Talk:Local Interstellar Cloud

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One-fifth?[edit]

The article states that this cloud has "approximately one-fifth the density of the galactic interstellar medium." Wouldn't this make the cloud an area of low density in the interstellar medium, a semi-void rather than a "cloud"? AnarchyElmo (talk) 00:37, 28 October 2008 (UTC) I've added a sentence to make the cloud's relation to the Local Bubble and the medium more clear. Feel free to change/correct it. AnarchyElmo (talk) 00:43, 28 October 2008 (UTC)

It's still unclear. It's intuitively hard to grasp why a cloud is less dense than the surrounding volume. It's not a cloud in the ISM though, it's a cloud in a less dense Bubble in the ISM. Had to read about the ISM and the Local Bubble to figure this out. -- Henriok (talk) 10:44, 25 June 2009 (UTC)

"The Local Bubble is an area of low-density" - it is not an 'area' but a volume. — Preceding unsigned comment added by 92.14.30.2 (talk) 00:09, 6 March 2012 (UTC)

Question[edit]

If this cloud is so hot does it have any effect on the Earth as we move through it? Kevlar67 00:38, 3 March 2007 (UTC)

Actually, the cloud is relatively cool. The Local Bubble is much hotter, but even less dense. The effect of the Interstellar medium in general has much more to do with its density, and subsequent effect on the Sun's magnetic field, than it does with its temperature. At these densities, there's not much heat to be transferred over relatively small volumes. TCC (talk) (contribs) 01:42, 3 March 2007 (UTC)
So why does the article say "The Solar System entered the Local Interstellar Cloud ... The cloud has a temperature of 6000° C, about the same temperature as the surface of the Sun.", then? We're in the cloud, the cloud is 6,000°, why aren't we all burned to a crisp? Sorry if I've completely missed the point of your explanation, but your statement "the cloud is relatively cool" seems to directly contradict the main article. Stroller (talk) 09:46, 26 May 2009 (UTC)
Temperature is really a measure of how fast molecules are moving. If it's fast then it's hot, if it's still, then it's cold. Matter is really scarce in space so there's nothing to stop them from racing like hell, and therefor be "hot". The Local Interstellar Cloud is immensely thin, orders of magnitudes thinner than the best vacuum we can make on earth. It's literary tens of molecules of stuff in a volume the size of a soda can. These molecules might be extremely hot, but they have no chance of influencing the billions of billions of molecules of molecules that would make up the air inside a regular soda can on Earth. -- Henriok (talk) 11:03, 25 June 2009 (UTC)

Units of measurement[edit]

Given that the Interstellar-Medium (surely a -Large, or even -Ginormous?) gives the relative density in molecules per cubic meter, should this article's measurement of density also be the same?

Tim


The temperature in the cited font is 7000 Kelvin. I think that it was an error of conversion. The cloud is not hot, it´s very cool. —Preceding unsigned comment added by 189.58.154.189 (talk) 15:48, 26 February 2011 (UTC)

Standard temperature and pressure[edit]

I don't understand what it means to say that "The cloud has a temperature (at STP) of 6000° C". STP is defined as a temperature of 20 C. How can a thing have a temperature of 6,000 C at a temperature of 20 C?

If this is not an error, it needs to be explained better.

Agemegos (talk) 02:10, 13 December 2007 (UTC)

References needed[edit]

[1] has a density of 0.264 atoms/cc, whiile [2] shows perhaps 0.1, but it's hard to read. What should it be? UncleDouggie (talk) 18:33, 17 September 2009 (UTC)

Picture?[edit]

File:3 Solar Interstellar Neighborhood (ELitU).png Does not this article need a picture? --Hame fan harif (talk) 08:57, 6 July 2012 (UTC)

Thanks for pointing out the need for an image. However, your suggested image does not actually show the clouds, which are diffuse but distinct collections of interstellar dust. I've uploaded a NASA image which does a decent job, though I'm not quite happy with it in terms of what it shows. Huntster (t @ c) 12:06, 6 July 2012 (UTC)