Physicists are excited because they've found the Higgs boson.
But what is the Higgs boson? Why do we even care?
Come with Planet Science as we investigate hidden
particles...
What is the Higgs boson?
The Big Bang was the beginning of the universe as we know it.
Billions of tiny particles were made. These particles were the
building blocks of the universe, zipping around at the speed of
light.
About a trillionth of a second after the Big Bang, the Higgs
field switched on. The Higgs field is made up of lots of Higgs
bosons, a type of particle. As the universe grew, the Higgs field
grew.
The Higgs field switched on one
trillionth of a second after the Big Bang
Imagine you're swimming through treacle. It would slow you down.
When particles travel through the Higgs field, it's like they are
travelling through treacle.
Instead of zipping around, particles slowed down. Some particles
travelled slower than others. This made these particles heavier -
they got more mass.
Some particles, like electrons, do not get slowed down by the
Higgs field as much. This means that they don't get as much
mass.
Some particles, like photons, which form lightwaves, remain
massless. They move through the Higgs field at the speed of light,
as if it's not there.
The Higgs field slows down most
particles and gives them mass
Without the Higgs field, particles wouldn't have mass. They'd
still be zipping around at the speed of light. Without mass, they
would never have come together to form planets, stars and even
us!
Why do we care about the Higgs boson?
Scientists had a model for the way the universe works. They knew
what most of the particles in our universe are. But they weren't
sure why there is a variety of particles with lots of different
weights.
The Higgs boson was suggested 50 years ago as a particle that
would give other particles mass. It is the key to telling us why
other particles are the way they are.
But scientists had never seen it. So how did they know their
theory about the universe was right?
If the Higgs boson didn't exist, our best theory about the way
the universe works would have been very wrong.
What if the Higgs boson doesn't
exist? Our theory about the universe would be wrong!
The discovery of the Higgs boson means that scientists are on
the right lines. Their picture of what everything is made of and
how the universe works is probably correct.
It suggests that one of science's greatest theories is probably
right. If you were a physicist, you'd be excited too!
The discovery of the Higgs boson could lead to new and exciting
particles being found and help scientists answer even more
questions about how the universe works.
How did scientists find the Higgs boson?
How do you look for one tiny particle in a sea of other
particles?
Scientists use the
Large Hadron Collider (LHC). The LHC is an enormous pipe, 27
miles in diameter, which fires protons at each other near to the
speed of light. Protons whizz around the LHC and crash
together.
When the particles that make up protons collide, you get a flash
of energy. Electrons, quarks and protons are all produced in this
flash of energy. Occasionally a Higgs boson is produced.
Scientists crash protons
together inside the Large Hadron Collider to look for the Higgs
boson. Photo by John
McNab.
But, the Higgs boson doesn't hang around for long. As soon
as the Higgs boson is created, it decays into other particles.
These particles can then decay into other particles. This makes
looking for the Higgs boson very difficult and very time
consuming.
What happens next?
Finding the Higgs boson is just the first step. Scientists want
to know if the Higgs boson behaves as their theory predicts. If it
behaves differently, it could tell us something new.
Scientists can use what they know about the Higgs boson to find
other particles. For example, dark matter makes up a quarter of the
universe, but we don't know what dark matter is.
Keep listening. You never know what scientists will find
next!