Michio Kaku - How Big Can the Cosmos Get?

michio 100 125 years ago best scientists thought that the entirety of the universe maybe a couple thousand three thousand light years and then every decade it seemed in the 20th century the universe got bigger and bigger and bigger because it wasn't the universe getting bigger was always that way is our understanding how can we begin to get our hands around how big the universe really is well sometimes I get asked the question is there a wall out there that says the end the end of the universe do not pass this point well if there is a wall that what lies on the other side of the wall and is the universe infinite until you hit a second wall I like to answer it in the following way look at Columbus Columbus was asked a question where is the end of the world is there a wall out there such that you fall off a waterfall and that's the end of the world well Columbus may have said the following that in two dimensions as far as you can see the universe seems to be infinite you can go in a straight line and you never reach a wall it you just go round and around the earth says Columbus but in three dimensions in three dimensions looking out from outer space you see that it's nothing but the earth that the earth is finite in three dimensions so in two dimensions the earth does appear to be infinite you know you can go round and around and around but in three dimensions the universe is dust of all so today we think that perhaps our universe may be three dimensional you go in a straight line and you never hit a brick wall but perhaps just perhaps you come back to where you started from if I had a telescope perhaps the farthest object you can see is the back of your head because perhaps light went all the way around the universe and you can see the back of your head with a telescope but the universe from the fourth dimension maybe of all just like Columbus said for the earth now that we don't know for sure okay what is what looking that would be a finite closed universe but it's possible it could be open and infinite I mean that there are other possibilities so if the universe was a sphere of some sort a bubble it would be infinite in three dimensions you fire an arrow the arrow comes back and eventually comes back this way or but the universe is finite in four dimensions it is nothing but a ball called a hyper sphere that's one possibility or it could really be perhaps infinite in all directions we don't know for sure the best evidence we have today shows that the universe seems to be flat we can't detect with our instruments of curvature but that could mean that our ball our bubble is just very very big and we're just like bugs bugs on a piece of a bubble and all we can see just like with Columbus all we can see - the horizon is flat well let's now deal with what we know for sure we can look back with our telescopes and see approximately 14 billion light years the years ago we're reflecting the speed of light over this period of time so we we know we can't see beyond that so it seems not to make sense that just because we can see beyond that because light didn't have a chance to even going as fast as it does at 300 thousand kilometres per second even going that fast over 14 billion years that's as far as light could have been so that it would be highly unlikely to think well that's the end just because I can't see beyond it so we physicists now have a candidate which takes us before the Big Bang itself the Big Bang is called a singularity where gravity becomes infinite now that's silly I mean how can gravity be infinite singularity is nothing but a term to hide our ignorance it's basically a statement that I am clueless physics does not give you infinite things nothing is infinite in that sense like infinite gravity therefore a string theory we think takes you before the Big Bang to the pre Big Bang era and that's where all the action is today many of my colleagues are proposing different kinds of pre Big Bang scenarios and we hope to test them with our next generation of space satellites now what the implications of that would be is if there is pre Big Bang which means we're not the first which means there's other stuff other space-time other things out there beyond that which we can see number one number two is because of the inflationary theory of the of the of the creation of this particular universe that itself may lead to multiple universes so we now seem to have good physics to be able to to to say that there are different ways we can have other kinds of existences other universes beyond ours there are several ways you can address that one is the Bible which talks about the universe being created from the mist in other words a universe from nothing now that actually has a certain amount of Appeal that there are bubble simply popped into existence as a quantum fluctuation of nothing if you take a look at our universe for example it has no spin it's quite remarkable you add up all the spins of the galaxies they sum to 0 maybe that's because we came from nothing nothing has no spin and when the universe popped into existence of course all the spins have to cancel to zero because we came from nothing also electric charges and negative charges positive and negative cancel each other exactly why is it that positive charges are immediately canceled by a negative charge if there was a slight imbalance in charge our bodies would be ripped apart we'd be thrown into outer space overcoming gravity that's how powerful this balance between positive and negative charges are why is that because maybe the universe came from nothing nothing also has zero net charge and maybe that's why we came from there also matter antimatter there's almost an exact cancellation between matter and antimatter so there's a lot going for the idea that the universe popped into existence out of nothing but there's the other possibility perhaps we are a baby universe that we have an umbilical cord connecting us to our parent universe when we have our satellites in out of space in the next decade we will have snapshots of the infant universe baby pictures of the infant universe we will have baby pictures when the baby was coming out of the womb and perhaps we'll have evidence of an umbilical cord an umbilical cord connecting our baby universe to a parent universe in the same way that a soap bubble can give rise to baby soap bubbles perhaps our universe came from a parent universe if we find that what are the implications of that in terms of the extent of all reality all that is it means that we have to have a physics that goes beyond just our universe our universe is governed by something called the standard model which seems to fit the particle data and relativity but if we came from another parent universe we have to have a physics that even goes beyond the standard model beyond the quantum I mean beyond relativity and that could be string theory so that is a metaphysics of physics beyond physics each soap bubble has its own physics but there is a metaphysics that that glues everything together this also by the way answers a philosophical question that st. Thomas Aquinas asked many many many centuries ago he said is God a prisoner of time does God have to say oh my god I'm late I'm late I have to be on the other side of the galaxy right now is he a prisoner of time like us or is the outside of time st. Thomas Aquinas said God has to be outside of time but that seems so bizarre so strange it never went anywhere until now because if we have a soap bath a bubble bath of universes each universe has its own clock so if we look at the bubble bath where are you standing where are you standing looking at each bubble which has its own clock you are outside time and that's exactly what st. Thomas Aquinas said that we have to be outside time

Channel: Closer To Truth

Views: 117,444

Rating: 4.8748465 out of 5

Keywords: Michio Kaku (Academic), Cosmos, Universe, did the universe design itself, how vast is the universe, nature of physical laws, quantum mechanics questions, structure of the universe, what exists, theoretical physics, how big can the cosmos get, how big will the universe get, City College of New York, Physics of the Future, futurism, michio kaku, michio kaku string theory, Closer to Truth, life's big questions, pbs science show, robert lawrence kuhn, multiverse, multiple universes

Id: S_Vu8a0MLaQ

Length: 8min 34sec (514 seconds)

Published: Sun Aug 24 2014