total lunar eclipse, which saw parts of Australia, Europe, Africa,
and Asia experience earth shadow obscuring the full Moon, turning
it blood red. That entire spectacle evolved over five hours,
(26:14):
starting with the first dusky bite of the Moon, and
totality lasting a total one hour and twenty two minutes.
The Sun will put on an even better display next year,
when its shadow crosses both polar regions of Earth. A
ring of fire annual eclipse will cut across Antarctica in February.
That's when the Moon's just a little bit too far
away from the Earth for a total solar eclipse. But
(26:35):
then a total solar eclipse will occur over the Arctic
in August, providing a spectacular show not just for anyone
at the North Pole, but also for people in Greenland,
Iceland and Spain. The next total solar eclipse in Australia
will be on July the twenty second, twenty twenty eight,
with a path of totality crossing the Western Australian Kimberley
Coast and then passing through the Northern Territory, southwestern Queensland
(26:57):
and New South Wales before reaching the South Pacifica coast
at Sydney at two o'clock in the afternoon. This is
space time, and time now to take a brief look
(27:22):
at some of the other stories making US and science
this week with a science report. A new study warns
that boys who are exposed to passive smoking as a
child could go on to have kids of their own
with impaired lung function. The findings, reported in the General Thorax,
found that a dad's childhood passive smoking could put his
kids at risk, and that risk is further heightened those
(27:44):
kids are childhood passive smokers themselves. The authors say that
the study highlights the intergenerational harms of smoking. They urge
fathers to intercept this harmful legacy by avoiding lighting up
anywhere near their children. Bit of good news now, Earth's
protective ozone layer is healing and the ozone hole in
twenty twenty four was smaller than it has been in
(28:06):
recent years. The findings in a new study by the
World Meteorological Organization indicate that the low level of ozone
depletion last year was in part due to naturally occurring
yide fluctuations. However, the report also found that the long
term positive trend reflected the success of international action, with
only China going against the trend, showing continued high levels
(28:29):
of chlorofluorocarbon emissions compared to previous years. Total stratospheric ozone
cover was higher over much of the globe, and the
depth of the Adarctic ozone hole in twenty twenty four,
which appears over Antarctica every southern hemisphere spring, was below
the nineteen ninety to twenty twenty average. Chlorofluorocarbons are chemicals
that destroy the Earth's protective stratospheric ozone layer. They do
(28:52):
this by releasing chlorine atoms when exposed to ultraviolet light,
creating an ozone hole and allowing harmful UVB radiation to
reach the planet's surface. Or once used in refrigerants and aerosopropellants,
the production of most CFC's has now been phased out
under the Montreal Protocols. Israel has started using the first
(29:14):
fully operational directed energy weapon, the Ion Beam. The new
anti missile aser defense shield will eventually replace existing interceptor
missiles like Arrow and Iron Dome, as well as the
Patriot Atti missile missile. The idef's announcement follows the deployment
back in June of a scaled down version of the
Ion Beam platform, which is so far successfully shot down
(29:34):
some forty drones fired at Israel by Hesbala terrorists financed
by the Islamic Republic of Iran. The new, more powerful
Ion Beam M batteries shoot out not only drones but
also missiles, rockets and mortars, and at longer ranges, potentially
even shortly after they're launched. Current IDEF plants call for
three variants of the energy weapon. The light ten kilowa
(29:57):
laser beam, which is already in operation and used by
ground forces short wrench targets. The new version is the
Ion M variant, which fires a two hundred and fifty
millimeter fifty killer what beam which can be mounted on
trucks and fired while mobile. And there's also a full
size directed energy weapon version which can fire a four
hundred and fifty millimeter one hundred killer what laser beam. Well,
(30:20):
it seems flat earthers have found a new way to
try and con weak minded people into believing their claims.
Their latest spiel involves offering money to anyone who can
prove the Earth is round, but they're not allowed to
use science, mathematics, or even photos from space. These unfair
conditions make it virtually impossible to prove the Earth is round,
and so it allows the pseudo scientific community the falsely
(30:43):
clam of victory. However, as Tim Mendem from Austrange Skeptics explains,
one man tried and the matter eventually wound up in
court with contract law rather than science being the eventual winner.
Speaker 4 (30:55):
This is a fellow a flat Earth proponent name then Garcia,
who put out a challenge five thousand dollars for anyone
who could provide real world proof that the Earth is
a sphere. Now, his criteria for this You couldn't use
scientific instruments, you couldn't use satellite imagery, you couldn't use
math based geodetic measurements or traditional astronomical observations. So you think,
(31:18):
what else do we have, and he was offering this
five thousand dollars, so someone took it up. The contract
said that you have to use the Ptolemaic measurement, which
is the curvature of the Earth, which is eight inches
per mile square, which is actually not correct.
Speaker 1 (31:34):
Egypt.
Speaker 4 (31:34):
I know he was in Egypt, but this actual figure,
it's not exactly accurate apparently. So what's happening is that
this guy has a challenge out here for someone to
prove this measurement system which is not exactly accurate, without
using any other sort of scientific equipment. Now someone did it.
They claim they did it, that he didn't pay up.
So the person who's supposed that you know, that approved
(31:56):
the Earth was round, took the flat earth. The court
or the court knocked it out. No, no, you can't
get your five thousand bucks. And a lot of people saying,
you know who are science based, saying, hey, O a second,
this guy is saying the Earth is flat, and in
the court of law you're saying it is. The thing
is that what the judge wasn't saying the Earth is flat.
He also wasn't saying it is around.
Speaker 1 (32:13):
What he was saying is that contract.
Speaker 4 (32:14):
It's the legal contract, and you didn't comply with the
ridiculous elements of this legal contract. So it's in the.
Speaker 1 (32:20):
Templications for you guys that skeptics, because you have a
very substantial reward for anyone who can prove science. Yeah.
Speaker 4 (32:29):
Yeah, we've been one hundred thousand dollars under scientific conditions
that there are greed conditions. The skeptics don't set the rules.
It's that the conditions are agreed by both sides.
Speaker 3 (32:36):
Right.
Speaker 4 (32:37):
It's not like I'm going to set up this thing
and you have to do it, right. This is is
that they let's find out a way to test this
particular claim the flat earth is a bit different because
it's not their specific claim of stunning skill that they have.
You're going to have both science have to agree with
the fair test beforehand. Otherwise the test doesn't go ahead
for our one hundred thousand dollars talents. And we've had
people apply for it, and we've tested people and so
(32:58):
sign no one's been able to prove that they can
do the things they say they can do. But this
particular thing I'm proving, the flat Earth's very similar thing
to what happened in the eighteen hundreds with fellow name
Alfred Russell Wallace, who was one of the developers of
the theory of evolution, who was also scientist in many
different areas. And someone else stood up this thing proved
the Earth is the sphere. And he went and did
an experiment on a canal, posts and all sorts of things,
(33:20):
and proved quite definitively that the Earth was curved. And
then the guy said, no, One'm not going to pay you.
So they took in the court and went on and
on and not Wallace said, not paying more money for
the court than he would ever have got for the
challenge amounts. So this is very well, then it is
the principle. Yet but in this particular case there was
a money principle, not not not the scientific principle. So
people are disappointed that in a court of law the
(33:41):
flat earth theory was not thrown out as ridiculous. And
the story goes is that the law was not looking
at the science, but also wasn't necessarily looking at how
reasonable the conditions were. It's just that the challenge that
did not comply with the unreasonable conditions, So that would
then be used to say the court of law, yeah,
they didn knock that flat Earth, but clearly said for
the contract scientific Unfortunately.
Speaker 1 (34:02):
That's timidum from Australian Skeptics, and that's the show for now.
(34:23):
Spacetime is available every Monday, Wednesday and Friday through Apple Podcasts, iTunes, Stitcher,
Google podcast, pocker Casts, Spotify, Acast, Amazon Music, Bytes dot com, SoundCloud, YouTube,
your favorite podcast download provider, and from space Time with
Stuart Gary dot com. Space Time's also broadcast through the
(34:44):
National Science Foundation, on Science Zone Radio and on both
iHeartRadio and tune In Radio. And you can help to
support our show by visiting the space Time Store for
a range of promotional merchandising goodies, or by becoming a
Spacetime Patron, which gives give you access to triple episode
commercial free versions of the show, as well as lots
of burnus audio content which doesn't go to air, access
(35:07):
to our exclusive Facebook group, and other rewards. Just go
to space Time with Stewart Gary dot com for full details.
Speaker 2 (35:15):
You've been listening to space Time with Stuart Gary. This
has been another quality podcast production from bytes dot com
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