PFE031: Thunderstorms

Thunderstorms are awesome am I right?

Lightning! Thunder! Rain [sometimes]! Pretty. Loud. Pretty LOUD!

So why am I looking to muck pretty awesome things up with numbers? Because, I don't know, it's you who's reading this, it's probably more of your fault anyways [see above image].

Right, so we're going to review a common and fairly well known trick: the five second rule.

Not that one, the one about lightning and thunder.

Lightning and thunder happen at basically the same time... at the location of the lightning. So if you get hit by lightning you'll see the flash and hear the thunder at the same time [or you won't because your brain will be rather well-done, I don't know]. But as you move away from the lightning [generally a good idea] everyone knows that the thunder slides away from the lightning too... in time. That is, you see a flash and then... BOOM.

Let's science this up now. Light goes fast. I mean, really fast. Count one second: "one one thousand". Light from the earth is basically to the moon in that time. So we can pretend that light's instantaneous for any distances on earth that we are ever going to care about.

Sound, on the other hand, is comparatively pokey. Since sound travels through something [air in this case] it is a little bit dependent on the properties of that material, but at 50F [a reasonable temperature for a thunderstorm I figured] sound travels at about 1107 feet per second. How fast is that? Well, let's see, it's certainly faster than I can run [thank goodness! Otherwise there would be sonic booms all the time]. If we then convert that into seconds per miles [which might seem like a weird unit unless you're a runner] we get about 4.77 seconds per mile - it takes sound just under five seconds to travel a mile.

BUT WAIT! THERE'S MORE!

So apparently sound travels faster when there's more humidity in the air. This is actually a little bit complicated, but a simple model gives about a half a percent increase. This brings our timing down to an even shorter 4.75 seconds per mile. Whatever.

This gives us our standard five second rule [unlike the food one above, this one is rooted in SCIENCE, YEAAA!!!]. Start counting time as soon as you see lightning and stop as soon as you hear the corresponding thunder [if the storm is too active it can be tough to tell which boom corresponds with which flash - you're on your own in these cases]. Take the number of seconds and divide by five [then round up a teensy bit if you want to be more accurate] and that will tell you how far away the lightning is. If you counted 8 seconds you're looking at ~1.6 miles away. Is it just that easy? It's just that easy.

But... who cares how far away it is? What we really care about is

Shh. I'm counting between the lightning and the thunder to see if the storm is coming or going.

whether the storm is coming, leaving, or passing us by. If we repeat the above process, we can get the distance to the strongest part of the storm over a period of time. If the distances are shrinking head for cover. Of course, you can also probably tell if the lightning is getting brighter and the thunder is getting louder and if it starts pouring on your poor unprotected head - but this way is way more fun.

That's thunderstorms.

PFE030: The Higgs Mechanism Part 3 - The Discovery

The LHC is a pretty awesome machine. It took ten years to build the final component and uses five smaller accelerators to seed it. It is essentially the largest and most complex thing humans have ever built and the largest computing grid we've ever put together is employed to process the largest amount of data ever generated. It's also the largest refrigerator [okay, cryogenic facility but it's more fun to think about how much beer/potato salad would fit inside than super conducting magnets]. It also has reached the highest energy and luminosity in any man-made device ever. Whatever.

Kegs too.

I reiterate these things to emphasize how awesome of a machine it must be and how hard it must be to find whatever it's looking for.

While the Higgs field is everywhere and interacting with most things, it's hard to directly observe it. Luckily it has a side business creating additional particles, the Higgs boson. We can create, observe, measure, and quantify these particles - all those tasty things us physicists like doing. Unfortunately, it's not very good at making them. Lots of other boring particles [the kind of stuff we're made of and a zoo of other yawny stuff] are far easier to make. It's like looking for a needle in a haystack of haystacks [okay it's nothing like that because you or I could eventually suss out the needle and I have no idea how to even turn on an LHC - but it's really really hard].

Luckily, there are piles of physicists sorting out exactly how big the haystack is supposed to be. If it looks even teeny weeny bit [that's a technical term - move along] bigger than it's supposed to, then ta-da! We've got... something!

Just 365 short days ago [really they were all pretty average length days] on July 4, 2012 - it was announced that they had found something. It was definitely a boson, probably spin zero [remember that the Higgs is the only spin zero particle so far], and was consistent with the expected properties of the Higgs boson.

Put out the flag, grill some hot dogs, and call it a day, right?

If you look very closely you can see the SSC - the experiment that would have made this discovery an American one instead of a European one.

It's not done. We're not satisfied that easily. See, the predictions for this particle aren't just that they're a pain to make, but super specific. It should be this tall, this fast, this smart - it should have have these friends and hate those people. So on and so forth. But there are a bunch of crazy people who make things up [cough cough like me] who suspect it could be very slightly different. And to rule them out, or confirm their theories, they need measurements far more accurate than the general properties determined so far. Lot's more to do!

That's how you find a Higgs!

Spoiler alert: next week is both practical and not about particle physics!

PS - that isn't quite the end of the story. It appears that things could be rather more complicated than previously expected as indicated in my signoff. There may already be evidence of a second Higgs - don't go telling your friends or anything yet - but this is a key component of many popular theories whatever that means.

PFE029: The Higgs Mechanism Part 2 - How It Acts

Last week, we heard about why we need the Higgs mechanism to fit in with everything else we know about little things. This week we are going to look at "how it interacts with stuff".

Personally I've always been a fan of this

graphic but whatever, it's super confusing. Let's start with the Higgs at the bottom. The line connecting it to itself means that it interacts with itself. The rest of the lines coming out of it means that it interacts with quarks, W and Z bosons [the weak bosons] and some of the leptons [in particular, the electron plus two others]. Notably absent from that list are gluons, photons, and those other leptons [neutrinos].

Okay, what?

It turns out that these are the particles that have mass. Of course, this is what was mentioned last week. Particles that have mass - a resistance to motion - interact with the Higgs. So the Higgs must somehow resist motion. Since the mass of a particle is proportional to how strongly it interacts with the Higgs, it appears that the Higgs itself, somehow, causes a resistance to motion.

Remember that pushing a monster truck is hard even in space with no gravity and no friction - that's because it still has a giant mass.

At this point people usually try to describe the Higgs as something like "sand that we are all moving through that slows us down - the heavier we are, the more we slow down". Of course this is a terrible description. Okay, not terrible, but still misleading.

The problem is that now everyone is thinking about aerodynamics - a frisbee flying in the regular fashion or flopping through this "Higgs sand" all sideways. But of course, that has nothing to do with it. The frisbee interacts with the Higgs field in the same way no matter how its moving.

Let's think of it a different way - in terms of what doesn't interact with the Higgs. Well there are gluons, but no one wants to have to think about those if they don't have to. There are neutrinos, but since the question of their mass is rather complicated and unclear, we'll ignore them too. Luckily, we still have photons or light - something that we are all familiar with!

Light particles don't interact with the Higgs - they may cross paths, but won't even notice it. What evidence of that do we see? They go at the speed of light!

"Wow, thanks there. Light goes at the speed of light? Great one. Now it all makes perfect sense."

Don't think of "the speed of light" as, well, "the speed of light" quite so much - think of it as the universal speed limit. The fastest that anything is allowed to go.

And since photons don't interact with the Higgs, they are always cruising along at a chill 669 million miles per hour.

But everything else [people and cars and toasters are made up of quarks and electrons] travels slower because they keep interacting with the Higgs field so much.

At this point its somewhat important to differentiate between the Higgs field and the Higgs boson. The field exists everywhere. It is here. It is there. It is in a box. It is in a fox. At any time and at any place, any particle that is allowed to interact with it [quarks, airplanes, electrons,... but not photons] does. This constant uniform behavior makes sure that all electrons have the same mass everywhere.

The boson - the particle - associated with all this nonsense, is a result of the fact that the field interacts with itself. A field doesn't have to do this, but because this one does, the Higgs boson itself has a mass.

That's how the Higgs acts.