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Comment: ...of Government and Enterprise Working Together (Score 1) 98

by Roger W Moore (#49827861) Attached to: Mystery Company Blazes a Trail In Fusion Energy

This is exactly why you let private entrepreneurs do things rather than the government. It'll get done better, cheaper, and faster.

Actually you will typically only get two out of those three. Saying that there should never have been any tax spent on this is really not understanding what these entrepreneurs are doing. The reason that any of these startups are even possible is because of the huge amount of work which has been done on fusion in the past by governments. If none of that money have been spent there would be no fusion start ups because we would not have enough knowledge about fusing plasma to make any sort of even vaguely viable bid for investment funding. In addition some of the startups are actually get tax money to help them startup.

Rather than denigrate the government paid research that got us here you should be looking at a research system which is doing exactly what it should be and working extremely well as a whole. The, yes often ponderous, ship of state takes science on the long, risky and costly journey across a vast ocean of knowledge which does not appear to be very relevant to improving our quality of life until it gets within sight of something extremely useful. Then the entrepreneurs take over and rapidly construct a fleet of many different craft to get to the new shore which is now in sight. Most will sink without trace on the way to that shore but those that arrive rapidly explore and open up new territory for us all to benefit from.

So what we have here is a great example of the system working as it should. It's not a case of tortoise vs. hare and more a case of the tortoise carrying the hare until it is close enough to the finish that it can sprint across the line and win the race faster than either one could by themselves. Government research is slow and it is expensive but that is because they take on the big, slow and expensive research which private enterprise lacks the stamina to do. A successful team plays to each member's strengths and that's exactly what appears to be happening here. So don't complain - all those tax dollars you probably previously complained were wasted on fundamental research may well be about to be paid back ...and with a lot of interest if any one of these companies are successful.

Comment: November Revolution (Score 1) 59

I doubt any revolution in particle physics would ever come from *WITHIN* particle physics.

Really? It has already happened once with something called the November Revolution. This was the discovery of the charm quark which completely revolutionized our understanding of what baryons and mesons were and ushered in the quark model.

Prior to that there was the prediction of anti-matter by Dirac followed by its discovery a few years later which showed that we could unite quantum mechanics and Special Relativity. Prior to that there was Rutherford's discovery of the atom which completely changed our understanding of the nature of matter and all the early work with particles which lead to quantum mechanics. In fact if you look back at the last century or so of physics many of the major paradigm shifts in the field have come from particle physics or its clear precursor.

If you think that getting a PhD merely requires you to accept certain beliefs then you have a very poor understanding about how science works. Good PhD students will challenge the beliefs of those examining them and defend their work using the data and analysis they have in their thesis.

As for damaging careers coming up with some radical new idea will greatly enhance anyone's career...provided that they put in the ground work to do the studies needed to convince others of its worth. Big experiments are an issue because the amount of ground work to get one of these funded is huge and this limits the scope of ideas to ones which are clearly going to work.

Lastly though as for thinking of the Standard Model as the truth absolutely nothing could be more wrong. In fact we usually start by pointing out one of its most obvious flaws: there is no gravity in it! Indeed we particle physicists spend all our time trying to break it by looking for physics beyond what it allows for. Whoever finds physics beyond the Standard Model is likely to end up with a Nobel Prize so I'm not sure why you would think we would not he extremely motivated to break it and why this would not be really good for anyone's career.

Comment: Depends on Comparison (Score 2) 256

by Roger W Moore (#49819889) Attached to: Fuel Free Spacecrafts Using Graphene

However, electrons are very nearly massless, so unless they're somehow exciting them with massive amounts of energy, the propulsion from the electrons is unlikely to be significant.

It depends on what you compare it to. Since this process was hitting the graphite with photons it makes sense to compare the thrust produced to that created purely by bouncing photons off a material. Electrons might be light but they have more mass than a photon and so the thrust should be significantly higher.

Comment: No Charge Violation! (Score 2) 256

by Roger W Moore (#49819151) Attached to: Fuel Free Spacecrafts Using Graphene
That may be correct but the article you linked has an incredibly misleading title. This process does not convert photons into electrons it simply imparts the photon's energy to one or more electrons which, in the case of thrust, causes them to be ejected from the graphite. The coupling of electrons to photons is extremely well understood, in fact it is the second most accurately tested scientific theory ever discovered (the first being special relativity). The only way to create electrons from photons is to also create an equal number of positrons. However this requires far higher energy processes ~1 MeV of energy which is many orders of magnitude higher than the energies involved in visible light and would easily break apart graphite which is something they ruled out.

Comment: In lab = Surrounded by Electrons (Score 1) 256

by Roger W Moore (#49819081) Attached to: Fuel Free Spacecrafts Using Graphene

Where the heck those extra electrons came from?

They could easily come from all the material which is surrounding the graphite. As the charge builds up on the graphite due to all the electrons being expelled it will develop an increasingly strong electric field eventually will pull electrons from the walls of the chamber. Since the vacuum will also not be perfect the remaining gas molecules could also transfer charge by moving back and forth between the graphite and the chamber walls.

A similar effect exists in the LHC where the electrons are 'helped' to leave the walls by synchrotron radiation hitting the walls of the beam pipe and are then dragged along by the electric field of a bunch of protons forming a electron cloud. This effect is one of the primary limiting factors on the number of protons we can have in an LHC beam.

Comment: Even More Thrust (Score 2, Interesting) 256

by Roger W Moore (#49819015) Attached to: Fuel Free Spacecrafts Using Graphene

So they'd need to carry hydrogen and split off its electrons or something to neutralize the charge.

Actually this could provide more thrust. Use sunlight to propel the craft until it has built up a large enough electric charge that the efficiency of the thrust begins to drop (since it will take an increasing amount of energy to expel the electrons from something with a large positive charge) and then introduce a stream of neutral gas into the sponge. This should strip the electrons off the gas and the remaining positively charge ions will then be repelled by the positive graphite and provide even more thrust.

Of course this means that you need to have a fuel source but it's likely to be far more efficient than current rocket fuel plus there it no need for it to be something explosive like hydrogen - you could probably use Xenon which is a noble gas and so extremely inert and so a lot safer.

Comment: Mass was the bigger problem (Score 1) 59

Actually before the Higgs the problem with the model was that the particles all had non-zero masses. This breaks symmetries which we observe to be held in nature and was a huge problem and also gave rise to the violation of unitarity: if there were no masses there would be no unitarity violations.

Part of the beauty of the Higgs mechanism is that not only did it explain how the particles could have masses while the symmetries of nature we observe are preserved but it also called out the unitarity violations which the non-zero particle masses caused!

Every model has its problems though. The issue with the SM is that the Higgs mass is so much lighter than the Planck scale. This means that there has to be something probably not much higher in mass than the scales we have already probed. However this is not a hard constraint. The higher the energy of this new physics the less "natural" but with only one universe to play with there is no way to be certain that a one in a million chance did not occur when setting up the laws of nature....it's just not very likely.

Comment: Re:Some doubts (Score 1) 106

by Roger W Moore (#49815245) Attached to: Does a Black Hole Have a Shape?
It sounds like he was answering a different question: "What is the shape of a black hole?". That's a perfectly reasonable question to ask. Asking whether they have a shape is akin to asking: "Does something which exists have a shape?". In fact this article is actually a violation of Betteridge's law because the answer is 'yes', Black Holes do indeed have a shape although that answer imparts no useful information whatsoever.

Comment: Some doubts (Score 1) 106

by Roger W Moore (#49814113) Attached to: Does a Black Hole Have a Shape?
Asking questions like "Does a Black Hole have a shape?" makes you have doubts about those qualifications though. In physics you need to be careful to be precise. Anything which exists has a shape and yet he is not questioning the existence of Black Holes nor even whether they are spherical but rather whether they appear distorted from spherical by their gravitational field bending light.

Comment: RPV SUSY (Score 1) 59

Any SUSY is going to provide a dark matter candidate.

Actually that is not quite correct. A majority do but there are searches conducted at the LHC for something called R-parity violating SUSY. In these models the lightest SUSY particle can decay and SUSY does not explain Dark Matter.

These models are generally less popular because there are very strong limits on them from existing data. In particular these models allow for flavour changing neutral currents and thing like baryon number violation and there are extremely strong limits on both processes not being seen (although we do eventually expect to see baryon number violation).

Comment: No assumption re: SUSY (Score 1) 59

Does the higher energy and luminosity have any real chance of creating dark matter that we didn't see at the lower energy

Nobody can really answer that: we are going beyond the energy frontier and nobody can really say for certain what, if anything, we will find. However if those two broad assumptions I stated above (weakly interacting and thermally produced) are true for Dark Matter then, barring some pathologically strange model for new physics, we should see Dark Matter whether it is from SUSY or something else.

The reason these assumptions put a limit on the mass is that the heavier the particle the earlier the universe will cool to the point that no more can be produced. If this happens really early on i.e. very massive particles, then these particles will be so dense that they will interact and annihilate back into whatever produced them and so there will be very few left, too few to explain Dark Matter. Similarly if they are too low in mass then there will be far more of them because they decouple from the universe later when it is less dense but then the lower mass per particle means that there is still not enough to explain Dark Matter.

For a weakly interacting particle this 'sweet spot' turns out to be within reach of the LHC. This makes no assumption whatsoever about Supersymmetry only that the particle interact with the weak force. However if they only interact through the Higgs then the mass will be higher or (worse) if via gravity then much, much higher. Another possibility is that Dark Matter was not thermally produced in which case you need to know the production mechanism to find out what it says about the mass.

Fundamentally, there may be no basis for anything.

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