Experiment Aims for Signal Emitted During Birth of Universe

(ambient music)

Ebax is a balloon borne telescope.

It's designed to make baby pictures of the universe.

There's a light that was emitted

when the universe was very very young, before the formation

of galaxies and clusters and stars and planets.

And that light carries the imprint,

it's like a photograph of what the universe looked like

when it was 380 thousand years old.

It also carries an imprint

potentially of what the universe was like

when it was much, much less than one second old.

(dreamy piano music)

So the first thing that we need to do as scientists

is figure out everything that's happened up until this point

in the history of the universe.

This tells us so much important information

about the fundamental aspects of our universe.

How big is it?

How old is it?

How energetic is it?

What's it made of?

Is it gonna live forever?

Is it going to die?

And furthermore, if we can really accurately measure

everything that has happened in the universe up until today,

we actually have a really good chance

of knowing and predicting what will happen

to the universe in the future.

The aim of the project is to measure what's called

the primordial gravitational wave background.

This is a signal that we believe was generated

in the moments just after the Big Bang.

Unfortunately, this signal is extremely faint.

It's very difficult to see, so in order for us experimenters

to see or measure this signal, we need to create experiments

that have unprecedented a sensitivity to this polarization.

We use extremely tiny technology that needs to be made

in a microfabrication facility

to probe the largest scales of the universe.

We use sensors that exist on the micron scale,

one millionth of a meter,

to probe the universe

which exists on the billions and billions of meters scale.

So the light will come in from the sky,

just like a telescope that you would think of,

an optical telescope.

It hits that first big mirror,

then it hits the second mirror,

and then it comes and is directed into the space

that's now occupied by this barbel looking thing,

and that is actually just a weight.

That is a weight that is now in place of the camera.

There's gonna be a very large camera

that holds cryogenically cooled detectors,

and they're cooled down to very, very low temperatures

to reduce the intrinsic noise

so that the very, very faint signal from the sky

is the thing that we see

instead of noise coming from our detectors.

There's a very specific process

that we have developed here at UC Berkeley

in order to fabricate a very specific type of detector

called a spiderweb transition edge sensor bolometer.

These detectors are fabricated by taking a silicone wafer,

depositing a very thin film,

about one micron thick, of silicone nitride,

and then on top of that we use several layers of metal,

which becomes the sensor of the detector.

Then on top of that, we add a gold layer,

which then is patterned into the shape of a spiderweb

which will actually sense the radiation

or absorb the radiation.

The photons which have this signal imprinted on them

will come through the optics of our experiment

and then fall on to these spiderweb structures

and those spiderweb structures absorb the radiation,

and that radiation will then cause the sensor to heat up

or cool down depending on how much radiation there is.

Those temperature readings will then correspond

to amounts of polarizations in different parts of the sky.

As we measure those different polarization levels

in different parts of the sky,

we're actually measuring this faint pattern

that we originally sought out to measure.

This signal would actually be the oldest signal

that scientists have ever measured,

and through measurement of this signal,

we can actually measure the energy scales

at which the universe was created.

This is one huge step towards

achieving the holy grail of physics,

a grand unified theory,

as we will actually have an experimental verification

of just how much energy the universe had

when it came into existence.

(intense music)