Comments on: Revealing the Veil http://blogs.discovermagazine.com/badastronomy/2007/07/31/revealing-the-veil/ I am an astronomer, writer, and skeptic. I likes reality the way it is, and I aims to keep it that way. My real name is Phil Plait, and I run the Bad Astronomy blog. Mon, 01 Dec 2008 22:27:55 +0000 http://wordpress.org/?v=2.3.1 By: HarareFlyer http://blogs.discovermagazine.com/badastronomy/2007/07/31/revealing-the-veil/#comment-44115 HarareFlyer Sun, 16 Sep 2007 06:33:15 +0000 http://blogs.discovermagazine.com/badastronomy/2007/07/31/revealing-the-veil/#comment-44115 Phil, great writing. Stumbled here. Now feeded up. More please. Phil, great writing. Stumbled here. Now feeded up. More please.

]]> By: Jack Hawkins http://blogs.discovermagazine.com/badastronomy/2007/07/31/revealing-the-veil/#comment-44090 Jack Hawkins Thu, 02 Aug 2007 15:55:31 +0000 http://blogs.discovermagazine.com/badastronomy/2007/07/31/revealing-the-veil/#comment-44090 I don't understand: how can this thing be 10,000 years old when according to Genesis the world is only 6,000 years old? I'm kidding of course. This is a beautiful image of a truly impressive event, and a great article. Thank you. I don’t understand: how can this thing be 10,000 years old when according to Genesis the world is only 6,000 years old?

I’m kidding of course.

This is a beautiful image of a truly impressive event, and a great article. Thank you.

]]> By: Anne http://blogs.discovermagazine.com/badastronomy/2007/07/31/revealing-the-veil/#comment-44088 Anne Thu, 02 Aug 2007 05:39:46 +0000 http://blogs.discovermagazine.com/badastronomy/2007/07/31/revealing-the-veil/#comment-44088 The nebula is beautiful! From that description, though, it's not clear why it's not just a sphere. Certainly inhomogeneities in the interstellar medium will have some effect, but in fact the Rayleigh-Taylor instability is what leads to the complex shapes that nebulae have. That instability is how a heavier fluid on top of a lighter fluid begins to exchange places, and you can build a <a href="http://peridot-faceted.livejournal.com/2871.html" rel="nofollow">little toy to demonstrate it</a>. The nebula is beautiful! From that description, though, it’s not clear why it’s not just a sphere. Certainly inhomogeneities in the interstellar medium will have some effect, but in fact the Rayleigh-Taylor instability is what leads to the complex shapes that nebulae have. That instability is how a heavier fluid on top of a lighter fluid begins to exchange places, and you can build a little toy to demonstrate it.

]]> By: Lyle Gaulding http://blogs.discovermagazine.com/badastronomy/2007/07/31/revealing-the-veil/#comment-44087 Lyle Gaulding Thu, 02 Aug 2007 05:15:56 +0000 http://blogs.discovermagazine.com/badastronomy/2007/07/31/revealing-the-veil/#comment-44087 Indeed, very like a dragon. Indeed, very like a dragon.

]]> By: Seed's Daily Zeitgeist: 8/1/2007 - General Science http://blogs.discovermagazine.com/badastronomy/2007/07/31/revealing-the-veil/#comment-44086 Seed's Daily Zeitgeist: 8/1/2007 - General Science Thu, 02 Aug 2007 02:55:47 +0000 http://blogs.discovermagazine.com/badastronomy/2007/07/31/revealing-the-veil/#comment-44086 [...] Revealing the Veil Star death brought us this incredible image. [...] […] Revealing the Veil Star death brought us this incredible image. […]

]]> By: MattFunke http://blogs.discovermagazine.com/badastronomy/2007/07/31/revealing-the-veil/#comment-44089 MattFunke Wed, 01 Aug 2007 21:01:53 +0000 http://blogs.discovermagazine.com/badastronomy/2007/07/31/revealing-the-veil/#comment-44089 Irishman: <i>MattFunke, your math appears off.</i> Oops. You're exactly right. Thanks for the correction. I realized it myself some time afterward... I multiplied where I should have divided. (Always use dimensional analysis!) Irishman: MattFunke, your math appears off.

Oops. You’re exactly right. Thanks for the correction. I realized it myself some time afterward… I multiplied where I should have divided. (Always use dimensional analysis!)

]]> By: Irishman http://blogs.discovermagazine.com/badastronomy/2007/07/31/revealing-the-veil/#comment-44091 Irishman Wed, 01 Aug 2007 15:45:05 +0000 http://blogs.discovermagazine.com/badastronomy/2007/07/31/revealing-the-veil/#comment-44091 MattFunke, your math appears off. Light speed is 1,079,252,848.8 km/hr http://en.wikipedia.org/wiki/Speed_of_light 600,000 km/hr is 1800 times slower than light speed. WJM, what is a "shock wave"? It's the propogation of the interface between high velocity and slower particles. As the shock wave progresses through the material and reaches thinner and thinner regions of space, the wave dissipates. The momentum and energy transfer slows the faster particles and speeds up the slower particles. Some of the faster (higher energy) particles keep going because they don't hit local dust, and they spread further and further apart as they travel away from the source. The "wave" dissipates because there's not a local enough collection of interference. But collisions continue to happen until every particle has one (or more) and all the energy is dissipated. MattFunke, your math appears off.

Light speed is 1,079,252,848.8 km/hr
http://en.wikipedia.org/wiki/Speed_of_light

600,000 km/hr is 1800 times slower than light speed.

WJM, what is a “shock wave”? It’s the propogation of the interface between high velocity and slower particles. As the shock wave progresses through the material and reaches thinner and thinner regions of space, the wave dissipates. The momentum and energy transfer slows the faster particles and speeds up the slower particles. Some of the faster (higher energy) particles keep going because they don’t hit local dust, and they spread further and further apart as they travel away from the source. The “wave” dissipates because there’s not a local enough collection of interference. But collisions continue to happen until every particle has one (or more) and all the energy is dissipated.

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