Science with Crossbows

From today’s seminar: “Of course, you cannot do this experiment in ordinary atmospheric pressure. It will explode. We observed this. It was quite messy.”
Also, the presenter was a German scientist with a group trying to model planetary accretion. Their experiments needed to propel marble-sized samples into a 1kg dust target in vacuum. The found the best way of doing this was with a small holder mounted to an arrow which was fired from a crossbow. The crossbow was placed in the vacuum chamber and was fired remotely. The holder and arrow would be stopped as soon as they were no longer accelerated by the bowstring and the samples would then fly out of the holder to the target.
It’s worth pointing out that the title of the presentation was “What can Wilhelm Tell teach us about planetary accretion?”
I imagine the paperwork needed to approve the purchase of the crossbow for the lab went something like this:
Item: Crossbow
Quantity: 1
Reason: SCIENCE!

On Distant Things

Voyager 1 has passed the range of solar wind (subatomic particles streaming out from the sun). After examining the data transmitted back, scientists determined that this has been the case since June.
It’s moving at 60,000 kph, and in just a few more years it’ll cross the threshold to interstellar space ((The heliopause.)) and become the first manmade object to make it into enormous emptiness between the stars. “Enormous emptiness” doesn’t come close to conveying how hugely enormous and empty the space between stars is.
According to the Wikipedia, it’s been 33 years, 3 months, and 9 days since the probe was launched, and it’s been on-mission for 31 years, 11 months, and 10 days. That’s pretty incredible, considering the technology of the day.
Its radioactive power sources have enough fuel left to power the probe (with decreasing functionality as available power decreases) until about 2025.
Although it’s merely a tiny thing hurtling through space, it pleases me that it’s been operating since before I was born, and will continue its journey — albeit out of power — long after I’m dead. I can only hope that at some point in the future, humanity will venture to the stars. I hope that when that happens, they leave Voyager to coast though the inky blackness of space as a testament to the vision of those who sent it.

Small Things

The 21″ telescope on campus recently got an upgrade.
Or, more precisely, the observatory got an upgrade: light bulbs.
Due to various mishaps over the last few years, the incandescent-bulbs-dipped-in-red-paint have burnt out, shattered, or otherwise stopped working. They’ve been replaced with red-tinted CFL bulbs, which run a lot cooler, and have the tinting applied at the factory. Presumably they’re designed to deal with the extra insulation of the red coating without overheating.
That, and one of the PhD students put a red rope light around the elevated platform and steps, so undergrads coming to observe for their classes don’t trip and die on the steps.
Before, it was difficult and dangerous to negotiate the observatory floor due to poor lighting. Now it’s downright festive.
Who knew that such small improvements would be so nice?

Big News Forthcomimg

Assuming we don’t get scooped in the next week or two, it looks like the small group I do Astro research with has made a cool discovery.
More details after we publish. No sense in counting our chickens before they hatch. I’m just excited though.


Astronomy always seems like something that’s incredibly awesome: you get to look into the depths of space, unravel the mysteries of the universe, and even the general public “gets it”…unlike, say, physics.
It’s not like that at all. Not at all.
Instead, you sit in a windowless, stuffy room all night, look at lolcats online, and occasionally go upstairs into the bloody freezing dome to make sure the telescope hasn’t exploded, fallen off it’s mounts, or generally gotten into trouble (( Since it’s controlled by an ancient computer running Fedora Core 1, it occasionally gets into trouble. )). Oh, did I mention the whole “staying up until 6am, two nights in a row, even though you have both classes and a day job” thing? Don’t forget the eating-Easy-Mac-because-the-kitchenette-sucks aspect as well.
Oh well, at least I get paid for it. Wait…I don’t get paid? Son of a…

Poor Photons

Last night, I found myself up at the observatory again. Surprisingly it was not a Dark and Stormy Night, but there were a few clouds that kept us from opening for some time.
Personally, I find it somewhat of a downer that these photons originated in a star mumbledy-mumbledy brazillion miles away, flew through the uncharted depths of space past wonders unknown by human minds, avoided vast interstellar dust clouds and other celestial obstructions, and traveled on a path destined to intersect the imaging system of a particular telescope on a particular mountain on the third planet of a rather ordinary, uninteresting star in the spiral arm of one of billions of galaxies…only to be intercepted at the very last possible moment by a wayward floating blob of water vapor a few hundred feet above the telescope.
The final result of their mumbledy-mumbledy brazillion mile tour of the universe was not, unfortunately, to be detected by advanced equipment, analyzed by up-and-coming scientists, and hopefully used to allow said scientists to better understand the universe. Rather, the result was that a particular blob of floating water vapor was heated by some infinitesimal fraction of a degree while the scientists below shake their fists and curse the clouds.
Truly, a rather pedestrian end to a photon that has traveled so far.

Mars Update

Not only did the University of Arizona’s Phoenix lander land safely on the surface of Mars yesterday and get some neat photographs, but the HiRISE camera (also owned and run by the University of Arizona) on the Mars Reconnaissance Orbiter managed to snap a picture, from orbit, of the Phoenix lander parachuting to the surface.
Talk about a long shot: the Phoenix lander was all bundled up for the descent, and was less than two meters in diameter. To get the picture, the MRO had to rotate 62 degrees off-down-axis and take the picture from a highly inclined angle. My back-of-the-envelope calculations show that the MRO was about 602km (~375 miles) away from Phoenix when it took the photograph. That’s some impressive photography.
This is the first time in history that a spacecraft has photographed another spacecraft landing on Mars.
I seem to have recovered somewhat from the excess champagne consumed yesterday. All of us here at the UofA are still quite giddy about it. Regular posting will resume shortly.

Slow Blogging Day

Today will be a slow blogging day: the University of Arizona’s Phoenix lander will be landing on Mars in a little more than three hours, so I’ll be on campus for most of the day.
If anyone in the Tucson area wants to stop by, say hello, and (hopefully!) celebrate the landing, feel free to drop me an email and we can meet up.