Comments on: Giant Bubbles of Hot, Hot Gas! http://www.sundriesshack.com/2006/06/21/giant-bubbles-of-hot-hot-gas/ Delivering the Best of the New Media Since 2004. Tue, 22 May 2012 02:51:03 +0000 hourly 1 http://wordpress.org/?v=3.3.2 By: Mr. Science Guyhttp://www.sundriesshack.com/2006/06/21/giant-bubbles-of-hot-hot-gas/comment-page-1/#comment-233676 Mr. Science Guy Thu, 22 Jun 2006 20:03:07 +0000 http://sundriesshack.com/?p=2507#comment-233676 Argh. This is one of those cases where your facts are right, and yet your conclusion is unwarranted. Not to say that the people involved haven't achieved something remarkable, it's just not remarkable in the way you think. Personally, I'm impressed that they managed to measure plasma densities and temperatures that are that extreme, but the survival of the spacecraft is no more of an accomplishment than the survival of <i>any</i> spacecraft. (Well, any interplanetary spacecraft, anyway; the radiation environment outside the magnetosphere is harsher than the comparatively balmy area where the ISS orbits.) The trouble comes with the definition of 'temperature'; your intuitive understanding will work perfectly well as long as there's some atmosphere around, but in vacuum, it doesn't really mean what you think. I'm trying to avoid going into all the thermodynamics, because this comment is long-winded enough already (sorry, you got me where I live...) but think of it this way--many spacecraft have been through these bubbles already, and never noticed, because their internal temperature was unaffected. This particular satellite was the first with the right instrumentation in the right place to detect them. Argh. This is one of those cases where your facts are right, and yet your conclusion is unwarranted. Not to say that the people involved haven’t achieved something remarkable, it’s just not remarkable in the way you think. Personally, I’m impressed that they managed to measure plasma densities and temperatures that are that extreme, but the survival of the spacecraft is no more of an accomplishment than the survival of any spacecraft. (Well, any interplanetary spacecraft, anyway; the radiation environment outside the magnetosphere is harsher than the comparatively balmy area where the ISS orbits.)
The trouble comes with the definition of ‘temperature’; your intuitive understanding will work perfectly well as long as there’s some atmosphere around, but in vacuum, it doesn’t really mean what you think. I’m trying to avoid going into all the thermodynamics, because this comment is long-winded enough already (sorry, you got me where I live…) but think of it this way–many spacecraft have been through these bubbles already, and never noticed, because their internal temperature was unaffected. This particular satellite was the first with the right instrumentation in the right place to detect them.

]]> By: Jimmiehttp://www.sundriesshack.com/2006/06/21/giant-bubbles-of-hot-hot-gas/comment-page-1/#comment-233677 Jimmie Thu, 22 Jun 2006 14:23:41 +0000 http://sundriesshack.com/?p=2507#comment-233677 Fair enough. I'll be a bit more specific in my amazement. Not only am I amazed that we have the means to measure such a temperature but I"m also amazed that we manage to put anything into space that can withstand the rigors of being there and survive, much less report back with any meaningful data. I understand enough about thermodynamics to know that atmosphere is critical. Nevertheless, to have a craft move from inside the magnetosphere to the outside and have it be useful to us is a big accomplishment. I also think it's neat that we didn't have to go far, astronomically-speaking, to find something else to make our big-brains say "Hmmmm....where'd <i>that</i> come from?" Fair enough. I'll be a bit more specific in my amazement. Not only am I amazed that we have the means to measure such a temperature but I"m also amazed that we manage to put anything into space that can withstand the rigors of being there and survive, much less report back with any meaningful data.

I understand enough about thermodynamics to know that atmosphere is critical. Nevertheless, to have a craft move from inside the magnetosphere to the outside and have it be useful to us is a big accomplishment.

I also think it's neat that we didn't have to go far, astronomically-speaking, to find something else to make our big-brains say "Hmmmm….where'd that come from?"

]]> By: Jimmiehttp://www.sundriesshack.com/2006/06/21/giant-bubbles-of-hot-hot-gas/comment-page-1/#comment-233665 Jimmie Thu, 22 Jun 2006 08:58:16 +0000 http://sundriesshack.com/?p=2507#comment-233665 It still strikes me as quite an accomplishment considering all the thought and work that had to go into building that craft and conceiving of makeing it survive a temperature that warm. It still strikes me as quite an accomplishment considering all the thought and work that had to go into building that craft and conceiving of makeing it survive a temperature that warm.

]]> By: Mr. Science Guyhttp://www.sundriesshack.com/2006/06/21/giant-bubbles-of-hot-hot-gas/comment-page-1/#comment-233658 Mr. Science Guy Thu, 22 Jun 2006 04:29:54 +0000 http://sundriesshack.com/?p=2507#comment-233658 Don't be <i>that</i> impressed by the 18,000,000 degF number; at gas densities that low, the conductive heat absorbed by a spacecraft is very small. Don't be that impressed by the 18,000,000 degF number; at gas densities that low, the conductive heat absorbed by a spacecraft is very small.

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