Really Obvious Science and Really Useful Science; Pluto Redux

Really Useful Science: The microwave engine

Now this really is cool: Roger Shawyer, an engineer in south-east England has designed a new kind of engine for spacecraft that has no moving parts and doesn't require fuel. It's called the Emdrive and it uses microwaves inside a resonant cavity, so it only needs a source of electricity to power it.

Better still, Shawyer has built a working prototype and measurements indicate that it produces about the same amount of thrust as the ion engines that powered SMART-1.

There are apparently still some questions about the Emdrive but if everything pans out the first real applications are likely to be space probes - all that would be needed is solar panels to provide power.

It's also been suggested that if an Emdrive could be built using superconductor technology, a 1000-watt drive - about the power of a microwave oven - could lift a 3-tonne mass off the ground.

Really obvious I: The MacBeth Effect

Psychologists have proved that when we think we've done something wrong, we really do feel better after washing. The phenomenon has been called "The MacBeth Effect" in honour of Lady MacBeth's "out, damned spot" performance.

It strikes me that these guys have got too much time on their hands - after all, I think we all knew this to be true; hell, even Shakespeare knew it was true. As for practical applications, I can't think of a single one...

Really Obvious II: Snails' need for speed

Scientists at MIT have created a mathematical model of how snails move and proved that (wait for it) snails move faster on thin slime. I think Shakespeare could have told them that, too.

Pluto reclassification redux

The new planet definition that came from the IAU last month is under fire. It seems that by the strict interpretation of the definition, Jupiter isn't a planet (it hasn't cleared its orbit of smaller bodies such as the Trojan asteroids) and Earth may not be either (Earth is surrounded by small bodies such as Horseshoe asteroids). Also, the new definition excludes all the extra-solar planets that have been discovered over the last few years - the fact of which was one of the reasons a proper definition was needed in the first place.

The whole mess will probably have to wait until the next general meeting of the IAU in 2009 before it's all sorted out.

For my own part, I think the definition should basically be something like, if it's big enough to pull itself into a roughly spherical shape and it formed from the parent star's accretion disk, it's a planet.