APOD and General Astronomy Discussion Forum
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Fusion requires being tightly bound physically and a lot of heat (energy). Gravity forms the "walls" inside the Sun to keep the fusion reaction contained, and the immense pressure creates the necessary heat. What would form those walls and provide the heat in open space?Ron-Astro Pharmacist wrote:Has anyone ever theorized fusion in space? Our sun has and it seems to work fine.
You'll need to be more clear what you mean by that. Fusion as a practical energy source requires that it be sustained. That requires dense plasmas. Fusion of free particles in space must certainly occur, given the observed energy of even fairly weak cosmic rays. Most often, the result of cosmic ray collisions is spallation, a fission process (which as discussed elsewhere is believed responsible for most of the lithium, beryllium, and many light isotopes in the Universe). But statistically, fusion should happen occasionally. That is fusion in space, but it isn't useful as an energy source.Ron-Astro Pharmacist wrote:Has anyone ever theorized fusion in space? Our sun has and it seems to work fine.
I was pondering how much difficulty gravity has been in making a containment field for sustained fusion.Chris Peterson wrote:You'll need to be more clear what you mean by that. Fusion as a practical energy source requires that it be sustained. That requires dense plasmas. Fusion of free particles in space must certainly occur, given the observed energy of even fairly weak cosmic rays. Most often, the result of cosmic ray collisions is spallation, a fission process (which as discussed elsewhere is believed responsible for most of the lithium, beryllium, and many light isotopes in the Universe). But statistically, fusion should happen occasionally. That is fusion in space, but it isn't useful as an energy source.Ron-Astro Pharmacist wrote:Has anyone ever theorized fusion in space? Our sun has and it seems to work fine.
No difficulty at all. As you increase mass, you increase the density at the center of that mass. At some point it's high enough to support sustained fusion.Ron-Astro Pharmacist wrote:I was pondering how much difficulty gravity has been in making a containment field for sustained fusion.
No. Gravity isn't involved in that experiment at all. It uses another mechanism for confinement.So to say - If the experiment from Beyond's post was able (a big if?) to be done in a low gravity environment would it be easier to accomplish?
I would have emphasized pressure (the primary factor for fusion power)Chris Peterson wrote:No difficulty at all. As you increase mass, you increase the density at the center of that mass. At some point it's high enough to support sustained fusion.Ron-Astro Pharmacist wrote:
I was pondering how much difficulty gravity has been in making a containment field for sustained fusion.
Pressure works for me, too. The two are mathematically related, so if you know the molar mass and the temperature, you can convert between the two.neufer wrote:I would have emphasized pressure (the primary factor for fusion power)Chris Peterson wrote:No difficulty at all. As you increase mass, you increase the density at the center of that mass. At some point it's high enough to support sustained fusion.Ron-Astro Pharmacist wrote: I was pondering how much difficulty gravity has been in making a containment field for sustained fusion.
rather than simply density (the primary factor for fission power).
Nobody would reasonably call the product that Domino's produces "pizza", so that can't be a pizza deliver robot. Perhaps it's a "pizzoid food product delivery device".Beyond wrote:Domino's reveals it's new pizza delivery robot in Australia.
http://www.msn.com/en-us/video/tunedin/ ... spartandhp
Maybe in Oz you just have good enough taste to not tolerate what Domino's passes off as "pizza" here.Nitpicker wrote:By chance, I had some pizza from Domino's (in Oz) the other week (ordered online and delivered by someone who was probably human). The particular "gourmet" pizzas we ordered were surprisingly good and I remarked that they had significantly lifted their game, compared with past offerings.
(Of course, Chris, we have disagreed on Italian food before. There are probably a lot of things that I'd call pizza and you wouldn't.)
Yeah, the same thing is happening here. A new class of "fast food" has drawn people- especially younger people- away from the traditional places. That's forcing those old chains to consider different menus and different presentations.Nitpicker wrote:I'm seeing a lot of (traditionally dreadful) fast food chains here in Oz, attempting to improve their menus, simply to stay in business. It appears that they can't survive on the diabetic welfare class alone -- they need the hipster youth market, too.
