The whole episode is worth watching, but this little section (at 10:52) of MythBusters’ attempt to build an earthquake machine there demonstrate the resonance frequency in a water tank provides a nice visualization.
Category: Natural World
Landing the Mars Rover: 7 Minutes of Terror
NASA gets dramatic. But the drama is oh so appropriate when you see what they have to do to land a rover on Mars. There are so many steps to the landing — heat shields, atmospheric friction, parachute, rockets — that it’ll be amazing if it works, and the video is a wonderful “strike the imagination” introduction to the physics of forces.
Epigenetics: How our Environment Affects what our Genes Do.
The middle-school introduction to genetics tends to start with Mendel‘s pea experiments and end with Punnet Squares. The focus is on dominant and recessive genes and what’s expressed given various combinations.
However, the way genes behave are not quite that simple. Tim Spector’s new book, Identically Different, goes into the ways that people’s behavior and environment — the things they eat; the chemicals that surround them — affect the way their genes behave. Even identical twins can be profoundly different depending on things that happen in the womb.
Perhaps the most intriguingly argument is that the behavior of grandparents can affect their grandchildren. In the post World War II period in Britain food was scarce, and some people tended to episodes of starvation alternating with binge eating. Spector links this to an increase in the obesity of their grandkids.
The idea that your behavior can affect the expression of your kids’ genes is more akin to Lamark’s view of evolution than Darwin’s.
DarwinTunes: Watching Music Evolve
Take randomly generated sound waves (using sine curves for example), mix them together to get beats, and then let people decide which ones sound best. Let the best ones mate — add in small mutations — and wait a few thousand generations for the sound patterns to evolve into music.
That’s what DarwinTunes does, and they let you participate in the artificial selection process (artificial as opposed to natural selection).
The details are included in their article: Evolution of music by public choice by MacCallum et al. (2012).
The Best Color Scale? Not Rainbow
Even though rainbow color maps look pretty, Borland and Taylor (2007; pdf) argue that they’re rarely the best choice for showing data.
The rainbow color map confuses viewers through its lack of perceptual ordering, obscures data through its uncontrolled luminance variation, and actively misleads interpretation through the introduction of non-data-dependent gradients.
–Borland and Taylor (2007): Rainbow Color Map (Still) Considered Harmful in IEEE Computer Graphics and Applications.
They recommend the much more boring (but visually useful) greyscale and bi-colored schemes, for things like temperature maps and so on where the data is continuous.
How do we know how big the Universe is?
About Fire (Flames Really)
Ben Ames explains the science of flames.
It skims over pyrolysis; chemiluminescence, where the chemical reaction (combustion/oxidation) produces excited atoms and molecules that need spit out (emit) blue light to get to their ground state); and the incandescent light emission of microscopic soot particles which produce the yellow parts of the flame.
I’m not sure who the guy chained to the rock is. It might be Prometheus, who stole fire from the gods, but I don’t remember him being sent into hell in the myth.
Observing the Venus Transit
It’s pretty amazing how ecstatic seeing a simple circle with a little blobby dot can make a person feel. Following Ron Hipschman’s instructions, I installed a small aperture (~0.5 mm) solar projector at the newly established Muddle Home Solar Observatory (MHSO). The kids and I used it, and SunAeon’s app, to observe Venus transiting the Sun. It was, in a word, awesome.
For us the transit occurred late in the day, so by the end we had trees getting in the way.
If it seems odd that the trees are at the top of the image, it’s because the images in pinhole projectors are inverted. If I flip it around the right way, the image would actually look like this.
