Every cosmologist and astronomer agrees: our Universe is 13.7 billion years old. Using cutting-edge technology, scientists are now able to take a snapshot of the Universe a mere heartbeat after its birth. Armed with hypersensitive satellites, astronomers look back in time to the very moment of creation, when all the matter in the Universe exploded into existence. It is here that we uncover an unsolved mystery as old as time itself - if the Universe was born, where did it come from? Meet the leading scientists who have now discovered what they believe to be the origin of our Universe, and a window into the time before time.
Features scientists Edwin Hubble, Martin Bojowald, Neil Turok and Paul Steinhardt, and treats of issues around the Big Bang, initial singularity, the string theory, the M-theory, dark energy and gravitational waves.
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Features scientists Edwin Hubble, Martin Bojowald, Neil Turok and Paul Steinhardt, and treats of issues around the Big Bang, initial singularity, the string theory, the M-theory, dark energy and gravitational waves.
Thanks for watching. Follow for more videos.
#cosmosspacescience
#throughthewormhole
#season1
#episode4
#cosmology
#astronomy
#spacetime
#spacescience
#space
#nasa
#beforebigbang
#Whathappenedbeforethebeginning
#morganfreeman
Category
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LearningTranscript
00:00The Big Bang.
00:03A torrent of energy that propelled our universe from nothing into everything,
00:10creating both space and time.
00:14It's the best theory yet of what happened at the beginning of time.
00:20But a new generation of scientists is daring to contemplate what was once thought impossible.
00:25Are we wrong about the Big Bang?
00:30And might we soon discover what happened before the beginning?
00:39Space.
00:41Time.
00:43Life itself.
00:46The secrets of the cosmos lie through the wormhole.
01:00How did the universe begin?
01:02We've all heard of the Big Bang.
01:04But how do we really know that's the way it was?
01:08I mean, after all, nobody was around to see it happen.
01:10And if that question seems hard to answer, try this one.
01:16What happened before the universe began?
01:20I first encountered this eternal question at the Methodist Church.
01:28In the book of Genesis, God said,
01:36God then created the heavens and the earth.
01:46But if everything began at this moment, how was God around to create it?
01:52Could there ever have been a time before time?
02:03It's a question that has intrigued scientists and philosophers, and the rest of us, for more
02:09than 5,000 years.
02:11But in the 1920s, a scientific discovery shone some new light on the beginning of time and
02:19what might have come before, thanks to this man, Edwin Hubble.
02:26Atop Mount Wilson in Southern California, Hubble aimed a powerful new weapon at the heavens,
02:33the mighty Hooker 101-inch telescope.
02:37As he looked through it, he became the first man to appreciate the true scale of the universe.
02:46Hubble saw that small patches of blurry sky were not gas clusters, but in fact, other galaxies.
02:54The universe was filled with not thousands, but hundreds of billions of them.
03:01Remarkable as this discovery was, Hubble's observations would lead to an even more profound conclusion.
03:11The universe is expanding, every single galaxy drifting farther and farther apart.
03:21Run this picture back in time, and all the math points to a single moment of an infinitely
03:26small, infinitely dense beginning to our universe.
03:30Scientists have a name for this initial state, a singularity.
03:38Before this Big Bang, there is nowhere and no when.
03:43There is literally nothing before this beginning.
03:47Run the clock forward from that singularity, and the starting gun is the Big Bang.
03:53A colossal explosion of energy and matter that gave birth to everything we see in the sky today.
04:07It also created space and time.
04:11As all the radiation and matter shoots out in different directions, the universe eventually starts to cool.
04:18The gravity causes matter to clump together, and stars are born, and then explode.
04:26Later, swirling disks of dust and rocks gather around newer stars.
04:40Eventually, several billion years after the Big Bang, we get a planet like Earth.
04:51This mind-twisting story has become the new dogma.
04:57But however robust, the Big Bang is still just a theory.
05:03Princeton professor of physics Dr. David Spurgle has spent much of his career trying to understand if and how this cataclysmic event happened.
05:12People sometimes call him Mr. Universe.
05:19For Spurgle, the Big Bang is still the most complete and scientifically sound model of the early universe.
05:28Everything around us came from the hot Big Bang.
05:31The universe started out, Big Bang theory, very, very hot, very dense.
05:36Hot radiation cooled, from that emerged matter, radiation, everything that makes up the world around us.
05:46And here we are at Bell Labs at Crawford Hill, the place where the hot Big Bang theory really all started in some ways.
05:56Arneal Penzias and Robert Wilson are a pair of radio astronomers who worked here at Bell Laboratories.
06:01What they were doing is they were studying the microwave sky as Bell Labs was exploring the idea of using it for microwave communication.
06:09It was 1964.
06:13At this point, the two men were not trying to solve any big cosmic questions.
06:17They were just trying to get the darn thing to work.
06:21For starters, a mysterious hiss was interfering with their radio signal.
06:26Penzias and Wilson were really good radio astronomers, so they built a really nice telescope.
06:32And they designed it so there shouldn't be any background.
06:35Yet it was there.
06:36This background hiss they heard was coming from every corner of the sky.
06:41Wilson and Penzias tried everything, even sweeping the dirt and leaves out of the antenna.
06:47But still, there was noise.
06:49They tried cooling the receivers with liquid helium.
06:52Still, there was noise.
06:55They even removed the family of nesting pigeons and their associated droppings.
06:59And still, the noise would not go away.
07:03Sometimes science consists of cleaning up a lot of stuff and seeing what's left behind.
07:09Having eliminated anything they could think of, they realized there had to be something else there.
07:16The only possibility was that it was coming from someplace outside our galaxy.
07:20And that seemed like such a far out idea.
07:22We just didn't know what to do with that result.
07:26Consulting with a team of Princeton physicists, Wilson and Penzias realized that the only reason something could come from every part of the sky is if it were actually a faint echo of a huge cosmic event.
07:40We had really measured the background temperature, the remnant noise from the creation of the universe.
07:46After 40 years of speculation and calculation by some of the most famous scientists in the world, the two radio engineers had stumbled upon a faint cry from our own cosmic birth.
08:00The cause of the hiss had to be the leftover heat from the Big Bang.
08:06A picture of the beginning of time and space was starting to emerge.
08:12This balloon is our whole universe.
08:15As I expand the universe, notice how all the things on the balloon move apart from each other.
08:23We're not in the center of the universe, it's the whole universe that's expanding, expanding in time.
08:28Same is true with the radiation.
08:30It's not that the microwave radiation is coming towards us and we're in the center of the Big Bang.
08:34The whole balloon is filled with radiation from the Big Bang.
08:38As the balloon expands, the radiation gets colder.
08:41The bigger the balloon, the colder the universe is.
08:44We can now run the universe back in time.
08:46The universe is contracting, getting hotter, getting hotter, getting hotter, hotter still.
08:52We're now back at the moment of initial singularity.
08:55We're at the moment in which the Big Bang started.
08:57Everything, all of space is contracted right here.
09:00This is when the hot radiation was generated.
09:03It's not generated in one spot, it's generated everywhere.
09:06The Big Bang happened everywhere on the surface of the balloon.
09:10The accidental discovery of cosmic microwave background radiation earned the two radio engineers
09:16the Nobel Prize for Physics.
09:19It also gave scientists the first good estimate of when the Big Bang happened,
09:25between 12 and 14 billion years ago.
09:29Our understanding of the universe would never be the same.
09:36But for David Spurgle, listening to the echo of the Big Bang from a hill in New Jersey was not good enough.
09:42He wanted to time travel back to that first moment when light filled the universe and see it.
09:50What he needed was a rocket.
09:52A rocket which would take a picture of the earliest moment of the universe.
10:052001.
10:07With the launch of the Wilkinson Microwave Anastotropy Probe, or WMAP,
10:13scientists were attempting to see as far back as they could to the beginning of our world.
10:19Spurgle's dream was taking flight.
10:22When we look at the microwave background, we're looking out in space back in time.
10:27We're looking back to when the universe was only 300,000 years old.
10:31That's the moment at which the universe became cold enough that electrons and protons combine to make hydrogen.
10:37Hydrogen's transparent to microwave light.
10:40So light could then travel freely from then to now.
10:44Two years later, the results are in.
10:47First results from NASA's Wilkinson Microwave Anastotropy Probe.
10:51The WMAP delivers on its promise.
10:54A crystal clear baby picture of the universe just 380,000 years after its birth.
11:03These pictures are worth more than a thousand words.
11:12This is a picture of me as a baby.
11:15Notice the high forehead?
11:16The ears?
11:17The nose?
11:18Classic smile.
11:21While I'm certainly older and hopefully wiser than I was in this picture,
11:26the basic DNA is the same.
11:28We try to do the same thing in cosmology.
11:30We take the universe's baby picture and we see what it looked like when it was a few days old.
11:37We can then use that picture to look at how we got from the baby picture to the universe we see today.
11:42But perhaps even more excited, we can take the picture and go further back in time
11:48and learn about the universe's beginnings.
11:51Learn about where the baby came from.
11:54Equivalently what happened in the first moments of the Big Bang.
11:57The details of our birth are actually imprinted in this picture.
12:03But what happened between that moment of singularity and the WMAP image 380,000 years later?
12:11For Dr. Alan Guth, a physicist from MIT, this missing moment in our universe's timeline was the key to everything that came before and after the Big Bang.
12:25The universe that we see is, in fact, unbelievably uniform.
12:28And that's hard to understand because conventional explosions don't behave that way.
12:32But other scientists have different ideas about what might have happened at that moment of singularity.
12:38The physical laws break down, the mathematical equations just don't make sense anymore.
12:43The beginning of time is about to get a whole lot stranger.
12:55Forty years after two radio astronomers first heard a faint whisper from our own cosmic birth,
13:01David Spergel now has his baby picture of the universe.
13:06Despite the vibrant colors visible in the WMAP image,
13:09it only describes a miniscule variation in temperature across the universe.
13:16When we look at the WMAP map, what we're seeing are tiny variations in the temperature of the universe from place to place.
13:23Variations that are one part in 10,000, one part in 100,000.
13:27So I think of the universe we look at with the WMAP satellite as not being chaotic,
13:31but being very ordered, homogeneous and smooth.
13:34But if time and space started in a cataclysmic explosion of energy,
13:39wouldn't the universe be uneven and messy in all directions?
13:44Not exactly. So I can't start this from not exactly, can I?
13:49For Dr. Alan Guth, what happened during this early moment in time was an intriguing mystery that had to be solved.
13:58Figuring this out became his life's work.
14:02There had been in cosmology a serious problem in understanding the uniformity of the universe.
14:07It has the same intensity in every direction that we look to one part in 100,000.
14:13And that means that the Big Bang was unbelievably uniform.
14:16And that's hard to understand because conventional explosions just don't behave that way.
14:21We've set up a balloon that's going to be dropped from a very high height up there on a crane.
14:28The balloon is filled with paint and we'll get to see what kind of a splat a typical explosion makes.
14:33So this is what a typical explosion might look like. And as you can see, it's anything but uniform.
14:53There are spots here and spots there and white spots in between.
14:57The early universe was nothing like what's on the canvas here.
15:00Alan needed something that would immediately smooth out all the hot, dense plasma that had just come into existence.
15:08I came across this idea of inflation.
15:11The idea that gravity can, under some circumstances, act repulsively and produce a gigantic acceleration in the expansion of the universe.
15:21And that this could have happened in the very early universe.
15:24The key idea behind inflation is the possibility that at least a small patch of the early universe contained this peculiar kind of repulsive gravity material.
15:33And all you need is a tiny patch of that and the Big Bang starts due to this repulsive gravity effect.
15:39Cosmic inflation takes place right after a pop from nothing into something.
15:45About one trillion trillion trillionth of a second afterwards, a force field takes all the highly compressed space created in that first singular moment,
15:54which is still almost infinitely small, and drives it out.
16:01A tiny fraction of a second later, the universe has doubled in size 100,000 times.
16:08A different kind of painting illustrates this idea.
16:13We're going to paint in time-lapse photography a growing sphere.
16:18Instead of getting the splop that we had when we just dropped the balloon,
16:22here we should see a very smooth growth of an early universe.
16:26With this smooth and orderly expansion, our universe was formed.
16:32This idea of inflation has now essentially become the standard version of cosmology.
16:36It makes a number of predictions which have been confirmed,
16:39so it agrees very well with what we see.
16:46With the addition of inflation, the Big Bang Theory became a cohesive three-act play.
16:53Act One.
16:55A singularity pops into existence out of nowhere and no when,
17:00containing in one single dot all the energy that will ever be in our universe.
17:06Act Two.
17:08Inflation suddenly takes hold.
17:10An unimaginably rapid expansion of space smoothly spreading out that energy,
17:15bringing order to the universe.
17:17It's now a massive soup of evenly expanding plasma.
17:22Act Three.
17:24The universe cools.
17:26Matter starts to clump together under the force of gravity,
17:29eventually forming stars, galaxies, and planets.
17:37For most cosmologists, this three-act play is the best explanation
17:42for what happened at the beginning of the universe.
17:48But not for everybody.
17:50Interpreting this as a beginning is indeed just a crutch.
17:55It's not derived from any theory.
17:57It's just a place where the theory itself breaks down.
18:00Dr. Martin Boyewald is a professor of physics
18:03at the Institute for Gravitation and the Cosmos at Penn State.
18:07He is a rising star in a new generation of cosmologists,
18:11which is challenging some long-held beliefs about the universe.
18:15Inflation may have fixed Act Two.
18:18But Martin thinks the play still starts with a very unlikely Act One.
18:22The sudden and singular pop from nothing into the entire universe.
18:28Singularity just means we don't understand the theory well enough.
18:33Alan Guth used the theory of inflation to dig down to a trillion trillion trillionth of a second after the beginning.
18:43Martin went a million times closer.
18:46In Boyewald's theory, time is not free-flowing, but made up of discrete measurable chunks.
18:53These chunks of time are called space-time atoms.
18:58It's a very different way of thinking about what happened before the beginning.
19:03Here we have a beautiful old grandfather clock.
19:10As we can see, there's a pendulum.
19:13It's swinging in a continuous way, thereby telling the clock how time is proceeding.
19:18They're not discrete marks, but rather a continuous motion of the pendulum.
19:25This is the classical picture of time, measured continuously.
19:29Now in quantized time, it's a whole different story.
19:33For quantized time, we have a picture as given by the second hand of the clock here.
19:38It's not continuous.
19:39It's not the pendulum swing, which we could stop at any time, at any position.
19:45Here, the different positions are given by certain discrete sets.
19:49Between one tick and the next one, it's a finite amount of time which cannot be further subdivided.
19:56In Bojewa's version of the early universe, you never get to nothing.
20:01The second hand on the quantized clock marks not just the beginning of one moment, but the end of another.
20:08The tick that signals dawn in our universe marks one second past midnight in the last.
20:15So we have this balloon universe.
20:20If we imagine what it could have been before the Big Bang, it was collapsing, so the volume was shrinking.
20:27Now, if we follow the usual evolution according to general relativity, that would have been ending in a singularity.
20:35The whole balloon would just completely deflate.
20:39But with the atomic nature of space and time, the attractive behavior of gravity changes.
20:45It becomes repulsive at these high densities.
20:47The collapse stops.
20:49Then the forces turn around, so there's a repulsive force which makes the universe re-expand.
20:54At some point, we're not sure yet, but it might re-collapse at some time in the future, so all the air might go out again.
21:07The volume would decrease, the density would increase, and then probably approach another Big Bang.
21:14The universe expands and contracts, but it never actually begins.
21:20There could have been a series of universes before this one, and more to come after this one.
21:27Boyewal is working through the problems and conundrums that all radical new theories face.
21:34His theory is by no means complete, and it may never be.
21:39We're still working on the equations.
21:42We don't have the complete answer yet, but it seems to be the best theory yet to address these issues.
21:53But in 2001, two of the leading cosmologists in the world published a paper suggesting an even more radical approach to what happened at the beginning.
22:03For these two scientists, there was another answer, so strange and unexpected that it had never been considered.
22:10There are bangs and bangs and bangs forever.
22:13Our universe may not be the only one, but one of hundreds, thousands, maybe an infinite number.
22:21It's an inspiring and daunting suggestion.
22:25The universe is an endless cycle prompted by an endless series of bangs forever.
22:38When you look out into space, gaze at a distant star, you also look back in time.
22:45Light from distant galaxies can take billions of years to reach us.
22:51Now we know there's a limit to how far back we can see, an edge to the visible universe.
22:57The light from that cosmic backdrop has taken 13.7 billion years to make it to Earth.
23:04What lies beyond that curtain?
23:07According to Professor Martin Bowiwal, time becomes squeezed and distorted as it nears a singularity and then bounces back out into another expansion.
23:19But perhaps there's an altogether different way to look at what happened before the beginning.
23:28South African scientist Dr. Neil Turok is now daring to go further into the past than almost anyone else.
23:35From the moment he entered the field of theoretical physics, the South African scientist was looking for new answers to age-old problems.
23:44There is a conventional wisdom in the field and people are very slow to adopt new ideas.
23:52And frankly, many people have built their careers on the status quo and they don't want a new idea coming along and rocking the boat.
24:01For Neil, the WMAP announcement brought up familiar feelings about seeing the universe through a slightly different lens than some of his colleagues.
24:10In the WMAP press announcement, of course, the scientists involved linked it explicitly to inflation and said this dramatically confirms inflation.
24:20And this made me squirm.
24:23My point of view was that the information contained in the WMAP data was in itself not sufficient to prove or refute inflation.
24:37He wasn't alone.
24:40Across the Atlantic, another intrepid scientist labored to uncover the truth behind what happened before the beginning.
24:47Paul Steinhardt is the Albert Einstein Professor of Physics at Princeton University.
24:53As a young man, Paul was inspired to study science by the moon landings.
24:58We choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard.
25:11In 1999, the two men combined forces to see if they could answer some of the problems with the inflationary model of what happened at the beginning.
25:20Inflation had some extraordinary successes, so it's tough competition to compete with inflation.
25:26So I will not tell you all the ideas that were attempted and dumped in the wastebasket.
25:31We have similar objectives, which is to shake the field up once in a while and come up with something bold and original and different and to improve on the status quo.
25:43I organized a conference with Neil Turok.
25:46We had a common interest in string theory, which were just coming out at that time, whether they might stimulate some new ideas in cosmology.
25:55String theory was developed in the last 35 years as an attempt to devise a single theory explaining everything in the universe.
26:04In it, everything is made of minute, vibrating strings.
26:09But for the mathematics of string theory to work, there has to be more than the three dimensions of space that we see.
26:15Rather, there are ten dimensions plus time.
26:19Space-time is a flexible substance, like a membrane, and it can stretch and shrink.
26:26So we knew these things could move, but nobody had really studied the dynamics of that process.
26:32So we brought in experts like Bert Overt, who is one of the most proficient developers of particle physics models based on string theory.
26:43And he gave a beautiful series of lectures in which he described to us this idea of our three-dimensional world being embedded in a brain world,
26:51separated by a small gap from another brain world along an extra-spatial dimension.
26:56And as we sat there, we both had the same thoughts.
26:59Which is, if you imagine that this is really the structure of the universe, there's a new possible interpretation for what is the Big Bang.
27:06What have we not been facing up to? You know, what is the elephant in the room?
27:10And the number one question was the singularity.
27:14We both sort of approached Bert from both ends.
27:17And cornered Bert after his lecture.
27:20Each of us finished the sentence of the other.
27:22And said, you know, well, what about if these things collide? What would happen then?
27:26Is it possible the Big Bang is not a beginning, but is a collision?
27:30And his response was, maybe.
27:33The meeting soon broke up.
27:36But the three men had all been invited to attend the same play in London that evening.
27:41We met at the train platform, and then we began to really imagine this idea in more detail about what it would mean if the Big Bang were not a beginning, but the Big Bang were a collision.
27:56And then we had a train ride to London where we just brainstormed about this in a very loose and unstructured and un-mathematical way.
28:05We asked ourselves the question, could we invent something which was different than the inflationary picture, that was different than the standard picture?
28:12We had some rough ideas how to do it, but it wasn't at all obvious.
28:16Time was flying past us as the train was moving along.
28:19It's one of those rare occasions when you're having a conversation, you feel like a really exciting idea is emerging.
28:24So that sixth sense that something important is happening.
28:27Coming up with this rough idea for how things might work is, of course, exciting.
28:34But in having an idea like that, and then deciding to really pursue it, you are condemning yourself to years of misery.
28:44Because you now have to flesh this out.
28:48And to solve this mystery, Neil and Paul would turn to one of the toughest mental challenges of the human mind.
28:56The incredibly strange world of 11-dimensional space.
29:01And universes parallel to our own.
29:08Albert Einstein was a formidable thinker.
29:12His theories of relativity were ground-breaking developments that triggered a century of cosmic insights.
29:19But even more fundamental was his realization that time and space are intertwined.
29:26The three dimensions of space are really part of a four-dimensional fabric called space-time.
29:34But now, there's a new movement in theoretical physics.
29:39It's called string theory.
29:41String theory.
29:42And out of string theory comes M-theory.
29:47In M-theory, there are not four, but an astounding 11 dimensions.
29:53Ten dimensions of space plus one of time.
29:58What is M-theory?
30:01Okay.
30:02So, M-theory is an attempt to...
30:07Let me start again.
30:08Three-dimensional, infinite worlds stretching off...
30:12Let me start again.
30:13Why would one even think about...
30:15I mean, how does one make that not sound crazy in two sentences?
30:19So, M-theory is a promising unified theory of all the fundamental forces and constituents that we observe in nature.
30:32In a sense, you could describe it as the culmination of all the developments in theoretical physics over the 20th century.
30:39In order to make this theory work, one needs to have more than the usual three spatial dimensions.
30:44So, a key idea behind M-theory is that there are more than the three dimensions of space that we experience.
30:51There are hidden dimensions.
30:53In fact, there are seven more.
30:55And the reason we're not aware of them is that they are so, so tiny that in order to see them, you'd need an enormously powerful microscope.
31:05Far more powerful than any we have.
31:08Our three-dimensional world lives in a surface embedded in a space with an extra spatial dimension that separates it from another such surface.
31:20One possibility that springs from these extra dimensions is that this other three-dimensional world could be just a fraction of a centimeter from ours,
31:29and yet hidden from our view.
31:31These surfaces are called brains, standing for membrane, which is to remind us that these surfaces are elastic.
31:38They can stretch, they can wiggle, they can warp, they can move along this extra dimension.
31:43All of the particles we're made of are actually curled up little brains, and all the dimensions of space we travel in are comprised of brains themselves.
31:54And so everything in the universe is composed of these geometrical objects.
31:59I don't know if I can repeat that again.
32:02Caution.
32:03You have entered a place called brain world.
32:07We're stuck like flies on flypaper on our brain world.
32:11We simply can't reach out into the extra dimension, even 10 to the minus 30 centimeters, to touch the other brain world.
32:18It was through this world of brains that Paul and Neil stumbled onto a potentially radical new theory of what happened before the beginning.
32:29So here I have a piece of material, and it looks like a two-dimensional object because one of the dimensions goes up and one goes side to side.
32:38But if we look a little bit closer at this object and look at it from the side, you'll see that actually there are two pieces of material separated by a tiny gap.
32:49And you could think of this gap as being the fourth dimension of space.
32:54And the collision of these two three-dimensional worlds, the one we live in and another one, would have been the Big Bang.
33:03It would be a collision instead of a springing from nothingness.
33:07So if the brains existed before and after, that means space and time existed before.
33:12They could have helped set up the conditions we observe in the universe today.
33:15They collide and they move apart again.
33:20The Big Bang is not the beginning.
33:22That means we have more time to solve all the cosmological problems that inflation was designed to solve.
33:28So we began to imagine, could we replace that idea with something that occurred before the Bang?
33:33And as we were going along the train ride, we, you know, we began to imagine lots of possibilities.
33:38So that by the end, it seemed like a very exciting alternative to the standard Big Bang inflationary picture.
33:46For the next 18 months, the three men and another physicist, Justin Curie, worked feverishly to clarify and justify their initial spark of creativity.
33:56Now we had to make the mathematics work, and this involved developing a lot of new physics to explain the motion of brains moving along extra dimensions under the influence of a force which is trying to draw them together.
34:09This mathematics didn't exist before.
34:11A new theory of the universe starts to come alive.
34:18The picture we had in mind was two three-dimensional worlds stretching off to infinity, but separated from each other by a tiny gap, a fourth dimension of space.
34:28The two three-dimensional worlds are actually pulled together by a very, very weak force.
34:34The force has to be very, very weak, otherwise the Bang would occur too quickly.
34:41We know that the cycles can't be too short because the universe has already gone 14 billion years since the last bay.
34:48A trillion years is probably a good, you know, typical value for what we expect the length of a cycle to be.
34:53As the brains approach, the force gets stronger and stronger.
34:58And when they collide, the kinetic energy of the brains is then converted into the hot radiation that fills both three-dimensional worlds and looks like the Big Bang.
35:10So that when the brains move apart again, they're now filled with the matter and radiation that was created at the collision.
35:17This then causes the brains to begin to expand again and cool, creating a new period of expansion, cooling, creation of new atoms, molecules, stars, and galaxies.
35:29Now had an explanation for the Big Bang.
35:32This is normally referred to as cosmic singularity, some sort of breakdown in the laws of physics, which in the standard Big Bang theory, you simply ignore.
35:40But in this picture, you were actually providing an explanation for it.
35:44It was, in fact, the collision between these two brain worlds.
35:47It was a theory of what was the cosmic singularity.
35:51It was a radical and elegant solution to one of the great cosmic mysteries of all time.
35:57According to Neil and Paul and their colleagues, Bert and Justin, there was always a time before time.
36:05After almost two years of work, it was time to present this new theory to their fellow scientists.
36:15At a conference in Finland, the two physicists laid out their theory.
36:19The reception was icy.
36:21The criticism was that we were simply assuming or asserting the brains would be flat and parallel to begin with,
36:26without showing why that should be the case.
36:28We'd been so excited about this idea, and yet everyone else was just poo-pooing it.
36:33To be fair, I mean, the session did not go well for us.
36:38The next morning, we were both rather depressed, so we began to travel along the river near Rovaniemi
36:44and have this discussion about, well, what could we replace this idea with?
36:48So we began to think about something that wasn't yet included in the theory,
36:52which was the idea of dark energy.
36:54Dark energy is a recent and totally surprising astronomical discovery,
37:00a mysterious force that's causing the universe to expand even faster.
37:05Eventually, the dark energy will expand the universe so much that it will be nothing but cold and empty space.
37:11In the language of M theory, that translates to a flat brain.
37:17The dark energy phase stretches out the three-dimensional worlds
37:22and makes them very flat and very empty and very parallel.
37:27Of course, that mainly clicked with another idea.
37:29Well, we're using something now, but we're using it before the bang.
37:33Well, maybe the source of dark energy then was actually the same as the one now,
37:39and the universe is cyclic somehow.
37:41So you could have a bang followed by a normal period of the universe like we live in today,
37:49followed by a second bang in our future, followed by another bang and so on.
37:54There are bangs and bangs and bangs forever.
37:58The theory was now complete.
38:01Two brains come together, inject one another with energy.
38:05Then dark energy takes a trillion years or so to spread that energy out.
38:10The brains flatten and then come together again.
38:14This cycle happens endlessly.
38:19Neil Turok and Paul Steinhardt had come up with a remarkable alternative theory to the Big Bang
38:25and cracked the door onto what happened before the beginning.
38:30As different as the models are, they produce the same exact variations in the background radiation.
38:36The same WMAP image fits both ideas.
38:40It's certainly the case that when WMAP made its announcement,
38:43the way most people interpreted that announcement was,
38:46it's beautifully consistent with the Big Bang inflationary picture.
38:50To us, it meant that the cyclic model was in the game as much as inflation was.
38:55But which theory is right?
38:57The answer to one of the biggest cosmic mysteries of all,
39:02was there a time before our time,
39:06could be circling the Earth a million miles over our heads?
39:12What happened before the beginning?
39:19The question is posed.
39:21Signs are drawn.
39:22The closing arguments are being prepared.
39:25Is the answer nothing?
39:27Did a Big Bang suddenly and inexplicably burst into life from a time of no when and a place of nowhere?
39:35Or could we have bounced from the contraction of another universe that existed before ours?
39:42Or are we living a trillionth of a trillionth of the width of an atom away from a parallel universe,
39:50and every trillion years these parallel worlds bump into one another
39:55and fill each other up with huge amounts of energy and matter?
40:00Professor Martin Bollewal's bouncing universe is still a work in progress.
40:07But for proponents of the cyclic and the Big Bang inflation model,
40:12the answer to how and when the universe started
40:15may be moving toward us across time and space like tiny ripples in the cosmic ocean.
40:22Gravitational waves.
40:25Gravitational wave is pretty much like a sound wave.
40:29We're used to a sound wave traveling from me to you as I speak,
40:36as a compression and expansion of the air between us.
40:41And so the molecules get more densely packed and further apart
40:45as the wave moves from me to you.
40:48But gravitational waves ripple not air molecules, but space itself,
40:53which means that they can stretch out or compress a beam of light
40:58and cause a shift in its color.
41:01So if space is expanded, we'll see the radiation shifted to red frequencies, longer wavelengths.
41:07But if it's coming towards us, we'll see it's slightly bluer than it would otherwise have been.
41:12And so by carefully analyzing the pattern of radiation on the sky,
41:17we can in fact infer if there are gravitational waves traveling through our part of the universe.
41:24And rocket technology will get the scientists far enough up into space to spy these gravitational waves.
41:36The Planck satellite is the successor to WMAP.
41:43It will be measuring the sky with about twice the resolution and about ten times the sensitivity.
41:48The Planck satellite is really the first device we have,
41:50which seems to have a strong capability of maybe finding these gravity waves.
41:55And if we're lucky, that'll tell us what happens during the first moments of the Big Bang, or maybe even before.
42:08For proponents of the Big Bang inflation model,
42:12finding significant gravitational waves would be the final step in proving that there was a giant expansion of whooshing energy
42:18from a place of nowhere and no when.
42:25But Paul Steinhardt and Neil Truroch are also looking forward to the Planck satellite results.
42:31In their cyclic model of the beginning of the universe,
42:34two brains coming together would be a much less intense collision,
42:38and the chances are that gravitational waves would be almost nonexistent.
42:43If we observe these gravitational waves in the Planck satellite,
42:47that will support the inflationary theory and rule out the cyclic picture,
42:51and converse, if we don't see them, that would strongly support the cyclic picture.
42:56But no matter which description of the beginning of the universe appears to be more accurate,
43:01the true winner will be our own scientific understanding.
43:07Yeah, to me, it's man against nature.
43:09We're trying to figure out nature's secrets.
43:11If we're lucky, we'll be surprised.
43:15These tiny, almost undetectable waves will have a tsunami-like effect on the future direction of cosmology.
43:24Instead of appearing from nowhere and know when and rising from stardust to humankind,
43:31we may have to consider the mind-boggling premise that we are just the latest version of an endless series of universes.
43:39We still might not know what happened before the beginning, but we would know that something did.
43:47The final answer may be close at hand.
43:51The final answer may remain in relatively small circumstances of open space,
44:05close the slammed Uber shuddled on Reddit,
44:07so we don't have to consider the natural sensors.
44:09The key of this isertas.
44:11And because of the Alpha and the Alpha enjoying the Titanic had a huge stream,