Applying to Grad School

I haven't posted here in quite some time. I've been spending more time on my LJ and Twitter accounts (try this same username both places), and works' been pretty draining for the past year. But I wanted to post that I'm applying to return to graduate school for my PhD in either physics or astronomy, with research focusing on physics education research (PER) or astronomy education research (AER), respectively.

Stephen Hawking to retire

Stephen Hawking is facing a mandatory retirement clause at Cambridge University at the end of the year. But we all know that good physicists don't ever quit, they just go emeritus, stop teaching, and do research full time.

Asteroid 2007 WD5

Among all the hype about how asteroid 2007 WD5 has a 1 in 75 chance of hitting Mars on January 30 everyone's missing what I think is the most exciting part. According to NASA/JPL simulations it passed closed enough to Earth in early-/mid-October that our planet's own gravity is probably what actually slung it into Mars's path.

You know what's even more exciting?

We didn't discover it until November.

Comety goodness!

Tonight I saw Comet Holmes through a telescope. The last time I've seen any comet through a telescope was Haley's Comet way back in the 80's, in my childhood. I missed both Hale-Bopp and Hyukatuke (sp?) in the mid 90's somehow.

Check out the Wikipedia page on Comet Holmes. Scroll down a couple screens to "Location in 2007" and you'll see a nice finding chart - it's in Perseus, currently North of the left "arm" of the π shape that I see in it. It's clearly visible to the naked eye - I was in a brightly lit city, on campus near some lights, and I still was able to point it out to people who are NOT experienced observers. First find the stars of Perseus, and then you'll realize that one of the North-most stars is actually a bit fuzzy, and that's it.

Through a telescope it resolves into a HUGE fuzzy blob - bigger than planets, bigger than the Ring Nebula, bigger than Andromeda, maybe as big as the space between H and Χ Perseus. (Use the biggest diameter telescope you can, lowest power.) With some careful studying and averted vision you'll be able to see that the brightest center section is elongated (left/right in my tele's field of view, I think East/West actually), it's surrounded by a glowing cloud, and one edge of the cloud is crisp/sharp and slightly brighter (right in my field of view, I think the East edge) while the opposite edge fades away, presumably into the tail. There are no bright stars in the same field of view; focus while looking at a dim star, and keep your eyes on it to view the comet most easily.

It's just amazing. Go look at it, naked eye, binoculars, tele, whatever. The thing is exploding, this's probably its last pass around the Sun. (If it somehow survives, it'll be back in a scant 7 years.)

Nowak 1; NASA 0

A Florida judge Friday handed a legal victory to a former astronaut [Lisa Nowak] accused of assaulting a romantic rival [Colleen Shipman], ruling evidence found in her car and statements she made to police after her arrest were inadmissible at trial. ...no written consent was obtained to search her car.
...
On the audiotape of the interview [and Miranda rights], there was no audible response from Nowak on whether she understood that her statements could be used against her in court, and when she was asked whether anyone had threatened or promised her anything to get her to talk to police, [Judge] Lubet wrote. "Thus, there is nothing in either the audio recording or the transcript of the interview that demonstrates that defendant understood these two rights and waived them."
...
she was "subjected to a barrage of questions" beginning in the predawn hours and was questioned for six hours without being given the opportunity to sleep or make a phone call. "Defendant had not slept during the preceding 24 hours," the judge said.
...
Nowak's attorneys in August filed a notice of intent to rely on an insanity defense, saying in court documents her diagnoses include a litany of more than a dozen psychiatric disorders.

http://www.cnn.com/2007/US/law/11/02/nowak.ruling/index.html

As Foxtrot puts it, "And she made it into the astronaut corps how?"

Google Sky

Latest from Google Earth is Google Sky. If you download the Google Earth program, you now have the option to view the sky instead of just the Earth. The images for the sky come from the Sloan Digital Sky Survey (SDSS), the Palomar Observatory, and the Hubble Space Telescope. The video demo of the sky aspect looks really promising, and I'm in the process of downloading installing it right now (yay Mac version!).

I can't wait until they *really* get with it and include not only visual wavelengths (as SDSS, Palomar, and the HST all are), but also start including IR (such as IRAS and 2MASS) and radio and microwave (like COBE), and so on. All wavelengths are crucial to astronomy, not just what our eyes can see.

Meanwhile, I'm waiting for the makers of TheSky to sue Google over the name. And if you want a head slapper, find Sally Ride's mistake.

Rockin' Astrophysicist

After a 30-year leave of absense to become Queen's lead guitarist, Brian May finally finished writing his astrophysics doctorate thesis. We don't know yet if his thesis committee has accepted it, and the actual graduation wouldn't be until next May (2008).

N-body problem

Next time you need some entertainment, check out this Planet simulation game. Although "solving" the three-body problem is not possible, simulations are trivial. For a couple goals, try to get a "Mercury" type planet - closer to the Sun than the Earth, highly elliptical orbit. When you get it, it will precess naturally due to Earth's gravitation (rather than due to general relativity as Einstein proved). And a harder goal is getting a Moon to orbit the Earth (I haven't managed yet).

Planet of "hot solid water"

The BS-factor on this article is really danged high. First off, the actual sources - here's the pre-print abstract for the reference paper by Gillon, Pont, et al. (A&A May 2007), the paper has been accepted for publication in Astronomy and Astrophysics, but has not yet been published; and an earlier paper by Etangs (A&A January 2007) has already been published and if you're on a college/university campus you can click on "Full Refereed Journal Article" near the top to read the whole thing (I'm currently home and so cannot read it). I have to admit that I cannot read the full articles as of yet, but based upon what I have read I don't see a convincing argument.

Gillon, Pont, et al., and earlier Etangs studied this planet GJ 436b (its star was the 436th object in the GJ catalog, whatever that catalog was, and as the second object in that system it's labelled b) and determined its mass from how much its star wobbled (via the Doppler effect). Etangs predicted an evaporation rate based upon the star's luminosity and determined that the planet would have to have a density of at least 3g/cm³ - if the density were too low, the whole thing would just blow away from the stellar wind. Gillon et al. determined its radius from how much it dimmed its parent star when crossing in front of it (called transiting or eclipsing). Knowing its mass and its radius gives a density whose value is not explicitly stated in what I can see from home, but I'm guessing is in the range of 1-3g/cm³.

Now, I admit that density is a KEY thing when determining the composition of a planet. Gas giants (Jovian planets) have densities around 1g/cm³. Icy dwarf planets and moons (Plutinos, Kuiper Belt Objects, comets) are more like 3g/cm³. Rocky planets (terrestrials) top out the chart at 5g/cm³. However, the first problem in this situation is that icy bodies usually are NOT pure water ice (H₂O) - they're a bunch of dry ice (CO₂), methane ice (CH₄), and probably even some ammonia ice (NH₃). But they're not just water ice, so knowing a body's density does NOT fully specify its composition, just the phase and general class of composition.

Second, there's multiple ways to get the same density. Instead of being a body that's uniformly icy material, it could be high density gas or liquid in the middle, for example Jupiter is believed to have a core of liquid hydrogen. This is less likely than icy material, but it's still a possibility, and I'm not sure if there's enough information to rule this possibility out. Related (objection 2a) is that just because a material is dense doesn't mean it's in a solid state, so even if it were water, it could still be super-dense liquid water.

Which in fact is much more likely than dense ice, since water reaches its peak density at 4ºC - if you cool it any more than that, even to freezing, it becomes less dense. So to reach a high density you CANNOT have what we normally think of as water ice. If perhaps it is solid, it will be some wierd other state of solid water that we should label something other than ice, but I'm more inclined to think that it's a wierd other state of supercooled or superpressurized liquid water - or more likely not water! I think they need a chemist here.

And lastly, calling it ice is deceiving b/c of the temperature claim - if it's hot, it's not going to be ice. In fact, if it's hot I'd expect the water to evaporate!

"Extraordinary claims require extraordinary proof." I have yet to see it in this case. There is one case which I am more inclined to believe - Barman has detected water vapor in the spectrum of HD 209458b, though it has yet to be confirmed by another researcher. Spectral analysis is the way to determine the chemical make-up of any material. Until I see this evidence, anything else is just circumstantial.

LA Fires threaten Griffith Observatory

Dangit, they just finisher renovating that thing, and now a wildfire is raging through the park in which the observatory is located.

The park is in the Hollywood Hills, about 10 miles north of downtown Los Angeles. It includes golf courses, tennis courts, the city's zoo and botanical gardens and the copper-domed Griffith Park Observatory.

The bright orange glow of the fire provided a striking backdrop for the white facade of the observatory into the evening hours.

*crosses fingers*

Happy Earth Day!

It's our Earth.



Please take care of it.



It's the only one we've got.



We live on a thin skin of livable air and water. When we destroy that, it's gone.



And take care of each other. We're what makes this lifeless rock livable.