OK, here we go.
In 2012, we discovered the Higgs boson.
It was a historic moment.
I remember it vividly because the science community was just
so super pumped when we finally found it.
They'd been working for so long to do it.
In fact, that is what the Large Hadron
Collider was built to do.
It succeeded in its mission, which is great, but now what?
Over the next two years, physicists, engineers,
and postdocs, and scientists are hand-building new components
and are set on creating a brand new system, the High-Luminosity
LHC.
This upgraded machine will produce 10 times more particle
collisions than the LHC used to.
It will make 15 million Higgs bosons every year.
So what do they do at CERN when the LHC is shut down?
Kind of a lot.
Hey there, you big bunches of particles.
I'm Trace.
Thanks for watching.
When it's running, the Large Hadron Collider
contains beams of charged protons shooting along
its superconducting pipes at nearly the speed of light.
The data gleaned from these particles smashing together
inside the largest scientific experiment
ever built is astronomical, to use just the right word.
When it's running, particle physicists all over the world
are rapt with attention.
They're writing papers, they're reading papers,
they're forming hypotheses, and they're
trying to get time in the experiments
at CERN to test them.
But right now, there's no beam in the LHC.
Here's the live view today.
Yeah, it's off.
When it's off, the particle physicists
don't have particles to peer at, but that doesn't
mean that they just sit idle.
Yeah, we all went away on vacation for two years.
That is Steven Goldfarb.
I am a physicist.
I work for the University of Melbourne
on the ATLAS experiment on the Large Hadron Collider
here at CERN.
Well, I think, in fact, we're working even more
during a shutdown than when there isn't a shutdown.
One, we continue to do analysis of the data, which
we do forever.
And some analyses are just very, very complex,
and so it takes a lot of effort to do them.
But then at the same time, you have
people who are working inside our detectors,
or just outside, preparing new components to be installed.
So right now what we are doing is pulling some magnets out
of the tunnel, putting magnets in, changing beam dumps,
digging tunnels.
For example, near the experiments like ATLAS or CMS
that people might know more, we're
building shafts and tunnels so that in the future
we can put more equipment and more service tunnels.
These kind of things are going on right now.
And that is Andrea Santa-Maria Garcia.
And I did my PhD here at CERN, and then I did a postdoc.
At CERN, a shutdown can actually be busier
than when beam is running.
I mean, look at the schedule.
This is what they're working on during what they call
the LS2, or Long Shutdown 2.
There is so much going on here, and there's so much to do.
And they're doing all of this for one reason,
because they achieved their goal of finding the Higgs boson.
I mean, if you think about it, it's
the same thing that you would do when
you reach the end of a race.
You go back to the starting line, and you race again.
And for CERN, that means creating the High-Luminosity
LHC.
But it sounds cool, but what does that even mean?
So luminosity is what we call the rate of particles colliding
per second.
Well, that's the peak luminosity,
and then what we call integrated luminosity's
all of the recorded data.
So now, what we want to-- we will
increase 5 times the rate of collisions, and 10 times
the recorded data.
And for these we need to do--
it looks obvious.
It's like, just run it more.
But actually, it's much more complicated than that.
Increasing the amount of data we're getting per second--
it taxes everything.
So the detector has to be able to recover.
Right now, when there's a collision,
it happens every 25 nanoseconds.
So in 25 nanoseconds, you have to be
able to have a particle go through,
measure that, and then recover and be
ready for the next collisions to happen.
It basically means they're going to pump up everything.
They're turning the LHC up to 11,
which means every link in the chain also has to be upgraded.
And this means that you need a lot of resolution,
and for this, you need a lot of computational work.
And actually, there are a lot of algorithms
that, from what the detectors see,
they reconstruct these jets.
And this is all computation.
It's crazy.
But also, we need new detectors, new ways
of pulling out the data fast.
It's incredible.
And then you've got all the software
that has to process everything, take that data and processes
it.
So all of that has to happen more quickly.
So the whole chain has to be made to work.
It kind of helps to think of it this way.
The ATLAS, the CMS, the LHCb are experiments
that sit on the Large Hadron Collider,
and they are like giant cameras.
Right now these cameras take pictures
of 20 particle collisions or so every
about two dozen nanoseconds.
The computers at CERN have to decide
if one of those collisions is worth storing in memory.
And if so, they save it and send it for further calculation.
Then they reset everything again before the next collision
happens.
This is a matter of nanoseconds we're talking about.
But the High-Luminosity LHC is going
to deliver 10 times more particle collisions
to the experiments than they get now.
That is so, so much more.
If they had 20 collisions before,
now they're going to have 200, and they still
have to do this whole job.
So you guys are like, here's some more beam.
And then they're like, oh, my god, we [INAUDIBLE]
to do with all this data?
That is exactly what's going on.
That seems like an OK way to go.
That seems like a good life.
Think of it this way.
Just like when you go to a football game,
you can't really take a clear picture of the action
if the camera isn't fast enough.
So because we are upgrading to the High-Luminosity LHC,
we also have to upgrade the "cameras," or experiments.
That way, the experimenters can see the collisions
better and more quickly.
And it means upgrading components,
and creating new sensors and new detectors and new systems.
And all of this is a lot, and it's been years in the making.
The technology has improved, so we're
working on improving our detectors
and preparing for this higher luminosity,
preparing for the idea that we're going
to have many more collisions.
And that changes things, is a game changer.
It means that our detectors have to work even faster.
We're talking about moving from 40 million collisions
per second to even more.
And it's insane, when you think about it,
but that's what we do.
Because they will need to detect many more practical collisions.
And so all of the detectors maybe they're
going to be stripped apart, and new ones will be built.
But they're starting-- they're already full in development.
And now is just the sprint to get it installed.
And you might be wondering, as I was, why?
We did this Higgs boson thing.
We know it's there.
What are we trying to do?
What is the goal?
You guys know we discovered the Higgs
boson, which was the main goal for this Large Hadron Collider.
And we did it, but it's a very weird boson.
It's like a very weird particle, and we still
don't know its properties.
So the first goal of the High-Luminosity LHC
is to have the range to study its properties.
That's the main goal.
We have a policy, which is actually
our theory, the standard model, we
call it because it's been working since 1969.
It's been perfect, which is really annoying.
We hate that.
We want to find evidence that breaks it.
That's the only way to go forward
is to find where what we measure,
where the physical world differs from the model.
If it answered all the questions, we'd be fine.
We'd be done.
We're out of here.
But it doesn't, and there's huge questions out there.
When we say particles here, we mean fundamental.
Something that's a point.
There's no structure to it.
It's the bottom of the chain.
It's the LEGO brick that cannot be broken anymore.
We're driven by, like, how do we find those?
How do we how do we understand them?
How do we measure all of their properties,
and then understand the rules behind them?
So we have really, really deep fundamental questions,
and just by having those questions,
that just automatically drives technology.
To do this, we need to get down to this scale,
so we need a higher energy, et cetera, et cetera.
But that's not all.
The hydrogen beam is going to be denser.
The collisions will be more frequent,
and the amount of data generated is just going to skyrocket.
We also want to accumulate more data,
so the energy at collision is going to be the same,
but the point is to accumulate 10 times more data per year.
If you see how we have advanced with the data
collection along the years during the LHC life,
the Higgs boson has only appeared with enough data
was accumulated.
Here it's not about doing many fancy things.
It's about statistics.
So we need to really increase the statistics
if you want to see something, not only the Higgs properties,
but anything new.
I mean, the driver behind all of this
is simply that we have these very important questions
that we're trying to answer, the very fundamental questions
that particle physics raises.
Where did we come from?
Why are we here?
Where are we going?
What's going to happen to this universe?
And what are we made up of, what are the fundamental components
of us?
Real quick, let me just go back to something that Andrea said.
It's about statistics.
We saw the Higgs boson after we accumulated enough data to find
the signal in the atomic noise.
So if CERN produces and catalogs 10 times the number
of collisions and creates 10 times more data every year,
that's how they'll see the next big thing.
That's how they're going to solve
more fundamental questions we have about the universe.
That's how they're going to see if the LEGO brick can
be broken into smaller parts.
And there's huge questions out there.
Right now, the standard model, which
has been working since 1969--
it's fantastic-- explains only 5% of the matter in the world.
There's a lot of area out there that we just simply
don't [? understand. ?] The Higgs boson could have clues
in it, and we've just started to measure .
We've really just started.
It's a potential window to new physics, but we don't know.
We don't know.
So we have to measure it as precisely as possible,
and for that, you need lots, and lots, and lots of data.
So before all this, I walked into the CERN control
center wondering, why is the LHC shut down?
What happens during a shutdown?
Does everybody just go home?
No way, past-Trace.
If we're really going to crank this up to 11,
we need a better atomic camera.
We need more particles, more collisions, higher resolution,
and more power.
We just need more.
Maybe you're watching this and thinking,
WTF is all this quantum particle stuff anyway?
What's going on here?
You should click over to Brilliant and learn about it.
They have a course specifically about quantum objects--
those are things smaller than atoms-- and it's great.
I never really understand something
until I get the why of it.
I'm just a curious guy.
I need to know why.
Passively watching something doesn't get me there,
but Brilliant does.
It's like the best school teacher
you've ever had combined with a good storyteller.
For example, I wanted to know more
about the interference in radio telescopes,
so I took their course on light and waves.
And it was awesome.
I found myself saying, huh a lot, which is a good thing.
And as you learn on Brilliant, there
are quizzes which aren't intimidating at all.
Instead, you get to check yourself and make
sure you're understanding as you're learning and growing.
The little quiz questions, they actually
make me feel like I get it and that I'm
on the right track, which is super great.
Try it out, and let me know if you agree.
Click over to Brilliant.org/Trace or grab
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The High-Luminosity LHC is slated to end its Long Shutdown
2 in February of 2021.
From there, it will spin back up,
and physicists, experimentalists,
and theorists around the world will kick up their work
to a fever pitch again.
But now they'll have 10 times the raw material to work with,
and I cannot wait to see what they do with it.
But in the meantime, we're still in upgrade mode,
which means there's a lot more stories to tell.
Thank you so much for watching, everyone.
This is part 1 in a multipart series on CERN.
The next one's going to be out soon.
And in that one, I look more closely
at one specific project happening
during the Long Shutdown 2.
So subscribe, click the bell to get notified
when that one comes out next week,
and send this video to someone who
doesn't know what CERN does.
Thank you, thank you so much for sticking around and watching
this video.
I hope you learned something.
I know I did while I was researching it and writing
it and traveling all over the place to tell it.
So thanks again.
Join the Patreon if you really want to kick up your support,
and I'm Trace.
I'll see you in the future.