I recently made a video about the search for the Higgs boson particle, and on that video there a lot of comments that basically just said: "Uh, what is
this thing?" You often hear people say that the Higgs gives things mass and that is theoretically, technically true. But why
does there have to be something that gives other things mass? You also hear
it called the god particle. I kinda dislike this personally – but
without understanding quantum mechanics and field theory and the standard model,
it's hard to get any deeper than that and understanding those things is really
complicated. So it's hard to explain, but you asked for it, so here it is! So, you know about forces. Electromagnetism
is the most common force in our daily lives. We see it when we stick a magnet to the refrigerator: there's a
force there. It's also the thing that's keeping me from falling through my chair
right now. Electrons pushing on electrons so that
atoms don't pass through each other. But there are also other forces. There's gravity, and there's the strong and weak nuclear
forces. The world had previously thought that these forces were continuously radiating fields that came out from the source of
the force. But quantum mechanics doesn't allow for continuousness in that way and so what we figured out, what scientists have
realized is that it's not a field in the traditional way of understanding
a field. It's actually a distribution of particles. And the strength of any given field is actually the density of those particles at that point. So for
example a magnet which we know has a force around it has a high density of these invisible
particles called virtual particles snapping in and out of existence around it. The density of the particles is much higher
near the magnet, and drops off exponentially as you move away. These particles are very weird and wibbly and
difficult to conceive of. But because they're constantly snapping in and out of existence
they can't exist in the way that normal matter does without violating the law of
conservation of energy, which says that things can't just start existing.
So they aren't matter. But these virtual particles are actual particles. The trick has been
to coax them into existence so that we can study them. Because mass and energy are equivalent, given the right circumstances
we can dump enough energy into a system to actually make these virtual particles real
particles. We do this using particle accelerators and we've done it before.
This is how we know that these force carrier particles actually exist.
Physicists figured out that they probably should exist and then they created the circumstances
necessary, dumped a bunch of energy in and then they did exist and we said
"There! There it is!" So those are the virtual particles that create forces like electromagnetism that, you know,
two magnets won't pull each other apart. But mass doesn't feel like a force
in that way. Mass is just something that you have all the time. Why does
there need to be something to explain that? The idea is that the universe is permeated with an even distribution of a force carrier particle for mass and that is called the Higgs field, or
the Higgs particles. So that is how, according to the standard model, we now
understand forces. The question is, is mass a force in the traditional way?
And physicists say that it is. Now this might seem weird to you
because mass just seems like a thing. It's a thing that you have. You have
molecules and atoms, and they have mass. But some things don't have mass. A photon
doesn't have mass, but it's very similar to an electron on an elementary level.
So why does an electron have mass and a photon not have mass?
And so physicists have sort of agreed upon the idea that it's the Higgs
field that gives particles mass and some particles interact with it and others do
not. But instead of electromagnetism, which radiates from a point, you know, an electric charge, mass doesn't
come from a point source. Mass –– my mass would be the same, we think, anywhere I am in the
universe. So the idea is that the Higgs field, which is the field that gives things mass, exists throughout the entire
universe. The other way of saying this is that Higgs force carriers,
the virtual particles, the Higgs boson, exist at an even density throughout the entire universe. Particles
without mass, like photons, don't interact with the Higgs force carriers and so they
don't have mass, and then are other particles, like the electron, which interact weakly with
the Higgs, and thus are light, and then the top quark, which is the
heaviest particle that we know of, interacts very very significantly with
the Higgs field, so it has lots of mass. So that is the idea, and I hope that you get it. If you ask me why any of these things
are this way, I can't get much deeper without – I have no idea.
But it's all just ideas in people's heads and numbers in computers
until we can actually coax the Higgs particle into existence
and say "There! There it is! It exists! We know why things have mass."
Scientists have a very good idea of what the Higgs boson should look like. They're
basically now just trying to find the energy level necessary to give it its mass, and so they're doing that
right now at CERN. It takes a lot of energy, a lot of time and a lot of data, which is
why we still aren't sure. But hopefully, by the end of 2012, we will know
for certain, and until then we're just waiting and of course here at SciShow we will
keep you informed. If you have questions, we will do our damndest to answer them
in the comments. If you have suggestions for other things we should be covering here on
SciShow, please tell us, cuz we love your ideas, and we will also be on Facebook
and Twitter if you would like to get in touch with us there. Goodbye.
