Wednesday, August 27, 2014

Sneeking in on Cat's Feet

The fog comes
on little cat feet.

It sits looking
over harbor and city
on silent haunches
and then moves on.

-- Carl Sandburg, 1916

This story sort of snuck into the media and disappeared almost as soon as it arrived. Not what you'd call too exciting, unless you're a Star Trek fan, but in my opinion, one of the greatest breakthoughs of the last 100 years, if the story is to be believed. Basically it's the validation of impulse drive -- a thruster that doesn't consume mass. (It consumes plenty of energy, but no mass) The mechanism has been observed for awhile. Essentially based on an asymmetric microwave resonant cavity. Microwave energy is pumped into the cavity, and a small amount of thrust is created due to the asymmetrical shape of the cavity. The microwaves are completely contained within the cavity, so the thrust isn't caused by microwave leakage. Instead the mechanism appears to be related to the variation of wave velocity within the cavity related to the cavity's width or diameter. NASA's thruster used low power and produced about 30 to 50 micro-newtons of thrust. Not very much, but measurable none the less. You can read about it here. To me there are two interesting aspects to this story. (1) A federal science agency just published data on a scientifically implausible device, and they don't exactly know why it works, but they know it works. and (2) a device has been demonstrated that most scientists would claim is impossible, but works just the same, which means that we are on the verge of a fundamental breakthrough in physics (or at least mechanics). This is how science works. A scientist runs an experiment and gets results that conflict with his theory. It's in that conflict that new theories arise.

Rosetta Craft Contacts Churyumov–Gerasimenko Comet

On August 6th, the ESA's Rosetta spacecraft successfully rendezvoused with the Churyumov–Gerasimenko Comet. Nice going ESA! The comet's furthest point from the sun is somewhere out between Mars and Jupiter, which is where it is now. It's closest approach to the sun will find it between Earth and Mars, so it isn't exactly next door. Quite the accomplishment. In the next few months Rosetta will send a lander down to the surface. Right now ESA is trying to figure out which landing area on the comet would be best.

Saturday, August 23, 2014

Opfer Müssen Gebracht Werden!* -or- Excrement Occurs

(*Sacrifices must be made!)

Before the Wright brothers were much more than a gleam in their father's eye, Otto Lilienthal was experimenting with heavier than air flight using gliders of his own design. He became known as "the Glider King" during his career and served as an inspiration to the public and to scientists working on flying machines, including the aforementioned Wright brothers. He is also famous for the quote (his last words), "Opfer müssen gebracht werden!", the English translation roughly being "Sacrifices must be made." These were the last words he told to his brother while laying on his deathbed a day after he had crashed one of his gliders and sustained serious life-ending injuries. Otto understood, as I am sure the folks at SpaceX understand, that the road to successful flight will have bumps and the odd pothole which in the case of aviation often takes on the form of spectacular accidents involving falling from great heights, crushing metal, and lots of fire. Accidents are not show stoppers, but rather the price that one is sometimes obliged to pay to discover greater understanding and ultimately more safe flight.
I'm sorry it happened, but I wish them greater success in the years ahead.

The above explosion was brought to you by SpaceX -- no small animals nor government funding was harmed in this event.