Seeing temperature, kinetic energy and color

We read that temperature is the average kinetic energy of a substance but you can (especially if you’re a visual learner) nicely internalize this from simple videos or animations. UCAR has a little animation with their definition of temperature. I however, adapted an interactive, 3d animation that I think does a nice job, and also introduces a couple of other interesting concepts too.

I’ve also used this model, at different times, to show:

  • The relationship between temperature and color emitted by objects. The main way we know the temperature of stars is because blue stars are hotter than red stars. Blue light has a shorter wavelength than red light, and things that are at higher temperatures emit shorter wavelengths.
  • Absolute zero (0 Kelvin) – where (almost) all motion stops and the objects stop emitting light.
  • Pressure in a gas – you really get a feel for the force exerted by the particles on the side of the box (although it might be even more interesting once I figure out how to add sound).

It is an interactive model, but it’s pretty simple because the only control is a slider that lets you set the temperature.

Finally, in the age of 3d movies, like Avatar, the models can be easily shown in 3d if you have the glasses (redcyan).

The model is easy to install and run on Windows, but you have to install the programming language VPython separately on a Mac (but that isn’t very hard). I have this, and a bunch of other models, at http://earthsciweb.org/GeoMod/.

Evil, mad, scientist!

Why have I not found this site before, Evil Mad Scientist Laboratories. A place where people will put serious thought, rigorous design and atrocious single-mindedness to create, well I’m not sure I can call it anything other than, “very interesting” projects. Applications of robotics that would make Asimov cry (probably with joy at human ingenuity, probably).

They carefully detail how to create such wonderful projects as:

And many more interesting and eclectic projects for an interesting middle school.

How to fly through space

Interplanetary spacecraft
Ion thruster spacecraft. Image from NASA.

To get anywhere in the solar system takes a long time and is not easy. The Mars rovers took years to get there and were built to be very light because heavier spacecraft are harder to lift into orbit and take more energy to get them where they’re going (and to slow the down when they get there). Getting humans to other planets, or even another solar system, is an even greater challenge. New Scientist magazine has a nice little article on different types of deep-space spacecraft that might work.