theastrophysicist

Spiral Galaxy Animation

Did you know that stars routinely enter and leave the spiral arms of the galaxy? In fact, the motion of the stars might even be in the opposite direction from what one might guess by the shape of the spiral!

The spiral arms are just regions where greater densities of stars are found. In turn, when gas enters the spiral arms, they get compressed, allowing newer, brighter, younger stars to form (presumably shown with the red blips in the animation).

I have a minor complaint though… If I were the author of the animation, I would flip the colour scheme so that brighter younger stars show up bluer.

Reminds me of traffic density waves…

Suppose you were stuck 30m under the ground, but you really wanted to know where the moon was (never mind why). What do you do?

Of course, you build a muon detector! You’d need quite a good one too, one that can determine the direction from which the muons came from. But still, beats digging yourself out of that hole. At least you’d learn some cool physics while you’re at it.

Wow… just look at those arcs! Possibly the nicest image I’ve seen showing gravitational lensing at work… The force is strong with this one!

Is it too much to ask what galaxy cluster this is?

printedlies:

We’re learning about galaxies in astronomy right now.  the universe is so fucking fascinating. it’s impossible to fathom how TINY we really, truly are.

Incredible.

Not that I can read Japanese or anything, but this looks exactly like what Professor Itai Cohen worked/is working on. Disclaimer: I have not worked with him, so I don’t know any details.

From what I recall from a talk he gave last semester, he takes 3-D videos of them to study their flight (one can easily see why this is useful). That isn’t all though: he attaches small magnets to them, and while they are flying around peacefully, he turns on a magnet to give them a kick, disorienting them suddenly. What he wants to do is examine how the fruit flies reorient themselves properly to maintain their flight.

Possible application: mechanical bees that keep flying through explosions to disorient them. Deadly.

soresore:

研究ではさらに、ハエの動きと空気力学をシミュレートするコンピューターモデルを用いた分析が行なわれ、ハエの翅と体の接合部が、トーション(ねじり)ばねのような働きをすることが明らかになった。トーションばねは、ぜんまい仕掛けのおもちゃや、昔の時計に用いられているタイプのバネだ。ハエは、この「バネ」を制御する筋肉をわずかに動かすだけで、翅の傾斜角度を変え、方向転換を発動させることができるという。

Spent a good portion of this week trying to install PYRAF on my 64 bit windows 7 laptop. Of course, my laptop is set to dual boot into Ubuntu, but seeing as to how I rarely restart and boot into Ubuntu, I decided that its finally time to try out a virtual machine. I’ve finally succeeded, and here’s some documentation on the path I took.

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Venus and Mercury, taken on 4/5/2010, on a surprisingly clear evening. 15 second exposure. Unfortunately, I was in a hurry and didn’t notice that I’d screwed up the shot slightly. Later that evening though, was fortunate enough to observe a satellite passing into Earth’s shadow. Wow!

This should be a mandatory homework problem for anyone taking physics.

Here’s my take on this article: Biologists have been getting a basic assumption about the sexuality of an animal wrong. One cannot deduce the sex of an animal from its behaviour or appearance. A particular implication is the discovery of lesbian couples in these Albatrosses, but I think the more important issue is that this could invalidate many studies of animals where the sexes of the animals are determined solely from behaviours / appearances.

Of course, I’m no biologist, and I must confess that I did not finish reading the article… Way too long and I have a prelim tomorrow.

dyfl:

This article is super-great. Engagingly written (even if it overdoes it in spots) and full of fascinating factoids and weird personalities. Sure, the Jeff Koons stock-photo accompaniment is kinda weak, but whatevs: this is a great read.

MEB commenting on Steven Strogatz’s latest post