Comments on: M83’s nursing arms

By: DeiRenDopa

DeiRenDopa — Sat, 13 Sep 2008 13:19:16 +0000

@Nathan: I will mention that the “gas” could not “slam” (presuming that’s what’s really going on at all) if it were not ionized; it would just pass right through, because it’s what in the lab we would call a “hard vacuum”, and gas particles barely interact unless they actually collide.

OK, I’ll bite; what’s the mean free path of a gas particle (atom or molecule) in the ISM (interstellar medium)? Just an order of magnitude estimate will do thanks.

Oh, and I checked and Phil’s blog does not use the word “slam” … where did you quote it from, may I ask?

By: Neil Williams

Neil Williams — Thu, 04 Sep 2008 09:55:15 +0000

@ Sirian, diderick – same thing happening with the feedblitz email updates – back to normal please Phil.

By: Nathan Myers

Nathan Myers — Thu, 04 Sep 2008 01:58:48 +0000

@shane: Everybody who reads comments at all knows, now, that Phil’s pulling a fast one. I will mention that the “gas” could not “slam” (presuming that’s what’s really going on at all) if it were not ionized; it would just pass right through, because it’s what in the lab we would call a “hard vacuum”, and gas particles barely interact unless they actually collide. Plasma particles, by contrast, interact at macroscopic distances, so it really matters that, and how much, these “gases” are ionized.

By: diederick

diederick — Wed, 03 Sep 2008 16:53:26 +0000

I’m with Sirian on this. Google reader is a lot more convenient than keeping bookmarks, but if I only get the first few lines of every post I can’t use it. Usually when you change anything on your blog you tell your readers about it and what your reasons are. This is a sudden and unannounced thing, so I’m guessing the Discovery guys are responsible and didn’t tell you. I hope you can change it back.

By: tom

tom — Wed, 03 Sep 2008 16:15:58 +0000

wow.
When Hubble splashes in a few more years, we won’t even need a telescope above the atmosphere!

By: Gary Ansorge

Gary Ansorge — Wed, 03 Sep 2008 13:42:38 +0000

CanadianLiegh:
At the time I read Tau Zero,(two weeks ago) I had just discovered WOWIO and was able to read it online for FREE.!!! A few days later, I received my copy of Greg Bears book City at the End of Time, which posits the exact opposite scenario, in which humans 100 trillion years down the line are struggling to survive the dissolution of all matter, etc. I really liked the juxtaposition of those two points of view,,,

Of course, Andersons book was written long before we discovered the accelerating expansion of the universe. It was based upon the cyclical theory of the universe.
Gregs story wonders what it would be like when that expansion becomes really significant,,,

Cool books!

GAry 7

By: IVAN3MAN

IVAN3MAN — Wed, 03 Sep 2008 09:39:32 +0000

I’ve already given up on the RSS (Really Slow Service!) Feeds because they tend to arrive several hours late at the best of times. Far better to bookmark a direct link to Bad Astronomy on one’s browser toolbar.