October 31, 2022 • 43 mins
Why did Einstein refer to quantum entanglement as "spooky action at a distance?" What is locality? Could quantum systems allow for faster than light communication? Could that violate causality? It's a spooky quantum episode of TechStuff!
See omnystudio.com/listener for privacy information.
Mark as Played
Transcript
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Speaker 1 (00:04):
Welcome to tech Stuff, a production from My Heart Radio.
Hey there, and welcome to tech Stuff. I'm your host,
Jonathan Strickland. I'm an executive producer with my Heart Radio
and how the tech are you? And Happy Halloween. This
episode is publishing on Halloween, October thirty one, two thousand
(00:28):
twenty two. That's for those of you in the future
who are listening back on this episode. So throughout this month,
I have published a few episodes that are at least
tangentially connected if I'm being generous to to scary spooky stuff.
It's a little tricky with tech because I don't want
to go into like really big paranormal kind of things
(00:52):
and technology that purports to do stuff that's impossible, because
that really just comes down to debunking. I want to do, um,
you know, some stuff that that has spooky names, but
ultimately it's not that scary stuff like vampire power and
zombie computers, although those are scary. The phrase ghost in
the Machine was an episode that kind of thing. But
(01:13):
on Halloween itself, I thought we could chat about something
Einstein himself referred to as spooky action at a distance,
and this does tie into tech. We are going to
talk about tech, not just theories and physics, and we're
also going to talk about tech that's in the realistic
world and in like science fiction ee kind of applications. Now,
(01:37):
Einstein when he said spooky action at a distance, wasn't
trying to describe, you know, ghosts involved in a long
distance relationship or anything. So we're not gonna have any
specters making you know, erotic FaceTime calls to each other.
That's not what we're talking about here. Instead, we're going
to talk about quantum mechanics. So at the heart of
(02:02):
this concept of spooky action at a distance is this
idea of quantum entanglement and how quantum entanglement violates locality.
So Einstein was a truly brilliant physicist and mathematician, but
he was no Einstein. Okay, all right, that makes no sense.
(02:23):
He was and Einstein he was the Einstein. But there
were certain leaps he wasn't yet ready to make, and
a big one of those is how quantum mechanics isn't
necessarily confined to locality. Einstein had issues with quantum mechanics
in general because quantum mechanics has a lot of elements
(02:45):
to it that seemed completely alien to us based on
our understanding of classical physics, and there were certain bits
of that that Einstein had some real problems with. So
what is locality, Well, it what it sounds like, right.
It's locality is it describes that there's a limitation, like
a regional limitation on physical events and their consequences. So,
(03:10):
in other words, locality would tell us that an event
in one part of the world could not possibly affect
something very far away instantaneously, because that would violate locality.
You know, if I were to sneeze right now and
then a tree where to fall over in the Philippines,
you wouldn't say those two things were immediately connected because
(03:33):
that violates locality. There's no there's no causal, uh agent
there to make that happen, right to to go from
my sneeze to the tree falling over in the same
instant to make that makes sense. So this is a
little different. Actually, it's a lot different from the classic
(03:54):
butterfly effect. That is another concept that doesn't violate low cality.
So the butterfly effect is a way to describe aspects
of chaos theory, and in the butterfly effect, a small
change in a variable or a state can lead to
a much larger change in a later state. So a
(04:18):
classic example is a butterfly flaps its wings on one day,
and that little disturbance in the air ultimately contributes to
potentially provides the necessary impetus for a tornado that happens
several weeks later. Or you might hear another version of
this where a butterfly flaps its wings in South America
(04:38):
and that contributes to a tsunami that later hits Southeast Asia.
That kind of thing. The idea that little things can
be the changing factor that determines whether or not a
larger thing in the future happens or doesn't. Right, But
this doesn't violate locality because you have that aspect of
(04:59):
time that allows something to develop further from an initial event.
With the quantum entanglement, the idea is that these things
are happening instantaneously. There is no time between event one
an event too. You have event one, an event two
is a consequence of event one, even if those two
(05:20):
events are happening on opposite sides of the world. That
is what Einstein had a problem with, you know, because
he wanted to try and figure out how can you
describe event one making event to possible if they're not
in the same locality, and quantum mechanics said that does happen,
and Einstein was like, no, that that can't be the
(05:44):
way it works. It has to be that there are
local events, local variables, perhaps hidden variables, that explain why
these things happen. And it looks like there's some sort
of correlation or perhaps cause relationship between these events to us.
But that's because we're misinterpreting things. We're not looking at
(06:06):
the actual cause. That's what Einstein was saying. He was
just not able to make a jump to understanding quantum entanglement.
You can understand why, right, because this idea that something
happens in one place and that can cause a reaction
that is literally a world away at the very same time.
(06:26):
That flies in the phase of our own experience. Right
if you were to drop a piece of pizza and
you saw it hit the floor, you would be shocked
to learn that you caused an earthquake on the other
side of the world at that exact same moment, like
pizza hits the floor, earthquake across the world from you,
and that you were somehow the cause of it. That
(06:46):
wouldn't make sense. Even if somehow vibrations from the pizza
hitting the floor managed to travel all the way through
the Earth to the other side, it would take time
for the vibrations to go through the entire planet. It
would take the speed of sound through that various media
for it to get there, and then, you know, who
knows what happens once it hits the core. We'd have
(07:08):
to watch a lot of science fiction and horror movies
to figure that out. So maybe your whale of anguish
also would contribute. You know, you just lost a piece
of pizza, so obviously you're going to have a grieving period.
But we're still limited to the speed of sound here.
It takes time for sound to make its way anywhere.
So even if it were somehow able to go through
the entire Earth and cause this earthquake, it would take
(07:29):
a lot of time. It would not be an instantaneous reaction.
This really gets to one of the big obstacles when
it comes to understanding or explaining quantum effects. Because the
quantum level, the quantum world obeys a different set of
rules from the classical realm stuff that is impossible in
our day to day existence is commonplace and quantum systems.
(07:53):
So let me give you another example. Heisenberg's uncertainty principle
explains that we have a emit when it comes to
describing particles, and we're really talking about like quantum particles,
sub atomic particles, that kind of thing. So the classic
example is describing a particle's position and its momentum based
on initial conditions. So Heisenberg hypothesized that the more we
(08:17):
know about one of these two conditions i e. Its
position or its momentum, well, the less then we can
know about the other one. So if we had perfect
knowledge of a particle's position, we would know nothing about
its momentum. We would be unable to describe where and
at what speed this particle was moving, so it'd be
(08:37):
kind of like a snapshot, Like a perfect snapshot, we
could see the position of the particle at that moment
in time, but we would know nothing else about it. Likewise,
if we had perfect knowledge of the particle's momentum, we
would be unable to describe its position at all. So
because of this limitation, we cannot know with certainty both
(08:57):
pieces of information. So we typically will describe particles like
these as existing within a range or zone of potential
positions at any given time. You can think of it
almost like a cloud that this particle could exist within UH,
and it could be anywhere within that cloud at any
(09:18):
given time that you could take the the opportunity to
detect it, and in that instant detect where the particle is.
Then all those possibilities collapse into one fixed position. But
before you look, it could be anywhere in that cloud.
So there are regions within that cloud where the particle
(09:39):
is more likely to be found in a given moment,
but there's at least the possibility that it could be
at any point within the cloud at any specific time. Now,
not only is this different from what we experience in
our day to day life, where we can explain with
decent confidence a person's position and momentum, it can lead
(10:00):
to other weird quantum effects that really make a difference
in technology, such as quantum tunneling. So this has a
real effect on electronics and circuits, particularly with things like
UH processors computer processors. So when we're talking about electronics,
you can think of electronics at a very very very
(10:20):
basic level as being all about controlling where the flow
of electrons can go and what work the electrons will
have to do along the way as they make their
way to their destination, which is typically a positive terminal.
You know, electrons are negatively charged, and so opposites attract
it wants to go to the positively charged terminal. Electrons
(10:43):
are subatomic particles and they behave according to the quantum
effects described by folks like Heisenberg. So if we wanted
to focus on a single electron within a circuit, we
would have to describe its location as existing within a
sort of zone or field. We can't point to the
specific location as the electron moves through the system, but
(11:04):
we can describe an area of probabilities where the electron
could be well. One of the most important components in
circuitry is the transistor, which acts like a gate. The
gate can allow electrons to go through or it can
prevent them from going through, So it's really a switch, right.
(11:24):
It forms the basis of much more complicated systems, but
it only works if you know it can actually keep
electrons from going through. Well, it's possible that a zone
of probabilities of an electron's position can actually overlap a gate.
So if the gate is very very thin, it's possible
(11:46):
for the zone to extend to the other side of
a closed gate. This means that it's technically possible for
an electron to exist on the other side of the
closed gate, even though the electron would otherwise have been
prevented from passing through because again the gate is closed. Well,
if something is possible, that means that sometimes it happens. Right,
(12:09):
even if you think, well, the electron didn't physically move
through the gate, that the fact that there's a chance
for it to be on the other side means that
sometimes it is on the other side. So in a
system like this, an electron can sometimes be on the
opposite side of a closed gate and then keep on going.
This is not good if your goal is to control
(12:30):
the flow of electrons, because the whole purpose of the
gate is to stop them from going. So this means
you're gonna start getting errors, and that that's because electrons
are going through parts of your system that they're supposed
to not be able to go through. So let's imagine
what this would look like in our day to day existence, Like,
if this same effect happened in our world, what would
(12:52):
that be like. Well, we would not exist in fixed positions.
We would exist in a world of possibilities from moment
to moment, and we would only be in a specific
position when someone was actually looking at us. So this
means that sometimes we're in one spot as opposed to another.
Maybe you walk up to a door and in the
next moment you're on the other side of the door,
(13:13):
even though you never opened the door. You didn't physically
pass through the door. You're just now on the other
side of the door. Now, you wouldn't want this because
like imagine writing in a car and then suddenly you're
not in the car, you're next to the car while
going down the highway. That would be bad, right, So
we don't want the quantum effects in our classical system,
(13:35):
so it doesn't have happened in our experience. But this
does happen at the quantum level, and we know it
does because we've seen the results as chip manufacturers have
made chips with smaller and smaller components. If you just
keep doing that, you start to see errors because you
got you have this issue with quantum tunneling. So this
requires computer manufacturing. Chip manufacturing companies to change the architecture
(13:59):
and the materials they're working with when they're creating circuits
in an effort to mitigate or prevent this from happening. Um.
It's one of the reasons why people say there is
an ultimate limit to scaling down individual components on chips,
because you start run up against quantum effects and they
become harder and harder to manage. All Right, we're just
(14:21):
getting started, but let's take a quick break. Okay, So
quantum systems behave in ways that are hard for most
of us, myself included, who have limited exposure to the
(14:42):
subject matter to really understand. I fully admit this, like,
I quote unquote no about these quantum effects, but I
by no means understand them. I have looked into them
and read about them extensively, and at the end of it,
I feel like like I understand that these things happen,
but I don't understand why they do. It's just it's
(15:05):
beyond me. It is a level of mastery with mathematics
and science that I lack. It feels like science fiction tunneling. Definitely,
it seems weird. Well, so does entanglement. Getting back to
that spooky action at a distance. Einstein himself was particularly
weirded out by this concept. See Einstein was looking over
(15:28):
quantum hypotheses back in the nineteen thirties and pointed out
that according to the math, the proposals would mean that
it would be possible for quantum particles to sort of
pair up in a way. And in this pairing, one
particles features would depend upon the other particle, and vice versa.
They would complement one another, and not in the oh
you look nice today kind of way. They would compliment
(15:51):
one another, and that one uh, one feature of one
particle would be the opposite of another feature of the
same feature of another particle, I should say. So, here's
an example. We can describe electrons as having a certain
spin that she has to do with magnetic polls. I'm
not going to go into the whole thing, but yeah,
electrons have a spin. They actually have three inherent properties.
(16:15):
They have a mass, they have a charge, and they
have spin. The spin describes how the electron spins around
its own axis, and we can describe the spin as
having an up or a down direction. So a pair
of entangled electrons, this is from a very oversimplified approach,
A pair of entangled electrons would have one electron with
(16:36):
a spin of up, and the other electron has a
spin of down. And should anything change the spin of
one electron, the spin of the other electron would change instantly.
So if electron one went from up to down, then
electron two would go from down to up at that
same moment. No matter how far apart they were. You
could move them across the universe and this would remain
(17:00):
the same until the system collapses and entanglement is severed. Uh,
and the bit about you know, disturbing the system really
gets to be important, Like this idea of the system collapsing.
Quantum systems are extremely delicate things. Yes, you can separate
(17:20):
these entangled particles and move them across the universe from
one another and the entanglement will persist. But if you
disturb the system at any given point, it collapses and
that entanglement no longer exists. So they can collapse with
the tiniest kinds of disturbances. Observing the system is enough
to do that, and we call this the observer effect,
(17:42):
that the act of observing changes the phenomenon we're trying
to observe. Now, this idea, this is one of those
quantum ideas that I think we can actually kind of
grab onto if we look at it from a different perspective. Right,
the idea that just by observing something or measuring something
have changed it. I think that this is something we
(18:03):
can understand if we take that idea into a totally
different context. So, for example, let's say that we've set
up a social experiment, and our experiment consists of an
empty room. You know, maybe there's like a chair and
a table there, but that's it. And we bring into
this room a test subject. Uh, maybe we've got one
(18:23):
group of test subjects and we tell them nothing about
the experiment. We literally just bring them into the room
and leave them there, and then we tell them, like,
you know, you're just gonna wait here. We'll be back.
That's it. But let's say we have a second group
and we're doing the same thing with them. We bring
them into the room and we tell them they're gonna
wait there. But we also mentioned that the room is
(18:44):
under constant observation that there are hidden cameras that you
can't see. They're hidden so well you cannot see them
in the room, but they will be recording everything, and
people will be reviewing the footage and even watching a
live feed but just sit there, weight will be back. Well,
you can easily imagine that if you have a group
where you didn't say anything about the room being under surveillance,
(19:07):
you're gonna observe some behaviors that you're likely not gonna
see in the other group, where people are thinking they're
being watched the whole time. Now, knowing that you're being
observed is enough to influence you so that you don't
get too wacky while killing time waiting for whatever is
supposed to happen next. Now, obviously, quantum particles aren't shy
or embarrassed or feel shame when we observe them. That's
(19:30):
not what's going on. They don't yell out cheese it.
It's the heat when we observe them. But when we
do observe them, all the possible quantum states they inhabit
collapse down into just one state, so we get a
defined outcome as opposed to all possible outcomes. All right,
let's get back to entangle. In nineteen sixty four, a
(19:51):
physicist named John Stewart Bell presented a theorem that provided
a testable means for this entanglement hypothesis, and he showed
that quantum mechanics could explain correlations between distant quantum events
better than any sort of local theory could, so unthinkably
to the Einstein's of the world. Bell's theorem passed Ockham's razor,
(20:14):
and yes, I brought up Okam's razor, just so I
could explain what that is. Let's say you've got something
weird going on. You've come up with some potential explanations
that caused the weird stuff. In fact, let's get specific.
Let's say that the weird thing is that you found
a particularly cold spot in your basement, and when you
(20:35):
walk through it, you get that unsettling feeling that you've
passed through something strange. Now, let's say you come up
with a couple of potential explanations for this cold spot,
and in one you suggest that the basement is haunted
and the cold spot represents a ghost, so you passed
through some spectral form of a spirit. But your other
(20:57):
explanation is that it's winter and the spot you pass
through is both far from most hating events, and the
one that is closest is a bit clogged up and
needs to be cleaned out. Well. Explanation one that there's
a ghost requires first that you prove the existence of ghosts,
because you can't say it's something that hasn't been proven
(21:17):
to exist, right, You have to prove that first. And
if ghosts do exist, why do they exist? What are they?
How are they formed? How do they get here? What
keeps them here? All that kind of stuff. For the
answer to be ghosts, we actually need to be able
to understand a lot of unanswered and potentially unanswerable questions,
whereas the second explanation far more straightforward and it's testable,
(21:41):
So the second explanation is actually the simplest. From that perspective,
we could also go with Mr. Spocks philosophy. When you
eliminate the impossible, whatever remains, however improbable, must be the truth.
That one's tricky though, because sometimes something that we believe
to be impossible turns out to act really be possible.
It's just that we don't understand what's going on yet,
(22:03):
or we have, you know, uh, the wrong point of
view when we're looking at the thing, and so we're
focusing on something that appears to be impossible, when if
we had a different perspective we would realize what's really
going on. So Mr Spock I gotta pick some bones
with you on that one. Well, Bell's theorem showed that,
as weird as the concept of quantum entanglement is, it
(22:27):
was a far simpler explanation than trying to jump through
hoops to explain apparent correlation strictly through locality. It became
easier to explain these apparently connected events are at a
distance are happening through entanglement than trying to invent scenarios
in which two separate and unconnected local events produced results
(22:50):
that only appear to be connected. Bell showed that this
spooky action at a distance appeared to be a valid thing.
Now here's the kicker. As soon as you attempt to
measure an entangled particle, that connection, that interdependence between the
two particles severs. So if one electron is spinning up
and the entangled electron is spinning down, which is something
(23:12):
that we don't know yet, we haven't measured it, and
then we measure electron one, we see that it's spinning up.
We know at that moment of measurement that electron two
was spinning down, But we also know that this connection
has been severed. It doesn't exist anymore. Now they're going
to spin independently of one another. So measuring the spin
of electron one again will give you no information about
(23:35):
electron two. They're no longer connected. You cannot draw any conclusions.
Same thing. If you measure electron two, you don't know
anything about electron one. You only know at the moment
of that that measurement, when the two were still entangled.
This is an oversimplification, obviously. Bills there explains how experimental
(23:55):
results should show that metrics prove correlations above what you
would exspect if locality and local hidden variables were the
only factors. So, in other words, practical experiments would prove
that correlation happens beyond what can be explained if locality
is a firm, in escapable element, and experiments have shown
(24:16):
that we do in fact see correlation beyond what we
can explain by locality. So this might be spooky action
at a distance, but the point is it's real. We
have observed the effects. Now, this isn't to say that
there is universal agreement and acceptance of Bell's theorem, or
rather the interpretations of Bell's theorem. This is still an
(24:39):
ongoing area of research and experimentation, but at the very
least the investigations show that locality, at least the way
we understand it now, is not a factor, or at
least not the only factor. Okay, we've got some more spooky,
complicated quantum things to get through in a moment. But
(25:00):
let's take another quick break. Okay, let's talk about a
related quantum effect. In fact, it's very closely related to
some of the other ones we've chatted about already. You know,
(25:21):
Quantum tunneling shows us that when we're looking at quantum systems,
we need to think in probabilities as opposed to fixed values.
And electron has a probability of existing at a certain
point within a region that it could exist within, right,
We don't know for sure until we measure it, so
we can just say there's a probability that it exists
(25:43):
within this region. Uh So, that's one example of this,
But we can extend that to lots of different quantum states,
where a quantum system could potentially inhabit any one of
those quantum states at any in time, and it's not
until we measure that it collapses down into a fixed value. Well,
(26:06):
there's a related concept called superposition, and in superposition, the
ability of a quantum system is to exist in multiple states,
all at the same time until the system collapses again,
until we measure it. So instead of saying there's a
probability of the system existing at any given state at
any given time, we instead say, with superposition, that exists
(26:29):
in all states at the same time until we measure it,
at which point it collapses into a single one. Now, again,
this is really hard for us to imagine compared to
our day to day you know experiences. Things are either
one way or another in our world, right, I mean
they can't be always. Uh Like, Like take a classic
(26:52):
light switch. Your your little light switch that flips up
or down, so that shows it has two positions, right,
it has off and it has on. So the light
switches either off or it's on. It cannot be both.
You know, you might be able to position the switch
so it's precariously balanced between the two, but it's not
actually off and on at the same time. It's one
(27:14):
or the other. Either the circuit is open or it's closed.
But in quantum systems, we can have a system occupy
all possible states simultaneously until measured. They can be in superposition.
It's also something that really got Irwin Schrodinger in a tizzy. Specifically,
(27:34):
Schrodinger was responding to what is called the Copenhagen interpretation
of quantum mechanics. We're not gonna dive down too far
into the different interpretations. That is a matter for a
different episode, but I do want to talk about Schrodinger
for a second. He wanted to illustrate the absurdity and
paradox of superposition, and so he presented a thought experiment. Imagine,
(27:57):
by the way, this is a thought experiment that has
animal cruel t in it. So fun times, but yeah,
that's kind of how these things go. So imagine you've
got a box and inside this box you have a
kitty cat. Also in the box is a sealed flask
of poison. There's also some radioactive material in there that
will eventually decay, that will atoms will decay from this
(28:22):
radioactive material. You've also included in the box a Geiger counter,
and it's connected to a circuit so that if the
Geiger counter detects a decaying atom, it'll send a signal
through the circuit that will cause the flask to shatter
and the poor kitty cat will be poisoned and die. Now,
here's the thing. We don't know exactly when an atom
(28:44):
will decay. You know. Again, we know a range of
when the atom will decay, but we don't know precisely
when that might happen. So you've got your kitty cat
in this box, you leave it alone for a few hours,
and you come back to the experiment. Well, there's a
chance that an adam has decayed in that time, and
if that happened, that means the Geiger counter would have
(29:05):
gone off, caused the flask to break, and would have
killed the cat. However, there's also a chance that that
has not happened yet. That would mean the cat would
just be bored, but otherwise unharmed. So, according to superposition,
before you open the box, the cat is both alive
and dead at the same time. It's only when you
(29:27):
open the box and observe i. E. When you measure
the system, that the possibilities collapse into a single reality
and you either have a lively kitty cat or you
have a kitty corpse that you're going to have to
clean up. Schrodinger was really illustrating how this idea is weird,
and it brings up the question at what point precisely
(29:48):
would a quantum system in superposition collapsed down into a
single state. Now there are other interpretations of quantum mechanics
besides the Copenhagen one, and these take into account other
factors besides observation and measurement. But again it gets super complicated,
and honestly, I would just mess it up if I
(30:08):
were to attempt to even explain them, because they require
a level of understanding that I just don't have. But
this is where we get that Schrodinger's cat scenario. So
if you've ever heard of Shrodinger's Cat, that's what this
comes from. It was really a critique on this interpretation
of superposition. Shrodinger was saying, isn't this inherently absurd? Based
(30:31):
upon our experience, superposition is one of the aspects of
quantum mechanics that we can actually exploit using quantum computers.
You've probably heard me talk about quantum computers that they
rely on cubits. That's q u, b I T s.
That is the basic unit of information for a quantum computer.
(30:52):
So in classic computers we have bits, and in quantum
computers we have que bits. So a bit is a
single unit of digital information. It is the smallest unit
that we can have, and we typically represent a bit
is having a value of either zero or one. So
this gets back to our light switch, right. You can
(31:13):
think of it as being off or on. It can
have one of two values, and that is it. That's
as far down as you can get when you break
down digital information. Cubits, on the other hand, get more complicated.
A cubit, thanks to superposition, can both be a zero
and a one simultaneously. Technically, it can be all values
(31:35):
in between zero and one, sort of like balancing that
light switch between off and on. But what good does
this do for you to have a unit of information
that can be both zero and one at the same time. Well,
let's say we've got a computer problem we need to
solve that has a lot of potential pathways to a solution,
but we don't yet know which pathway is the best,
(31:58):
the one that represents the quote un quote right answer.
With a classic computer, you have to evaluate each pathway individually,
and then at the end you have to compare all
the results against one another to determine which one is
the right one. If there are lots of pathways, this
can mean a ton of computational work has to be
(32:18):
put into the effort, and potentially that the amount of
time required to complete the calculation is longer than the
age of the universe, meaning it's practical for all intents
and purposes, it's impossible will be extinct before the computer
finishes the problem. So let's take this approach to the
(32:40):
way we encrypt things the modern cryptography, and we're going
to keep this at a very high level. Essentially, your
typical encryption method takes two very large prime numbers. Remember
a prime number is a number that's only divisible by itself.
It takes these two large prime numbers, then multiplies those
(33:01):
two prime numbers together and this creates a product which
then we can use to encrypt data in some way.
And the only way to decrypt the data to reverse
the process of encryption is to have the correct very
large prime number factors that we were used to make
that product. So if you don't know the prime numbers,
(33:23):
you can't reverse this process. Well, a classic computer would
need to go through all possible prime numbers in an
effort to find the right ones that were used to
make this product. It's a process called prime factorization. So
a number might be the product of just two prime numbers.
So the number ten, for example, is the product of
(33:45):
two and five. Two tomes five is ten. Well, two
and five are both prime numbers. But larger numbers might
break into multiple prime factors, like the number one thousand three. Well,
that can be broken down to the primes of two, two, again,
thirty one, and one thousand nineteen. You multiply all those together,
(34:07):
you get one twenty six thousand, three fifty six. Computers
are pretty darn good at multiplying numbers and getting a result.
They are not as efficient when they take a result
and work backward to determine the factors used to produce
that product, and that's the secret sauce behind modern cryptography.
(34:27):
A classic computer could take logger than the age of
the universe to solve a particularly difficult prime factorization problem,
but a quantum computer with sufficient cubits and the right
algorithm could theoretically solve for all possible factors to create
a particular product. The cubits are able to serve both
(34:51):
as zeros and ones at the same time, so if
you've got enough cubits that are all in superposition, you're
essentially working out all possible solutions in parallel simultaneously, you'd
actually get results that would have probabilities assigned to them.
So again, once you get your results, it's not that
you have, you know, the one and only answer, but
(35:13):
you have various potential answers that are assigned probabilities. Typically
you're looking at you know, the highest probability is likely
to be right, because you know, once we get quantum
computers that have these these reliable cubits and superposition and
the right algorithms. Uh, this is you know, just a
(35:34):
matter of time before it happens, then it will require
us to shift to an entirely different kind of cryptography
because once you do have these sufficiently powerful computers, it
becomes uh an easy task to reverse the cryptographic process,
and you just end up having essentially a skeleton key
(35:56):
to all encrypted information. It's trivial how how easy it
is at that point, assuming that you have a a
properly powerful quantum computer and the appropriate algorithm to reverse
the process. So that's why there's so much work being
put into quantum cryptography, a process that would make it
(36:20):
more difficult for a quantum computer to crack a cryptographic scheme,
so that way we could maintain secret information. Otherwise there's
no chance of having secrecy through digital transfer. Now let's
get to a science fiction e element of the quantum
(36:42):
world that people have talked about. So, in quantum systems
we can have entanglement, and that entanglement can exist even
if you were to separate to sub atomic or quantum particles. Uh,
two opposite ends of a universe. Does that mean we
could have a system and which we have one entangled
system and say a spaceship on the opposite side of
(37:04):
the galaxy from us, and the other entangled system is
here on Earth, and then we could have instantaneous communication
between the two. Right, we get to have these two
systems and because they're entangled with one another, we could
send information back and forth. Wouldn't that mean we'd be
violating Einstein's theory that nothing can go faster than the
(37:25):
speed of light, And doesn't in fact mean we could
violate causality? Could we actually end up getting an effect
before the cause? Well, the simple answer is no, So
that's a relief, right, But why Well, measuring an entangled
particle in one location will cause the entanglement to sever,
(37:46):
but you can't actually send any useful information. That way,
it becomes a local measurement. Now it's a local measurement
that's in two separate locations that are millions of light
years apart. And you could say, well, be because of
the state of this system. We know what the state
of the system on the other side of the the universe was,
but it was only at that moment of measurement. We
(38:09):
don't know what state that systems in now because the
entanglement has been severed. So you haven't actually sent any
useful information. Uh, So there's no way to communicate. There's
no way to do that. If you were to try
and communicate, your communication would be in the form of
classic bits style communication, which means you would be limited
to the speed of light. So entanglement might be spooky.
(38:32):
It cannot bright the laws of physics, Captain, so uh
that I'm happy to report because otherwise we would have
some really tricky things ahead of us. Because if you
can violate causality, and there's all sorts of things from
time travel to the whole concept of like multi verses
(38:52):
and stuff, it gets really wibbly wobbly. Timmy, why me,
as the doctor would say, So, I'm thankful that as
far as we understand it now, that's a that's a
non starter. But that doesn't mean that our understanding of
quantum mechanics is by any measure complete. It definitely is not,
and that we may learn other ways that we can
(39:16):
exploit quantum systems to our benefit. That is really interesting stuff.
And like I said, I understand the end result stuff, right,
I can get my mind wrapped around that. I don't
understand the how at all. Um. I remember when I
(39:36):
was looking into something tangentially related to this, which was
string theory. I was writing an article about how string
theory works for how stuff works years ago, and I was,
I mean, it's a good thing. I'm already balked because
I was ready to tear my hair out, but that
would require reversing nature's whims and I am not able
to do that. But yeah, I was ready to tear
(39:56):
my hair out because I was doing a deep dive.
I was looking at interviews with uh physicists and scientists
and mathematicians, and I remember there was a point where
one of them was asked, point blank, do you understand
string theory? And his response was, I have dedicated my
(40:18):
life to the study of this. But if you want
the real raw answer, no, Like, I understand what the
math tells me, and I understand why we need to
account for things like multiple dimensions, for example, but I
don't understand the theory at that granular level. And my
(40:42):
reaction was, well, if the people doing the groundbreaking research
into this field don't understand it, what chance do I have.
So to me, the quantum world in general, not just
string theory, but quantum mechanics in general, is this kind
of spooky world because things behave in ways that seem
(41:05):
counterintuitive to me because it is very different from the
experience we have in the macro world. But yeah, fascinating stuff,
and as I said, it actually does affect our our
electronics and technology today. I've talked to in the past
about other things that are related to this, this high
(41:26):
level understanding of physics where we know it's true because
we've experienced the consequences things like relativity, which we know
to be true, because if relativity weren't true, then our
satellites would behave totally differently than the way they do.
But because we know we have measurable outcomes with our
(41:48):
our satellite systems, that uh, uh, confirm relativity. We understand
that's a real thing. I think that's amazing. I'm sure
it's some thing that Einstein himself, while he may have
suspected would one day become true, would have delighted in
seeing that there would be actual ways to experimentally prove
(42:11):
his theory. That would have been phenomenal. I'm sure. All right,
that's it. I hope you have a happy Halloween. Be safe,
be spooky, enjoy yourselves. If you have suggestions for future
topics of tech stuff, I invite you to trick or
treat by reaching out. One way to do that is
to download the I Heart Radio app is free to download,
(42:33):
free to use. You can use the little search bar
to navigate over to tech Stuff. There you will see
that there's this little microphone icon. If you click on that,
you can leave a voice message up to thirty seconds
in link. You can even let me know if you
would like me to use it in a future episode,
in which case I will. I won't. Otherwise I would
just reference it, but I wouldn't use the recording. Or
you can always reach out to me on Twitter. UH,
(42:56):
as long as Elon Musk doesn't nuke the whole thing
into orbit. Uh the handle. There is tech Stuff H
s W and I'll talk to you again really soon. Y.
Tech Stuff is an I Heart Radio production. For more
(43:17):
podcasts from my Heart Radio, visit the i Heart Radio app,
Apple Podcasts, or wherever you listen to your favorite shows.
Welcome to tech Stuff, a production from My Heart Radio.
Hey there, and welcome to tech Stuff. I'm your host,
Jonathan Strickland. I'm an executive producer with my Heart Radio
and how the tech are you? And Happy Halloween. This
episode is publishing on Halloween, October thirty one, two thousand
(00:28):
twenty two. That's for those of you in the future
who are listening back on this episode. So throughout this month,
I have published a few episodes that are at least
tangentially connected if I'm being generous to to scary spooky stuff.
It's a little tricky with tech because I don't want
to go into like really big paranormal kind of things
(00:52):
and technology that purports to do stuff that's impossible, because
that really just comes down to debunking. I want to do, um,
you know, some stuff that that has spooky names, but
ultimately it's not that scary stuff like vampire power and
zombie computers, although those are scary. The phrase ghost in
the Machine was an episode that kind of thing. But
(01:13):
on Halloween itself, I thought we could chat about something
Einstein himself referred to as spooky action at a distance,
and this does tie into tech. We are going to
talk about tech, not just theories and physics, and we're
also going to talk about tech that's in the realistic
world and in like science fiction ee kind of applications. Now,
(01:37):
Einstein when he said spooky action at a distance, wasn't
trying to describe, you know, ghosts involved in a long
distance relationship or anything. So we're not gonna have any
specters making you know, erotic FaceTime calls to each other.
That's not what we're talking about here. Instead, we're going
to talk about quantum mechanics. So at the heart of
(02:02):
this concept of spooky action at a distance is this
idea of quantum entanglement and how quantum entanglement violates locality.
So Einstein was a truly brilliant physicist and mathematician, but
he was no Einstein. Okay, all right, that makes no sense.
(02:23):
He was and Einstein he was the Einstein. But there
were certain leaps he wasn't yet ready to make, and
a big one of those is how quantum mechanics isn't
necessarily confined to locality. Einstein had issues with quantum mechanics
in general because quantum mechanics has a lot of elements
(02:45):
to it that seemed completely alien to us based on
our understanding of classical physics, and there were certain bits
of that that Einstein had some real problems with. So
what is locality, Well, it what it sounds like, right.
It's locality is it describes that there's a limitation, like
a regional limitation on physical events and their consequences. So,
(03:10):
in other words, locality would tell us that an event
in one part of the world could not possibly affect
something very far away instantaneously, because that would violate locality.
You know, if I were to sneeze right now and
then a tree where to fall over in the Philippines,
you wouldn't say those two things were immediately connected because
(03:33):
that violates locality. There's no there's no causal, uh agent
there to make that happen, right to to go from
my sneeze to the tree falling over in the same
instant to make that makes sense. So this is a
little different. Actually, it's a lot different from the classic
(03:54):
butterfly effect. That is another concept that doesn't violate low cality.
So the butterfly effect is a way to describe aspects
of chaos theory, and in the butterfly effect, a small
change in a variable or a state can lead to
a much larger change in a later state. So a
(04:18):
classic example is a butterfly flaps its wings on one day,
and that little disturbance in the air ultimately contributes to
potentially provides the necessary impetus for a tornado that happens
several weeks later. Or you might hear another version of
this where a butterfly flaps its wings in South America
(04:38):
and that contributes to a tsunami that later hits Southeast Asia.
That kind of thing. The idea that little things can
be the changing factor that determines whether or not a
larger thing in the future happens or doesn't. Right, But
this doesn't violate locality because you have that aspect of
(04:59):
time that allows something to develop further from an initial event.
With the quantum entanglement, the idea is that these things
are happening instantaneously. There is no time between event one
an event too. You have event one, an event two
is a consequence of event one, even if those two
(05:20):
events are happening on opposite sides of the world. That
is what Einstein had a problem with, you know, because
he wanted to try and figure out how can you
describe event one making event to possible if they're not
in the same locality, and quantum mechanics said that does happen,
and Einstein was like, no, that that can't be the
(05:44):
way it works. It has to be that there are
local events, local variables, perhaps hidden variables, that explain why
these things happen. And it looks like there's some sort
of correlation or perhaps cause relationship between these events to us.
But that's because we're misinterpreting things. We're not looking at
(06:06):
the actual cause. That's what Einstein was saying. He was
just not able to make a jump to understanding quantum entanglement.
You can understand why, right, because this idea that something
happens in one place and that can cause a reaction
that is literally a world away at the very same time.
(06:26):
That flies in the phase of our own experience. Right
if you were to drop a piece of pizza and
you saw it hit the floor, you would be shocked
to learn that you caused an earthquake on the other
side of the world at that exact same moment, like
pizza hits the floor, earthquake across the world from you,
and that you were somehow the cause of it. That
(06:46):
wouldn't make sense. Even if somehow vibrations from the pizza
hitting the floor managed to travel all the way through
the Earth to the other side, it would take time
for the vibrations to go through the entire planet. It
would take the speed of sound through that various media
for it to get there, and then, you know, who
knows what happens once it hits the core. We'd have
(07:08):
to watch a lot of science fiction and horror movies
to figure that out. So maybe your whale of anguish
also would contribute. You know, you just lost a piece
of pizza, so obviously you're going to have a grieving period.
But we're still limited to the speed of sound here.
It takes time for sound to make its way anywhere.
So even if it were somehow able to go through
the entire Earth and cause this earthquake, it would take
(07:29):
a lot of time. It would not be an instantaneous reaction.
This really gets to one of the big obstacles when
it comes to understanding or explaining quantum effects. Because the
quantum level, the quantum world obeys a different set of
rules from the classical realm stuff that is impossible in
our day to day existence is commonplace and quantum systems.
(07:53):
So let me give you another example. Heisenberg's uncertainty principle
explains that we have a emit when it comes to
describing particles, and we're really talking about like quantum particles,
sub atomic particles, that kind of thing. So the classic
example is describing a particle's position and its momentum based
on initial conditions. So Heisenberg hypothesized that the more we
(08:17):
know about one of these two conditions i e. Its
position or its momentum, well, the less then we can
know about the other one. So if we had perfect
knowledge of a particle's position, we would know nothing about
its momentum. We would be unable to describe where and
at what speed this particle was moving, so it'd be
(08:37):
kind of like a snapshot, Like a perfect snapshot, we
could see the position of the particle at that moment
in time, but we would know nothing else about it. Likewise,
if we had perfect knowledge of the particle's momentum, we
would be unable to describe its position at all. So
because of this limitation, we cannot know with certainty both
(08:57):
pieces of information. So we typically will describe particles like
these as existing within a range or zone of potential
positions at any given time. You can think of it
almost like a cloud that this particle could exist within UH,
and it could be anywhere within that cloud at any
(09:18):
given time that you could take the the opportunity to
detect it, and in that instant detect where the particle is.
Then all those possibilities collapse into one fixed position. But
before you look, it could be anywhere in that cloud.
So there are regions within that cloud where the particle
(09:39):
is more likely to be found in a given moment,
but there's at least the possibility that it could be
at any point within the cloud at any specific time. Now,
not only is this different from what we experience in
our day to day life, where we can explain with
decent confidence a person's position and momentum, it can lead
(10:00):
to other weird quantum effects that really make a difference
in technology, such as quantum tunneling. So this has a
real effect on electronics and circuits, particularly with things like
UH processors computer processors. So when we're talking about electronics,
you can think of electronics at a very very very
(10:20):
basic level as being all about controlling where the flow
of electrons can go and what work the electrons will
have to do along the way as they make their
way to their destination, which is typically a positive terminal.
You know, electrons are negatively charged, and so opposites attract
it wants to go to the positively charged terminal. Electrons
(10:43):
are subatomic particles and they behave according to the quantum
effects described by folks like Heisenberg. So if we wanted
to focus on a single electron within a circuit, we
would have to describe its location as existing within a
sort of zone or field. We can't point to the
specific location as the electron moves through the system, but
(11:04):
we can describe an area of probabilities where the electron
could be well. One of the most important components in
circuitry is the transistor, which acts like a gate. The
gate can allow electrons to go through or it can
prevent them from going through, So it's really a switch, right.
(11:24):
It forms the basis of much more complicated systems, but
it only works if you know it can actually keep
electrons from going through. Well, it's possible that a zone
of probabilities of an electron's position can actually overlap a gate.
So if the gate is very very thin, it's possible
(11:46):
for the zone to extend to the other side of
a closed gate. This means that it's technically possible for
an electron to exist on the other side of the
closed gate, even though the electron would otherwise have been
prevented from passing through because again the gate is closed. Well,
if something is possible, that means that sometimes it happens. Right,
(12:09):
even if you think, well, the electron didn't physically move
through the gate, that the fact that there's a chance
for it to be on the other side means that
sometimes it is on the other side. So in a
system like this, an electron can sometimes be on the
opposite side of a closed gate and then keep on going.
This is not good if your goal is to control
(12:30):
the flow of electrons, because the whole purpose of the
gate is to stop them from going. So this means
you're gonna start getting errors, and that that's because electrons
are going through parts of your system that they're supposed
to not be able to go through. So let's imagine
what this would look like in our day to day existence, Like,
if this same effect happened in our world, what would
(12:52):
that be like. Well, we would not exist in fixed positions.
We would exist in a world of possibilities from moment
to moment, and we would only be in a specific
position when someone was actually looking at us. So this
means that sometimes we're in one spot as opposed to another.
Maybe you walk up to a door and in the
next moment you're on the other side of the door,
(13:13):
even though you never opened the door. You didn't physically
pass through the door. You're just now on the other
side of the door. Now, you wouldn't want this because
like imagine writing in a car and then suddenly you're
not in the car, you're next to the car while
going down the highway. That would be bad, right, So
we don't want the quantum effects in our classical system,
(13:35):
so it doesn't have happened in our experience. But this
does happen at the quantum level, and we know it
does because we've seen the results as chip manufacturers have
made chips with smaller and smaller components. If you just
keep doing that, you start to see errors because you
got you have this issue with quantum tunneling. So this
requires computer manufacturing. Chip manufacturing companies to change the architecture
(13:59):
and the materials they're working with when they're creating circuits
in an effort to mitigate or prevent this from happening. Um.
It's one of the reasons why people say there is
an ultimate limit to scaling down individual components on chips,
because you start run up against quantum effects and they
become harder and harder to manage. All Right, we're just
(14:21):
getting started, but let's take a quick break. Okay, So
quantum systems behave in ways that are hard for most
of us, myself included, who have limited exposure to the
(14:42):
subject matter to really understand. I fully admit this, like,
I quote unquote no about these quantum effects, but I
by no means understand them. I have looked into them
and read about them extensively, and at the end of it,
I feel like like I understand that these things happen,
but I don't understand why they do. It's just it's
(15:05):
beyond me. It is a level of mastery with mathematics
and science that I lack. It feels like science fiction tunneling. Definitely,
it seems weird. Well, so does entanglement. Getting back to
that spooky action at a distance. Einstein himself was particularly
weirded out by this concept. See Einstein was looking over
(15:28):
quantum hypotheses back in the nineteen thirties and pointed out
that according to the math, the proposals would mean that
it would be possible for quantum particles to sort of
pair up in a way. And in this pairing, one
particles features would depend upon the other particle, and vice versa.
They would complement one another, and not in the oh
you look nice today kind of way. They would compliment
(15:51):
one another, and that one uh, one feature of one
particle would be the opposite of another feature of the
same feature of another particle, I should say. So, here's
an example. We can describe electrons as having a certain
spin that she has to do with magnetic polls. I'm
not going to go into the whole thing, but yeah,
electrons have a spin. They actually have three inherent properties.
(16:15):
They have a mass, they have a charge, and they
have spin. The spin describes how the electron spins around
its own axis, and we can describe the spin as
having an up or a down direction. So a pair
of entangled electrons, this is from a very oversimplified approach,
A pair of entangled electrons would have one electron with
(16:36):
a spin of up, and the other electron has a
spin of down. And should anything change the spin of
one electron, the spin of the other electron would change instantly.
So if electron one went from up to down, then
electron two would go from down to up at that
same moment. No matter how far apart they were. You
could move them across the universe and this would remain
(17:00):
the same until the system collapses and entanglement is severed. Uh,
and the bit about you know, disturbing the system really
gets to be important, Like this idea of the system collapsing.
Quantum systems are extremely delicate things. Yes, you can separate
(17:20):
these entangled particles and move them across the universe from
one another and the entanglement will persist. But if you
disturb the system at any given point, it collapses and
that entanglement no longer exists. So they can collapse with
the tiniest kinds of disturbances. Observing the system is enough
to do that, and we call this the observer effect,
(17:42):
that the act of observing changes the phenomenon we're trying
to observe. Now, this idea, this is one of those
quantum ideas that I think we can actually kind of
grab onto if we look at it from a different perspective. Right,
the idea that just by observing something or measuring something
have changed it. I think that this is something we
(18:03):
can understand if we take that idea into a totally
different context. So, for example, let's say that we've set
up a social experiment, and our experiment consists of an
empty room. You know, maybe there's like a chair and
a table there, but that's it. And we bring into
this room a test subject. Uh, maybe we've got one
(18:23):
group of test subjects and we tell them nothing about
the experiment. We literally just bring them into the room
and leave them there, and then we tell them, like,
you know, you're just gonna wait here. We'll be back.
That's it. But let's say we have a second group
and we're doing the same thing with them. We bring
them into the room and we tell them they're gonna
wait there. But we also mentioned that the room is
(18:44):
under constant observation that there are hidden cameras that you
can't see. They're hidden so well you cannot see them
in the room, but they will be recording everything, and
people will be reviewing the footage and even watching a
live feed but just sit there, weight will be back. Well,
you can easily imagine that if you have a group
where you didn't say anything about the room being under surveillance,
(19:07):
you're gonna observe some behaviors that you're likely not gonna
see in the other group, where people are thinking they're
being watched the whole time. Now, knowing that you're being
observed is enough to influence you so that you don't
get too wacky while killing time waiting for whatever is
supposed to happen next. Now, obviously, quantum particles aren't shy
or embarrassed or feel shame when we observe them. That's
(19:30):
not what's going on. They don't yell out cheese it.
It's the heat when we observe them. But when we
do observe them, all the possible quantum states they inhabit
collapse down into just one state, so we get a
defined outcome as opposed to all possible outcomes. All right,
let's get back to entangle. In nineteen sixty four, a
(19:51):
physicist named John Stewart Bell presented a theorem that provided
a testable means for this entanglement hypothesis, and he showed
that quantum mechanics could explain correlations between distant quantum events
better than any sort of local theory could, so unthinkably
to the Einstein's of the world. Bell's theorem passed Ockham's razor,
(20:14):
and yes, I brought up Okam's razor, just so I
could explain what that is. Let's say you've got something
weird going on. You've come up with some potential explanations
that caused the weird stuff. In fact, let's get specific.
Let's say that the weird thing is that you found
a particularly cold spot in your basement, and when you
(20:35):
walk through it, you get that unsettling feeling that you've
passed through something strange. Now, let's say you come up
with a couple of potential explanations for this cold spot,
and in one you suggest that the basement is haunted
and the cold spot represents a ghost, so you passed
through some spectral form of a spirit. But your other
(20:57):
explanation is that it's winter and the spot you pass
through is both far from most hating events, and the
one that is closest is a bit clogged up and
needs to be cleaned out. Well. Explanation one that there's
a ghost requires first that you prove the existence of ghosts,
because you can't say it's something that hasn't been proven
(21:17):
to exist, right, You have to prove that first. And
if ghosts do exist, why do they exist? What are they?
How are they formed? How do they get here? What
keeps them here? All that kind of stuff. For the
answer to be ghosts, we actually need to be able
to understand a lot of unanswered and potentially unanswerable questions,
whereas the second explanation far more straightforward and it's testable,
(21:41):
So the second explanation is actually the simplest. From that perspective,
we could also go with Mr. Spocks philosophy. When you
eliminate the impossible, whatever remains, however improbable, must be the truth.
That one's tricky though, because sometimes something that we believe
to be impossible turns out to act really be possible.
It's just that we don't understand what's going on yet,
(22:03):
or we have, you know, uh, the wrong point of
view when we're looking at the thing, and so we're
focusing on something that appears to be impossible, when if
we had a different perspective we would realize what's really
going on. So Mr Spock I gotta pick some bones
with you on that one. Well, Bell's theorem showed that,
as weird as the concept of quantum entanglement is, it
(22:27):
was a far simpler explanation than trying to jump through
hoops to explain apparent correlation strictly through locality. It became
easier to explain these apparently connected events are at a
distance are happening through entanglement than trying to invent scenarios
in which two separate and unconnected local events produced results
(22:50):
that only appear to be connected. Bell showed that this
spooky action at a distance appeared to be a valid thing.
Now here's the kicker. As soon as you attempt to
measure an entangled particle, that connection, that interdependence between the
two particles severs. So if one electron is spinning up
and the entangled electron is spinning down, which is something
(23:12):
that we don't know yet, we haven't measured it, and
then we measure electron one, we see that it's spinning up.
We know at that moment of measurement that electron two
was spinning down, But we also know that this connection
has been severed. It doesn't exist anymore. Now they're going
to spin independently of one another. So measuring the spin
of electron one again will give you no information about
(23:35):
electron two. They're no longer connected. You cannot draw any conclusions.
Same thing. If you measure electron two, you don't know
anything about electron one. You only know at the moment
of that that measurement, when the two were still entangled.
This is an oversimplification, obviously. Bills there explains how experimental
(23:55):
results should show that metrics prove correlations above what you
would exspect if locality and local hidden variables were the
only factors. So, in other words, practical experiments would prove
that correlation happens beyond what can be explained if locality
is a firm, in escapable element, and experiments have shown
(24:16):
that we do in fact see correlation beyond what we
can explain by locality. So this might be spooky action
at a distance, but the point is it's real. We
have observed the effects. Now, this isn't to say that
there is universal agreement and acceptance of Bell's theorem, or
rather the interpretations of Bell's theorem. This is still an
(24:39):
ongoing area of research and experimentation, but at the very
least the investigations show that locality, at least the way
we understand it now, is not a factor, or at
least not the only factor. Okay, we've got some more spooky,
complicated quantum things to get through in a moment. But
(25:00):
let's take another quick break. Okay, let's talk about a
related quantum effect. In fact, it's very closely related to
some of the other ones we've chatted about already. You know,
(25:21):
Quantum tunneling shows us that when we're looking at quantum systems,
we need to think in probabilities as opposed to fixed values.
And electron has a probability of existing at a certain
point within a region that it could exist within, right,
We don't know for sure until we measure it, so
we can just say there's a probability that it exists
(25:43):
within this region. Uh So, that's one example of this,
But we can extend that to lots of different quantum states,
where a quantum system could potentially inhabit any one of
those quantum states at any in time, and it's not
until we measure that it collapses down into a fixed value. Well,
(26:06):
there's a related concept called superposition, and in superposition, the
ability of a quantum system is to exist in multiple states,
all at the same time until the system collapses again,
until we measure it. So instead of saying there's a
probability of the system existing at any given state at
any given time, we instead say, with superposition, that exists
(26:29):
in all states at the same time until we measure it,
at which point it collapses into a single one. Now, again,
this is really hard for us to imagine compared to
our day to day you know experiences. Things are either
one way or another in our world, right, I mean
they can't be always. Uh Like, Like take a classic
(26:52):
light switch. Your your little light switch that flips up
or down, so that shows it has two positions, right,
it has off and it has on. So the light
switches either off or it's on. It cannot be both.
You know, you might be able to position the switch
so it's precariously balanced between the two, but it's not
actually off and on at the same time. It's one
(27:14):
or the other. Either the circuit is open or it's closed.
But in quantum systems, we can have a system occupy
all possible states simultaneously until measured. They can be in superposition.
It's also something that really got Irwin Schrodinger in a tizzy. Specifically,
(27:34):
Schrodinger was responding to what is called the Copenhagen interpretation
of quantum mechanics. We're not gonna dive down too far
into the different interpretations. That is a matter for a
different episode, but I do want to talk about Schrodinger
for a second. He wanted to illustrate the absurdity and
paradox of superposition, and so he presented a thought experiment. Imagine,
(27:57):
by the way, this is a thought experiment that has
animal cruel t in it. So fun times, but yeah,
that's kind of how these things go. So imagine you've
got a box and inside this box you have a
kitty cat. Also in the box is a sealed flask
of poison. There's also some radioactive material in there that
will eventually decay, that will atoms will decay from this
(28:22):
radioactive material. You've also included in the box a Geiger counter,
and it's connected to a circuit so that if the
Geiger counter detects a decaying atom, it'll send a signal
through the circuit that will cause the flask to shatter
and the poor kitty cat will be poisoned and die. Now,
here's the thing. We don't know exactly when an atom
(28:44):
will decay. You know. Again, we know a range of
when the atom will decay, but we don't know precisely
when that might happen. So you've got your kitty cat
in this box, you leave it alone for a few hours,
and you come back to the experiment. Well, there's a
chance that an adam has decayed in that time, and
if that happened, that means the Geiger counter would have
(29:05):
gone off, caused the flask to break, and would have
killed the cat. However, there's also a chance that that
has not happened yet. That would mean the cat would
just be bored, but otherwise unharmed. So, according to superposition,
before you open the box, the cat is both alive
and dead at the same time. It's only when you
(29:27):
open the box and observe i. E. When you measure
the system, that the possibilities collapse into a single reality
and you either have a lively kitty cat or you
have a kitty corpse that you're going to have to
clean up. Schrodinger was really illustrating how this idea is weird,
and it brings up the question at what point precisely
(29:48):
would a quantum system in superposition collapsed down into a
single state. Now there are other interpretations of quantum mechanics
besides the Copenhagen one, and these take into account other
factors besides observation and measurement. But again it gets super complicated,
and honestly, I would just mess it up if I
(30:08):
were to attempt to even explain them, because they require
a level of understanding that I just don't have. But
this is where we get that Schrodinger's cat scenario. So
if you've ever heard of Shrodinger's Cat, that's what this
comes from. It was really a critique on this interpretation
of superposition. Shrodinger was saying, isn't this inherently absurd? Based
(30:31):
upon our experience, superposition is one of the aspects of
quantum mechanics that we can actually exploit using quantum computers.
You've probably heard me talk about quantum computers that they
rely on cubits. That's q u, b I T s.
That is the basic unit of information for a quantum computer.
(30:52):
So in classic computers we have bits, and in quantum
computers we have que bits. So a bit is a
single unit of digital information. It is the smallest unit
that we can have, and we typically represent a bit
is having a value of either zero or one. So
this gets back to our light switch, right. You can
(31:13):
think of it as being off or on. It can
have one of two values, and that is it. That's
as far down as you can get when you break
down digital information. Cubits, on the other hand, get more complicated.
A cubit, thanks to superposition, can both be a zero
and a one simultaneously. Technically, it can be all values
(31:35):
in between zero and one, sort of like balancing that
light switch between off and on. But what good does
this do for you to have a unit of information
that can be both zero and one at the same time. Well,
let's say we've got a computer problem we need to
solve that has a lot of potential pathways to a solution,
but we don't yet know which pathway is the best,
(31:58):
the one that represents the quote un quote right answer.
With a classic computer, you have to evaluate each pathway individually,
and then at the end you have to compare all
the results against one another to determine which one is
the right one. If there are lots of pathways, this
can mean a ton of computational work has to be
(32:18):
put into the effort, and potentially that the amount of
time required to complete the calculation is longer than the
age of the universe, meaning it's practical for all intents
and purposes, it's impossible will be extinct before the computer
finishes the problem. So let's take this approach to the
(32:40):
way we encrypt things the modern cryptography, and we're going
to keep this at a very high level. Essentially, your
typical encryption method takes two very large prime numbers. Remember
a prime number is a number that's only divisible by itself.
It takes these two large prime numbers, then multiplies those
(33:01):
two prime numbers together and this creates a product which
then we can use to encrypt data in some way.
And the only way to decrypt the data to reverse
the process of encryption is to have the correct very
large prime number factors that we were used to make
that product. So if you don't know the prime numbers,
(33:23):
you can't reverse this process. Well, a classic computer would
need to go through all possible prime numbers in an
effort to find the right ones that were used to
make this product. It's a process called prime factorization. So
a number might be the product of just two prime numbers.
So the number ten, for example, is the product of
(33:45):
two and five. Two tomes five is ten. Well, two
and five are both prime numbers. But larger numbers might
break into multiple prime factors, like the number one thousand three. Well,
that can be broken down to the primes of two, two, again,
thirty one, and one thousand nineteen. You multiply all those together,
(34:07):
you get one twenty six thousand, three fifty six. Computers
are pretty darn good at multiplying numbers and getting a result.
They are not as efficient when they take a result
and work backward to determine the factors used to produce
that product, and that's the secret sauce behind modern cryptography.
(34:27):
A classic computer could take logger than the age of
the universe to solve a particularly difficult prime factorization problem,
but a quantum computer with sufficient cubits and the right
algorithm could theoretically solve for all possible factors to create
a particular product. The cubits are able to serve both
(34:51):
as zeros and ones at the same time, so if
you've got enough cubits that are all in superposition, you're
essentially working out all possible solutions in parallel simultaneously, you'd
actually get results that would have probabilities assigned to them.
So again, once you get your results, it's not that
you have, you know, the one and only answer, but
(35:13):
you have various potential answers that are assigned probabilities. Typically
you're looking at you know, the highest probability is likely
to be right, because you know, once we get quantum
computers that have these these reliable cubits and superposition and
the right algorithms. Uh, this is you know, just a
(35:34):
matter of time before it happens, then it will require
us to shift to an entirely different kind of cryptography
because once you do have these sufficiently powerful computers, it
becomes uh an easy task to reverse the cryptographic process,
and you just end up having essentially a skeleton key
(35:56):
to all encrypted information. It's trivial how how easy it
is at that point, assuming that you have a a
properly powerful quantum computer and the appropriate algorithm to reverse
the process. So that's why there's so much work being
put into quantum cryptography, a process that would make it
(36:20):
more difficult for a quantum computer to crack a cryptographic scheme,
so that way we could maintain secret information. Otherwise there's
no chance of having secrecy through digital transfer. Now let's
get to a science fiction e element of the quantum
(36:42):
world that people have talked about. So, in quantum systems
we can have entanglement, and that entanglement can exist even
if you were to separate to sub atomic or quantum particles. Uh,
two opposite ends of a universe. Does that mean we
could have a system and which we have one entangled
system and say a spaceship on the opposite side of
(37:04):
the galaxy from us, and the other entangled system is
here on Earth, and then we could have instantaneous communication
between the two. Right, we get to have these two
systems and because they're entangled with one another, we could
send information back and forth. Wouldn't that mean we'd be
violating Einstein's theory that nothing can go faster than the
(37:25):
speed of light, And doesn't in fact mean we could
violate causality? Could we actually end up getting an effect
before the cause? Well, the simple answer is no, So
that's a relief, right, But why Well, measuring an entangled
particle in one location will cause the entanglement to sever,
(37:46):
but you can't actually send any useful information. That way,
it becomes a local measurement. Now it's a local measurement
that's in two separate locations that are millions of light
years apart. And you could say, well, be because of
the state of this system. We know what the state
of the system on the other side of the the universe was,
but it was only at that moment of measurement. We
(38:09):
don't know what state that systems in now because the
entanglement has been severed. So you haven't actually sent any
useful information. Uh, So there's no way to communicate. There's
no way to do that. If you were to try
and communicate, your communication would be in the form of
classic bits style communication, which means you would be limited
to the speed of light. So entanglement might be spooky.
(38:32):
It cannot bright the laws of physics, Captain, so uh
that I'm happy to report because otherwise we would have
some really tricky things ahead of us. Because if you
can violate causality, and there's all sorts of things from
time travel to the whole concept of like multi verses
(38:52):
and stuff, it gets really wibbly wobbly. Timmy, why me,
as the doctor would say, So, I'm thankful that as
far as we understand it now, that's a that's a
non starter. But that doesn't mean that our understanding of
quantum mechanics is by any measure complete. It definitely is not,
and that we may learn other ways that we can
(39:16):
exploit quantum systems to our benefit. That is really interesting stuff.
And like I said, I understand the end result stuff, right,
I can get my mind wrapped around that. I don't
understand the how at all. Um. I remember when I
(39:36):
was looking into something tangentially related to this, which was
string theory. I was writing an article about how string
theory works for how stuff works years ago, and I was,
I mean, it's a good thing. I'm already balked because
I was ready to tear my hair out, but that
would require reversing nature's whims and I am not able
to do that. But yeah, I was ready to tear
(39:56):
my hair out because I was doing a deep dive.
I was looking at interviews with uh physicists and scientists
and mathematicians, and I remember there was a point where
one of them was asked, point blank, do you understand
string theory? And his response was, I have dedicated my
(40:18):
life to the study of this. But if you want
the real raw answer, no, Like, I understand what the
math tells me, and I understand why we need to
account for things like multiple dimensions, for example, but I
don't understand the theory at that granular level. And my
(40:42):
reaction was, well, if the people doing the groundbreaking research
into this field don't understand it, what chance do I have.
So to me, the quantum world in general, not just
string theory, but quantum mechanics in general, is this kind
of spooky world because things behave in ways that seem
(41:05):
counterintuitive to me because it is very different from the
experience we have in the macro world. But yeah, fascinating stuff,
and as I said, it actually does affect our our
electronics and technology today. I've talked to in the past
about other things that are related to this, this high
(41:26):
level understanding of physics where we know it's true because
we've experienced the consequences things like relativity, which we know
to be true, because if relativity weren't true, then our
satellites would behave totally differently than the way they do.
But because we know we have measurable outcomes with our
(41:48):
our satellite systems, that uh, uh, confirm relativity. We understand
that's a real thing. I think that's amazing. I'm sure
it's some thing that Einstein himself, while he may have
suspected would one day become true, would have delighted in
seeing that there would be actual ways to experimentally prove
(42:11):
his theory. That would have been phenomenal. I'm sure. All right,
that's it. I hope you have a happy Halloween. Be safe,
be spooky, enjoy yourselves. If you have suggestions for future
topics of tech stuff, I invite you to trick or
treat by reaching out. One way to do that is
to download the I Heart Radio app is free to download,
(42:33):
free to use. You can use the little search bar
to navigate over to tech Stuff. There you will see
that there's this little microphone icon. If you click on that,
you can leave a voice message up to thirty seconds
in link. You can even let me know if you
would like me to use it in a future episode,
in which case I will. I won't. Otherwise I would
just reference it, but I wouldn't use the recording. Or
you can always reach out to me on Twitter. UH,
(42:56):
as long as Elon Musk doesn't nuke the whole thing
into orbit. Uh the handle. There is tech Stuff H
s W and I'll talk to you again really soon. Y.
Tech Stuff is an I Heart Radio production. For more
(43:17):
podcasts from my Heart Radio, visit the i Heart Radio app,
Apple Podcasts, or wherever you listen to your favorite shows.
TechStuff News
Hosts And Creators
Oz Woloshyn
Karah Preiss
Popular Podcasts
Stuff You Should Know
If you've ever wanted to know about champagne, satanism, the Stonewall Uprising, chaos theory, LSD, El Nino, true crime and Rosa Parks, then look no further. Josh and Chuck have you covered.
Dateline NBC
Current and classic episodes, featuring compelling true-crime mysteries, powerful documentaries and in-depth investigations. Follow now to get the latest episodes of Dateline NBC completely free, or subscribe to Dateline Premium for ad-free listening and exclusive bonus content: DatelinePremium.com
Las Culturistas with Matt Rogers and Bowen Yang
Ding dong! Join your culture consultants, Matt Rogers and Bowen Yang, on an unforgettable journey into the beating heart of CULTURE. Alongside sizzling special guests, they GET INTO the hottest pop-culture moments of the day and the formative cultural experiences that turned them into Culturistas. Produced by the Big Money Players Network and iHeartRadio.