Cold Fusion

[bobsmith1492]

That's kind of pathetic fusion... it's just a small particle accelerator, which isn't worth it since it takes more energy to launch the particles than you get back. It looks like fusion alright though. I think the fusion we're looking for would be something self-sustaining.

 

[Munkies123]

my head hurts

 

[Minotar]

Ok Dr. Pizza, here goes... The sun produces a magnetic field for a number of reasons... The reasons are what makes the sun, THE Sun. Therefore, to produce a miniature "sun" on Earth would, essentially, have to recreate the internal workings of the Sun. Here are the reasons why our own Sun has a magnetic field: Immense mass creates immense gravity which compresses hydrogen atoms. As we delve deeper inside our star, it is thought that there is a point at which the gravity is so strong that it compesses the hydrogen present into "metallic" hydrogen having the properties of a metal (the core). At this point, the hydrogen is 10 times the density of gold! Above the core, is a layer of hydrogen that behaves like a liquid. The "drag" of this liquid-like hydrogen against the metallic hydrogen, creates the magnetic dynamo that creates the immense magnetic fields of our Sun. The point at which this occurs is called the tacholine.

Now, just because they are able to sustain a self-sustaining fusion reaction on Earth, does not equate to a "miniature sun". As you can already see, our Sun is FARRRRRR more complicated than people truely imagine. To recreate that on Earth is truely impossible. Now, if you were to say, "can we create something similar?", then I would say, "Kind of." hehehe. Really, the fusion reactions done on Earth are only similar to the Sun, in basic principles and nothing more. And that is not even getting into the other reactions that occur in the sun. It is far more complicated than has been discussed here.

Now, Mr. JAGedlion.... The experiment you listed is a well-known way to create fusion, but it is not so different than any other deuterium burning technique. The key is that they still had to use heat to start the reaction. In addition, this experiment was conducted on an extremely small scale. The energy input required is relative. The article you sighted is still interesting and I would be interested in checking out the actual scientific publication for this. I still would not consider this "cold" fusion. By "cold" we mean room temperature or lower, correct?

 

[the splat in the hat]

LOL...

 

[0marTheZealot]

Iron is the most stable element. Fusion of iron requires more energy than it gives off, making it an energy sink.

 

[Soccerman06]

Originally posted by: 0marTheZealot
Iron is the most stable element. Fusion of iron requires more energy than it gives off, making it an energy sink.

I thought Helium was the most stable element ? Since its in the top right of the periodic table and is a Noble element.

 

[0marTheZealot]

Originally posted by: Soccerman06

Originally posted by: 0marTheZealot
Iron is the most stable element. Fusion of iron requires more energy than it gives off, making it an energy sink.

I thought Helium was the most stable element ? Since its in the top right of the periodic table and is a Noble element.

Helium is chemically stable, not as nucleonically stable as iron is.

 

[Wreckage]

Originally posted by: coomar
isn't a hydrogen bomb an uncontrolled fusion reaction

Actually it's just the opposite. A hydrogen bomb uses fission. Splitting an atom to cause a change reaction.

Fusion instead of destroying atoms creates them. The intense heat and pressure of the sun turns hydrogen into helium and so on up the periodic table.

I wish cold fusion were possible, but I have yet to see any reasonably theory that makes it feasible.

 

[f95toli]

Originally posted by: Wreckage

Originally posted by: coomar
isn't a hydrogen bomb an uncontrolled fusion reaction

Actually it's just the opposite. A hydrogen bomb uses fission. Splitting an atom to cause a change reaction.

I wish cold fusion were possible, but I have yet to see any reasonably theory that makes it feasible.

Yes and no, in a hydrogen bomb an ordinary fission bomb is used to start an uncontrolled fusion reaction in hydrogen.

 

[Minotar]

Originally posted by: OmarTheZealot
Iron is the most stable element. Fusion of iron requires more energy than it gives off, making it an energy sink.

Hmmm... Interesting thought process, but not entirely accurate unfortuneately. First, modern chemists find most of the common rules they once thought of chemistry to not be so valid anymore. For instance, helium was once considered to be among the most stable elements, but now, we know that a number of helium based compounds can be easily synthesized. Second, while iron does have a stable nucleus, that does not neccessarily mean that it is THE most stable nucleus. As far as fusion goes, iron is the "known" cut-off point. As the size of the nucleus increases further, it becomes more and more difficult for fusion to occur. This does not mean it is impossible, but just more difficult. To say that iron has the most stable nucleus is not correct at all. The opposite trend in stability is observed when you try to split an atom (i.e. fission). In this case Helium is much much more difficult to split than Iron, so the helium nuclei would be much more stable in that case. It is really all relative when we talk about stability of the nucleus, because different nuclei are more stable under different conditions and it aso depends on what you are doing with the nuclei in question.

 

[JAGedlion]

Although I may be mistaken, upon reviewing the article http://www.nature.com/nature/journal/v434/n7037/full/nature03575.html
the fusion reaction is infact done below room temperature being noticable actually below O degrees C.

Realizing that some may not be able to access Nature I'll paste a peice.

A typical run is shown in Fig. 2. The chamber's deuterium pressure was held at 0.7 Pa throughout the run. First, the crystal was cooled down to 240 K from room temperature by pouring liquid nitrogen into the cryogenic feedthrough. At time t = 15 s, the heater was turned on. At t = 100 s, X-ray hits due to free electrons striking the crystal were recorded. At t = 150 s, the crystal had reached 80 kV and field ionization was rapidly turning on. At t = 160 s and still not above 0 °C, the neutron signal rose above background. Ions striking the mesh and the surrounding aperture created secondary electrons that accelerated back into the crystal, increasing the X-ray signal. At t = 170 s, the exponential growth of the ion current had ceased, and the tip was operating in the strong field regime, in which neutral molecules approaching the tip ionize with unity probability. The neutron flux continued to increase along with crystal potential until t = 220 s, when we shut off the heater. Then, the crystal lost charge through field ionization faster than the reduced pyroelectric current could replace it, resulting in a steadily decreasing crystal potential. At t = 393 s, the crystal spontaneously discharged by sparking, halting the effect.

Though I am no physicist and therefore dont want to draw conclusions the image referenced I will note is said to be an entire run and at the end point the temperature is reported at 282K or around 9 degrees Celcius. Thats pretty chilly in my book.

BTW they do mention that heating such crystals it possible and well known, this experiment was published April of 2005 as something new.

I should also note by the way, this came to my knowledge from slashdot a couple months ago

 

[silverpig]

Originally posted by: Minotar

Originally posted by: OmarTheZealot
Iron is the most stable element. Fusion of iron requires more energy than it gives off, making it an energy sink.

Hmmm... Interesting thought process, but not entirely accurate unfortuneately. First, modern chemists find most of the common rules they once thought of chemistry to not be so valid anymore. For instance, helium was once considered to be among the most stable elements, but now, we know that a number of helium based compounds can be easily synthesized. Second, while iron does have a stable nucleus, that does not neccessarily mean that it is THE most stable nucleus. As far as fusion goes, iron is the "known" cut-off point. As the size of the nucleus increases further, it becomes more and more difficult for fusion to occur. This does not mean it is impossible, but just more difficult. To say that iron has the most stable nucleus is not correct at all. The opposite trend in stability is observed when you try to split an atom (i.e. fission). In this case Helium is much much more difficult to split than Iron, so the helium nuclei would be much more stable in that case. It is really all relative when we talk about stability of the nucleus, because different nuclei are more stable under different conditions and it aso depends on what you are doing with the nuclei in question.

No no, he's actually fairly correct. You can fuse all the elements below iron and get energy out of the process, with the lightest fusing most easily and giving the biggest net energy gain. You can split most of the elements above iron (it gets complicated right around iron) and get energy out of the process, with the tendency of heavier elements to split with the biggest net energy gain.

However, if you try to fuse elements above iron, it will take more energy than you get out of the process. Same thing with splittling atoms lower than iron... it's an energy sink.

 

[Minotar]

Originally posted by: silverpig

Originally posted by: Minotar

Originally posted by: OmarTheZealot
Iron is the most stable element. Fusion of iron requires more energy than it gives off, making it an energy sink.

Hmmm... Interesting thought process, but not entirely accurate unfortuneately. First, modern chemists find most of the common rules they once thought of chemistry to not be so valid anymore. For instance, helium was once considered to be among the most stable elements, but now, we know that a number of helium based compounds can be easily synthesized. Second, while iron does have a stable nucleus, that does not neccessarily mean that it is THE most stable nucleus. As far as fusion goes, iron is the "known" cut-off point. As the size of the nucleus increases further, it becomes more and more difficult for fusion to occur. This does not mean it is impossible, but just more difficult. To say that iron has the most stable nucleus is not correct at all. The opposite trend in stability is observed when you try to split an atom (i.e. fission). In this case Helium is much much more difficult to split than Iron, so the helium nuclei would be much more stable in that case. It is really all relative when we talk about stability of the nucleus, because different nuclei are more stable under different conditions and it aso depends on what you are doing with the nuclei in question.

No no, he's actually fairly correct. You can fuse all the elements below iron and get energy out of the process, with the lightest fusing most easily and giving the biggest net energy gain. You can split most of the elements above iron (it gets complicated right around iron) and get energy out of the process, with the tendency of heavier elements to split with the biggest net energy gain.

However, if you try to fuse elements above iron, it will take more energy than you get out of the process. Same thing with splittling atoms lower than iron... it's an energy sink.

Um, saying the statement, "Iron is the most stable nucleus" is COMPLETELY different than saying, "Fusion of Iron requires more energy than it gives off" The two statements mean two TOTALLY different things. While the second statement IS true, the first statement is definately FALSE!!!! I thought I made that clear in my reply?

 

[Minotar]

Originally posted by: JAGedlion
Although I may be mistaken, upon reviewing the article http://www.nature.com/nature/journal/v434/n7037/full/nature03575.html
the fusion reaction is infact done below room temperature being noticable actually below O degrees C.

Realizing that some may not be able to access Nature I'll paste a peice.

A typical run is shown in Fig. 2. The chamber's deuterium pressure was held at 0.7 Pa throughout the run. First, the crystal was cooled down to 240 K from room temperature by pouring liquid nitrogen into the cryogenic feedthrough. At time t = 15 s, the heater was turned on. At t = 100 s, X-ray hits due to free electrons striking the crystal were recorded. At t = 150 s, the crystal had reached 80 kV and field ionization was rapidly turning on. At t = 160 s and still not above 0 °C, the neutron signal rose above background. Ions striking the mesh and the surrounding aperture created secondary electrons that accelerated back into the crystal, increasing the X-ray signal. At t = 170 s, the exponential growth of the ion current had ceased, and the tip was operating in the strong field regime, in which neutral molecules approaching the tip ionize with unity probability. The neutron flux continued to increase along with crystal potential until t = 220 s, when we shut off the heater. Then, the crystal lost charge through field ionization faster than the reduced pyroelectric current could replace it, resulting in a steadily decreasing crystal potential. At t = 393 s, the crystal spontaneously discharged by sparking, halting the effect.

Though I am no physicist and therefore dont want to draw conclusions the image referenced I will note is said to be an entire run and at the end point the temperature is reported at 282K or around 9 degrees Celcius. Thats pretty chilly in my book.

BTW they do mention that heating such crystals it possible and well known, this experiment was published April of 2005 as something new.

I should also note by the way, this came to my knowledge from slashdot a couple months ago

After carefully reading the scientific article you site, I am not convinced that this is a so-called "cold-fusion" reaction. Yes, alpha particles are released... Yes, neutrons are also released. But, the energy released is not proportional to an actual fusion reaction that we see with D-D fusion reactions. In addition, there are numerous nuclear reactions that release alpha particles and neutrons. The article FAILS to mention the possiblility of alpha-decay reactions of the ErD2 target, which could very well be the reaction that is occuring, and NOT fusion as the writers seem to think! It is really not even close in that respect. The writers make a valid assessment of their data and come to logical conclusions, however I feel that more needs to be studied before they can conclude that this is an "actual" fusion reaction mechanism. In reality, they may have stumbled onto a completely new reaction mechanism yielding products similar to D-D fusion reactions. The writers do state that this technology would be useful as a good source of neutrons, which I would agree. Otherwise, I am not convinced that this is "cold-fusion" in the respect that the original poster was looking for.

 

[Muse]

Originally posted by: bobsmith1492
From everything I've heard, cold fusion has been brought up repeatedly over the years and repeatedly disproven. I doubt it is much more than science fiction.

That's what I figure. But I talked to a guy a week ago who told me he thought it has the best chance of success. I mentioned the European consortium that's presently building an extremely expensive project that will presumably (if successful) be the first successful fusion reactor sometime in the next 1/4 century and he dismisses it as impossible, that they are just doing it to do it. I didn't pursue this but I took his meaning to be that they are going to be making a living at this venture but it will be a failure when all is said and done. He thinks hot fusion is an impossibility.

 

[Minotar]

Originally posted by: Muse

Originally posted by: bobsmith1492
From everything I've heard, cold fusion has been brought up repeatedly over the years and repeatedly disproven. I doubt it is much more than science fiction.

That's what I figure. But I talked to a guy a week ago who told me he thought it has the best chance of success. I mentioned the European consortium that's presently building an extremely expensive project that will presumably (if successful) be the first successful fusion reactor sometime in the next 1/4 century and he dismisses it as impossible, that they are just doing it to do it. I didn't pursue this but I took his meaning to be that they are going to be making a living at this venture but it will be a failure when all is said and done. He thinks hot fusion is an impossibility.

Whoever you talked too, definately does not know much about fusion. Fusion has already been successfully performed and controlled at the JET Tokamak reactor, and the reactor you speak of being built in Europe is the ITER reactor, which is on track for a success, albeit a very expensive one involving cutting edge technology. Go to their website and check it out for yourself. It is not a question of can it be done (because it already has), but can it be done profitably. On the other hand, so-called cold fusion is much more science fiction than science fact. And, all of the papers and studies I have seen always leave out important details: details that would proove the experiment flawed, such as what I have already pointed out. Cold fusion? Maybe one day...

 

[Muse]

Originally posted by: Minotar

Originally posted by: Muse

Originally posted by: bobsmith1492
From everything I've heard, cold fusion has been brought up repeatedly over the years and repeatedly disproven. I doubt it is much more than science fiction.

That's what I figure. But I talked to a guy a week ago who told me he thought it has the best chance of success. I mentioned the European consortium that's presently building an extremely expensive project that will presumably (if successful) be the first successful fusion reactor sometime in the next 1/4 century and he dismisses it as impossible, that they are just doing it to do it. I didn't pursue this but I took his meaning to be that they are going to be making a living at this venture but it will be a failure when all is said and done. He thinks hot fusion is an impossibility.

Whoever you talked too, definately does not know much about fusion. Fusion has already been successfully performed and controlled at the JET Tokamak reactor, and the reactor you speak of being built in Europe is the ITER reactor, which is on track for a success, albeit a very expensive one involving cutting edge technology. Go to their website and check it out for yourself. It is not a question of can it be done (because it already has), but can it be done profitably. On the other hand, so-called cold fusion is much more science fiction than science fact. And, all of the papers and studies I have seen always leave out important details: details that would proove the experiment flawed, such as what I have already pointed out. Cold fusion? Maybe one day...

I favor your attitude, although I haven't been keeping up on it. I majored in physics for the first 3 years of my undergraduate work, but switched to math because I couldn't envision myself professionally in the field of physics (neither in math, really, but I had to major in something eventually). As my physics studies became more and more specialized at the course level, I found the work less and less interesting, perhaps with the exception of nuclear physics.

Anyway, cold fusion has much of the mystique of perpetual motion, alchemy, the Holy Grail, the philosopher's stone, Heaven, the reflection of Narcissus, the pot of gold at the end of the rainbow, the fountain of youth, what have you?

I find it hard to believe that a high level European scientific consortium would embark on an extremely expensive venture that is prima facia a wild goose chase. Just look at the recent major success of a European scientific cooperative space mission. I forget the details, but I was extremely impressed at the high level of success. Was it to Mars? I forget.