A star is born ...

[DrS]

Or at least, it will be once the National Ignition Facility (NIF) in California switches its great experiment on. While looking at nuclear fusion, it seems that it will also examine the way the Sun works (as I understand it), as well as trying out the process as a potential energy source.

The full BBC report is HERE but I wondered what the forum's physicists thought of it all. Is this all feasible, or pie in the sky (not literally in the sky, of course!) ?

Doesn't this also allow some answer to those who claim that we have no way of knowing how stars work, what happens when they die, and how they're born ... or those who claim alternative answers ?

[Mulder]

There have been problems with laser fusion experiments in the past but this one looks good. It will create an implosive shockwave to produce huge pressures. I believe the 'new trick' this time is having enough lasers to prevent the plasma leaking out. It ought to work OK.

[Trinoc]

Sometimes I wonder whether we keep hitting things with bigger and bigger hammers just because we can ... fusion, LHC, etc. I wonder, if we ran up against a point where we were stuck and had to find another way, would we be able to think of ways to do these things that don't simply involver bigger and more energy all the time.

I'm thinking of something like when the Hubble telescope turned out to have dodgy optics. We could just have said "Tough, we can't do anything for a few years until we fix it", but instead whole new image processing techniques were devised to get good data out of the images. There are ideas being tried all the time to accelerate particles using machinery which is tiny compared to what we actually use, but as long as the big bucks and kudos are in building things like the LHC they probably won't be taken seriously. There were even some pretty good attempts at low-temperature fusion going on - muon catalysis and so on - until they all got tarred with the Pons & Fleischmann brush.

[Nukapai]

Dork-answer alert.

This topic made me think of Spiderman 2.

[DrS]

Dork-answer alert.

This topic made me think of Spiderman 2.

Nerd-answer alert.

Why?

[Nukapai]

Nerd-answer alert.

Why?

Because of Doctor Octavius and his fusion gizmo.

[DrS]

Ah! Thankyou

[SorryImPsychic]

Or at least, it will be once the National Ignition Facility (NIF) in California switches its great experiment on. While looking at nuclear fusion, it seems that it will also examine the way the Sun works (as I understand it), as well as trying out the process as a potential energy source.

If the Sun really worked the way 'official Science' says it does then if we reproduced that supposed nuclear fusion on earth to emulate that self sustaining thermonuclear reaction of the Sun only one thing can happen -KABOOM

[Trinoc]

If the Sun really worked the way 'official Science' says it does then if we reproduced that supposed nuclear fusion on earth to emulate that self sustaining thermonuclear reaction of the Sun only one thing can happen -KABOOM

So, since confined fusion has been achieved on Earth and it didn't go KABOOM, I think we can safely assume your "unofficial science" theories are wrong.

[Croydon Bob]

If the Sun really worked the way 'official Science' says it does then if we reproduced that supposed nuclear fusion on earth to emulate that self sustaining thermonuclear reaction of the Sun only one thing can happen -KABOOM

All you have done here is show that your understanding is very limited.

[Trinoc]

All you have done here is show that your understanding is very limited.

... in the same sense that a homeopathic medicine contains a very limited amount of active ingredient ...

[edd]

Sometimes I wonder whether we keep hitting things with bigger and bigger hammers just because we can ... fusion, LHC, etc. I wonder, if we ran up against a point where we were stuck and had to find another way, would we be able to think of ways to do these things that don't simply involver bigger and more energy all the time.

Well, we do actively look for other ways anyway. It's not like we want to rely on only the one tool.

I suspect a lot of this is reporting bias, the fact that the most interesting thing about a big experiment is the stuff that only it can do and that cheaper ways of approaching a problem are often tried first and you simply don't hear about them.

For example, table-top experiments to test short range gravity in order to examine brane world ideas aren't as exciting as a huge project that bangs stuff together, and they're not often reported in the popular press as a result.

[Trinoc]

For example, table-top experiments to test short range gravity in order to examine brane world ideas aren't as exciting as a huge project that bangs stuff together, and they're not often reported in the popular press as a result.

True, but if there was a significant amount of table top high energy experimenting going on I would expect to see it reported in places like Scientific American (which is probably where I have seen what little of it I have).

[Cuddles]

Is this all feasible, or pie in the sky?

Yes, it's entirely feasible. Inertial confinement fusion like this is a bit behind magnetic confinement in that it has not yet achieved break even (meaning getting more energy out than in). NIF should achieve this, and show that inertial confinement is at least possible as a potential source of power.

Doesn't this also allow some answer to those who claim that we have no way of knowing how stars work, what happens when they die, and how they're born ... or those who claim alternative answers ?

Not really. Shooting lumps of beryllium with lots of lasers is so different from the processes in the Sun that there's really not much of a direct connection between the two. Magnetic confinement and hydrogen bombs are much closer analogues to stars.

Sometimes I wonder whether we keep hitting things with bigger and bigger hammers just because we can ... fusion, LHC, etc. I wonder, if we ran up against a point where we were stuck and had to find another way, would we be able to think of ways to do these things that don't simply involver bigger and more energy all the time.

When it comes down to it, yes, it is because we can. However, it's not just because we can, it's because we want to find out what happens when we do. We've already looked at lower energies, and the only way to get to higher energies is, in fact, to use more energy.

There are ideas being tried all the time to accelerate particles using machinery which is tiny compared to what we actually use, but as long as the big bucks and kudos are in building things like the LHC they probably won't be taken seriously.

What ideas would these be? I can tell you with absolute certainty that if someone worked out a way of achieving TeV energies in a small lab instead of needing kilometres of accelerator, every particle physicist in the world would jump all over it. One of the biggest problems in accelerator and particle physics is that it's almost impossible to get funding for the equipment needed because things like the LHC are a tad expensive. Being able to build one in every university instead of needing multiple countries involved would be the biggest breakthrough in particle physics since accelerators were first invented.

Another important point to consider is that practical applications of technology are always many years behind any new developments. Construction of parts of the LHC started over a decade ago, and the design was obviously been worked on long before that. There will of course have been many advances since then, but you can't suddenly turn around and start all over again. That would waste billions of pounds and ensure that no project ever got finished.

There were even some pretty good attempts at low-temperature fusion going on - muon catalysis and so on - until they all got tarred with the Pons & Fleischmann brush.

It's a common misconception, but Pons and Fleischmann were never the main problem with cold fusion, they were simply the most prominent face of it. The problem is simply that no-one has ever shown decent evidence that it is possible. There have constantly been claims made about it, both before and after P&F, but no-one has ever shown anything that can be reliably replicated. Even worse, even the unreplicated experiments aren't good evidence of fusion. They either show excess heat or neutrons or products, but never all at the same time.

As always, if someone actually showed good, replicated evidence of cold fusion, physicists would be all over it. Most of us don't bother with it because it seems pretty clear that it won't actually work. There's no real theory predicting it to be possible, and no experimental evidence. If someone can change one of those two problems, then it may be worth another look. Until then, there are far more promising lines of work to be following.

True, but if there was a significant amount of table top high energy experimenting going on I would expect to see it reported in places like Scientific American (which is probably where I have seen what little of it I have).

There is not any table-top high energy physics. The things that can be done on a table top may have been considered high energy back in the '30s, but we've come a long way since then.

[SorryImPsychic]

So, since confined fusion has been achieved on Earth and it didn't go KABOOM, I think we can safely assume your "unofficial science" theories are wrong.

Please note: I said the "self-sustaining thermonuclear reaction" which would be necessary for sun under the Nuclear Fusion Model....this does not equate with "confined nuclear fusion' achieved on Earth.

the KABOOM still applies.