Local Interstellar Cloud

[porkchopsnapplesauce]

<p>&nbsp;</p><p>Hi All,</p><p>I was looking through wiki when I saw the following information listed for the Local Interstellar Cloud.&nbsp; Can someone please confirm that the temperature it has listed is correct?&nbsp; I really don't understand how that is possible.&nbsp; Thanks in advance</p><p>"The <strong>Local Interstellar Cloud</strong>, casually called the <strong>Local Fluff</strong>, is the interstellar cloud (roughly 30 light years across) through which our solar system is currently moving. The Solar System entered the Local Interstellar Cloud at some time between 44,000 and 150,000 years ago and is expected to remain within it for another 10 to 20,000 years. The cloud has a temperature of 6000&deg; C, about the same temperature as the surface of the Sun."</p><p>http://en.wikipedia.org/wiki/Local_Interstellar_Cloud</p><p>&nbsp;</p>

 

[MeteorWayne]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>&nbsp;Hi All,I was looking through wiki when I saw the following information listed for the Local Interstellar Cloud.&nbsp; Can someone please confirm that the temperature it has listed is correct?&nbsp; I really don't understand how that is possible.&nbsp; Thanks in advance"The Local Interstellar Cloud, casually called the Local Fluff, is the interstellar cloud (roughly 30 light years across) through which our solar system is currently moving. The Solar System entered the Local Interstellar Cloud at some time between 44,000 and 150,000 years ago and is expected to remain within it for another 10 to 20,000 years. The cloud has a temperature of 6000&deg; C, about the same temperature as the surface of the Sun."http://en.wikipedia.org/wiki/Local_Interstellar_Cloud&nbsp; <br />Posted by porkchopsnapplesauce</DIV><br /><br />It's quite possible that is correct. We tend to think of temperature based on experience in our very dense surface atmosphere, but that's not really what it is.</p><p>It is a measure of the average kinetic energy of the particles. So while the cloud is a vacuum (in our experience) with 1 particle per 4 cm^2, the motion of the particles is very high. Paradoxically, were you out there, you would freeze quite quickly, while surrounded by 6000C particles!</p><p>http://en.wikipedia.org/wiki/Temperature</p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[michaelmozina]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>It's quite possible that is correct. We tend to think of temperature based on experience in our very dense surface atmosphere, but that's not really what it is.It is a measure of the average kinetic energy of the particles. So while the cloud is a vacuum (in our experience) with 1 particle per 4 cm^2, the motion of the particles is very high. Paradoxically, were you out there, you would freeze quite quickly, while surrounded by 6000C particles!http://en.wikipedia.org/wiki/Temperature <br /> Posted by MeteorWayne</DIV></p><p>I suppose that the natural next question is: What sustains the cloud at that temperature?&nbsp; Wouldn't the particles in the cloud tend to "cool off" over time? </p> <div class="Discussion_UserSignature"> It seems to be a natural consequence of our points of view to assume that the whole of space is filled with electrons and flying electric ions of all kinds. - Kristian Birkeland </div>

 

[UFmbutler]

What cooling mechanism do you propose?&nbsp; In order for something to cool it must be emitting(line cooling) or hitting something(collisional cooling), or some other form of radiative cooling.&nbsp; If it's just floating through space not really doing anything then it can stay at such a high temperature pretty easily. <div class="Discussion_UserSignature"> </div>

 

[Boris_Badenov]

<p><font size="2">That was an absolutely fascinating Wiki article. (Wayne, do you wear earplugs to keep the encyclopedia from falling out?)</font></p><p><img src="http://upload.wikimedia.org/wikipedia/en/8/87/Localcloud.gif" alt="" /></p> <div class="Discussion_UserSignature"> <font color="#993300"><span class="body"><font size="2" color="#3366ff"><div align="center">. </div><div align="center">Never roll in the mud with a pig. You'll both get dirty & the pig likes it.</div></font></span></font> </div>

 

[MeteorWayne]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>That was an absolutely fascinating Wiki article. (Wayne, do you wear earplugs to keep the encyclopedia from falling out?) <br />Posted by boris1961</DIV><br /><br />LOL, it's the curse of being a reading addict.</p><p>BTW, no, I just keep a large bowl between me and the keyboard and scoop up what falls in it to the top of my head </p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[derekmcd]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>What cooling mechanism do you propose?&nbsp; In order for something to cool it must be emitting(line cooling) or hitting something(collisional cooling), or some other form of radiative cooling.&nbsp; If it's just floating through space not really doing anything then it can stay at such a high temperature pretty easily. <br /> Posted by UFmbutler</DIV></p><p>There is always the metric expansion of space 'cooling off' the CMBR and redshifting various other EM radiation... but we won't go there. </p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[michaelmozina]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>What cooling mechanism do you propose?</DIV></p><p>I would think that photon emissions would do the trick.&nbsp; Wouldn't the ions and atoms just radiate away their heat over time? </p> <div class="Discussion_UserSignature"> It seems to be a natural consequence of our points of view to assume that the whole of space is filled with electrons and flying electric ions of all kinds. - Kristian Birkeland </div>

 

[porkchopsnapplesauce]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>It's quite possible that is correct. We tend to think of temperature based on experience in our very dense surface atmosphere, but that's not really what it is.It is a measure of the average kinetic energy of the particles. So while the cloud is a vacuum (in our experience) with 1 particle per 4 cm^2, the motion of the particles is very high. Paradoxically, were you out there, you would freeze quite quickly, while surrounded by 6000C particles!http://en.wikipedia.org/wiki/Temperature <br />Posted by MeteorWayne</DIV></p><p>&nbsp;</p><p>Wow, I guess I didn't really think of it that way.&nbsp; As far as the cloud maintaining that temperature goes, wouldn't the particles try to seek an equilibrium&nbsp;and expand the size of the cloud until it is no longer discernable from its surroundings?&nbsp;Is it gravity that keeps it together?</p>