Neil deGrasse Tyson - Mind-Blowing Facts About The Universe- Top Speech

in universe we are told and I have to believe it that everywhere is as it were the same as everywhere else there's no one place which is the edge of the universe how can that be well Richard first of all you said you're told it so you have to believe it I will never require you to believe anything good thing is right it will only ever be it will only ever be about how compelling is the evidence to you we look around the universe and it looks like we're in the center what an ego supporting concept that is you can either go around continuing to think that feeling good about yourself or study the problem and learn that in an expanding universe where the speed of light is finite at 186,000 miles per second forgive me using miles per second for thumb I'll see you do your you got that on tape an Oxford professor it's true nobody talks about kilometres in Britain oh good all right so we have the good we share not only most of our language we shared miles still and inchworms what do they call them they're not centimeter worms right there he doesn't have that sort of stuff in Britain that's Europe [Laughter] because Britain is not Europe as we're constantly reminded that's right here we have the English breakfast and the continental breakfast they're very different breakfasts that you can order here so this horizon problem is actually quite simple and rather than explain the full up nature of it let me just give a simple example that is entirely analogous when you're a ship at sea and you look out your horizon in every direction is the same distance from you depends on your height above the sea level that's why ship decks are high they see farther beyond the curvature of the earth than you do just standing on the on the main deck so your horizon is a perfect circle centered on you you can conclude that is the extent of the entire earth or you can imagine suppose I'm in another spot well that horizon is still true for whoever happens to be in the middle of it but now you've moved to a new place and you will see a horizon corresponding with that spot and so everybody has a horizon at sea yet no one at any time is thinking that that's the full extent of the ocean or the full extent of the earth we have a horizon in the universe so does the andromeda galaxy the galaxies with names that look like phone numbers we've got if you travel to those galaxies they will see the edge of the universe now in three dimensions in every direction at the same distance from them just as we see for ourselves that does it for me provided that the horizon is that which we are capable of seeing I could have I could follow that if you said that from for any part of the universe the horizon is the bit before the expanding universe has disappeared over the horizon it is no longer visible yes but it's still there even though we can't detect it it's true with the ocean when you're at sea yeah but is anybody on my side it's you want it to be a harder problem than it is I'm just simply saying so here you go here you go the the radius to that to our horizon is about 14 billion light years Gus it okay if we sat here or return to this spot a billion years from now that horizon will be 15 billion light years away yeah it's actually in expanding horizon because the light from 15 billion years light-years away will have had time to reach us right now it's still on route yeah I have no problem with that but but beyond the 14 billion year the problem is the universe wasn't born yet yeah okay that's the prob okay so so you can't see the universe before it existed so why doesn't somebody invent the kind of telescope okay I'm getting out of my depth here let's let's get back to no just to clarify you can just to clarify so it takes light time to reach us and the universe hasn't been here forever when you combine those two facts you get an edge of the universe and so the universe has been here for 14 billion years the farthest thing that could send us any information is 14 billion light years away I get that but what about the guys who are on the edge of what we can see what of how can they see beyond the other side Oh because here's here's an interesting point you don't know whether or not the entire universe is infinite and our horizon is the universe could be twice our horizon or infinitely larger than our horizon same with the ocean you don't know how much bigger the ocean is then your horizon is you can keep sort of wandering around maybe you'll hit land as we've done of course so now you go there if the universe is really really big that will be the center of their own horizon and whatever is the age of the universe is for them at that time that will be the radius to their horizon okay let's look at the cosmic abundance of elements in the universe the number one element is hydrogen next helium next oxygen this is in order of abundance next carbon next nitrogen next perhaps the most important element of them all you see it the most lists other yes there we go now what about life on Earth let's see what's the number one element then life on Earth hydrogen well how does that happen well because as we know at least you know human life you learn in biology classes mostly water then what is h2o h2o there's H two H's hydrogen okay how about next not helium why not helium well because helium is Noble we learned that earlier this evening didn't we so human is not in us you could inhale it you sound like Mickey Mouse but it won't interact with us so even if it were available to us there's nothing you would do with it so it's in the universe but not in life because it's not chemically active that's next oxygen next carbon next nitrogen next together life on Earth is one for one in sequence made of the most common ingredients in the universe than we are chemically based on carbon your carbon-based life it turns out the carbon is then a federal element there is you can make more kinds of molecules using carbon than all other kinds of molecules combined so whatever chemical experiments are going on on the surfaces of planets across the galaxy if we find life any time soon or ever the chances are good that it's going to have carbon as its base as its chemical base and you combine all these elements and all kinds of interesting ways [Music] science fiction stories like talking about silicon-based life silicon sits directly below carbon on the periodic table which means they bind similarly to the same other atoms how does carbon is five times as abundant as silicon you don't need silicon to make this work carbon is there for you what do you think are the odds that there is life elsewhere you know they must be high and I'll tell you why people say what have you found life yet no well there you know that's like going to the ocean this has been said before taking a cup of water scooping up and say there are no whales in the ocean you know here's my data you know you you need a slightly bigger sample and so if you look at for example what we call the radio bubble this is the sphere around Earth centered on earth which is the farthest our radio signals have reached in the galaxy and they're about 70 light-years away we've been transmitting radio signals being advertently leaking into space for about 70 years 70 light year radius sphere well how big is the galaxy well shrink that sphere down to maybe the size of a BB and then the galaxies on that scale would be the size of this stage that's how far our radio signals have traveled and those aren't even the ones we sent on purpose the ones we sent on purpose have traveled much less so no we haven't actually reached as far into the galaxy as we'd like before we would say definitively that there's no one intelligent living today but here's some very simple facts I can review them in 90 seconds you look at the formation of the earth and the earliest sign of fossil life subtract a few hundred million years at the beginning of Earth when earth was a shooting gallery earth was still accreting the the birth materials of a solar system it's hostile to complex chemistry over that time not fair to start the clock then wait a couple hundred million years now start the clock and wait around and see when you have the first signs of single-celled life at most four hundred million years at most Earth has been around for four and a half billion so earth without any help from us with basic ingredients found throughout the unit managed to create life simple though it was so an earth one of you know eight planets get over it what one of sorry [Applause] earth was an ordinary star to suggest and and what are the ingredients of life the number one atom in your body is hydrogen number two atom is oxygen together making mostly water that's in you next is carbon in this order next is nitrogen next is other stuff my favorite element other yeah you look at the universe the number one element to the universe is hydrogen next is helium chemically inert couldn't do anything with it anyway next is carbon I'd let thing I let that oxygen there next is oxygen next is nitrogen one-for-one we're not even made of odd things the most common things in the universe are found here on earth and we're made of them and carbon one of the most chemically furred the most chemically fertile element on the periodic table it's not a surprise we're carbon-based life is just the extreme expression of complex chemistry so that's what life that's what biology is so all these people who want to imagine imagine because they remembered the chemistry class that that silicon sits right below carbon on the periodic table so it bonds similarly to carbons so they want to imagine silicon-based life I'm saying okay fine but you don't have to this five times as much carbon in the universe as silicon there's no need to even have to go there we got enough to imagine just simply with the carbon atom at the center of these of these huge biological molecules point is it happened relatively quickly with the most common ingredients in the universe - now say life on Earth is unique in the universe would be inexcusably egocentric yeah I agree with that [Laughter] and I would go further and say that if ever you meet somebody who wishes to claim that he believes so she believes that life is unique in the universe then it would follow from that belief that the origin of life on this planet would have to be a quite stupefyingly rare and improbable event and that would have the rather odd consequence that when chemists try to work out theories models of the origin of life they what they should be looking for is a stupendously improbable theory an implausible theory if there was a plausible theory of the origin of life remember yeah that's right because because it would happen because then life would have to be everywhere everywhere so you're worried that you will die before aliens come visit you okay there are hallucinogenic drugs that can solve that problem and your brain won't know the difference so if you so here's here's the thing if you want to communicate with intelligent aliens across the gaps of space you would use things that move at the speed of light radio waves have good sort of penetration properties of interstellar gas clouds and this sort of thing all right so now let's find a planet and send a radio signal well that radio signals gonna have to arrive there at a time where they have not only intelligence but technology suppose some other civilization was sending us radio waves and it arrived 200 years ago presumably we would have counted ourselves among the ranks of intelligent creatures in the universe at that time but we would have had no capacity to receive radio waves because radio waves weren't discovered yet and so in fact if you want to communicate with a civilization it has to be right in the slice of time where they where the life on that planet achieved until complexity and intelligence and technology and maybe technology is not a forever thing maybe technology escalates to the point where so dangerous that they render themselves extinct so perhaps there's only a narrow window over which you could actually have a radio wave conversation with aliens so I think the only hope really is that we get visited by highly intelligent aliens that figured out a way to cross the gaps of space-time but thereby not being limited by the the speed of light as a speed limit of the universe as we say something like it's not just a good idea it's the law but if you warp space-time you can cheat that as they do in Star Trek with their warp drives and things so if they would visit us now here's now you were depressed before you don't know depression until what I'm about to tell you so now imagine if they visit us in a spacecraft what are we doing that we in the United States we don't even have a spacecraft to launch our own astronauts we're hitching a ride with them we're buying seats on the Russia for tens of millions of dollars okay and what will that do it will go into low-earth orbit where we will boldly go where hundreds have gone before all right that is the state of human space exploration at this moment now aliens come from the gaps of space and they land okay I have two hypotheses three one of them is they have already landed but they accidentally arrived during comic-con and no one could distinguish them from any other costumes that were being worn and then they left because no one cared that they came so that's it's a remotely a remote possibility but I'm allowing that and the probability of this all right so another possibility is that they took a good look at us and concluded there's no sign of intelligent life on earth not worthy of their attention a third possibility there may be more but these are the three that I carry with me is that they are so much smarter than we are by the way what would that take not much what's the next closest animal to humans in intelligence chimpanzees chips and what's the DNA difference 2% tops yet what's the update what's the most they can do they can stack boxes and reach a banana okay maybe they'll put up an umbrella rudimentary sign language maybe our toddlers do that our toddlers so here's a only a 2% difference in DNA and the chimp is stacking boxes but we have poetry and music and the Hubble telescope so our hubris ends up saying what a difference that 2% makes what a difference that makes maybe that difference is just as small as the 2% maybe the difference between the Hubble telescope and stacking boxes is as small as the 2% indicates because now consider some other species 2% beyond us just as we are 2% beyond the chimp what would we look like to them they would roll the smartest human foot Stephen Hawking roll them forward and say this one is slightly smarter than the rest because he can do astrophysics calculations in his head like little Timmy over here who just came back from preschool alien Timmy oh look you just compose your 12th sonnet that's beautiful well you just read derive the fundamental principles of calculus they've put it on the refrigerator door yes that's what their toddlers would be doing because our toddlers do what the smartest chimps do if aliens came and they had only that much more intelligence than us the gap that is between us and chimps and we have DNA in common if they were only that they could enslave the entire earth and we wouldn't even know it maybe that has already happened and we are living our lives as though we are expressing the free will of the human species yet we are nothing more than an ant farm on their shelf so we are their ant

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Keywords: neil degrasse tyson, science, astrophysics, Mind-Blowing, Mind-Blowing Facts About The Universe, sciencetoday, cosmos

Id: PuCuw3c6ga4

Length: 19min 58sec (1198 seconds)

Published: Wed Apr 11 2018