My friend told me today about a researcher in her department who is publishing an article on the physics of frisbees. A frisbee works because of the difference in air velocities below and above the frisbee, similar to an airplane wing. Give it forward and angular momentum and it can rise into the air. That’s at least the basic idea. But apparently there are things we don’t quite understand, such as the influence the rim has and so on.
This reminded me of something that Feynman wrote in one of his books about his life (Surely You’re Joking Mr. Feynman and What Do You Care What Other People Think?)
At some point he was apparently stuck in one of the problems he was solving (something to do with QED) and he got fascinated by the shape the flow of water out of a tap. He spent some time working the physics of this and a small part of that gave him an idea for his research, which he went on to win the nobel prize for.
Just goes to show that not only is there physics in the most mundane things (cool physics at that) but there is also a connection between complicated abstract physics and the physics of everyday life.
Author Archive for J
I’m sure everyone has heard it before, but this is so cool that I can’t really mention this often enough.
Humans, animals and pretty much our entire planet, hell most of our solar system is made up of stuff that came out of stars which have gone supernova, exploded, kaboom.
When the universe first started, before the first stars collapsed, the only two elements that existed anywhere, were hydrogen and helium (and some traces of lithium, but we’ll just ignore that for now). Anything heavier than that was produced somewhere inside a star and many of the heavier elements (iron and such) were made in supernovae.
Thus we’re all little specks of star.
It doesn’t really get much cooler than that, now does it. Whenever people ask me why we should care about what astronomers do it’s these kinds of things I try to talk about. It is this kind of knowledge and understanding of the universe, which places our lives into a greater context I think. (Of course the physics we learn is pretty cool too :-)).
Today as I was doing cosmology homework, I found myself wondering, as I often do, how people did anything before the internet. (And yes I know in theory there are libraries and phone books.)
How cool is it that when I type Silk Damping into Google I get several papers and a couple of websites explaining exactly what I wanted to know.
As I was doing my homework I noticed that I’d forgotten the most important textbook in my office and so was stuck without a place to look up some important equations. To the rescue came:
There are few mathy things that I can come up with at the top of my head that MathWorld doesn’t at least have some entry on. It’s a really very useful resource when you don’t have your Math or even Physics text handy. (Of course Google knowing popular constants such as the conversion between parsecs and cm is also awesome!)
If we are talking about cool things the internet gave us, Simbad really also has to be mentioned. (Simbad is an astronomical search engine, which lets you search the sky for known objects by position. It also provides references associated with the objects.) I feel that a lot of planning of observations must have been much more painful before Simbad existed.
Today a neighbor brought by her grandson, who is in middle school and was signed up for some science olympiad. For this he had to learn some ‘basic’ astronomy, such as the difference between Population I and Population II stars. That made me realize how difficult it was for me to explain many astronomical things in laymens terms. I should probably work on that before I ever try to TA or teach and especially before I ever have to persuade any governmental agency to give me funding.
On a completely different note, I had a meeting on friday which reiterated to me again how completely dependent Astrophysics is on a good treatment of statistics. Because most of us work with large data sets everything we do relies on the type and strength of statistical test we use. The thing is that stellar astronomers always seem to drag a little behind extragalalctic astronomers, who have been working with large galaxy sets for so long that none of them can get away without doing their statistics right.
I can’t think of a cool statistics link so instead a pretty picture:
Today, Spitzer Space Telescope announced the first direct detection of a planetary object. Go infrared astronomy :-)!
http://www.spitzer.caltech.edu/Media/releases/ssc2005-09/release.shtml
Here is an “image” of the planets:
This is cool for a couple of reasons (although not the huge breakthrough news media are making it out to be). Until now extrasolar planets have been primarily detected by two methods. The first is by measuring the radial velocity of the parent star’s orbit, due to the gravitational tug of the planet. The second is by measuring the dimming of the light of the star, due to the planet’s movement in front of the star.
The technique used in this case is to actually detect the dimming of the star as the planet moves behind it and so directly be able to infer the planet’s brightness.
I have the bad feeling however, (and reading the Slashdot comments on this story gave me confirmation), that many people still get confused what we mean by “detecting” the planets. I fear that in people’s heads there are pretty pictures floating around with planets orbiting stars. In reality we cannot actually resolve the orbits of the planets and will not be able to for quite some time. Oh and on a last note, Spitzer didn’t actually discover these planets, they were previously discovered by transits.
And now some really geeky links: