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Comment Re:Seven milliseconds? (Score 3, Informative) 740

Actually a neutrino beam could make the trip faster than photons can in practice. One, because neutrinos could travel through the crust of the earth and thus avoid having to go around the curvature. Two, they would be traveling much closer to the speed of light than the photon-based signal, because that signal will be slowed by the index of refraction of the medium in which it travels, be it fiber optic cable or air (for radio waves).

Here's a link to an actual demonstration of an ASCII message sent via neutrino over 1035 meters

Comment Why read past the second paragraph? (Score 5, Insightful) 1255

First lines of 2nd paragraph:

I am not an education policy wonk: I’m just judgmental. But it seems to me that if every single parent sent every single child to public school, public schools would improve.

Thanks for telling me up front that you don't know what you're talking about so I got to save time by not reading the rest.

Comment Re:Wow. 20-40 TRILLION becquerels... (Score 2) 163

It's an appropriate unit of measurement, and also your analogy is off:

Yes, Bq is a unit of rate of decay. So measuring a release in Bq is saying "this is the rate of radiation the stuff is emitting", and that's what you need to know to know if you're getting a dangerous dose over your lifetime. If they said "atoms" or "kg" of material, it would tell you nothing useful by itself. 1 kg of U-238 is virtually harmless because it is so long lived, so it is infrequently emitting radiation, while 1 kg of Co-60 will just murder you.

As for your analogy, measuring the noise at a concert in watts is telling you the rate at which acoustic energy is emitted, and so is analogous to Bq. What you're advocating is equivalent to stating the integrated sound energy of the concert in Joules.

There's no perfect general unit for radiation, because the effect on a person will depend on the dose rate, the dose duration, the damage done by the type of radiation, where the contamination resides and moves over time both in the environment and in your body, etc. Bq is a good first unit for a general idea in this kind of situation.

Comment Re:yes, there are a reasonable number of positions (Score 2) 237

There are some programmer/IT people in my institution (a US National Lab) who want desperately to be real full-time scientists. They even have physics PhD's. They are from time to time given a bit of more direct participation, but it is clear that they will never be promoted into a regular scientist position, not while there are loads of PhD's coming off of 1 or 2 post-docs such that they have done nothing but hands-on research for the last 6-10 years.

These guys live in a kind of scientific purgatory, and presumably will eventually just give up.

The established career path at academic institutions is not easily back-doored.

Comment Re:Are ET3 and Musk actually connected? (Score 1) 258

"Anonymous Coward" the default name for people who aren't posting using an account. Create an account on the main slashdot page and your future comments will appear with your username. The posts will also appear with one more score point, for increased visibility.

Thanks for your info on the tubes.

Comment Are ET3 and Musk actually connected? (Score 2) 258

The ET3 website looks like some kind of scam. They are offering to sell licenses for their amazing technology for only $100! I've seen it listed on several articles about Musk's plans, but I suspect that some lazy journalist just googled some shit and found that page.

Does anyone know if Musk actually has a company working on this technology?

Comment Re:regarding constitutions (Score 5, Interesting) 413

Because the act of removing the president in this way is itself a violation of the constitution (I assume). The constitution has to be suspended in order for this extraordinary act to occur.

To give a hypothetical US example: let's say the people elect a President who turns out to be Literally Hitler, and has gotten Congress to back him (just like Hitler). So President Hitler and company prepare to conquer the world by force, much to the horror of the American people and the military. The people take to the streets, and the military leadership does not want to invade Mexico and Canada as ordered.

So, what do we do? The Constitution would have us wait for the next election cycle and vote these people out, but if we obey the constitution millions could be killed. Someone needs to do something, and the military is in the position to do it. The Joint Chiefs, with popular support, declare the Hitler government and congress to be disolved, and charges the Supreme Court with overseeing the creation and installation of a new government, because the Court is the only federal civil authority with any integrity.

None of that is even remotely authorized by the constitution, therefore the military tells us that "the constitution is suspended" in order to cary out this plan. That doesn't mean they go out and start violating every tenant of it, but they do have to violate parts (those which organize the government) in order to make it work.

Comment Re:What am I missing? (Score 5, Informative) 255

I'm an ion trapper, and though I don't work on this experiment, I've heard their group leader speak on exactly this topic a year or so ago, so hopefully I can do it justice from memory.

There are a couple challenges. One is "letting go". The atoms are trapped by very strong magnetic fields, and those have to be turned off rapidly to "let go" of the atoms. They turn off the superconducting magnet coils by heating them above their critical temperatures to make them normal-conducting and dumping all that energy into heat ("quenching" the magnet). Then the atoms are free to move around, but they weren't just sitting perfectly still in the traps, they had some thermal motion, which could fling them in any direction, including up. They've had trouble getting the atoms as cold as they had planned. They hoped they would be around 3 K, but I think they were stuck at 10 or 20 K for some unknown reason. So they aren't really just "dropping" the atoms. More atoms will go down than up if they are affected by gravity as expected, but it isn't remotely universal. Additionally their current trap is horizontal because the beam comes in from that direction, so there are only a few vertical cm in which to build up that bias.

Perhaps the bigger issue is actually knowing which way the atoms went. Their current trap was designed to do laser spectroscopy of atoms sitting in the trap, not tracking atoms as they fly around the beamline. What they do is wait until an anti-atom hits a surface and annihilates with a normal atom, and detect the radiation that is released from the annihilation. The radiation flies off in every direction though, so it takes some doing to build a radiation detection array that can reconstruct where in the apparatus the annihilations actually take place. As I mentioned, the current trap was not optimized for this particular study, so the reconstruction ability is pretty weak.

They are working on building the next generation of the experiment that will include a vertical trap, better detection arrays, and colder atoms, so that should be able to get to a better detection.

Comment Re:Find a technical solution, not a legal "solutio (Score 1) 687

Two big problems with that concept:

First, these lasers are very low power, milliwatt scale. What makes them dangerous isn't that they are so powerfulm but that the light is highly columned, so after the light enters an eye it can be focused down to high intensity on the retina. A window sensitive enough to be tinted by a laser would be tinted by the other more diffuse sources of light that you need to get through.

Second, laser pointer light doesn't stay pin-point over very long distances. 3 km away a laser pointer beam is at least a meter across.

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