Original subtitles

The Big Bang.

...A torrent of energy

that propelled our Universe from nothing into everything,

creating both space and time.

It's the best theory yet

of what happened at the beginning of time.

But a new generation of scientists

is daring to contemplate what was once thought impossible --

are we wrong about the Big Bang?

And might we soon discover what happened before the beginning?

Space, time, life itself.

The secrets of the cosmos lie through the wormhole.

♪ Through the Wormhole 1x04 ♪ What Happened Before the Beginning? Original air date on June 30, 2010

-- sync, corrected by elderman -- -- for www.Addic7ed.Com --

How did the Universe begin?

We've all heard of the Big Bang,

but how do we really know that's the way it was?

I mean, after all, nobody was around to see it happen.

And if that question seems hard to answer, try this one --

what happened before the Universe began?

I first encountered this eternal question

at the Methodist church.

♪ Sweet chariot ♪

♪ coming for to carry me home ♪

In the book of Genesis, God said,

"let there be light, and there was light."

God then created the Heavens and the Earth.

But if everything began at this moment,

how was God around to create it?

Could there ever have been a time before time?

It's a question

that has intrigued scientists and philosophers

and the rest of us for more than 5,000 years.

But in the 1920s, a scientific discovery

shone some new light on the beginning of time

and what might have come before,

thanks to this man -- Edwin Hubble.

Atop Mount Wilson in Southern California,

Hubble aimed a powerful, new weapon at the heavens --

the mighty Hooker 101-inch telescope.

As he looked through it,

he became the first man to appreciate

the true scale of the Universe.

Hubble saw that small patches of blurry sky

were not gas clusters, but in fact other galaxies.

The Universe was filled with not thousands,

but hundreds of billions of them.

Remarkable as this discovery was, Hubble's observations

would lead to an even more profound conclusion --

the Universe is expanding,

every single galaxy drifting farther and farther apart.

Run this picture back in time,

and all the math points to a single moment

of an infinitely small, infinitely dense beginning

to our Universe.

Scientists have a name for this initial state -- a singularity.

Before this Big Bang, there is nowhere and no-when.

There is literally nothing before this beginning.

Run the clock forward from that singularity,

and the starting gun is the Big Bang...

...A colossal explosion of energy and matter

that gave birth to everything we see in the sky today.

It also created space and time.

As all the radiation and matter

shoots out in different directions,

the Universe eventually starts to cool.

Gravity causes matter to clump together,

and stars are born...

And then explode.

Later, swirling discs of dust and rocks

gather around newer stars.

Eventually, several billion years after the Big Bang,

we get a planet like Earth.

This mind-twisting story has become the new dogma,

but however robust,

the Big Bang is still just a theory.

Princeton Professor of physics Dr. David Spergel

has spent much of his career

trying to understand if and how this cataclysmic event happened.

People sometimes call him "Mr. Universe."

For Spergel, the Big Bang

is still the most complete and scientifically sound model

of the early Universe.

Everything around us came from the hot Big Bang.

The Universe started out -- Big Bang Theory --

very, very hot, very dense.

That hot radiation cooled.

From that emerged matter, radiation,

everything that makes up the world around us.

And here we are at Bell Labs at Crawford Hill,

the place where the hot Big Bang theory really all started,

in some ways.

Arno Penzias and Robert Wilson are a pair of radio astronomers

who worked here at Bell Laboratories.

What they were doing is they were studying the microwave sky

as Bell Labs was exploring

the idea of using it for microwave communication.

It was 1964.

At this point,

the two men were not trying to solve any big cosmic questions.

They were just trying to get the darn thing to work.

For starters, a mysterious hiss

was interfering with their radio signal.

Dr. Spergel: Penzias and Wilson were really good radio astronomers,

so they built a really nice telescope.

And they designed it so there shouldn't be any background,

yet it was there.

This background hiss they heard

was coming from every corner of the sky.

Wilson and Penzias tried everything,

even sweeping the dirt and leaves out of the antenna,

but still there was noise.

They tried cooling the receivers with liquid helium.

Still there was noise.

They even removed a family of nesting pigeons

and their associated droppings.

And still the noise would not go away.

Sometimes science consists of cleaning up a lot of stuff

and seeing what's left behind.

Having eliminated anything they can think of,

they realized there had to be something else there.

The only possibility

was that it was coming from someplace outside our galaxy,

and that seemed like such a far-out idea.

We just didn't know what to do with that result.

Consulting 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.

We had really measured the background temperature,

the remnant noise from the creation of the Universe.

After 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.

The cause of the hiss had to be

the leftover heat from the Big Bang.

A picture of the beginning of time and space

was starting to emerge.

This balloon is our whole Universe.

As I expand the Universe...

...Notice how all the things on the balloon

move apart from each other.

We're not in the center of the Universe.

It's the whole Universe that's expanding -- expanding in time.

Same is true with the radiation.

It's not that the microwave radiation is coming towards us

and we're in the center of the Big Bang.

The whole balloon is filled with radiation from the Big Bang.

As the balloon expands, the radiation gets colder.

Bigger the balloon, colder the Universe is.

We can now run the Universe back in time.

The Universe is contracting,

getting hotter, getting hotter, getting hotter, hotter still.

We're now back at the moment of initial singularity.

We're at the moment in which the Big Bang started.

Everything -- all of space -- is contracted right here.

This is when the hot radiation was generated.

It's not generated in one spot. It's generated everywhere.

The Big Bang happened everywhere on the surface of the balloon.

The accidental discovery

of cosmic microwave background radiation

earned the two radio engineers the Nobel prize for Physics.

It also gave scientists

the first good estimate of when the Big Bang happened --

between 12 and 14 billion years ago.

Our understanding of the Universe

would never be the same.

But for David Spergel,

listening to the echo of the Big Bang

from a hill in New Jersey was not good enough.

He wanted to time-travel back to that first moment,

when light filled the Universe, and see it.

What he needed was a rocket...

We have ignition. Looking good.

Liftoff!

...A rocket which would take a picture

of the earliest moment of the Universe.

It's working its way through the liftoff...

2001.

With the launch of the Wilkinson Microwave Anisotropy Probe,

or WMAP,

scientists were attempting to see as far back as they could,

to the beginning of our world.

Spergel's dream was taking flight.

When we look at the microwave background,

we're looking out in space, back in time.

We're looking back

to when the Universe was only 300,000 years old.

That's the moment at which the Universe became cold enough

that electrons and protons combined to make hydrogen.

Hydrogen is transparent to microwave light,

so light could then travel freely from then to now.

Two years later, the results are in.

First results from NASA's Wilkinson microwave...

The WMAP delivers on its promise --

a crystal-clear baby picture of the Universe

just 380,000 years after its birth.

These pictures are worth more than a thousand words.

This is a picture of me as a baby.

Notice the high forehead, the ears, the nose...

Classic smile.

Well, I'm certainly older

and hopefully wiser than I was in this picture.

The basic DNA is the same.

We try to do the same thing in cosmology.

We take the Universe's baby picture,

and we see what it looked like when it was a few days old.

We can then use that picture

to look at how we got from the baby picture

to the Universe we see today.

But perhaps even more exciting,

we can take the picture and go further back in time

and learn about the Universe's beginnings,

learn about where the baby came from,

equivalently what happened

in the first moments of the Big Bang.

The details of our birth

are actually imprinted in this picture.

But what happened

between that moment of singularity

and the AP image 380,000 years later?

For Dr. Alan Guth, a physicist from M.I.T.,

this missing moment in our Universe's timeline was the key

to everything that came before and after the Big Bang.

The Universe that we see is, in fact, unbelievably uniform,

and that's hard to understand,

because conventional explosions don't behave that way.

But other scientists have different ideas

about what might have happened at that moment of singularity.

The physical laws break down.

The mathematical equations just don't make sense anymore.

The beginning of time is about to get a whole lot stranger.

40 years after

two radio astronomers first heard a faint whisper

from our own cosmic birth,

David Spergel now has his baby picture of the Universe.

Despite the vibrant colors visible in the WMAP image,

it only describes a miniscule variation in temperature

across the Universe.

When we look at the WMAP map,

what we're seeing are tiny variations

in the temperature of the Universe from place to place,

variations that are 1 part in 10,000,

1 part in 100,000.

So, I ink of the Universe we look at with the WMAP satellite

as not being chaotic

but being very ordered, homogeneous, and smooth.

But if time and space started

in a cataclysmic explosion of energy,

wouldn't the Universe be uneven and messy in all directions?

Not exactly.

I can't start this with "not exactly," can I?

For Dr. Alan Guth,

what happened during this early moment in time

was an intriguing mystery that had to be solved.

Figuring this out became his life's work.

There had been in cosmology a serious problem

in understanding the uniformity of the Universe.

It has the same intensity in every direction that we look

to 1 part in 100,000.

And that means that the Big Bang was unbelievably uniform.

And that's hard to understand,

because conventional explosions just don't behave that way.

We've set up a balloon that's gonna be dropped

from a very high height, up there on a crane.

The balloon is filled with paint,

and we'll get to see what kind of a splat

a typical explosion makes.

So, this is what a typical explosion might look like,

and as you can see, it's anything but uniform.

There are spots here and spots there

and white spots in between.

The early Universe was nothing like what's on the canvas here.

Alan needed something that would immediately smooth out

all the hot, dense plasma that had just come into existence.

I came across this idea of inflation,

the idea that gravity can, under some circumstances,

act repulsively and produce a gigantic acceleration

in the expansion of the Universe,

and that this could have happened

in the very early Universe.

The 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.

And all you need is a tiny patch of that,

and the Big Bang starts to do this repulsive-gravity effect.

Cosmic inflation takes place

right after a pop from nothing into something.

About one trillion, trillion, trillionth of a second

afterwards,

a force field takes all the highly compressed space

created in that first singular moment,

which is still almost infinitely small...

And drives it out.

A tiny fraction of a second later,

the Universe had doubled in size 100,000 times.

A different kind of painting illustrates this idea.

We're going to paint in time-lapse photography

a growing sphere.

Instead of getting the "splot" that we had

when we just dropped the balloon,

here we should see a very smooth growth of an early Universe.

With this smooth and orderly expansion,

our Universe was formed.

This idea of inflation has now essentially become

the standard version of cosmology,

and it makes a number of predictions

which have been confirmed,

so it agrees very well with what we see.

With the addition of inflation,

the Big Bang theory became a cohesive three-act play.

Act one...

A singularity pops into existence

out of nowhere and no-when,

containing in one single dot

all the energy that will ever be in our Universe.

Act two... Inflation suddenly takes hold --

an unimaginably rapid expansion of space

smoothly spreading out that energy,

bringing order to the Universe.

It's now a massive soup of evenly expanding plasma.

Act three...The Universe cools.

Matter starts to clump together under the force of gravity,

eventually forming stars, galaxies, and planets.

For most cosmologists,

this three-act play is the best explanation

for what happened at the beginning of the Universe.

But not for everybody.

Interpreting this as a beginning is indeed just a crutch.

It's not derived from any theory.

It's just a place where the theory itself breaks down.

Dr. Martin Bojowald is a Professor of Physics

at the institute for Gravitation and the Cosmos at Penn State.

He's a rising star in a new generation of cosmologists

which is challenging some long-held beliefs

about the Universe.

Inflation may have fixed act two,

but Martin thinks

the play still starts with a very unlikely act one --

the sudden and singular pop

from nothing into the entire Universe.

A singularity just means

we don't understand the theory well enough.

Alan Guth used the theory of inflation

to dig down to a trillion, trillion, trillionth of a second

after the beginning.

Martin went a million times closer.

In Bojowald's theory, time is not free-flowing,

but made up of discrete, measurable chunks.

These chunks of time are called "space-time atoms."

It's a very different way

of thinking about what happened before the beginning.

Here we have a beautiful, old grandfather clock.

As we can see, there's a pendulum.

It's swinging in a continuous way,

thereby telling the clock how time is proceeding.

They're not discrete marks,

but rather a continuous motion of the pendulum.

This is the classical picture of time measured continuously.

Now, in quantized time, it's a whole different story.

For quantized time, we have a picture

as given by the second hand of the clock here.

It's not continuous.

It's not the pendulum swing,

which we could stop at any time, at any position.

Here, the different positions are given

by certain discrete sets between one tick and the next one.

It's a finite amount of time

which cannot be further subdivided.

In Bojowald's version of the early Universe,

you never get to nothing.

The second hand on the quantized clock

marks not just the beginning of one moment,

but the end of another.

The tick that signaled dawn in our Universe

marks one second past midnight in the last.

So, we have this balloon Universe.

If we imagine what it could have been before the Big Bang,

it was collapsing, so the volume was shrinking.

Now, if we follow the usual evolution,

according to general relativity,

that would have been ending in a singularity.

The whole balloon would just completely deflate.

But with the atomic nature of space and time,

the attractive behavior of gravity changes.

It becomes repulsive at these high densities.

The collapse stops.

Then the forces turn around, so there's a repulsive force

which makes the Universe re-expand.

At some point -- we're not sure yet --

but it might recollapse at some time in the future,

so all the air might go out again.

The volume would decrease,

the density would increase,

and then probably approach another Big Bang.

The Universe expands and contracts,

but it never actually begins.

There could have been a series of Universes before this one

and more to come after this one.

Bojowald is working through the problems and conundrums

that all radical new theories face.

His theory is by no means complete, and it may never be.

We are still working on the equations.

We don't have the complete answer yet,

but it seems to be the best theory yet

to address these issues.

But 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.

For these two scientists,

there was another answer so strange and unexpected

that it had never been considered.

There are bangs and bangs and bangs forever.

Our Universe may not be the only one,

but one of hundreds, thousands, maybe an infinite number.

It's an inspiring and daunting suggestion --

the Universe is an endless cycle

prompted by an endless series of bangs,

forever.

When you look out into space,

gaze at a distant star,

you also look back in time.

Light from distant galaxies

can take billions of years to reach us.

Now we know there's a limit to how far back we can see,

an edge to the visible Universe.

The light from that cosmic backdrop

has taken 13.7 billion years to make it to Earth.

What lies beyond that curtain?

According to Professor Martin Bojowald,

time becomes squeezed and distorted

as it nears a singularity

and then bounces back out into another expansion.

But perhaps there's an altogether different way

to look at what happened before the beginning.

South African scientist Dr. Neil Turok

is now daring to go further into the past

than almost anyone else.

Africa!

Africa!

His radical view of the cosmos was influenced

by his parents' struggles during apartheid.

My father and mother were political activists

against the South African government.

They went to jail for their opinions.

But ultimately, democracy came to South Africa

and they were both elected members of parliament --

the only husband-and-wife members of parliament

apart from Nelson and Winnie Mandela.

They served as a model of persistence.

Just because at the moment

your ideas are not fashionable or agreed upon,

if you believe what you're doing is right, persist.

From the moment he entered the field of theoretical physics,

the South African scientist

was looking for new answers to age-old problems.

There is a conventional wisdom

in the field,

and people are very slow to adopt new ideas.

And, 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.

For Neil, the WMAP announcement

brought up familiar feelings about seeing the Universe

through a slightly different lens

than some of his colleagues.

In the WMAP press announcement,

of course the scientists involved

linked it explicitly to inflation

and said, "this dramatically confirms inflation."

And this made me squirm.

My point of view

was that the information contained in the WMAP data

was, in itself, not sufficient

to prove or refute inflation.

He wasn't alone.

Across the Atlantic, another intrepid scientist labored

to uncover the truth behind what happened before the beginning.

Paul Steinhardt

is the Albert Einstein Professor of Physics

at Princeton University.

As a young man,

Paul was inspired to study science by the moon landings.

We choose to go to the moon in this decade

and do the other things,

not because they are easy, but because they are hard.

In 1999, the two men combined forces

to see if they could answer some of their problems

with the inflationary model of what happened at the beginning.

Inflation had some extraordinary successes,

so it's tough competition to compete with inflation.

So I will not tell you all the ideas that were attempted

and dumped in the wastebasket.

We 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.

I organized a conference with Neil Turok.

We had a common interest in string theory,

which were just coming out at that time,

whether they might stimulate some new ideas in cosmology.

String theory was developed in the last 35 years

as an attempt to devise a single theory

explaining everything in the Universe.

In it, everything is made of minute, vibrating strings.

But for the mathematics of string theory to work,

there have to be

more than the three dimensions of space that we see.

Rather, there are 10 dimensions, plus time.

Space-time is a flexible substance, like a membrane,

and it can stretch and shrink.

So, we knew these things could move,

but nobody had really studied the dynamics of that process.

So we brought in experts, like Burt Ovrut,

who is one of the most proficient developers

of particle-physics models based on string theory.

And he gave a beautiful series of lectures

in which he described to us

this idea of our three-dimensional world

being embedded in a brane world

separated by a small gap from another brane world

along an extra spatial dimension.

And as we sat there, we both had the same thoughts...

...Which 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.

What have we not been facing up to, you know?

What is the elephant in the room?

And the number-one question was the singularity.

We both sort of approached Burt from both ends...

...And cornered Burt after his lecture...

...And each of us finished the sentence of the other...

...And said, "you know, well,

"what about if these things collide?

What would happen then?"

"And is it possible the Big Bang is not a beginning,

but is a collision?"

And his response was, "maybe."

The meeting soon broke up,

but the three men had all been invited

to attend the same play in London that evening.

We 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.

And then we had a train ride to London,

where we just brainstormed about this

in a very loose and unstructured and unmathematical way.

We asked ourselves the question, "could we invent something

"which was different than the inflationary picture,

that was different than the standard picture?"

We had some rough ideas how to do it,

but it wasn't at all obvious.

Time was flying past us as the train was moving along.

It's one of those rare occasions

when you're having a conversation

and you feel like a really exciting idea is emerging --

sort of that sixth sense

that something important is happening.

Coming up with this rough idea for how things might work

is, of course, exciting.

But in having an idea like that,

and then deciding to really pursue it,

you are condemning yourself to years of misery,

because you now have to flesh this out.

And to solve this mystery, Neil and Paul

would turn to one of the toughest mental challenges

of the human mind --

the incredibly strange world of 11-dimensional space...

And Universes parallel to our own.

Albert Einstein was a formidable thinker.

His theories of relativity were groundbreaking developments

that triggered a century of cosmic insights.

But even more fundamental

was his realization that time and space are intertwined.

The three dimensions of space

are really part of a four-dimensional fabric

called "space-time."

But now there's a new movement in theoretical physics.

It's called "string theory."

And out of string theory comes "m-theory."

In m-theory, there are not four,

but an astounding 11 dimensions --

10 dimensions of space plus one of time.

Uh, what is m-theory? Uh, okay.

So, uh, m-theory is an attempt to, uh --

let me start again.

Three-dimensional infinite worlds stretching off --

uh, let me start again.

Why would one even think about --

how does one make that not sound crazy in two sentences?

So, m-theory is a...

Promising, unified theory

of all the fundamental forces and constituents

that we observe in nature.

In a sense, you could describe it

as the culmination of all the developments

in theoretical physics over the 20th century.

In order to make this theory work,

one needs to have more than the usual three spatial dimensions,

so a key idea behind m-theory

is that there are more than the three dimensions of space

that we experience.

There are hidden dimensions.

In fact, there are seven more,

and 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

far more powerful than any we have.

Our three-dimensional world lives in a surface

embedded in a space with an extra spatial dimension

that separates it from another such surface.

One possibility that springs from these extra dimensions

is that this other three-dimensional world

could be just a fraction of a centimeter from ours

and yet hidden from our view.

These surfaces are called "branes,"

standing for "membrane,"

which is to remind us that these surfaces are elastic.

They can stretch, they can wiggle, they can warp.

They can move along this extra dimension.

All of the particles we're made of

are actually curled-up little branes.

And all the dimensions of space we travel in

are comprised of branes themselves.

And so everything in the Universe

is composed of these geometrical objects.

I don't know if I can repeat that again.

Caution --

you have entered a place called "brane world."

We're stuck like flies on fly paper to our brane world.

We simply can't reach out into the extra dimension --

even 10 to the minus-30 centimeters --

to touch the other brane world.

It was rough this world of branes

that Paul and Neil

stumbled onto a potentially radical new theory

of what happened before the beginning.

So, 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.

But 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.

And you could think of this gap

as being the fourth dimension of space.

And the collision of these two three-dimensional worlds --

the one we live in and another one --

would have been the Big Bang.

It would be a collision, instead of a springing from nothingness.

So, if the branes existed before and after,

that means space and time existed before.

They could have helped set up

the conditions we observe in the Universe today --

they collide, and they move apart again.

The Big Bang is not the beginning.

That means we have more time

to solve all the cosmological problems

that inflation was designed to solve.

So, we began to imagine, "could we replace that idea

with something that occurred before The Bang?"

And as we were going along the train ride,

we began to imagine lots of possibilities,

so that by the end,

it seemed like a very exciting alternative

to the standard Big Bang inflationary picture.

For the next 18 months,

the three men and another physicist, Justin Khoury,

worked feverishly to clarify and justify

their initial spark of creativity.

Now we had to make the mathematics work,

and this involved developing a lot of new physics

to explain the motion of branes moving along extra dimensions

under the influence

of a force which is trying to draw them together.

This mathematics didn't exist before.

A new theory of the Universe starts to come alive.

The 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.

The two three-dimensional worlds

are actually pulled together by a very, very weak force.

The force has to be very, very weak,

otherwise the bang would occur too quickly.

We know that the cycles can't be too short,

because the Universe has already gone 14 billion years

since the last bang.

A trillion years is probably a good, you know, typical value

for what we expect the length of a cycle to be.

As the branes approach,

the force gets stronger and stronger.

And when they collide, kinetic energy of the branes

is then converted into the hot radiation

that fills both three-dimensional worlds

and looks like the Big Bang.

So that when the branes move apart again,

they're now filled with the matter and radiation

that was created at the collision.

This then causes the branes to begin to expand again and cool,

creating a new period of expansion, cooling,

creation of new atoms, molecules, stars, and galaxies.

We now had an explanation for the Big Bang.

This 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.

But in this picture,

you are actually providing an explanation for it.

It was, in fact, the collision between these two brane worlds.

It was a theory of what was the cosmic singularity.

It was a radical and elegant solution

to one of the great cosmic mysteries of all time.

According to Neil and Paul

and their colleagues Burt and Justin,

there was always a time before time.

After almost two years of work, it was time

to present this new theory to their fellow scientists.

At a conference in Finland,

the two physicists laid out their theory.

The reception was icy.

The criticism was that we were simply assuming or asserting

the branes would be flat and parallel to begin with

without showing why that should be the case.

We'd been so excited about this idea,

and yet everyone else was just poo-pooing it.

To be fair, I mean, the session did not go well for us.

The next morning, we were both rather depressed,

so we began to travel along the River near Rovaniemi

and have this discussion

about "what could we replace this idea with?"

So, we began to think

about something that wasn't yet included in the theory,

which was the idea of dark energy.

Dark energy is a recent

and totally surprising astronomical discovery --

a mysterious force

that's causing the Universe to expand even faster.

Eventually, the dark energy will expand the Universe so much

that it will be nothing but cold and empty space.

In the language of m-theory, that translates to a flat brane.

The dark-energy phase stretches out the three-dimensional worlds

and makes them very flat and very empty and very parallel.

Of course, that immediately clicked with another idea.

Well, we're using something now,

but we're using it before the bang.

Well, maybe the source of dark energy then

was actually the same as the one now

and the Universe is cyclic somehow.

So, you could have a bang

followed by a normal period of the Universe,

like we live in today,

followed by a second bang in our future,

followed by another bang, and so on.

There are bangs and bangs and bangs forever.

Their theory was now complete.

Two branes come together, inject one another with energy,

then dark energy takes a trillion years or so

to spread that energy out.

The branes flatten and then come together again.

This cycle happens endlessly.

Neil Turok and Paul Steinhardt had come up with

a remarkable alternative theory to the Big Bang

and cracked the door onto what happened before the beginning.

As different as the models are,

they produce the same exact variations

in the background radiation.

The same WMAP image fits both ideas.

It's truly the case that when WMAP made its announcement,

the way most people interpreted that announcement was,

it's beautifully consistent

with the Big Bang inflationary picture.

To us, it meant that the cyclic model was in the game

as much as inflation was.

But which theory is right?

The answer to one of the biggest cosmic mysteries of all --

was there a time before our time? --

could be circling the Earth a million miles over our heads.

What happened before the beginning?

The question is posed. Sides are drawn.

The closing arguments are being prepared.

Is the answer "nothing"?

Did a Big Bang suddenly and inexplicably burst into life

from a time of no-when and a place of nowhere?

Or could we have bounced

from the contraction of another Universe

that existed before ours?

Or are we living a trillionth of a trillionth

of the width of an atom away from a parallel Universe,

and every trillion years,

these parallel worlds bump into one another

and fill each other up with huge amounts of energy and matter?

Professor Martin Bojowald's bouncing Universe

is still a work in progress,

but for proponents

of the cyclic and the Big Bang inflation model,

the answer to how and when the Universe started

may be moving toward us across time and space

like tiny ripples in the cosmic ocean...

...Gravitational waves.

Gravitational wave is pretty much like a sound wave.

We're used to a sound wave

traveling from me to you as I speak,

as a compression and expansion of the air between us.

And so the molecules get more densely packed and further apart

as the wave moves from me to you.

But gravitational waves ripple

not air molecules, but space itself, which means

that they can stretch out or compress a beam of light

and cause a shift in its color.

So, if space is expanded,

we'll see the radiation shifted

to red frequencies, longer wavelengths.

But if it's coming towards us, we'll see

it's slightly bluer than it would otherwise have been.

And so, by carefully analyzing

the pattern of radiation on the sky,

we can, in fact, infer if there are gravitational waves

traveling through our part of the Universe.

And rocket technology

will get the scientists far enough up into space

to espy these gravitational waves.

The Planck satellite

is the successor to WMAP.

It will be measuring the sky with about twice the resolution

and about 10 times the sensitivity.

The Planck satellite is really the first device we have

which seems to have a strong capability

of maybe finding"these gravity waves.

And if we're lucky, that'll tell us what happened

during the first moments of the Big Bang,

or maybe even before.

For proponents of The Big Bang inflation model,

finding significant gravitational waves

would be the final step in proving

that there was a giant expansion of whooshing energy

from a place of nowhere and no-when.

But Paul Steinhardt and Neil Turok

are also looking forward to the Planck satellite results.

In their cyclic model of the beginning of the Universe,

two branes coming together

would be a much less intense collision,

and the chances are

that gravitational waves would be almost nonexistent.

If we observe these gravitational waves

in the Planck satellite,

that will support the inflationary theory

and rule out the cyclic picture.

And conversely, if we don't see them,

that would strongly support the cyclic picture.

But no matter which description

of the beginning of the Universe appears to be more accurate,

the true winner will be

our own scientific understanding.

Yeah, to me, it's man against nature.

We're trying to figure out nature's secrets.

If we're lucky, we'll be surprised.

These tiny, almost undetectable waves

will have a tsunami-like effect

on the future direction of cosmology.

Instead of appearing from nowhere and no-when

and rising from stardust to humankind,

we may have to consider the mind-boggling premise

that we are just the latest version

of an endless series of Universes.

We still might not know what happened before the beginning...

But we would know that something did.

The final answer may be close at hand.

-- sync, corrected by elderman -- -- for www.Addic7ed.Com --