Well, I’m sure it’s beautiful in the daytime....

Anyway, I’m kicking off a new year of blog posts from a new country! I’ve been invited to the University of Jyväskylä in central Finland to give a presentation on my latest research project (for which blog posts are upcoming, when I get time). This is also good for the prospects of me getting a postdoc. Here. In Finland. (!!!) Apparently, this is the way the process often works: if the money is available, the top candidates for a postdoc position get invited out to give talks, as an interview of sorts. (It’s not universal, though.)

But the physics stuff is all tomorrow. For now, the first thing I noticed about Jyväskylä is that it’s very very cold, compared to almost anywhere in the US. Even though most of the country (America) is deeply frozen right now, it’s even colder here: -24 C on my way from the train station to the hotel.

I’ve also noticed that everybody seems to speak English very well, or at least anyone in any sort of service position, who I might have to interact with. The dominant language is …

Well, it’s that time of year again. The end, that is. That is the time of year that it is.

Everyone else is doing top 10 lists to reflect on their output this year, but I’m not convinced there’s anything so special about the number 10. Why stop there? With that in mind, here are all my favorite posts from the past year, representing a broad spectrum of topics: particle physics, thermodynamics, optics, fluid dynamics, rocket science, percolation theory, statistics, technology, law, and a few things just for fun.

• The coolest thing since absolute zero
• Could you light the Superdome with cell phones?
• An April Fool’s Planck, for science
• Positrons in space!! and EXTRA EXTRA (positrons)! Read all about it!
• A close look at the new CISPA
• Putting the JATO rocket car to rest
• Riding on water
• Have we really found a tetraquark?
• B meson decay confirmed!
• Interpreting Fourier transforms
• Do Teslas really catch on fire less than gas cars? and No, really. Teslas are safe
• Science comics
• Why vaccines are important
• More Higgs updates from Moriond and Higgs updates from Moriond and The Higgs boson, fermions, and you

Here’s hoping for more of the …

Again entering the realm of interesting physics from last month: a group of scientists proposed a new and quite promising explanation for the Mpemba effect, the observation that warmer water sometimes freezes faster than colder water.

The Definition

Oddly enough, even though the Mpemba effect has been known since ancient times, and its namesake paper was published over half a century ago, physicists can’t even seem to agree on a precise definition of the effect. What we know is that, if you take two containers of water (or, evidently, a water-based mixture like milk) which are identical in every respect except that one is at a higher temperature than the other, and you put them both in a freezer, under some conditions the one at the higher temperature will freeze before the one at the lower temperature. But what conditions are those? And what exactly does it mean to freeze first? Freezing is an extended process, after all; is it talking about when the water reaches zero degrees (Celsius), or when it begins to form ice, or when it is completely converted into ice, or something else?

Part of the contribution of this new paper is a proposal of …

Here’s a tidbit of science that I should have written about a long time ago. Last month, there was a surge of excitement in the particle physics community when the ATLAS detector team announced that they had pretty much conclusively observed the Higgs boson decaying to tau leptons for the first time.

Now, you might be forgiven for thinking “what’s the big deal? I thought we already found the Higgs boson?” Well yes. A year and a half later, physicists are fairly confident that what they found is the standard model Higgs boson. But back in July 2012, when the discovery was first announced, all anyone knew was that ATLAS and CMS had discovered a previously unknown particle with a mass of \(\SI{126}{GeV}\). It wasn’t clear just what kind of particle it was: the standard model Higgs boson, another kind of Higgs boson, or something else entirely. That question would be resolved by gathering more data on how the new particle interacts with other, known particles, and that’s what this most recent bit of news is about.

The Higgs search: a year in review

To understand all this in more detail, let’s back …

I’m aware that my last post was all about how I was going to return to blogging… and yeah, that never happened. It turns out that about ten days is not enough to catch up on research, file ten more postdoc applications, and deal with about 40 intro E&M students panicking over their upcoming final exam. Oh, and SLEEP. (And not become a hermit. Sometimes time spent with friends is important too.)

At this point I have 35 postdoc applications filed. To put it another way: I’ve applied to almost every job opening in the world in my field of research with a deadline since late November. It really makes the point that this particular corner of particle physics is a niche subject. Anyway, my understanding is that each position receives roughly about 200 applications, on average. If I have 35 chances to succeed at something with a probability 0.005 (that’s 1 in 200)… well, perhaps you know where this is going:

Yep, that means I have an a priori 84% chance of not getting any offer at all. For the record, when you realize you’ve applied for all the jobs and it’s …

When I arrived in Princeton last Friday, I was greeted with this headline:

Emergency meningitis vaccine will be imported to halt Ivy League outbreak

Emergency doses of a meningitis vaccine not approved for use in the U.S. may soon be on the way to Princeton University to halt an outbreak of the potentially deadly infection that has sickened seven students since March.

Well then. Perfect timing. But seriously, it is actually a perfect time to reflect on why vaccines are necessary in the first place. And it’s not (just) for the reason you might think.

If you’re vaccinated against a disease, not only does it mean that you won’t get sick, it also means that you won’t pass that disease on to other people. Vaccinations protect the people around you too. And conversely, even if you’re not vaccinated yourself, the more people around you who are, the lower your chances of catching the disease from someone else.

Let me illustrate this with a simple model of how a disease spreads. Imagine a world where people live in apartments on a perfect grid and only ever talk to their four neighbors, once a day.

Suppose …

Evidently my post from a week ago on the rate of fires in Tesla electric cars compared to gas cars couldn’t have come at a more appropriate time. People are still harping on the recent string of Tesla Model S fires, despite the fact that — as I showed in my last post — there’s no evidence to suggest that the fire risk in a Tesla is any greater than that of a regular car. In fact, if anything it seems to be slightly less.

In my last post I kind of hinted at the fact that the rate of fires isn’t the whole story. Even if a fire does happen, your risk of getting injured or killed is different in a Tesla than a normal car. Something similar goes for other types of accidents. So if you want to tell whether Teslas are safe, what you probably should be looking at is the overall rate of injuries and fatalities for Tesla drivers and passengers, compared to the equivalent for gas cars. And that number tells a very interesting story: Tesla CEO Elon Musk has written a new blog post which emphasizes that not one person has ever been …