Fusion reactor?

[rock]

Okay, we've all heard about the that debunked cold-fusion announcement a few years ago. Now, I just read this article about some kid in Utah who has built his own little fusion reactor. At first, I thought it was a joke because of the name (Farnsworth from Futurama), but it looks like a real article. And the website appears to be Salt Lake City's actual online newpaper.

Is this kind of desktop fusion not really a big deal? Why am I not reading about this elsewhere?

[ua549]

It is a big deal in the creativity department for a teenager to do.
In the realm of science it is nothing special.

[Moridin]

A fission reactor (or bomb) is a fundamentally simple device if you put aside all the safety and control involved, and the manufacturing/handling of the fissionable material.

A fusion reactor OTOH is a whole other ball of wax. Theoretically it is possible to build cold fusion reactor, and that would be a viable project for a small operation. So far though no-one has managed to get cold fusion to work in reality, so that option is out. The other type of fusion reactor requires massive amounts of energy to power massive electromagnets that contain the reaction, and supply the pressure needed to overcome the electric forces that keep atoms apart, and prevents them from fusing. (The idea behind cold fusion is to use isotopes that do not repel each other this way)

[mozilla4]

This has been done before. When I went to San Jose for the Intel International Science and Engineering Fair in 2001, some kid did the same thing. Basically it is hot fusion. More energy is put in to keep the reaction going then what is put out. http://www.geocities.com/cooljamg/images/plasma.jpg

[russ_watters]

Originally posted by Moridin
Theoretically it is possible to build cold fusion reactor...

I have my doubts. It sounds like an oxymoron.

[rock]

Ah. I see now the article never mentions "cold fusion". It must have been some creative reading on my part.

So then, this desktop experiment is really fusion, but requires more energy input than is output. That makes more sense.

[Moridin]

Originally posted by russ_watters
I have my doubts. It sounds like an oxymoron.

All the "cold" implies is that you don't need heat to cause atoms to bang together so hard they overcome the repulsive forces between the atoms. If you assume these forces are entirely electrical then "cold" fusion should be possible with the right ions.

Seeing as none of the experiments so far have worked I too have my doubts that cold fusion will ever happen, but I think that needs to be separate from the real science of finding our why cold fusion doesn’t work. (Which could open up the door to a solution. I doubt this will happen, but it doesn’t make cold fusion research a hoax like the ZPE stuff.)

Originally posted by mozilla4
This has been done before. When I went to San Jose for the Intel International Science and Engineering Fair in 2001, some kid did the same thing. Basically it is hot fusion. More energy is put in to keep the reaction going then what is put out.

Perhaps there is a need to differentiate between a reaction capable of producing power and one that is not. "Hot" fusion has been demonstrated that produces small amounts of energy, but it always requires massive amounts of energy, and extremely expensive equipment. I don't doubt that an energy -ve fusion hot reaction is possible at much lower energy/pressure levels.

[russ_watters]

Originally posted by Moridin
All the "cold" implies is that you don't need heat to cause atoms to bang together so hard they overcome the repulsive forces between the atoms. If you assume these forces are entirely electrical then "cold" fusion should be possible with the right ions.

That assumption violates the laws of physics though. Like in a chemical reaction there is a specific activation energy associated with bringing two atoms close enough together to fuse. Nuclear and chemical reactions aren't interchangeable.

The mechanism used in "cold fusion" is hydrogen (deuterium) in a solid solution with some metal (often palladium). The idea is that if the solution is dense enough the resulting pressure will overcome the repulsion between the atomic nuclei (pressure and temperature are essentially interchangeable). Trouble is there is a maximum solubility according to the rules of CHEMISTRY and that concentration is nowhere near high enough to overcome the activation energy specified by the laws of nuclear PHYSICS.

No one has yet even come up with a theoretical explanation for why cold fusion would be possible and the current laws of physics exclude it.

ZPE at least has one thing going for it: scientific theories predict it and scientists generally agree that it exist.

And in any case, that kid's HOT fusion reactor is one heluva cool science project.

[Moridin]

Read your own explanation and then consider the difference between a technical barrier and a theoretical one.

A technical barrier may seem impossible to overcome, but that doesn’t mean it is impossible. This is why some "barriers" like the speed of sound, and lithography below the wavelength of laser light used have fallen. They were seemingly overwhelming technical barriers, but they were not true barriers.

Now, just because something is "just" a technical barrier doesn’t mean we will find a way to overcome it, but it's worth keeping in mind that it isn't impossible. As I mentioned above, I do not think we will ever get cold fusion to work, but IMO the barriers qualify as technical since it does not directly violate established laws of physics.

[russ_watters]

Originally posted by Moridin
Read your own explanation and then consider the difference between a technical barrier and a theoretical one.

Lol, thats one of my biggest pet peves, people not knowing the difference between a theoretical and a technical one. But I was pretty explicit in that the barriers to fusion are THEORETICAL in nature, NOT technical (did you misread my post?). Activation energy is derived from the physical properties of the particles and isn't something that can be gotten around.

As I mentioned above, I do not think we will ever get cold fusion to work, but IMO the barriers qualify as technical since it does not directly violate established laws of physics.

And I said, they DO. Pons and Fleischman when first challenged began trying to come up with explanations such as discovering fusion without neutron or gamma ray emissions (to explain why they found no neutron or gamma rays). Such things go against what we know about nuclear physics. They DO violate the established laws of physics.

Now it is always possible that even a theoretical barrier can be broken. Science is still advancing and we have a lot to learn. But I wouldn't bet on this one. The theories it breaks are just far too well established.

[Moridin]

I'm not referring to Pons and Fleischman, rather I'm talking about cold fusion in general. Clearly the reason their experiment didn’t show the correct neutron emissions was that they didn't successfully achieve cold fusion. The idea of cold fusion did not originate with them, and there is real science behind it despite that very public blunder. (Again I want to make perfectly clear that this does not imply I think cold fusion will ever be a reality.)


If you just assume that the particles must have some set amount of energy to overcome a barrier a number of other common devices like Bipolar junction transistors are theoretically impossible as well. Any time you have any energy at all there is a change that such a barrier can be overcome. The challenge is to manipulate that chance in such a way that it occurs or does not occur according to your wishes.

[russ_watters]

Originally posted by Moridin
If you just assume that the particles must have some set amount of energy to overcome a barrier a number of other common devices like Bipolar junction transistors are theoretically impossible as well. Any time you have any energy at all there is a change that such a barrier can be overcome. The challenge is to manipulate that chance in such a way that it occurs or does not occur according to your wishes.

Activation energy is not a barrier to be overcome, its a fundamental property of an atom (in the case of fusion) or molecule (in chemical reactions). Its like mass or specific heat capacity.

Or maybe I'm misinterpreting. Are you saying you can control or predict a random distribution of energy levels in a probability function (bell curve representing the energy of particles in a substance? Thats another oxymoron. If its random, its random.

And in any case, its the first, not the second that the cold fusion guys are claiming to be able to do.

[Moridin]

Originally posted by russ_watters
Activation energy is not a barrier to be overcome, its a fundamental property of an atom (in the case of fusion) or molecule (in chemical reactions). Its like mass or specific heat capacity.

Or maybe I'm misinterpreting. Are you saying you can control or predict a random distribution of energy levels in a probability function (bell curve representing the energy of particles in a substance? Thats another oxymoron. If its random, its random.

And in any case, its the first, not the second that the cold fusion guys are claiming to be able to do.

I don't believe anyone with any credibility is claiming they are currently doing anything of the sort, at least not in any remotely useful way.


Since the thermal energy of any given particle is random (following the probability curve you describe), some will have the activation energy required. The question is how many. If this number is too small you are not going to get a useful result.

If you can manipulate the situation so more enough particles have the required activation energy then it may be possible to build a practical cold fusion device. Hence by position that cold fusion is *theoretically* possible.

IMO if there was a simple way of ding this it would have been done already, and we would have working cold fusion devices. This doesn’t mean this is impossible, and that research into ways of accomplishing it are pointless which is why I consider it a technical problem. It may well be an insurmountable technical problem, but I'm not arguing that it is a problem that will (or even can) ever be solved.

[russ_watters]

Originally posted by Moridin
I don't believe anyone with any credibility is claiming they are currently doing anything of the sort, at least not in any remotely useful way.

I find "credibilty" and "cold fusion" to be mutually exclusive.

Anyway, call me pessimistic, but I'm not budging. And I think we've about covered the arguement.