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Is this an another way of saying that the only way to fuse to Hydrogen is to create a structure as large and with gravitational features that of a star? Then a
by kamaal 8y ago
Is this an another way of saying that the only way to fuse to Hydrogen is to create a structure as large and with gravitational features that of a star?
Then a star/solar energy is the only way you will ever have large scale fusion energy generation and harvesting.
- DennisP 8y agoNo, it's saying that large-scale fusion using hydrogen fuel requires a star, because hydrogen fusion reactions are very improbable. That reaction only happens when four nuclei collide at once. Fortunately we have other fusion fuels that are much more likely to fuse, including deuterium, which makes up 1/2500 of the hydrogen atoms in the ocean. Most projects target the easiest fuel, deuterium-tritium; while tritium isn't naturally available on Earth, it can be bred from lithium.
- wbl 8y agoNope! The p-p chain only has pairwise interactions. The issue is the p+p->d step is very disfavored, thanks to the weak step. D+T is all strong interaction.
- bjelkeman-again 8y agoCould that be explained with less jargon? I’d like to understand it.
- ravar 8y agoThere is a chain of individual steps that need to happen to create the final product of hydrogen fusion, helium. One of the crucial steps is the production of deuterium from two protons. This step is incredibly slow and limits the rest of the chain. However if you skip the slow step and start by fusing deuterium and tritium you can have a much faster and efficient reactor.
- DennisP 8y agoThanks, that was interesting. Apparently the five-minute video I got my statement from led me astray.
- pfdietz 8y agoIndeed. After a D nucleus forms in the sun, it reacts (with a proton, to form 3He and a photon) within a few seconds. The 3He+3He reaction is also slow, but not as slow as that first step.
- simonh 8y agoI suppose the universe doesn't owe us a cheap, easy, unlimited source of energy. A lot of people seem to think that it's inevitable we will achieve amazing, magical feats of technology given sufficient time and effort that are unthinkable today. Maybe. But it's also just as possible that we already know most of the general parameters of what is possible in the universe, and the peak practical feats of technology that will ever be open to us are not all that far off from what we have now. How can we tell?
- narag 8y agoNuclear tech is not even a century old. The idea that we can't do any better in a thousand or a million years seems so improbable to me that I can't take it seriously. There is some kind of extrange pessimism around that mindset: that we will be extinct much sooner, or that the Sun will die and thus Humanity, as if there's no obvious way to escape that apocalypsis.
- peterashford 8y agoI think that significant swathes of human kind throughout history have assumed that their current state of existence is the peak and final form of humanity. While it is always logically possible that this is the case, it has never yet been true.
- rectangletangle 8y agoAgreed, the accepted models in physics are laughably incomplete. There is still a tremendous amount we still don't know. Although it's possible we've peaked, I have doubts. It is also a self fulfilling prophecy to declare that we have reached our technological apex, and not striving to progress further.
- Koshkin 8y ago> do any better in a thousand or a million years From what I can tell, there is a much bigger chance that we'll do much worse - and much sooner.
- 8y ago