This week on CenterStage, a University at Buffalo physicist targets an unscientific account of the cosmos.
On April 15th, 2015, the Center for Inquiry – Transnational at Amherst, New York presented a lecture by Will Kinney, titled “A Universe Just for Us.”
The idea that human beings occupy a privileged position in the cosmos is ancient, and persistent. Five centuries after Copernicus wrenched the Earth from the center of the universe, modern cosmology is again returning full-circle to theorize a special role for sentient beings in cosmic structure through the so-called “Anthropic” principle.
In our next two episodes physicist Will Kinney makes the case that this principle is ultimately useless and disturbingly anti-scientific.
Will Kinney is a professor in the Department of Physics at the University at Buffalo, State University of New York. His research focuses on the physics of the very early universe, including inflationary cosmology, the Cosmic Microwave Background, Dark Matter, and Dark Energy. He has authored more than fifty published research articles.
To center stage, bringing you the best from the Center for Inquiry, a nonprofit organization that seeks to foster a secular society based on science reason. Freedom of inquiry and humanist values.
Presenting lectures and events at its headquarters in Amherst, New York, and in New York City, Washington, Los Angeles and elsewhere. There’s always something thought provoking and controversy along on stage at some center for inquiry. Join us now on center stage.
Welcome to Center Stage. I’m Debbie Goddard director of outreach at the Center for Inquiry. Today on center stage, a university at Buffalo physicist targets an unscientific account of the cosmos.
And I’m Tom Flynn editor of Free Inquiry magazine. On April 15th, 2015, the Center for Inquiry Trans National at Amherst, New York presented a lecture by Wil Kinney titled A Universe Just for US.
The idea that human beings occupy a privileged position in the cosmos is ancient and persistent.
Five centuries after Copernicus wrenched the earth from the center of the universe. Modern cosmology is again returning full circle to theorize a special role for sentiment beings in cosmic structure through the so-called anthropic principle.
In our next two episodes, physicist Wil Kinney makes the case that this principle is ultimately useless and disturbingly anti scientific.
Wilkins is a professor in the Department of Physics at the University at Buffalo State University of New York. His research focuses on the physics of the very early universe, including inflationary cosmology, the cosmic microwave background, dark matter and dark energy. He has authored more than 50 published research articles.
Dr. Kinney is introduced by my co-host, Tom Flynn, and now Wil Kinney presents Part One of a universe just for us.
The idea that human beings occupy a privileged position in the cosmos has a long and generally intellectual disreputable history, as our speaker this evening has written, five hundred years after Copernicus wrenched the earth from the center of the universe and set it free among the stars. Modern cosmology is again returning full circle to hypothesize a special role for Ascendiant beings in cosmic structure that ideas most current and perhaps trendiest incarnation is the anthropic cosmological principle. Something I found so ridiculous that more years ago than I’d like to think about. I poked fun at it and one of my science fiction novels. But hardly anybody reads my science fiction novels. So that’s another reason why tonight’s talk is important. Our speaker is Wil Kinney. He’s a professor in the Department of Physics at the University of Buffalo, SUNY, where he’s been on the faculty since 2003. Dr. Kinney received his B.A. from Princeton and B HD from the University of Colorado, Boulder. He’s worked as a research associate at Fermi National Accelerator Laboratory, the University of Florida, Columbia University. And I left out a couple of things just about everywhere. His research focuses on the physics of the very early universe, including inflationary cosmologist, the cosmic microwave background, dark matter and dark energy that kind of covers the waterfront. He’s authored more than 50 published research articles and received the Sunni Chancellors Award for Excellence in Teaching in 2014. Now, these lectures, co-sponsored by the Center for Inquiry Western New York, the U.B. Free Thinkers and the U.B. passed a fiery Iain’s whose whose ad can be seen in the corner here. So please put your noodle’s appendages together for our speaker, Wilkening.
Thank you very much for the kind introduction. So how many you’ll be positive variance are actually here? Raise your hands, OK. Can I get a Robin from the choir? Yeah. Good. All right. So here I just want to restart this real quick so that my timer Ashley tells me how long I’ve really been speaking. So I want to talk tonight about this idea, this ancient idea that is one that we can’t seem to get away from, even in modern cosmology, that the idea that we human beings are special in some way in the cosmic order. And this is a truly ancient idea. And I want to and I don’t want to spend a lot of little time talking about the history of that, the history of how we need the specialness of humans in a cosmic sense. And then I want to say to modern cosmology in the second half of the talk and talk about this modern idea of the anthropic principle. Define what it is, which is a very slippery thing, actually, and discuss it critically and come up and give you a list of my objections to it. Why? I think it’s not a really good idea. And what I think we can do that we can do a little bit better. So I want to start with. A quote from Giordano Bruno, the Renaissance mystic and philosopher who said in fifteen eighty four, God is infinite. So his universe must be two. He is glorified not in one, but in countless suns, not in a single earth, a single world, but in a thousand thousand, I say, and instability of world. This was not a popular idea at the time, and he was burned at the stake by the Inquisition in the year sixteen hundred. And it’s hard to imagine actually coming from a modern perspective, how such a pious argument could have been viewed as so heretical. And I want to look at the history of this and sort of look at this idea, because I think one of the things here, one of the really radical things of what Bruno is saying at the time was he was removing human humans. He was removing us from our special position in the cosmos. If there was an infinity of world, we are no longer special. And I think this was one of the most dangerous things that Bruno had to say. And I think they realized it at the time. So let’s go back a long time and look at the sort of the evolution of this the history of this idea. And so let’s go back to Aristotle, who made an argument of cause and effect in the universe, called the argument for the prime mover. And Aristotle said, since everything that’s in motion must be moved by something. Suppose there is a thing in motion which was moved by something else in that by something else and so on. But the series cannot go to infinity. So there must be some first mover in the world. There has to be an original cause to any motion. Now, this cause and effect argument relies on something that was central to Aristotle’s concept of physics, which was that motion is an unnatural state, that anybody in motion will eventually come to rest in a privileged reference frame in the world. And that. So that motion is something that needs to be explained. You have to have a cause for something to be moving.
Because in Aristotle’s physics, the natural state of material bodies was at rest relative to the Earth.
This was really important and this was one of the things that we’re going to see changing as we go on into the Copernican revolution. Ptolemy’s ideas and Ptolemy’s geocentric cosmology was really perfected by Claudius Ptolemy, who wrote The Syntaxes in the year 150. Ptolemy was of Greek ancestry, a Roman citizen, a pagan, lived in Alexandria, Egypt, and he systematized Aristotle’s idea of geocentric cosmology and a manuscript titled As a Tax and Taxes. And this picture, this geocentric picture of cosmology under undergirded by Aristotle’s rules of physics, was survived for fifteen hundred years. This was the standard picture of cosmology in in the world for a millennium and a half. And here’s Ptolemy’s universe. The Earth at the center, the moon rotating around the earth. The other planets going on outward and so on. In this picture, the earth is special or the center of the universe. All right. And we’ll return to this or we talk a little bit later. All of this would probably have been lost in the dark ages when Europe descended into medieval theocracy, warring clans and the dark ages kicked in, except for the influence of the Islamic world. And in particular, I want to talk a little bit about the preservation of these manuscripts in the Battle Hikma, the House of Wisdom. So this was founded by Abbasid the Abbasid Caliph Al-Rashid, who ruled from seven eighty six to eight or nine. It was fully established under his son Mamoon, who ruled from eight 13 to eight thirty three. And this was at the height of the Golden Age of Islam from which lasted from the 9th to the 13th centuries. This was a time when Baghdad was a cosmopolitan center of art, culture, poetry, music, and it was international.
There are Christian scholars, Muslim scholars, all working together on, for example, some of the things that were were accomplished at the House of Wisdom, this Proteau University that was founded by the caliphs, where translations of Pythagoras, Plato, Euclid, Aristotle, the list goes on, and Ptolemy the Syntaxes. Ptolemy’s original title for this was renamed the Alma Jast Arabic for The Greatest, which is the title which we know mostly today. Original work was done there as well.
More new science was done, in fact, that the some of the scientists of the golden age of the caliphate’s can be can be credited with beginnings of invention of the scientific method. They refine the atomic system. They constructed the first observatories in the Islamic world. They invented algebra. The scholar Mohammed bin Moossa, Alcoa SEEMY and wrote the Katab al Dubah, which was the first expression in human history of algebraic methods. This library, the House of Wisdom, the battle Hikma was destroyed by the Mongols and the siege of Baghdad and 2058 by the Mongol who Lajo Khan. And at this time the Tigris was said to run black with ink from all of the books that were destroyed and with the blood of the scholars who were killed by the Mongol invaders. And this was the end of the Golden Age of Islam. Right. About the same time as this was happening in the European world, there was a Roman Catholic scholar. Thomas Quietus, who was aware of these manuscripts and was actually a beneficiary of these translations that had been done in Baghdad of all of these ancient Greek texts into Latin and Arabic, and Aquinas borrowed directly from Aristotle’s arguments in his five ways, which were five logical proofs for the existence of God.
And one of those five ways in which is from acquaintances, Summa Theologica is whatever is put in motion must be put in motion by another with a lot of text in between, therefore is necessary to arrive at a first mover put in motion by no other. And this everyone understands to be God. So he then takes Aristotle’s idea of the first mover and pins it on the Roman Catholic God.
And this is one of his five proofs. And most of the other five proofs are similar in nature, arguing infinite regressions to a first cause or a first mover or something similar to that.
And he also adopted the tarmac universe. OK? And acquires his vision in his adaptation of this originally pagan idea above the Earth is the realm of the celestial spheres perfect, inhabited by God and the angels below the Earth. Literally inside of it is hell to which all things solid and evil sink down sort of the drain of the universe. And in-between a middle earth are humans where material creatures in an imperfect world and worst were halfway between divinity and sin. And the key point here is that humans are special in the cosmic order. Very special. Right. We made in the image of God and capable of transcending the imperfections of the Earth and achieving the perfection of heaven. So an acquaintance’s world, the human beings are of a very special kind. The universe is basically all pointed at us. And this reflects in many ways in his writings and in particular, for example, he uses it to justify the political system of feudal monarchies because. Ptolemy’s universe are distinct places built into the structure of the universe itself, Antone’s universe is also inherently hierarchical. Right. There are higher things and lower things. For example, here’s a quote on his is from his concept of how one defines goodness, the judgment of goodness, if anything, does not depend on its order to any particular thing. It does not dependent good the goodness of a thing. It’s not about relationships. It’s about absolute position, but rather upon what it is in itself and on its order to the whole universe, wherein every part has its own perfectly ordered place. This hierarchical world is the one of the medieval church.
Copernicus published his book De Revolution of US in his 15 43. He probably began it in 15, 14 and much like Charles Darwin. He realized how radical his his ideas were and was afraid to publish them. And he didn’t see a copy of his book in print until he was on his deathbed in fifteen, forty three. And he was right. It was radical.
If the social and political order of the material world, and this is acquaintance’s vision, derives its legitimacy from the inherent order of the universe itself. Right.
Society and the cosmos are reflections of each other and they still are. Today are our concept of cosmology, reflects our concept of our own culture and to a certain degree, vice versa. So the idea then that the Earth is just one of many completely destroys that order and by extension, the foundation of the society? Right. Copernican ism was, in fact, I would argue, deeply radical. And it is sentencing. Bruno realizes it is sentencing for heresy. Bruno told the judges, quote, Perchance you who pronounce my sentence are in greater fear than I who receive it. And this is what he told the judges when they sentenced him to be burned alive. And he was right. Their world was about to collapse. The Renaissance was right around the corner and the loosening of the European theocracy was already underway. And Copernican ism had a lot to do with it. It removed the human beings from our special place in the universe. It’s difficult to argue that we’re special and we’re just one one of many planets. So here’s Copernicus’s universe in which the earth was no longer special. But one of many planets required not just a change of perspective. OK, it required a change of political and philosophical perspective, but it also required a change of physics. Aristotle’s physics had to be revised in order to come to accommodate Copernican ism. And you had to introduce the idea that motion is relative. You think about it. If motion is an absolute. Then how come when the Earth is moving around the sun of this tremendous velocity, how come things don’t fly off of it? How come we don’t feel the motion of the earth? How come we can’t perceive it at all? And of course, the answer is relativity. We’re sharing the motion of the earth. Motion is not something in a modern perspective that’s defined in an absolute sense. But only can be defined by the relative motions of two objects. And Copernicus realized this completely. Indeed, the evolution of us, he wrote. Every observed change of place is caused by a motion of either the observed object or the observer, or, of course, by an unequal displacement of each. This was the first real expression of relativity in modern science. And you had to have an idea of relativity in order to accept Copernican ism, because otherwise the idea that the earth could be moving and we could have no sense of it would be ridiculous. All right. There are many good reasons to believe in Ptolemy’s system. The lack of parallel observe parallax of the stars, which turned out to be because they were just a lot further away than anybody realized. But also this question of motion. How could the entire earth be in motion and have us have it not be perceived by us? Copernicus started along the way toward defining a formalized version of relativity that was later completed by Galileo. And we’ll see the contrast with Galileo in a minute. Of course, at the time, all this was philosophy, right? One system, another system. In fact, Ptolemy’s system worked better because Copernicus hadn’t yet hit on the idea of an elliptical orbit. His system was actually less accurate and required more epicycles than Ptolemy’s did. So by Ockham’s Razor, anybody at the time would have stuck with the Ptolemy Me system easily because Copernicus’s system was vastly more complex and was less accurate. Soon afterward, there was data. And here was the data that prove the Copernican system was right and the Tommy system was wrong, it was Galileo was discovering the phases of Venus and 16 tap. It’s often stated that it was Galileo’s discovery of the moons of Jupiter that that killed the atomic system, but not really. In Ptolemy’s system, things orbited on epicycles around empty points in space. Jupiter, Venus and Mercury, for example. But this is a killer, right? This is an observation that allows you to tell the difference between the Copernican and Tommy systems using data. And the reason is really simple to see in the Ptolemaic system.
Rotates on an epicycles whose center is fixed to the sun. So the center of this epic cycle moves around exactly with the sun. This is how Ptolemy ensure that Venus wouldn’t stray too far from the sun in the sky, that it would always stay close to it. But in this sort of an arrangement, Venus is always between the Earth and the sun. And you’re. Oh. And Venus will only have a crescent face. But in the Copernican system, where Venus actually goes around the backside of the sun. And the reason that it doesn’t stray too far from the sun is because its orbit is smaller than the Earth. Then you see all the phases of Venus from the full to the crescent.
And the Crescent is apparently larger because Venus is going to be closer to us than that. Galileo saw this and immediately realized that this was a death knell for the Ptolemaic system and was a beautiful confirmation of the Copernican one. Galileo also took Copernicus’s idea of relativity. And made it a little bit more scientific. Galileo, in fact, invented science, at least in the European world. And Galileo wrote in his treatise, Dimo, to any two observers movie at constant speed and direction with respect to one another will obtain the same results for all mechanical experiments. This is beautiful because he took what was a philosophical statement of Copernicus and turned it into a concrete and operational one. He gave it a. He related it directly to the idea of measurement. Any experiment you do will not tell you that you’re in uniform motion. You can only define motion by using relativity. You can only defined motion by the relative positions of two objects. Notice that Aristotle’s argument of the first mover is now dead. Right, because you can’t define any pursuit, because motion need not have a cause at all. Because motion isn’t defined in any absolute sense. And so this was also, in addition to everything else, a firm refutation of Aristotle and acquaintances argument of a first mover in the universe. Relativity, of course, continue to be important.
As a part of this relativistic idea, Copernicus put forth another principle, a related principle. That idea is that the earth is not at the center of the universe. The earth is in some sense, ordinary. It’s one of eight planets. Right, or five at the time. Right. So the Copernican principle, the idea that the Earth is not at the center of the universe. When Albert Einstein invented a special in general theories of relativity, and in particular when Einstein, one of the first things he thought to do with general relativity was apply to the universe as a whole. He extended Copernicus his argument to a broader statement, a more global one. And so Einsteins version, extension of the Copernican principle is that nobody is at the center of the universe. Every point in the universe is pretty much the same as every other point. Mathematically, this is called the condition of homogeneity and I saw entropy. The universe is the same in every place, and it’s the same when you look in every direction. On average. I mean, obviously, things aren’t exactly the same here as they are outside and they’re not the same on the earth as they are in space. But if you average over a big enough region, the universe is the same everywhere. Einstein put this into his equations of general relativity, this simple cosmological principle that the universe had to be homogeneous and isotropic. And he came up with a dynamic universe, one that had to be either expanding or contracting. Now, as a side note, I’m not going to talk much about this, but Einstein thought this was so ridiculous that he cluj this theory to get rid of it and have a static universe by introducing what you call the cosmological constant. And then the expansion of the universe was discovered less than a decade later. And Einstein called it his greatest blunder, introducing the cosmological constant. Because even Einstein didn’t have the imagination to think of a dynamic universe, an expanding universe. So Einstein’s universe was not only expanding, but the universe that best fits modern cosmological data is also an infinite one, expanding forever into the future. So this is a realization, if you like, of Bruno’s mystical idea of an Infinity of Worlds. In fact, Einstein’s universe is one where the space of the universe is, in fact, infinite itself. And this is something that my friend Max Tegmark likes to call a type one multiverse. Just the fact that the universe goes on forever. And so if in an infinite universe, there are an infinite number of copies of us having this talk somewhere and some distance out there, right. Everything is going to happen over and over again. So I imagine that a lot of the a lot of you have a picture of the big bang that goes something like this. There was some big cosmic dense cosmic egg out there that at some point exploded and sent stuff off in all directions. Right. Expanding outward. Right. Yeah, that’s totally wrong. It beat the universe, cosmological expansion works. Nothing like that. So let me try to give you another analogy that gives you a more accurate picture. And what I want you to imagine is sort of a sheet of stretchy material. So this is a two dimensional analog to a real three dimensional universe. But imagine like a sheet of rubber that you can stretch in all directions. OK. With me so far. All right. Now draw a grid of identical squares on that sheet of rubber. As you stretched now stretch that sheet of reverence. Stretch it uniformly, all the squarest a square, and they all stay the same size. They just get bigger. Right. So as I stretch that out now, in fact, I can imagine taking the sheet, having the sheet, this flexible sheet. And in your imagination, send it off to infinity now. It goes off infinitely in every direction. So now I have this infinite, stretchy, two dimensional sheet with an infinite grid of identical squares drawn on it. It’s an infinite universe that goes forever in every direction. But this infinite universe can expand. I make all the squares a little bigger or a little bigger or a little bigger or a little bigger. Everything is moving away from everything else. The further away something is, the faster it’s moving away from you. And the universe at any given time is infinite. It’s homogeneous. Every point is exactly the same as other every other point. The squares are identical with each other. And it it’s just completely uniform in all respects. But it’s expanding. It’s not expanding into anything. It’s just everything in it is getting further and further apart. And this expansion goes off to infinity.
OK, you’re with me so far. Now. Turn the clock backward.
What happens if you look at our current universe and go back in time? Well, the squares were all smaller earlier. Right. Everything was closer and closer together. Everything was getting much closer and closer and closer together. So the early universe. All the hydrogen atoms in the universe today, we’re getting smushed closer together. So the unit early universe would’ve been very hot and very dense because the gas in it was compressed further backward in time. And Einstein’s equations of general relativity tell us that finite time in the past. All those squares went to zero size.
And this is the moment of the big bad.
When all of those squares we’ve drawn on the sheet, if you follow them backward in time and they go to zero size, that happened at a finite time. It happened at thirteen point eight billion years ago. And this is known experimentally to within a few percent. The observational error on that number is now about 200 million years. So we know the age of the universe to within 200 million years is thirteen point eight billion. And at that time, the density of the universe went to infinity. The size of the squares went to zero. But notice, there’s still even an infinitesimal amount of time after the big bang, just immediately after the Big Bang happened. You have an infinite grid of squares going off in all directions. The Big Bang didn’t happen in one spot and expand outward. The Big Bang was an infinitely large infinitely that space popping into existence all at once and then beginning to expand our.
But at even a moment after the Big Bang, the universe was infinite in extent.
Now we can only see a tiny little part of this because light can only travel so fast. And since the speed of light is, the speed of light is finite, the amount of space that we can see light coming from since the big bang is also finite.
We can only see out about thirteen point eight billion light years, give or take a couple of factors or two from cosmological effects. Right.
So we can only see out a certain distance in this. We see a little patch of this overall infinite space, but out there, infinities of infinities, infinities, and there always have been even all the way going back to the moment of the Big Bang.
So I want to talk about two ideas of where this big bang came from. Modern cosmological ideas of what happened before the Big Bang. And these are the two ideas that are really responsible for the resurgence in this idea, this is this anthropic idea.
And I want to explain sort of the origins of this and the two things that are at play here are the idea of eternal inflation.
On the one hand and the second is the idea of the string landscape. And I want to explain briefly both of these things and then start talking about how they they fall into this idea of humans being special in the universe.
So in the.
Nineteen eighties, it was realized by scientists like Alan Booth and Andre Day and Aleksey Stravinsky and a number of others that the universe itself. This big bang could be a product of quantum uncertainty. The basic idea is that nothing is not stable. In a quantum world, you any if you have a state of nothing that you can have fluctuations about that state such that this is essentially a statement of the Heisenberg uncertainty. You’re not supposed to put equations in public talks. But this is my only one. This is the height Heisenberg uncertainty principle written in a way you might not be used to it, which is that the uncertainty in the energy of a process and the uncertainty and the timescale also habitants have a Heisenberg relationship to them so that you can have a little energy fluctuations as long as they happen on short enough timescales. When you plug this into general relativity, on the other hand, you can have a runaway effect. A little tiny fluctuation in energy can multiply itself and result in an exponentially expanding bubble of space time that becomes arbitrarily large almost infinitely quickly. This is the idea of the inflationary universe. So the inflationary universe posits that the big bang was actually a universe from nothing. You can create a universe out of quantum fluctuations from nothing.
Now, if it can happen once, it can happen a lot of times, right?
So, in fact, it’s very natural in these inflationary theories to have this universe created from nothing happened over and over and over again. In fact, happened an infinite number of times. And so inside this one bubble, this huge bubble universe, our observable universe might be some tiny little thing here, we can only see this patch of it. So we can’t see the weird quantum outside of this thing. All we can see is a nice, smooth patch that we live inside. Not only did these bubbles happen infinitely many times in principle, but each bubble continues it for an infinite period of time and spawns other bubbles are from it. So you have an infinite number of bubbles themselves, producing an infinite number of child bubbles. Each of those has an infinite universe inside of it. So it’s an infinity of infinity of infinities in this picture of the inflationary multiverse. So the inflationary universe is a lot like a glass of beer you have. And in fact, what happens in a in a glass of beer is called a first order phase transition. That’s exactly the same thing that happens in the transition to inflationary bubble universe. OK. They’re the same kind of phase transition. And so you think of this as being the each of these little bubbles inside this huge infinite glass of beer contains inside that little bubble contains an infinite universe and infinite big bang universe, which is and we live happen to live in one of the. So how can you have an infinite universe inside a finite size bubble? This is where relativity comes in.
You do a neat trick where here is this expanding bubble and I’m drawing space and time in this diagram now so you can see in this bubble expands out in space. So the edge of the bubble traces a cone shape in space and time. Right. As it moves further out in time. It was further out in space. Well, in relativity and general relativity especially, I’m free to use whatever coordinate system I like. So what I can do is I can borrow a little bit of time and turn it into space and I can define my spatial hyper surface myse the spatial surfaces in my universe. Are these hyperbole, these infinitely large hyperbole that live inside of this cone?
So I can back up and show that to you one more time, because I put a lot of work into it. OK. So from outside, this bubble looks like a finite sphere, but from the inside, it actually contains an infinite open universe.
And we would live in one of these in this picture.
So everything we see or everything we ever can see in principle. Right. If we could go all the way out to infinity in our universe, we would still be inside that one bubble. But there exist an infinity of other universes, each forever separate from ours. It’s not completely true. Every once in a while, they can run into each other. People have looked for this and I haven’t seen it. So this is Bruno on steroids, right? And this it’s in this infinity of infinities, we are definitely not special since an Infinity of Worlds, there will certainly be an infinity of civilizations, even an infinity of other earths identical to our own. And in fact, in a multiverse, as individuals, we’re not even unique manifestations of ourselves. But one of an infinity of copies of ourselves. So even as individuals, we can’t claim uniqueness because there are an infinite number of copies of us as well. String theory. How do you make all this work in a real physical theory? This has in order to really do that, in order to really make this work in a proper physical theory. You have to have a concept of quantum gravity. You have to really understand how quantum mechanics applies to gravity in order to do this for real. Problem is, we don’t we don’t have a good theory of quantum gravity. We just have some good guesses. One of the better guesses we have is the idea of string theory. So this is the concept that fundamental particles, instead of being point light, are actually extended objects, little vibrating, one dimensional things. And now they’re multi-dimensional brains and all this stuff that you hear talked about. And in order for this to be this kind of theory, to be self-consistent, in order for this sort of model particles as one dimensional objects to work, it was discovered very quickly that the universe could not be four dimensional, three space in one time, that you needed to add extra spatial dimensions. So you needed either have a 10 or 11 dimensional universe in order for these theories to be self-consistent. OK, but the universe appears to be three dimensional, and the way you get around that is by a process called compact bifurcation. What you do is you take all the extra dimensions that you don’t want to see and you wrap them up on a really tiny like scale so that the circumference of the universe is so small in that direction that you’d never detect it. This compact bifurcation takes place at every point in space and time and string theory works getting ahead of myself. The thing is that there are a lot of different ways you can compact ify the extra seven or eight dimensions that you don’t need. Right. So there are many, many ways that you can fold up multiple dimensions into small surfaces. And each of those different ways corresponds to a different set of laws, a particle physics and string theory. So the way you fold up the extra dimensions tells you what your laws of particle physics look like in the resulting universe. It’s been estimated that the number of different ways to do this is about 10 to the power of 500, which I wrote out like this sometimes exponential notation hides the troops. Right. You got to write out all the zeros sometimes. Right. So 10 to the 500 is a really big number. That’s the number of string vacuum. Each of these vacuum is one way you can fold up those extra dimensions and hide them.
Ten to the five hundred is an enormously large number. For example, the number of possible positions that Chess’s tend to the fiftieth, the number of atoms in the universe is ten to the 80th and the number of possible positions and go is still only ten to the one hundred and seventy if.
So this is almost unimaginably large number.
And each of these.
Different ways of folding up the universe results in different physical constants, different particle content, different laws of physics. Well, that’s very disturbing, right, because, for example, look at this number. This is the fine structure constant. This is a dimensionless number that codifies basically tells you how strong electromagnetism is. And so it’s given by the electron charge squared divided by Plank’s constant times, the speed of light. If that bugs you, don’t worry about it. It’s just a number. And this particular number that tells you the strength of electromagnetism is one hundred thirty seven point zero three five nine nine zero seven four. And this 44 here is the experimental error. That’s the known experimental uncertainty on this number in these last two digits here. So this is known to one, two, three, four or five, six, seven, eight, nine, nine digits of precision. That’s one of the most precisely measured physical constants in the world. Right. This has been measured with exquisite preciseness. It has this incredibly strange number and nobody knows why. And in fact, if it were different by just a few percent, atoms and molecules wouldn’t be stable and life like us would be completely impossible. There would be no stars, there would be no molecules. There would be no chemistry.
There would be no nothing. This number has to be there. What is the charge of the electron?
So if this number is just a little different from what it is, the universe would be radically changed and we wouldn’t be here. And this is something, for example, that you’ll see creationists bring up a lot. Right. You know, there’s no explanation for this. Somebody had to put it just so. And there’s a lot of other examples and numbers like this. So in order to explain this right. And so now in somewhere in all of these 10 to the 500 universes, we just happened to find ourselves in one in which the fine structure constant is exactly equal to this incredibly precise number. And the universe is hospitable to life, which is kind of unsatisfying.
Right. Enter the anthropic principle.
Depending on who you ask, it will be stated differently from time to time. But here is the way that I’m going to I’m going to put it for the sake of argument. Anthropic principle is the idea that the values for physical constants, like the fine structure constant, are selected to enable the presence of observers. This is essentially using an a posterior or eye selection effect. Right. You say you have this incredible multiverse full of all of these different weird compact bifurcations, all these different particle physics theories. And in the simplest form, it’s a tautology. Right. We happen to find ourselves living in a universe that suitable for us to live in. Right. Just like we. Why is it that we happen to find ourselves on a little ball of rock, just the right distance from a star with liquid water and all that kind of stuff? That sounds like quite a coincidence that human beings would find themselves in an environment so hospitable to us. Right. Sort of the same thing. So, in fact, in the anthropic universe, most of these bubble universes are entirely devoid of life. But there’s a selection effect that comes in that says, well, only some of them will admit intelligent life, and therefore only some of them will have scientists capable observing these constants. And therefore, that’s the explanation of why we see the constant what it is. Now, like I said, in its simplest form, it’s almost a tautology there will be no life in universes that can’t have life. But the anthropic principle is often taken a little further in a sense that to state that we can use this fact to make predictions about things like neutrino masses, for example. And I’ll show you an example of a recent paper that claims to do exactly that. And that’s why I started a part company with this idea. Now, the originator of this, the first guy to express it, realized that it was contrary to the Copernican principle and the cosmological principle. And this is from Brandon Carter’s original 1973 paper on the anthropic principle, where he said it consists basically of a reaction against exaggerated subservience to the Copernican principle. Copernicus taught us a very sound lesson that we must and must not gratuitously assume that we occupy a privileged central position in the universe. Unfortunately, there’s been a strong but not always subconscious tendency to extend this to the most this most questionable dogma, to the effect that our situation cannot be privileged in any sense. So he’s saying that we need to now throw away the idea that we’re not special in order to make sense of physics. We need to abandon the Copernican concept and entertain the idea that at least in some sense, human beings are privileged or sentiment observers are privileged. Now, this would all be philosophy if you didn’t have people writing physics papers like this one that my friend Rafael, who so very conveniently put out last week. So this is anthropic origin of the Yewtree Noma’s from cooling failure. He’s arguing that steller cooling while I was you to put limits on neutrino massiah. So this is an example of the kind of physics paper that’s being written about this. Now, Rafael’s a really smart guy. He was Stephen Hawking’s graduate student. You know, he’s a he’s a he’s a very distinguished physicist. But I think he’s, like, totally off on this. I do not understand how you can write a paper like this and actually take it seriously. But Will. I’ll talk about Rafael. I’ll talk to Rafael about that the next time I see him. So let me give you another example of how the anthropic principle was used. And this was an argument that’s attributed to Steven Weinberg, the Nobel Prize winner for the electroweak theory, who wrote a paper in 1979 explaining why he thought on anthropic grounds there ought to be a cosmological constant, Einstein’s cosmological constant. Here he is, our current picture of the makeup of the universe, atoms, everything we see in this room, everything were made of everything, the areas made up of the planet, all that stuff. Stars make up about four percent of the mass of the universe. That’s all we’ve managed to identify directly. This is everything we know about. Indirectly, we have very strong evidence for two other components, one of them is called cold dark matter, which makes up 23 percent of the mass of the universe. We know that’s there because of its gravitational effects. It clumps into clusters of galaxies, galaxies and clusters of galaxies, makes halos. And we can see its gravitational effects indirectly. Nobody knows what the dark matter is, but we really have a very good idea that it’s there. Seventy three percent of the universe is even weirder stuff known as dark energy. Dark energy differs from dark matter and that it doesn’t clump under gravity. It does the opposite. It smooths out. And the only way you can detect dark energy is by looking at the expansion rate of the universe. The change in the expansion rate of the universe. And it was discovered, much to everyone’s surprise in 1998 that the expansion of the universe is not slowing down, as everyone expected. Because gravity should be pulling everything together and slowing the expansion down. But the expansion is actually speeding up. There’s a thing that’s working opposite to the normal idea of gravity, and we don’t know what it is, and so we’ve given it the name dark energy so that we can talk about it, even though we have no idea what it is. The thing is that Einstein’s cosmological constant, his greatest blunder, acts exactly like dark energy. If you calculate in a particle physics theory what you expect the density of dark energy in the universe to be. It’s a simple calculation that any quantum field theory student can do. You end up finding that the dark energy, the mass scale of the dark energy should be about the plant scale, about the scale of quantum gravity. So the density of dark energy in the real universe and units of what you would expect it to be from particle physics are given by this number 10 to the minus one hundred and twentieth. So the density of the cosmological constant is about 120 orders of magnitude too small. In the current in the real universe, compared to what our theories say it ought to be.
Nobody knows why. Now, watch carefully.
If we change this number to this one, did you see it? Marcos. If we change that to that, there is no stars, no planets, no life, no nothing. The universe is expanding too fast before structure formation happens and life never, never happens.
That tiny little shift.
Or somebody so Weinberg’s idea was this. This was entropic selection that, in fact the cosmological constant and all these different bubble multiverses was just took some random value anywhere between zero and the plot mass. And it was only in these unfathomably rare universes where it happened to be just that size that any life occurred. And all those other bubbles, they’re just completely empty, devoid of life altogether. And that we happen to find ourselves in this one. And to his credit, he actually predicted that the value of the cosmological constant should be pretty close to what we observe it today before it was discovered. He actually made a prediction that was born out.
So this is the idea of the anthropic principle that we can put limits on these physical numbers. We can guess their values. Based on whether or not. So I can take some constant like the fine structure, constant or lamda, the cosmological constant, the dark energy density and say I can predict what it ought to be based on whether or not life would be. Human beings would be possible in a universe with that. No. OK. That’s that’s the idea. Now to the criticism. I have three basic criticisms of the idea, the anthropic principle.
Number one, it’s not falsifiable.
I’m going to go into each of these in a little detail. What varies and what doesn’t? Which continent, which constants are subject to anthropic selection? Which ones are not? Finally, what do we mean by life? Do we mean us? Do we mean anything carbon based? Do we mean exactly how do we define life? And how does that definition affect how the kind of limits we would put on physical constants? By using anthropic arguments. So let’s start with the first one. I would argue that the anthropic principle is not science. Science is the process of finding natural explanations for things we do not understand. By contrast, the anthropic principle is an assertion that no explanation of certain phenomena is possible, even in principle. The anthropic principle consensus, an abdication of science and its close cousin to the idea of irreducible complexity. The argument used by creationists. So I want to run through the creationist syllogism for you. So a creationist argument goes something like, I don’t understand X the value of the fine structure, constant say. Nobody will ever understand acts because there is no explanation for it.
Therefore, God did it.
All right. So a creationist would tell you that God’s hand selected this number to be just the right thing, to make us possible because we’re special.
And God wanted us to be here.
The anthropic argument is eerily similar to this.
Except that it only changes the third element of this syllogism, instead of God doing it, it was done by anthropic selection in the multiverse. But the anthropic syllogism depends crucially on this idea that just because I don’t understand this, I assume that no one ever will understand it. No one will come up with a physical theory that explains the fine structure constant. It’s impossible. Forget it. You just have to choose it at random in a multiverse. And I think this is really disheartening. Because scientists, we really ought to be better than that. All right. And I’m amazed that otherwise credible scientists take this idea seriously because it’s saying I am going to give up any hope of ever explaining this as an axiom that goes into my physical theory.
This is even more problematic when you consider what’s called the measure problem. So to accept either one of those syllogisms, the creationist or the anthropic syllogism.
It means we have to be capable of inferring the shape of a probability to the shape of a probability distribution from one instance of it. We see one universe, one example of a fine structure constant. The only difference is that. Advocates of irreducible complexity assume that the probability district contribution is infinitely peak, that it only has one possible value. And anthropic principle requires that the probability distribution be approximately flat. That it has no preference for one value over another. That’s the only difference, is what they assume about the shape, a priori shape of the probability of the fine structure constant. For example. But in an infinite multiverse, you can’t define probabilities. Let me explain in a simple way why that’s true. Suppose I have a box and I put five red marbles and five green marbles in it.
And I ask you to pick one of them out. What are the odds that you’ll pick out a red marble? 50 50, right?
Now, suppose I tell you I have a box with an infinite number of marbles in it and they are arranged red, green, red, green, red, green, red, green. Now I ask you to pull a marble out of that box. What’s the odds that you’re going to pick a red marble out 50 50? Right. Well, now suppose I rearrange these marble. I keep the same box with the same marbles, but I take this one and I move it over there. I take this one and I move it over here. I take that one and I move it over there. I take that one to move it over there and so on. And I do this process infinitely an infinite number of times. I’ve taken the same set of marbles, infinite number of red and infinite number of greens, and I rearrange them. Another red, red, green, red, red, green. Now, what are the odds if I pull one out, I get a red marble two thirds, but it’s the same set. So depending on how I define my measure on the system, I can get any probability I wish in a set that’s infinitely large. I can’t do that in a finite set. But in an infinitely large set, I can. So in an infinite multiverse, I don’t even know how to define probabilities. This is referred to as the measure problem, and it’s an unsolved problem in cosmology and in the enemy’s multiverse theories. Nobody knows how to define the probability of a fine structure, constant being one thing or another. It’s all a matter of assumption and the anthropic arguments. There is no there is no a priori derivation from a fundamental measure. Consequently, you get ridiculous things like the idea Boltzmann brains. How many of you have heard of Boltzmann brains? Anybody? Now. OK. Couple, the Boltzmann brain is a simple idea. It’s like, OK, if we’re just like generating these crazy multiverses at random and we have an infinite of an infinite infinity of infinities of these things to choose from. Well, then. It’s far, far more likely if we’re just doing things at random to generate your brain in an empty universe, complete with the illusion that it has, that it’s in there, it’s in the real universe. In fact, the probability of that is far higher in these stringy models than actually producing a real universe with you in it. So for every one real universe with you sitting in it, there is going to be an infinite number of other universes with you being an isolated brain, just imagining you see all of it. Now, this does not tell you. I mean, this sounds like, you know, freshman philosophy majors after indulging in a few too many controlled substances. Right. And but that should tell you something. The correct thing to conclude when your model gives you stuff like this is that your model is Ron. But you still see serious scholarly papers on the Boltzmann brain problem. Right. But when your model gives you nonsensical answers, you should be thinking that the model you’re using is probably not self-consistent.
Probably not correct. Onto my second objection.
So my second objection lies, the assumption was allowed to vary in the universe and what’s not. For example, why do the fine structure constant and the value of the dark energy randomly vary from university universe? But not PI or Napier’s constant?
This is a serious question, right? So here’s the standard model of particle physics.
Six works, six leptons for forest carrier the Higgs bows on connecting them all together could give you a whole torque on that important.
The important thing for our purposes is there are 19 free parameters in this model, 19 numbers. The fine structure constant is one of them. There are 18 others that are just numbers that we have no explanation for that you have to set from experiment. You just have to go out and measure them.
We have heard part one of a universe just for us, presented by physicist Wil Kinney at the Center for Inquiry Transnational at Amherst, New York, on April 15th, 2015.
The original recording was engineered by Nora Hurley. The music was by Adam Fields. Postproduction was by Inquiry Media Productions.
This has been Episode 243. Visit us again on center stage.
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