Friday, July 06, 2018

Spiders fly via electrostatics

Interesting article on the spiders' ability to detect electric field and use it to propel themselves in air.

Thursday, February 22, 2018

Black Hole Apocalypse

I just happened to see that my DVR recorded a new Nova special, Nova: Black Hole Apocalypse. It's hosted by Janna Levin, a physicist who is recently pursuing outreach via books and hosting panels and such.

The early part talks a bit about LIGO's discovery, and then transitions with the non-astounding line "Today we know more about black holes than ever." Good to know that we've not gone backwards!

I'm wondering what's the apocalypse? Falling into the black hole? So what's new? I just don't get the title.

And I get that making an effort to showcase female scientists is worthwhile because it makes sense to (i) work a systematic bias, and (ii) show young folks that physics need not be a dominantly male enterprise. But I've seen only two males versus at least six females so far. I just checked the "Participants" tab in the first link above and I guess things get more evened out later in the show.

More generally, I wish these shows gave a little info about why these particular scientists were chosen to speak on the show. In other words, why don't they tell us what each researches (even if just a couple sentences and no more than maybe ten seconds)?

Anyway, I'm not sure when I'll get a chance to finish the show, but I'm generally a big fan of Nova shows.

Friday, February 16, 2018

Physics in the News and Olympics

  • There are two kinds of people in the world (I have a number of these but of course can hardly remember more than one at a time):
    • those who keep open many tabs in their browser and those who can't stand to see tabs open
    • those who can pick up a foreign language easily and those who get passed by quickly in language class
  • I only tend to see commercials while watching sports. But they've either gotten worse or I've become even more curmudgeonly. My faith in humanity can't afford any more dings. As just one example, why does it seem that every SUV commercial espouses the ability to drive when you shouldn't be on the roads? I'm thinking specifically of the Jeep commercials in which they show weather reporters in the middle of saying "It's not safe to drive" while some yahoo drives his (always geared towards men) vehicle into a clearly constructed soft pile of snow that a Smart 2 could probably tackle. As a whole, these commercials seem to appeal to our anti-social and selfish instincts; I don't care what effect I have on the environment or on others, I just want what I want. Indeed, I think they want certain things because there is a cost to others to demonstrate their importance. I won't even comment here about those who support the NRA. I'm sure this can't be a new observation, but I need to be able to keep these thoughts at bay in order to be civil to those around me.
  • Olympics
    • First off, I really don't like the tally of medals by country that I see everyday on the pages of US newspapers. When watching an event with competitors with whom I'm not familiar, I'll tend to root for any Americans. However, if given a reason, I'll gladly root against the American (if he/she appears un-sportsmanlike for example, or if I'm simply moved by some compelling story for someone from another country). But even so, aren't the Olympics about countries coming together and not yet another country versus country competition (such as the Davis Cup (tennis), the Ryder Cup (golf), and others in less snooty sports [e.g. the World Cup])? Update: Here's a nice story that typifies the Olympic spirit so much better than these annoying medal tallies.
    • There's lots of physics in sports generally, and the Olympics in particular:
      • A speed skating race was so close they apparently had to use slow motion video to decide the winner. The frame rate seems to be an obvious determining factor in the timing uncertainty.
      • Curling involves friction in a non-trivial way with the sweeping (as noted below). Chad is discussing both friction on ice and other physics at the Olympics.
  • Physics in the newspaper:
    • In the sport of curling, should one maximize the normal force at the expense of speed? Try a smartbroom
    • I keep telling my students that they have some instinctual sense of physics, but was surprised by the animals in this article. I particular the comment that we're not so good at counting because instead we can understand the sentence: "There is no non-vanishing continuous tangent vector field on even dimensional spheres" (if you somehow you lack instinctual understanding [jk] of this sentence, perhaps see this Wikipedia page).
  • Students are always questioning why they need to take certain classes. A teen in high school was questioning having to take math with the usual whine, "when am I ever going to use trigonometry?" I'm not terribly inclined to participate on those terms because I think most people will never use trigonometry (and so perhaps the answer is to rethink what we teach and give options possibly more directly applicable to the world, like this math class as a substitute for Algebra 2).

    Indeed, I think people, at least in this country now, tend to pursue willful ignorance (more anti-social behavior) and laziness, trying to do nothing that uses their brain. Instead, I questioned the teen on why they need take any more classes at this point. Can it really be argued that what they learn in an English class at this point will benefit them or the country more than what they learn in physics or math or really anything? Certainly one could launch into a soliloquy about improved writing skills from English, more informed electorate from history, etc. But it's not working: the electorate is not only ill-informed but appears to believe in fake news. Maybe we can co-opt the conservative push to allow the immigration of only the good ones into an even more radical policy: a test to maintain one's citizenship to be taken at regular intervals (perhaps every ten years to match the census). A sort of "common core" for citizenship (I'm forgetting who was against common core but I think it was the conservatives, but that seems to be antithetical to their immigration stance).