Mod this parent up.
No, it is still not even wrong, but we are closer to knowing if it could be right or wrong. This is not strong evidence, let alone proof, of string theory. This just gives it a way to be more compatible with relativity. The problem is that it could be just a good approximation of something else.
It's not even that good. It deals with the AdS/CFT correspondence. The "AdS" in that acronym stands for "Anti-de Sitter" space, i.e., a spacetime with a negative cosmological constant. Observation shows that we actually live in a universe with a positive cosmological constant, so the compatibility is with the wrong relativity.
All of this was theoretical until this recent finding. The researches created two mathematical models of the universe - one of them ten-dimensional (similar to some forms of modern theories of our universe, though the article points out their model was simpler). The other model was a one-dimensional universe filled with ideal springs. These models were identical, in the same way as the 3D universe and the event horizon - they're alternate ways of calculating the same thing.
The researchers discovered that simulations in both of these universe models have the same output - in other words, they do seem to be different ways of describing the same universe.
It's still theoretical. There is absolutely no experimental evidence for any of this.
...so before you call it horseshit, you could try to read what they are actually saying. Also, the particular theory they are talking about here has actually been tested, at least somewhat: people used it to compute some stuff about gluon plasma, which they then tested against LHC data, and it matched quite well. So the theories do work, and they can be used to compute real predictions.
Which papers are these? The two papers referenced above do not discuss this at all, and I am not aware of any LHC results dealing with quantum gravity. References would be appreciated.
That is exactly backwards. Unlike General Relativity, quantum mechanics was driven by experiment almost every step of the way. It was met with some derision (and worse, see, e.g., Nazi Germany), but it was experimentally based. (BTW, Einstein accepted that it explained the (then available) experimental data, he just thought that it wasn't the entire explanation.)
. But although the validity of Maldacena's ideas has pretty much been taken for granted ever since, a rigorous proof has been elusive. In two papers posted on the arXiv repository, Yoshifumi Hyakutake of Ibaraki University in Japan and his colleagues now provide, if not an actual proof, at least compelling evidence that Maldacena's conjecture is true."
None of this is evidence of anything, and anyone who takes these ideas for granted, without the slightest experimental proof whatsoever, can be assumed to be no longer talking about physics.
Not if you could get arrested just for parking your EV in a local school parking lot.
Probably not much, as long as they got certified. From Justices Shield Medical Devices From Lawsuits
Makers of medical devices like implantable defibrillators or breast implants are immune from liability for personal injuries as long as the Food and Drug Administration approved the device before it was marketed and it meets the agency’s specifications, the Supreme Court ruled on Wednesday.
IANAL, this is not legal advice, etc.
I have seen demos of exactly this. Don't know if it is on the market yet.
Operations are complicated, messy, things, and surgeons are very interested in heads-up type displays to help answer questions like, "is my scalpel actually placed where I think it is?" Just like fighter pilots, they frequently do not want to take their eyes off of what they are doing. (I have worked in medical telepresence, and one of the things the surgeons most wanted was these kinds of headsup displays.)
"Among the possible uses for Google Glass that early adopters are dreaming up, you can now add 'surgical assistance' to the list. With approval from the institutional review board, a UCSF cardiothoracic surgeon recently utilized Glass during procedures
I have been involved with getting electronics into operating rooms, and it is an expensive, complicated and time consuming process. FDA requirements apply to all medical devices; with RFI being a big problem, especially in an OR environment (which is full of "mission critical" electronic gear). To be blunt, if Google glass interferes with the electronics already in the OR, patients could die, and everyone involved with getting it there would be directly responsible.
From my perspective, the note-worthy thing about this story would be getting the certification needed to take Google Glass into the OR, as that would probably be the hardest thing to do, much harder than some trivial HIPAA scrubbing, and it puzzles me that that is not mentioned in the article. So, I have to wonder, did they actually do this, or is Google and UCSF just winging it and hoping no one dies during their trials?
The linked gif seems to show the debris "tail" mostly flowing back along the comet's direction of travel, with some off-axis blow evident in the later post-encounter image. I would have expected the "tail" to always be pointing *away* from the sun as it made this fly-by. Derp?
There are generally two tails - the dust tail (which lies along the orbit path, like bread-crumbs in a fairy tale) and the (plasma) gas tail (which is blown by the solar wind, mostly directly away from the Sun). When you are just past perihelion ( as at the end of the linked-to video above) the dust tail can actually point (more or less) towards the Sun.
So, why don't you measure the position of the incoming trajectory points and the outgoingetrajectory points, and then scale according to the known incoming orbit variables, and finally determine whether the outgoing orbit trajectory is parabolic or hyperbolic?
Oh, that will be done. But not today, and probably not for a few weeks (until it gets closer to the Earth). It's more fun to predict these things before the measurements are taken.
Yes, and it spins fairly rapidly (~2.4 hours period). However, we don't know what the spin angle is. Note that the cancelation you mention only applies for the equatorial component of thrusting, so the polar component could still change the semi-major axis, unless the spin axis is exactly perpindicular to the orbit plane. Note that, I was just trying to show, in a back of the envelope fashion, that there was likely enough thrust to be significant; I think that conclusion still stands.
I've got almost no intuition at these scales, but nudging a cometary nucleus by a few m/s seems like it would take a lot of energy -- maybe more than the processes acting on this comet are likely to generate.
Now, nudging one chunk at the expense of the others is a different question. When a comet fragments, how quickly do the pieces typically separate? If the nucleus splits, forcing chunks apart at tens of m/s, the ones forced along track might get the boost they need -- but I don't know within an order of magnitude how fast the chunks are likely to be separating. Anybody?
A lot of energy was available. It was about 3 radii from the Sun. It was hot enough to boil rocks.
Suppose it lost 1/3 of its mass as water (steam) (so that the water lost had 1/2 the total mass). That steam could have left in a few jets, each with a velocity of 100 m / sec. If there were 100 jets, all distributed randomly about the surface, then the net velocity change would be ~ (1/2) * 100 m / sec / sqrt(100) or 5 m / sec, which is considerably more than 0.7 m / sec.