Are We Creating Objective Reality or Finding it? With Charles Liu | Cosmic Queries #107

When the universe was the pinhole sized, it actually wasn't that massive. But at the moment of the Big Bang, the mass of the universe was less than a glass of water. And it's actually not enough to have turned it into a black hole at that time. You wind up with all this extra energy in there which then condenses into matter and becomes the galaxies and stars and planets and black holes that we HAVE TODAY. — I FEEL SO DUMB. WHY WAS THAT BOY SO DUMB? — This is Star Talk special edition. We're doing a cosmic queries grab bag who we've got with us, not only of course Gary O'Reilly. Gary. — Hey, Neil. — And of course, Chuck Nice. — Hey. — But the only way this becomes a party is when we bring in our geek and chief, — Charles Lou. Charles, how you doing, man? — Hey. It is a pleasure to be here. Thank you so much as always. — All right. Charles is a professor of astronomy. Is that the department? What's the name of the department, Charles? — Department is physics and astronomy. — Physics and astronomy. College of Staten Island. — College of Staten Island of the City University System of New York. Longtime friend. Many people don't know that Charles co-wrote the exhibit copy that lives in the Rose Center for Earth and Space. Uh he was with us at the birth of the whole facility. So — that was so much fun. We had a great time, didn't we, Neil? — It was all good. And Gary, former soccer pro. — Yes. — Dude. And I don't think Charles knows this yet. You you're a new American citizen as of a few days ago. — Y — Ah, freshly minted. — Welcome to the club, Gary. That's awesome. — Thank you. And the three gentlemen here are part of the reason why being an US citizen for me is fantastic. So, thank you. — Oh, wow. Okay. Thank you. Hope now we have to live up to that. — No pressure. — You're honored, sir. So, we're going to, you know, find topics that really only Charles could give us the best answer on that's what we put in this show. So, so let let's get this party started. All right. Who's got the first question? — All right. I'll dive in first. And uh thank you to all our Patreon members for their questions and their curiosity. If we don't manage to get to your question this time around, apologies. There's only so much time in the universe. Talking of which, let's start. Hannah Kentley from Oregon City. And guess where that is? Yes, Oregon. I'm a big supporter and love the show. So, here's my question for Dr. Lou. In a universe where gravity, matter, and information all seem to emerge from the same underlying rules, and observers like us made of that exact same material, what does physics currently think observers are for? Are creatures like us just accidental byproducts of the laws? Or does the universe actually need observers in order to manifest or realize its own information? — Oh, straight in the deep end. Here we go. — What is it? What does it mean for there to be information anywhere if there's no sentient thing to record it as such? — Yeah. — No, this is a actually a deep philosophical question right now. Yeah. in physics and the philosophy of physics, we've — if a big bang happens in the multiverse and there's no one there to see it, did it really happen? — Right? It's that kind of situation right uh early on in quantum mechanics right there were people like Neils Boore uh the Copenhagen interpretation of quantum physics which basically said that the universe is in a flux state of sort of unknown uh states in the quantum level until you observe it and then the wave function collapses is what they say and then reality appears right so in that kind of position it is absolutely necessary for observers to observe something in order for a wave function to collapse. — Just real quick, so it's called Copenhagen because Neil's Boore was — Danish was Danish. A B weren't there conferences there where a lot happened so that people associated these new thoughts with that country and that city — and that's right. — Okay. So I just want — Even to this day, yeah, Denmark is a hugely important part. They have a cosmology center there. Lots of neat science going on. — Yeah. Okay. Sorry to interrupt. Go on. — So, the question then has uh since moved on and clearly even back then Neils Boore wasn't saying that the universe didn't exist if there were no observers. It's just we didn't know what

the universe consisted of until it got measured. Right? But that has been taken to sort of its logical conclusion and by saying that yes actually observers are necessary and you'll find physicists today — that stick to that point. — If you don't have someone seeing what's there it's not actually there. I remember also something that you did a long time ago, Neil, uh, about reality in our brains. Uh, how the complexity in our neurons and the neural nets and so forth and consciousness and things like that rivals the complexity on the large scale of the universe itself in the galaxies and the stars and things like that. And the number of — we look at the total number of connections in the brain and you look at the total number of stars in the universe and they all interact with each other gravitationally and so and our neural circuitry all interacts with all the rest of the neural circuitry. So it may be that the universe is less complex than the human brain. Interesting possibility there — on the large scale. And so if you take that into the next level, before quantum physics was established, there was a philosopher named Renee Deart whom you've probably heard of before. Uh he's named Well, the Cartisian plane, the XY axis that you guys all did in algebra back in the day, right? — What do you mean you guys? You did it too. Like you didn't do it, too? It's — true. Okay. And what makes you think I actually showed up for algebra class? You're assuming facts that are not in evidence, sir. — Well, okay. This guy Decart basically said that reality is only conveyed to our brains through our senses, — right? — So each of us actually lives within a reality that is distinct from every other reality that is visible. So in your brain, Chuck, and in my brain and Neil's brain. — Yeah. And he I mean honestly that's demonstrable. Now we actually have psychological experiments that have been conducted to show how we actually do live in our own distinct realities based on our experience and where we are and how we are receiving the information of the world itself. Uh and one of those things that is most I'll say stark is how we remember things. — Yeah. events. We all remember events just in a very distinct way. — So go back to the point of observing. So correct me and you probably will have to the dual slit slit. Thank you. The dual slit experiment where particles go through and they look just singular and then all of a sudden they become waves but as soon as you observe them they go back to not wanting to be observed. So they become right — single again. So how does that sit in with that explanation of observing? That's actually one of the big questions about that. The Young's two slit experiment, which has now turned into a big part of explaining so-called wave particle duality. Yeah. — Right. Uh is one of the manifestations of this. If you're looking at it or trying to measure it with certain kinds of machines or detectors that are detecting waves, you'll find waves. But if you measure it using uh something that detects particles, you'll find particles. and you can switch midstream and get a whole different thing that you expected originally uh just by how you choose to measure it. And so it's a really amazing confluence between what's going on inside our heads, what's going on outside our heads, how much of it do we share and is really truly only our own. Uh and I wish Hannah I had an answer for you but it is still being discussed. It is not yet confirmed whether or not observers are necessary for the universe to actually have an objective reality. — You know, Charles, your account was so good. I think you should write a book on this. — You mean you mean this book? Look at — the physics answer book. — Wow. Chuck, you wrote that really quick, man. You work you work fast, brother. it was there or it wasn't there until I observed it and all of a sudden there it was. You know, it's amazing. — So, Charles, in that question there's a direct reference to information and information feels kind of intangible when you think about it — because I said in an earlier episode, you know, if I give you two oranges, you have two oranges. But if I give you two newspapers, you don't have twice the information than you would have had on one newspaper. So information is clearly a different thing from what we think of as material reality. — So could you give us like a quick primer

on what a physicist means when information isn't is the topic? — It's kind of hard, but I'll do my best. If you think about information as you're looking at a system with lots and lots of stuff, what is it about the stuff that distinguishes this stuff from other stuff? Okay, in other words, you have a blob of matter in the universe, then you have another blob of matter. What makes this blob different from that blob? It's the information you get from it. Okay? It's not the form. It's not for example the whether it's an atom or whether it's a proton whether it's a neutron but rather whether it's spin up or spin down or whether it is this temperature that. So it's information in the way that we think about it. Yes, but it also requires you to sort of think about it in systems of stuff and not just the things themselves but almost an abstract way of considering material. So material can have information completely courarssing through it and unlike quantum physics if no one's there to measure that information the information is still there. Correct? — Yes. It's kind of like a objective thing that's there no matter what. — But if you don't measure it then you don't know what it is. An example might be a bit. You've heard of the term a bit in a computer right? 16bit chip or something like that. The bit is the information one or zero or on or off. But it doesn't matter whether the bit is an electronic chip or whether it's a quantum bit or whether it's a pair electron posetron or something like that. That information is still the important piece of the input or output that you're getting from that system. Does that make sense? So uh a lot of computation and thinking requires about the information that the physical thing is carrying and not the thing itself. T-Mobile 5G home internet has some big news you should know about. They now have the fastest 5G home internet according to the experts at UCLA speed test. Now in practical terms it means photo backups happen faster. streaming a documentary doesn't stall halfway through. The physics of waiting reduced. What's also notable is that this jump in speed doesn't come with added complexity. Setup is simple. You plug it in and you're online in less than 15 minutes. And the value side of the equation holds up, too, with a plan price that's backed by a 5year price guarantee. So, if you want the fastest 5G home internet with a simple setup and savings that stick, get T-Mobile 5G home internet. Just visit t-mobile. com/home internet to check availability today. Price guarantee exclusions like taxes and fees apply. Fastest based on UCLA speed test intelligence data second half 2025. All rights reserved. If you change the chemistry of something, you haven't lost any information because the information has changed, but yet the thing itself is no longer the thing. For instance, you've set wood on fire. Okay? You end up with a charred remains and smoke and flames. The smoke is part of that information, but it's something else now. The flames are part of that information, but they're something else now. you know, they're the release of energy and heat and then what's left over is what's left over that is no longer a piece of wood. So even though you didn't lose any information, the thing is no longer the thing. So what is the importance of the information then? — Yeah. So I check Chuck I think you just stepped on the big toe of entropy. — Ah okay. Entropy and information are closely linked. — And you just stepped on its toe because a log — has much less entropy than a burned log. — Right. — Okay. And and so Charles, can you walk us through that? — I sort of can walk us through, but it it's long and complicated, right? But you hit your nail in the head that information has a lot to do with something. Okay, Gary, let's say you flip a coin. — Yes. — Okay. And it can be head or tail. Right now, what happens if you flip 10 coins? What are the possible combinations of heads or tails? — Well, one would imagine 50/50 over if you to if you toss them enough times. — That's right. Over if what if you tossed a hundred or a thousand or a million coins almost certainly you would wind up with 50% heads and 50% tails. — Yeah. — But there are actually a lot of

different combinations. In fact, if you flip 10 coins, there are,024 possible combinations. Coin one is head, coin two is tail, coin three is head, coin four is tail, coin five is head, etc., etc. But the number of heads and number of tails at the end of your flipping are many fewer than,024. There's only 11, right? 0 and 10, 1 and 9, 2 and 8, etc. Yeah. Right. So the out of the 1,024 flips that you can do, there's only 11 actual results that come up with the numbers of heads and tails. All of that extra stuff, the other 1,03 rolls are rolled into the entropy of that 10 coin flip. M — in other words, that stuff is the hidden information that will allow you to sort of come up with how often you're going to get five and five, four and six, and so on and so on. So, so entropy is hiding in there. The information you get off the top is hidden by that stuff inside. And then right now what people are doing with quantum computing is really trying to figure out the kinds of entropy, the kinds of disorder that can hide in your systems when you're actually just looking at the top of the system, finding out how many heads and how many tails there are. — Okay. — Is it my turn? — Yes. — Did I do it right? — Wait, wait. — Please correct me if I'm wrong. — No, no. I you No, you said it. What you said is just fine. I just want to make it clear that Chuck was saying something different and I have to point that out. Okay, if you roll 10 coins — and there's some chance that two will be heads and eight will be tails. Okay, that is not the total probabilities that Charles is talking about. Charles is talking about these particular two coins giving you heads and those particular eight coins giving you tails. And if each coin is specific in that enumeration, then you get to the 1024. But if it's just two heads and eight tails and you don't care which two coins are giving you the two tails, that's a different question asked of the 10 coins or of the 100 coins, whatever it is, is all I'm saying there. Yes, Neil is precisely correct. And so the stuff that's hidden, that information underneath, right, that actual specific coin flips and then the actual result information that you want, how many heads, how many tails, that difference could be said to be the entropy of the system that you don't see when you're getting the information out of the flips. — So it depends how close you wish to look as to regards which data you get back. — Yes, — absolutely. This happens when we boil water, for example. When you're trying to turn water from liquid to gas on your stove, what happens is that it stops at 100° C, right? A standard boiling temperature for a period of time. And then the steam that comes off is still 100° C, but it has so much more entropy. It's so many more possible states of the individual atoms moving around compared with the liquid versions. It's not a matter of how far apart they are. It's much freedom they have moving inside of it. — That's right. — And so in order to compensate for that, you have to heat the water up extra. You don't change the temperature, but you're changing the amount of energy inside because of the entropy increase that you have to put in order to turn it into gas. — In other words, the flame that was raising the water temperature gets the water to 100° and it stops raising the temperature. Where does that heat go? — Right. — Where does that heat? It's going somewhere — Into the transformation. Yeah. There you go. — Right. Right. Excellent. — All right. Let's keep going. — All right. Yeah, that was — Keep that coming. — It's freaking good. That's good stuff. Philosophical. We got we Yeah. All right. This is Andrew Martin. Hello, Drs. Tyson and Lou and the right honorable Lord. Nice. Well, thanks, buddy. Uh, I'm right. That's the first time I've ever been right and honorable. — He says, "I'm Andrew from Stanford. " Uh, Stafford. — Yes. — In the English Midlands. — Yes. — Who? We don't know what that means. We don't know. mean. — It's a town in the West Midlands of England. Very pretty. — Oh dear. — Yes. — Well, so good. So good of you to chime in from the staff in the Midlands. — The Shers, I say — it's the Shers. — In the Shire, I say indeed. I believe that's somewhere near — They make good whiskey there. — No. — Well, they may do, but it's not known for whiskey. No. — Right. Is it anywhere near Downtown Abbey? Because

Okay, guys. Okay, here we go. He says, "Anyway, I understand that a stars color is determined by its age and composition. I also know that its velocity relative to our collective selves can redshift its light. How do you resolve between the two? " In other words, how do you know a star is made of something and traveling at a certain velocity isn't really made of something else and traveling at a different velocity. — Man, people think deep about the — superb question and and in fact I will say that is actually a problem for astronomers. Sometimes we don't know whether or not the object's colors are caused by or the red shift of emotion as opposed to the expansion of the universe or the colors intrinsic to the objects themselves. The answer to this quandry is spectroscopy. — It is a technique where we divide the colors into component colors. So instead of just seeing red, you see very red and orang-ish red or orange-ish orang-ish red or orangeish orangish red and so on and so on — until you finally get to the most orange of all. — Okay. Yes. Until you get to that orange. But what happens is that by dividing all these colors up into little bits, the components of that reddishness that you see from a star are broken up into emission lines, absorption lines, and continuum radiation. And the patterns of those different lines and continuum are preserved regardless of whether or not you redshift due to velocity or not. So if something looks red which you thought was blue, you measure the object using spectroscopy and you take a look to see if the patterns absorption and emission lines have been preserved in the red part of the spectrum when you thought it should be in the blue. If they're preserved, then we know it was because of red shift. If they're not preserved, then we think, oh, there's something physical going on in the star that made that color change. — You know what else happens? A star can sit behind an absorptive gas cloud, a cloud with um dust in it, and it could shift a white star, the color that you'd see for a white star into a regime that makes it look red. Big challenge for us. Do we really know what's in our sighteline that could be messing with the star itself? — So, what you're saying is you're looking through this dust cloud. — Yes. — At the star, but you don't know. It's basically you don't know it. It's like a little screen. — You try to understand the dust cloud and sometimes you forget that they're there. And Charles, wasn't there a huge discovery made about the big bang? And because but because they didn't correct for the reening in our own galaxy of the cosmic microwave background, but there was some — Yes. There was some paper that had to be retracted because they not retract they you don't retracted not because it was fraudulent. It was just they had to say we messed up. — They were wrong. — Yeah. — Yes. That's right. — Yeah. Yes. Because the cosmic microwave background as it currently exists today produces the same wavelength of microwave radiation as dust of a certain composition at a certain temperature. Okay. And so that dust turns out to envelop our Milky Way galaxy at different thicknesses or different densities depending on which direction you look. — And so if you were unable to get that signal cleared away — from the cosmic microwave background, that interference will completely mess up your interpretation. — I was going to say it's like the tear function on a on a scale. — Yes. — You know what I'm saying? — Excellent point. That's what it is. — Very good. — Yes. So, so being able to see that, — how do we a make it go away? And if it's not possible, how do we navigate through this sort of natural filter that's there? — Neil, do you want to tell them about extinction curves or do you want me to do it? — No, we got you on here. You're the geek and chief. — All right. — I'm just the geek deputy. — It's a great question, Gary, and it's actually pretty complicated, but I'll try to make it as simple as possible. Essentially, the effect of dust in making things look dimmer and redder is known in astronomy as extinction. Okay? Not the kind where like dinosaurs go away because they're hit by an Earth is

hit by an asteroid, right? But the kind of extinction that says that your light has been extincted or extinguished because of this dust. — What you have to do is a actually understand what dust does. And so there's a whole branch of astrophysics that is done in a laboratory where you make dust that might approximate what interstellar dust is looks like, is made of, what shape, things like that. And then you shine light through it. And then you see what that dust does to the light that you might expect coming from a star or something like that. And then the second thing you do, you just have to measure where dust is throughout your lines of sight from Earth out into deep space. see how much dust and what kind is in that line of sight. And everything you see in that direction has to be corrected for this extinction. And so there's something called an extinction curve. Okay? And every kind of dust has a different extinction curve. So you look in a direction. Say I look at a galaxy that's uh in that direction far away. I first have to ask okay what does the galaxy's light look like from my telescope and the second thing is I have to ask somebody who did measurements of extinction say hey what is the dust capacity density and the dust variety in this line of sight and then that person will say oh that line of sight was measured to have this much extinction and these kinds of gases and dusts and then you go okay and then you make a correction to make your galaxy light what it would have looked like had the dust not been there. — Oh my god, — it's a complicated stuff. — That's insane. — So, the universe is not just sitting there waiting to be discovered. We have to figure this stuff out. — Yeah, — that just sounds awful. — Although it sounds awful in one way. Yes, it makes our ability to understand those distant galaxies that much tougher. It's also a blessing in disguise because it allows us to understand dust in the universe. Okay, — if we want to know what we humans are created out of, literally stardust, stuff that came off of stars, cooked in the hearts of stars, and then spewed out into the universe in the Milky Way galaxy. So, if we want to know where we came from as human beings or as life forms or even as planets, right, we need to understand that dust. So the combination of being forced to be able to compensate for that dust and know what's behind that dust has given us the opportunity to study the dust itself which I think is pretty — That is pretty awesome. But I will also say when you were talking about the discovery of the uh that the paper had to be retracted at first I was just like God man what you know these guys really screwed up. Now I'm like, "Yeah, I'm on their side. " Like, you know, basically the I'm surprised they're able anybody's able to find anything. That's right. Like basically every other week a paper should come back. My bad. It was dust. It was dust, guys. So there's another feature of that. There are I would call them ambulance chasing theorists who saw these results. saw these results and said I can explain that with a new model of the big bang and that there were people who published papers on these false results. — Oh, — so yeah. So that that's a that that's an important reality check on the front the moving frontier we do in science. — Charles, this sounds like an awful lot of manh hours to log chart and then — Oh yes — tabulate all of this information. Surely this is perfect for AI. Yes, people spent entire careers doing these kinds of maps. I'm sure Neil, you'll remember uh Schlaggel did a lot of this. Bruce Dra Some of the giants of our field are remembered for their legacy of making these maps happen. The problem with using an AI to try to make those maps is that you have to have the AI interpret just as uh the question was saying, how do you tell the difference between what dust is causing and what the light is causing from behind it? AI isn't sophisticated enough to tell that difference yet. It just sort of chooses the best option and sticks it in. So there's that human need to be able to disentangle these two effects which uh something like a large language model is still not quite able to do. Uh so AI eventually will be extremely helpful in refining maps — that we had found a long time ago and used optimal methods to figure out what they were. But they won't be able to make maps on their own because they don't have the decision-making capability yet to distinguish between the different things that are causing what we think dust might be causing. — Okay. — Wow. — At least that's my opinion — and you're sticking to it

— for now. — All right. Bring on another. — We ready for the next one? Okay. April Walsh. — Hello, Sir Neil Lord Chuck and Sir Charles. I'm April Walsh. It's Yes. And you're right, April. This is an easy one to pronounce. Uh, my 16-year-old son and I are obsessed with Star Tour. Well done. We absolutely love it and thank you for making it great. My question is, when all of the matter, here we go again. Dust, gas, etc. in the universe was condensed into something smaller than a pin head at the Big Bang, how did that not immediately create a black hole? — Ooh, — interesting. — Wonderful question. — Get out of that one, Charles. Uh it turns out that we don't have to get out of that one because the universe got for us. When the universe was the pinhole sized, it actually wasn't that massive. We think of the big bang or think about the big bang as rolling back the history of the universe and making it smaller and smaller. But at the moment of the big bang, the mass of the universe was well at 10 theus 43 seconds after the big bang, we'll call that the plunk time, the mass of the universe was less than a glass of water. And it's actually not enough to have turned it into a black hole at that time. M — something further happened to inject the universe with so much energy that inflation happened that you probably have heard of where at the nearly the beginning universe you wind up inflating the universe beyond its regular expansion rate by factors of many trillions and then you wind up with all this extra energy in there which then condenses into matter and becomes the galaxies and stars and planets. in black holes that we have today. So there was a period of time early on where black holes didn't even do but where did that energy come from? — Where that energy come from is still 100% unclear. — Oh no. — But there are some guesses. — We know where it came from. Came from Jesus. — That's part of the problem, right? A lot of people do in fact have a problem with that big bang cosmology at that early time because there seems to be no way for us to explain that injection of energy any way other than some sort of divine supernatural activity. But if we were to do that, then we'd just be like, "Oh, okay. We've given up on science. We're not going to try to figure out how it actually works. Let's just go home and have a, you know, drink and forget about it. " So we refuse to sort of give up and just say oh it was something that we'll never be able to understand. It was some divinity or it was some supernatural thing. So if we try to think about nature then the way you can actually inject energy has to do with something called spontaneous symmetry breaking. Neil um have you told uh our distinguished patreons about the fundamental forces in the universe? — Assume no. — Yeah. Okay. Assuming no. Currently, we think that the universe has four forces in it that sort of determine all of the transfer of energy and material and so forth around the universe. There's something called the strong nuclear force, the weak nuclear force, the electromagnetic force, and gravity. Okay. Now, gravity is its own strange beast because there is a hypothesis that gravity's uh as a force actually has more to do with the structure of spaceime than the transfer of little particles back and forth. But electromagnetism, the strong nuclear force and the weak nuclear force are now separate forces. They have different mathematical explanations and they behave differently depending on where they are and what size and scales and so forth are around. It makes sense to hypothesize that right around the time of the big bang there were not four forces but there was only one — and something happened at the quantum level to break forces off from one another and that break is called a spontaneous symmetry break. Okay. So when I was saying spontaneous symmetry breaking uh you can imagine something breaking and from the inside of that break that used to be symmetric this one beautiful force that followed all of its math now is two or now is three or now is four and the resulting chaos. It's almost like unleashing to some extent that entropy we were talking about when we're trying to boil water. But now we're unleashing just straight up energy in such huge densities, in such huge amounts that it would propel the universe to grow at such a rate and such

a speed that we pass the black hole thresholds and then you have to start all over again and turn that energy into matter and then make black holes thousands or even millions of years later. — Wow, that's pretty wild. Okay. So, how do you feel about I we didn't have her on the show, but we were supposed to. Uh I believe her name is Sabine Hoffen something. She's uh — something. — It is. I mean, I don't know. Uh but you guys know who I'm talking about. Hassenfelder. Okay. — Yeah. Mhm. Now, she says that anything anyone who tries to surmise what happened at the Big Bang is only telling a story because we don't have and we never will have data that will allow us to make a conclusion. How do you feel about that? Hm. Oh, that's a great um philosophical point of view. I would answer all of physics, all of astronomy is trying to tell a story, — right? The hypothesis of every explanation as to why something happens in our universe is a story. The difference between a story that is non-scientific and scientific is that the scientific story seeks to find ways to confirm or refute that story. And so we're always pushing in that direction. If you could tell a story that can be falsified but can be shown to be untrue based on observations or experiments or something like that then you are trying to do science. We have forever thought that oh we would never be able to see like the origins of our earth and yet here we are able to understand planets because we kept asking questions and finding ways to look further and further back in history. We used to think we could never understand how our solar system was formed. It must have been supernatural. Must have been divine. But no, now we know because we looked and we found ways to find a hypothesis that we could test. Now we're going further and further back. How can we find the formation of galaxies? birth of black holes? And now to the point of the big bang itself. The recent results from the DESI group, dark energy survey group are remarkable. They are looking at echoes of the imprints of matter and energy in the large scale structure of our current universe that were put in there very close to the big bang before even the cosmic microwave background was established. We're talking about like ripples in a pond that have been imprinted in the galaxy distributions of our universe for the past 13 and almost 14 billion years. And we're seeing that imprint, which itself is long past the beginning of the universe, but maybe that's fossilized information that could tell us about things like the Big Bang, which we just can't see anymore. — Damn. — So, it's a philosophical point. That's what science is so cool about. — And you have to watch out to presume that just because we have ideas about something that it'll never be tested. Uh there was one of the more boneheaded predictions made by a philosopher early 19th century was oh we I love this I'm paraphrasing I love this field astronomy uh we can know where the stars are we can know what colors they are but we will never know what they're made of — that is forever beyond our reach and he's presuming to know what something's made of you have to go there and sample in a lab this is like 10 minutes before spectra as applied to astronomy was invented and with spectra as Charles said earlier you can find out what the what are the chemical components of stars as one of the great triumphs of 19th and 20th century modern astrophysics but the fact that we didn't know and someone got clever and figured out how to know uh we are never stopped on the frontier just because we don't know how to do something yet that but that we'd still be in the caves if that's how we functioned as scientists. — Yeah. And that's why I always tell everybody that the questions are more important than the answers because we can't get all the answers now. But if we ask the right questions, someday we will be able to answer them. — The German poet Rea Maria Rilki — uh in his book Letters to a Young Poet. I hope I don't mangle this too badly. The one of the poems ends be patient with all that stirs within your heart. Learn to love the questions themselves.

— See, that's what I tell my wife when she's like, "Where where were you last night? " I'm like, "Sweetie, — you need to learn to love your questions. " — The answers are not really the whole issue here. — How'd that work for you? — Not probably, but you know. — Yeah. Yeah. So what we're dealing with here is known unknowns rather than known unknowables. So to try and get ourselves into the position where we do know different thinking again because we've used our own thinking that we've brought historically. So I mean it's not quite the change of angle of approach but a different way of thinking about the same conundrum subject. — Yes. How do we go about altering our thinking as to provide us with an answer for this? — Well, the history of science is not um linear nor is it continuous, right? What we found over the centuries uh is that people ask a question and they can't answer it and then you wait a sometimes a really long time. — Mhm. And then somebody just goes, "Hey, how about this? " And then someone goes, "Wow, that's neat. " Most people go, "Well, that's crazy. We can't ever figure that out. " And then somebody else says, "You know what? We probably could. " I'm thinking, of course, of general relativity, right? You know, you know that famous story. Uh people are trying to figure out gravity forever and how the speed, how light travels through the universe. And then over about a 15-year period, Albert Einstein first devises the special theory of relativity and then the general theory of relativity. And people like, "Oh, space bends and curves. That's very interesting, Albert, but how are we ever going to figure that out? " And a guy named Arthur Edington says, "I know how we can figure this out. " And organizes an expedition to see a total solar eclipse and take photographs. And sure enough, he was able to measure with his colleagues that very amount of curvature in spaceime that Einstein had predicted. And so people had been thinking about gravity ever since Newton's time. And then within that short 1015ear period, boom, we figured it out. But then we had to wait another long period of time to the next thing and the next thing. — Just to clarify, it's the eclipse itself is not what Eddington looked at. He needed the eclipse to darken the sky. — Yeah. — To see starlight from far away in the universe, — its path moving to the side of the sun. The sun is the most massive thing we have available to us. So if gravity is going to distort the fabric of space and time, the sun is our best chance at this. So he waits for — Neil. — Yeah. And then the starlight comes across very near the edge of the sun. He measures where it is on a very with great accuracy. Then waits six months till the sun is on the other side of the sky. Goes back to that same area and measures where the stars are on his frame. And they were had all moved in the presence of the sun having their path lengths go by the limb of the sun relative to 6 months ago. So that whole project took 6 months to confirm. And there was an eclipse in 1918 that he really wanted to use, but the world was still at war, of course. — And so that was a lost opportunity. It had It was delayed until 2019. Sorry. Delayed until 1919. — 1919, — right? Uh no. Yeah. You're completely right, Neil, in what you've said. I the key there uh Gary to sort of circle back to your point wasn't the eclipse but it was to use the eclipse as a way to measure the curvature — right — of space and time and thus the motions that are different — and then going back in 6 months you've got a constant because the stars will be the constant and you're working direct yeah I get that's fine thank you for — so when he looked at this the light from behind the sun — then the movement was meant that the light had to bend in order for him to see it the way he saw it. — Correct. Gotcha. That's it. — And the only thing that could have done that would have been the actual mass of the sun. The because the sun is so massive. — And the way to affirm that is wait 6 months. Now the sun is on the other side of the sun. Go back. Well, that's first of all I Jesus Christ. — No, this is smart people. These are smart people. I mean, HERE'S WHAT'S BUT IT'S SO SIMPLE, BUT IT'S SO BRILLIANT. — I FEEL SO DUMB. WHY WAS THAT BOY SO

DUMB? — NO, CHUCK, I feel like that all the time. It really is amazing how smart all of our predecessors have been. Yeah. — And we live in a time where people say, "I'm just scientists. What a scientist. " No, I'm going to look at my YouTube video and I'll figure it out. you know what do you think we do? That's all we do and try to figure stuff out. — So Charles, that information was always there. — It didn't just appear because Edington showed up with some calipers and measuring stuff. So it's looking at things and thinking what information is here that we are not thinking or seeing or identifying. Gary, one of the prevailing and persistent definitions of genius is the person who sees what everyone else sees but thinks the way no one else has thought. — Wow. — Yeah. — Oh, that's pretty cool. Eloquent. — It's not just looking, it's seeing. — Okay. — I'm not a look see guy, you know. To me, they're the same thing, but that's fine. — Oh, no. You can look at things but you won't see what is really there. — No, but that's like saying uh you heard me but were you listening to me? You know I mean I'm not a heard listen see. I'm not that guy. All right. — Don't come to me for that. — No, I'm not. — Okay. — I'm just you know as this discussion opens up it makes me think is that is the information we need there? We just don't quite know how to extract it right now. — In many cases yes. One of my colleagues right now is doing an amazing uh kind of theoretical work about uh quantum information. — Uh when you're trying to send information uh through say fiber optics or something like that — uh you lose information because there's noise in the system. Oh, — but this guy is like saying, "You know what? I can take that noise and learn, find information in there that we thought was lost and thus make my quantum communications that much better. " And it's amazing. It's like thinking about dust in the solar system and the galaxy blocking our view of things we want to see, but then turning around and saying, "You know what? That dust itself has information. I wonder what we can learn from that. It's that kind of thing that happens on every scale. — We're not talking about acoustic noise. We're talking about light noise. We have a light signal going through fiber optics. And so noise is a in a physics is a general term for randomness of of a signal that would interfere with your target signal. It's not just acoustic. It can be — interference background static all that stuff. Imagine if you could figure out stuff from that. you know, that just changes your whole dynamic of what you're trying to be able to transfer. — The original discovery of the cosmic microwave background using horn advertises in New Jersey. — Uh they said, you know, they're working for AT&T Bell Labs and AT&T said, "Let's find out what the noise is in the background so that when we send signals through the air, we will be able to understand that noise and possibly correct for it. " Okay. So, they open up their antennas and they get they look in every direction and there was this residual noise everywhere they looked and they said, "Okay, we're going to have to report this, but wait a minute. Let's look inside the antenna. " They looked inside the antenna. There was pigeon dung in the antenna. It's reported as a dialectric substance in the original research paper — which actually can be responsible for a noise level. So they cleaned out the pigeon poop in this antenna. And then they looked back and it dropped the noise level, but it didn't take it to zero. — And so they reported excess noise every direction in the universe. And that was the cosmic microwave background. Nobel Prize winning discovery after they removed the pigeon poop. — Yeah. Now, first of all, the pigeon should have got the Nobel Prize. — Got an assist should have got an assist. — Okay. Innoc brought the pigeon to Stockholm. — Here is the dialectric substance that helped us find the cosmic microwave background. — All right, picture this. You're shopping online when all of a sudden you see that one product that you've been looking for. So, you add it to your cart. As you're filling in your address, you realize you don't have your card anywhere near you. And just when you're about to give up, you see that purple pay button. One tap, boom, you're checked out in seconds. As someone who comes from a family of entrepreneurs, and as a guy whose entire career basically runs on the small business

hustle, I appreciate anything that makes it easier for people to actually finish the purchase. Shopify's Shop Pay button is used by millions of businesses around the world and it's why Shopify has the best converting checkout on the planet. It also helps boost conversions, meaning less carts go abandoned and more sales for you. Shopify is the commerce platform behind millions of businesses around the world and 10% of all e-commerce in the US from household names like Hines and Mattel to brands just getting started. See less carts go abandoned and more sales with Shopify and their Shopay button. Sign up for your $1 per month trial today at Go to shopify. com/startalk. Once again, shopifi. com/startalk. — Okay, let's see if we can fit in some more questions here. We've been very luxurious with our answers. You think we can like speed up? This is Carrie Manberg. It says Dr. Tyson, Dr. Lou, Chuck, Carrie from Kalamazoo here. — With observatories like Web and Ver Rubin already pushing the limits of what's technologically possible, what scientific and engineering breakthroughs do you think the next generation of telescopes will demand? And what new discoveries might those future inventions unlock? — That's not going to be a quick answer. Can we just pick like one thing? Uh, — go pick one. I'll pick one and we'll call that. — Just pick one breakthrough. I mean, — all right. But that's a tremendous question. Wonderful. Okay. The one breakthrough I think is going to be amazing is the ability to fly spaceships in formation. When you fly spacecraft that are basically going in lock step with one another, not deviating by even a millimeter over thousands or millions of miles of travel, then you can use something called laser interferometry and shine and position uh the light and the detectors in such a way that we can find gravitational waves from space uh at a level that's hundreds or thousands of times greater than we can on the ground. — So you're saying that these spaceships become an array. Is that what you're talking about? — Okay. — That's exactly what I'm talking about. And so that technological development, it's just the one that I'm going to mention this time around. But that will change the number of detections we have of gravitational wave events, colliding black holes usually, by a factor of a hundred or even a thousand. And that's going to be able to let us map the universe like a well struck gong. I think it's just amazing. — Wow. — That's good. And I'm looking forward to more telescopes that operate uh that are sensitive to things other than light because we've got the whole spectrum mapped out. All right. We've got and gravitational waves is another version of telescopes that operate outside of light. It's using gravitational waves. But there I'm looking for nutrino telescopes. There might be some other particles that dark matter telescopes. Things that will see the universe in whole not just different windows but whole other buildings in another windows in another building for what is otherwise is going out on out there in the universe. And this could be a new frontier opens up much the same way when we discover there's more than just visible light coming to us in the universe. Let's build a telescope to see in it. Oh my gosh. All right. Our eyes are so feeble compared to what the universe is trying to tell us. And right now we got the visual. We got the whole light spectrum figured out. It's time for new frontiers in cosmic discovery. — In NASA speak, we call that uh multi- messenger astronomy. — Oh, — where the messenger is not just light waves or electromagnetic radiation of any kind. — Didn't know they had a term for it. Particles and exotic things. Yeah. Multime messenger astronomy. Watch. Very cool. — Oh, and by the way, Galileo's famous book from6009 where he reported on his telescope observations of the universe, something no one had done before. The title of that book is Cidius Nunius, translated from the Latin Starry Messenger. The stars were the messengers. — Okay. — All right. Go for it. Next one. We did that in like four minutes. — Okay. Right. Yoges a joke. Uh hello Dr. Tyson Louu and Lord Nice your guest from India. The handy quantum physics answer book actually created a lot of questions in my mind than it answers — wait which book now again did you which book did this guest ask about? — I'll say it slower. The handy quantum physics answer book and is what's handy about it? — Oh you mean this handy quantum

physics answer book? — That one. Listen everybody, I I'm sorry that was a pretty self- serving, but I'm really proud of the book. I It really is a great opportunity. — So are we. We are proud of the book for — And you. — Oh, you're so kind. Thank you. Okay, please continue. — Does the Sean Ho effects imply that the universal speed limit is an environmental variable rather than a fundamental constant? If so, could an advanced civilization pump the vacuum to create local bubbles of infinite causality? And would this effectively turn the universe into a lossless energy distribution network? Answer is all yours. — Amazing. — Charles, you take this one. Charles, you — Amazing. — I haven't heard about the Charhurst effect being asked in a very long time. a scientist named Shanhurst uh I think it was around 1990 or so uh hypothesized that if you took um two perfectly smooth metal plates and brought them within a millimeter or a millionth of a millimeter within one another. You would create a zones because of the quantum fluctuations of the universe — where the index of refraction was less than one. What it means practically means is that in those tiny zones that are only a fraction of an inch across the speed of light could actually exceed in vacuum. Okay, this would be a hypothetical. There's been no way to be able to test it and the effect is tiny. All right. So, it would be 1 trillionth of a percent faster than the speed of light in vacuum across this zone which was less than a millionth of an inch across. Um, so it's this really neat effect that if we could test it, it would be neat to find. Unfortunately, we cannot create at least as far as we know uh if the Shanhorst effect is true these kinds of uh pumped spaces that our questioner is asking because the causality and the speed of light and the stuff like that at those micro levels cannot translate into a macrolevel thing like being able to draw energy from nothing. Okay. Now that said, uh, and I'll just stop with the technical mumbo jumbo in one sentence, the concept of zero point energy, which is what the Shanhor effect is talking about, uh, is still highly uncertain. We would love to find out more about it, and maybe someday we could in fact tap it to get something cool out of it for our use. Charles, is this related at all to the Casemir effect? We have two parallel plates with an evacuated space in between, but this has taken it up another level. Is that — correct? That's exactly we have a cosmological phenomenon inside. — That's right. — Quantum cosmological phenomenon rather than just a sort of a laboratory thing. I mean, is that — Yes, that's right. The Casemir effect is exactly what we're talking about here. Uh, Casemir, everyone, uh, in case you don't know, C A S I M I R. — That's okay. The scientist Dr. Casemir uh hypothesized it exists and it was in fact measured to exist that if you bring two plates of metal really close together you actually wind up with energy that sort of magically but not magically scientifically because of quantum physics — appears when you didn't think there was anything there right and so this is taking it to the next level the Shan horse effect would be like — and the two plates are attracted to each other by forces that are not gravity or electromagnetic It's a quantum. It's a — Quantum attraction. — Quantum. — That's insane. I love it. — Yeah. — All right. Next one. Let's get one more in here. Great question. Chuck or Gary. — All right. Here we go. This is Narav Shaw who says, "Hello, Astro gentleman. " Narav Shaw from Arizona. My question is, "Can you point me towards some resources where I can learn more about the universe theoretically and practically? As an ardent receiver of starlight, knowledge from star talk, I often paint an incoherent picture of the universe. I want to learn more so I can ask better questions. Well, I got I got a book for you, man. It's uh — it's called the uh quantum the handy. — No, it sounds like — Okay. It sounds like he's not in a hurry. So, my book, Astrophysics for People in a Hurry, that's not for him because he sounds like he's got time on his hands. Charles, how many pages is your book? — Uh, jeez, I don't know. Let's see. Uh

— it look pretty fat. — Everybody, just so you know. Yeah. Yeah. It's — 458 pages. Yeah. — Yeah. Okay. — That's a commitment. — Yeah. Uh, But not really because you got to understand Chuck's book is broken up so that it's almost like a resource. You don't have to read it straight through. Yeah. — You know, you can read about the scientists of quantum physics in some parts. You can read like from the beginning which is very good. The very beginning of the book is great for just like what is a particle? What is quantum? what like so you know even though it's like almost 500 pages don't look at it like it's oh 500 pages you know it's it's broken up in ways that you can digest it in chunks so it's really — resource is a good word for it — it's a resource — yeah you're very kind to say that yeah and then your description is exactly right Chuck I wrote that book specifically to say hey you could take it in whatever size pieces you want and whatever level you want to go at it — Chuck was not being kind. He was being factual. Don't confuse the two. If you if your book sucked and he said you wrote a nice book, then he's being kind. — You're very kind. Thank you very much. No, I would say if you want to go deeper into the mathematics, right, because the handy quantum physics answer book and many of the other books that about these topics are usually talking about deep concepts and ideas, but those ideas arose from the mathematical and the scientific depths of really trying to wrestle with the equations that described how the universe works or the calculations or the measurements that would give us a clue about how the universe works. So if you want I'll just mention this there is a group called open stacks uh s t a x and it is free for anyone who wishes. It's basically a set of textbooks. These are textbooks that are legitimately for people who want to learn or to major in something or to do, but it's free on the internet. And I encourage anybody who wants to look at some of those things to see like get a little taste of what an actual textbook looks like and see if you want to go deeper into it. drink deeply of that styian spring or if you would rather just have a little knowledge which of course as Alexander Pope says is a dangerous thing. — Mhm. — And always remember a mind is a terrible thing. — That it to waste or otherwise. — Yeah, that's right. That's the bad part. Sorry. Terrible. — Yeah, there's a lot of good stuff now. I encourage everyone to take a look. — All right, — I think that's all the time we have. Well, Deac and Chief, we love you, but our fans love you even more. — Uh I am I'm very happy to uh be with you guys always. Uh Gary, Chuck, Neil, um it's so much fun for me and I really appreciate. — Glad you do, — Chuck. Good to have you, man. — Always a pleasure. — All right, Gary. — Thank you, Neil. And thank you, Charles. Star Talk special edition cosmic queries and it's been a geek and chief grab bag. All right guys, good to have you. Neil deGrasse Tyson as always bidding you to keep looking up.