Tom Ligon wrote:Careful, now! Don't get carried away! You are extrapolating.
Extrapolation is a useful technique, but you have to verify it is valid.
I'm very pleased with this news, but do maintain a proper scientific attitude. The positive news we can take to heart is the recent silence is NOT due to the machine burning up or some other problems in the lab.
And the other thing is, silence on results is the correct thing to do when waiting for peer review.
Don't get too overly excited. Smiling contentedly is allowed. Watch this space.
If the news is good, he has prepared us to expect some explaining an analysis will be required to extrapolate to the next step. It may not be overwhelmingly good and can't start building Mars ships the following day. It won't be that we're there already. Hopefully it will be that we're on the right track.
Agreed, scientists should be careful. In this capacity, I am not a scientist. I am a fan! As a fan, I reserve the right to get carried away
Dr. Nebel can continue to be properly silent on results all he wants. I am going to extrapolate away in the mean time;)
My moderation will be that I would be content if they jump right to a continuous production 100MW machine and I will be willing to wait for the Mars ship.
Also note that since it is an uncooled pulsed machine (last I heard), if you're sitting there taking data all afternoon you probably aren't running at fusion conditions. Not to say they can't - there's a lot you can learn from low-power experiments even if the pulsed power capability is there - but "runs like a top" doesn't necessarily mean neutrons...
I'm going to wait for official results before I go over to the fusion lab and start making fun of people... although this update certainly sounds promising in that regard...
93143 wrote:Also note that since it is an uncooled pulsed machine (last I heard), if you're sitting there taking data all afternoon you probably aren't running at fusion conditions.
There's no reason it is necessary to assume that the "taking data all afternoon" means "continuous operation". My understanding of the WB6 machine was that power supply issues were the limiting factor on run-time. A better power source (which I believe the WB7 is supposed to have) may still result in pulsed operation, but longer pulses, perhaps even more frequent pulses.
If they are running one pulse, 0.1s long, per hour, that would be fantastic, and would provide enough information to validate or refute Dr. Bussard's theories.
In the medical research world, a peer review is conducted by two or three reviewers, who receive the presumptive paper and basically go over it with a fine toothed comb, looking for flaws in logic or methodology or statistics. This process can be quite drawn out - a minimum of two months to an average of four months to in some cases a year. Most of the time, the honesty of the primary investigator is assumed, so the reviewers would seldom ask to observe an experiment and check the results for themselves with their own meters etc.
However, in one case I was a part of, we were unable to replicate the original results; to such an extent we asked the original researcher for their original devices to do our own measurements on. Those devices did not function either ... which had us badly worried, until we noted that the original device had aged and changed dimensions over time, and did not correspond to a photograph taken when newly manufactured. When we recreated the original device from the photograph then things started to make more sense.
In the case of WB-7, well it's the physics world which I haven't had a lot to do with; and I do not think a peer review would ask to check the results of a fusion run with their own instrumentation. But they will hit the results and methodology pretty hard. And you can be sure that, since it is novel science and there is a lot riding on the outcome, they will engage in a minute inspection of the setup.
I would be surprised in it was less than two months for the peer review to return their findings. I hope that the panel has people who are not to biassed against polywell; because even in science, bias is a known confounding variable. What I hope for is a group of pragmatists, who are sufficiently dispassionate about their craft to take new stuff in their stride and just look at the physics.
And I hope it all vindicates Dr. Bussard's original vision - we need it sorely.
blaisepascal wrote:If they are running one pulse, 0.1s long, per hour, that would be fantastic, and would provide enough information to validate or refute Dr. Bussard's theories.
It would indeed be fantastic. I had the impression that the lack of cooling limited them to a couple of shots per day; I can't remember what that's based on. I was just trying to be cautious.
Yahoo! I'm pumped. This sounds like good news. I don't know about trying to read into Dr. Nebel's comments as to what the results are like, but if Dr. Nebel is pleased, I sure am too.
@93143: yes, Dr. Nebel said in a post here that cooling limited them to running two shots per day, but they might be doing some runs at less than full power, or maybe he was exaggerating slightly in the article. Or perhaps those two shots produce a lot of data to go over.
choff wrote:Maybe they could get Todd Rider or Richard Hull on the peer review, when the toughest skeptics are convinced then you can pretty much guarantee it works.
The toughest skeptics are usually those who have opinions they're unwilling to change no matter what the evidence is. While Richard Hull strikes one as having at least an open, though thoroughly convinced mind, Todd Rider's reputation and credentials would be somewhat damaged by a vindicated Bussard. Probably would not make the most reliable 'honest broker."
It would be like asking James Hansen to validate Steven MacIntyre's study of the hockey stick graph...oh wait, the New York times did that...
Tom.Cuddihy
~~~~~~~~~~~~~~~~~~~~~
Faith is the foundation of reason.
It is kind of interesting that Carlson isn't even curious. You'd think if you are going to shoot something down you would wait until there is something to shoot at. Until there's real data and we get to pour over it, there's not much point. Either way really - I hope this will work, but until real data shows up and we get some meat and ideas on which approximations make sense, there's not much point in being argumentative.
Interesting though from a psychological perspective.
Todd Rider's reputation and credentials would be somewhat damaged by a vindicated Bussard.
From my reading of Rider's paper, he seemed to have a sense of humor about it. (I know, it's easy to make jokes about other's views). Unless in the intervening years he's taken potshot after potshot at Bussard, maybe he wouldn't flat-out reject data in support of Polywell.
From what I've seen of Rider's writing, I don't think he has ever really analyzed a magrid machine. I believe his objections to the Polywell refer to the closed-box types. If EMC2 proves the system works, I would not be surprised if he uses that as his out.
I don't think he is as down on DD and DT fusion as he is on pB11, so I would still expect resistance from that quarter.
I've seen the "zero field at cusps" claim before and wondered what the heck they were talking about. There are a lot of ways of describing magnetic fields. Dr. Bussard used B-field (usually visualized as "flux line density"). Viewed that way, the funny cusp has fields from two close magnets superimposed, and is very strong, not zero. The corner and face cusps are hardly zero, either. What they are is radial. I've always assumed the nay-sayers were using some measure that says these radial field lines have no containment value, because in a tokamak you want the "lines" to be parallel to the interior walls of the torus. In fact, they're very strong in the required orientation, because what you need is to keep the electrons off the coils. Only the funny cusp is actually harmful.
What Carlson and a few others fail to realize is that the electrons have no interest whatsoever in the walls of the chamber. The few leakers where the lines are radial want only to get to the magrid. That shows a fundamental blindness to the underlying electrostatic nature of the machine which I consider a case of thermo-mindset.
Even Dr. Bussard had some conceptual problems with what I consider simple electrostatics. I caught him in a misunderstanding of PXL-1 once, and evidently he considered that an "ah-ha" moment. About a year ago he told me I had made a "discovery" in Manassas Park that was important in understanding these things, probably associated with catching that error. Essentially, I was thinking from a self-taught vacuum tube understanding. He had managed to confuse electron kinetic energy with voltage (which in this configuration is literally potential energy), causing him to get a sign wrong. That same underlying misconception had led him to expect the electrons would have high kinetic energy there (it was low, around 30 eV), but I understood they would have high KE only as they passed the electron gun, and would lose that KE rapidly after they passed it. I was dumbfounded by the error. He could not understand why my Langmuir probes were getting a negative voltage in a machine where no negative voltages were applied. The probes were in a central electron cloud. Their kinetic energy was "positive", but electrons are typically of the negative persuasion, so I knew instinctively that the probes were seeing a proper negative potential.
I know the main new feature of WB5 was intended to allow it to work correctly in the drive configuration that led to the incident above. It was intended to maintain high electron kinetic energy in the center, and would have produced a strong negative potential well (but the corner leaks would have been losses).
I caught a similar error years ago when working with a chemical kinetics professor on a time-of-flight mass spec theory. It stemmed from always solving the motion equations in terms of energy, never in terms of integrating thru potential gradients. Essentially, it is difficult to think in terms of negative kinetic energy, and it is easy to drop the sign. The "energy" approach is a convenient shorthand, but I doubt Poisson would have approved of it.
I suspect this mistake is amazingly common among physicists, and underlies Carlson's conceptual problem. Old vacuum tube guys like Simon and myself understand this aspect of the machines as a matter of course.
This sounds like good news. I don't know about trying to read into Dr. Nebel's comments as to what the results are like, but if Dr. Nebel is pleased, I sure am too.