You'll have to wait a few years until they integrate radar and track the bullet's flight. The first one might miss, but the one behind that will hit exactly. By then they'll have dropped the pretense of a human pulling the trigger too.

I recognize your username I think I've been able to answer one of your questions before. They're interesting, and you've got a great way of asking for clarification if you don't like the answer you get. Reminds me of the nineties on Slashdot. ;)

You're being pedantic (yes, in your other post too). NASA is a US government agency. Individual researchers in that agency are US government employees. As far as I can tell, this study was funded by internal NASA funds.

Somebody convinced someone in a responsible position within NASA, with the power to allocate funds and probably assign personnel, that this was something worth looking into. Normal people understand that when you say "NASA did this" or "IBM did this" or "Microsoft did this" that you don't mean that every individual associated with one of those entities was involved, but that someone was, and that there was some kind of institutional involvement. Funding certainly qualifies.

I imagine they'll get around to that, provided everything goes well, but they'd probably like to do some more ground testing before they invest millions putting up a satellite.

Your "major reason" is BS you made up. Have you heard of relativity?

If you're going to use P = F*v then the v has to come from the thruster, not from however you got the train up to mach 10 in the first place. Congrats though, you managed to dazzle the mods with some "math."

So you're arguing that NASA shouldn't test a potential new propulsion technique based on some shady logic founded on a description in a pop science magazine? Very rigorous of you.

Which NASA is working towards gathering. What's the problem?

Somebody convinced NASA that it was worth spending some money checking this out, so they build a small scale version and tested it. Results were positive, with some compromises in the experiment. The next step is to do a more rigorous experiment. If that's positive you invest a little more. Eventually, if everything goes well, you launch a test satellite. There's your extraordinary evidence.

Many crazy ideas are not worth testing. This one isn't nearly as crazy as the media likes to make it sound. The leading theoretical explanations don't involve any violations of conservation of momentum.

All (known) forces are between two charge carriers: electric charge for electromagnetism, mass for gravity, colour for the strong force, etc. You can use electromagnetic interactions to accelerate mass out the back of your rocket and because of that force symmetry the result is that your rocket accelerates in the opposite direction. You can drop a rock and it will accelerate towards the Earth, but the Earth also accelerates towards the rock. The symmetry means that momentum is conserved. Essentially, in order to change your momentum, you need something to push (or pull) on, thereby changing it's momentum, conserving total momentum.

For a reactionless drive you want to be able to change your momentum without pushing or pulling on anything. That idea has all sorts of problems. One of the proposed mechanisms for the EM drive is that it isn't actually reactionless at all: the asymmetric design of the drive canister causes the microwaves to push asymmetrically on the sea of virtual particles that are always popping up and annihilating. So the drive actually would have an exhaust, it would just be virtual particles that were encountered along the way instead of fuel you brought along.

I was surprised. He's usually pretty good. But this article is crap. Maybe someone hacked his blog.

The results, as he described them OR as actually reported in the paper, are weak support for the EM/Cannae drive. You can't conclude that it actually works from those results because there were some compromises in the experiment, like not running everything in a vacuum. But you also can't conclude it doesn't work.

This is a far better article.

The NASA experiment demonstrated that one man's idea of what was required for thrust generation was wrong. The null device differed from the real device only in not having some ridges machined into the case.

That doesn't mean the device really is producing thrust useful as a space drive, but it also doesn't mean it isn't. The experimenters reported "anomalous thrust," which is exactly what they saw. More experiments, in a vacuum to start, are required.

From the perspective of someone falling in, the outside universe experiences an infinite amount of time. So if it's going to end, it's going to end before the infalling observer has even the very short period of time required to cross the event horizon.

If the universe doesn't end, it will have infinite time to cool off and the black to hole to evaporate from Hawking radiation. To conserve energy that means the infalling observer must observe a greater and greater amount of Hawking radiation the closer he gets to the event horizon, and the horizon will always recede from him as the hole shrinks. When he eventually reaches the centre he'll discover that there's no black hole left.

Physicists originally called black holes "frozen stars" because the flow of time stops at the event horizon. Nothing can fall past an event horizon in outside time because that would take an infinitely long time to happen. It also can't happen from the perspective of an observer falling in, provided the outside universe has a finite lifetime. So you can never get a singularity.

I'm not really sure why that idea doesn't get more attention from today's physicists.

Not the original poster, but I agree. I think it's great to have strong female main characters, on an equal footing with strong male main characters. But this ain't it. They're taking a character who is male, both in mythology and in their own storyline, and changing him into a woman. Why? Because they can't write female leads so they'll just take a male one and give him boobs? Because a female main character can't be successful without all the momentum gathered by that character being male for a thousand years?

Ridiculous seems like a reasonable summary.

Hey, the condescending article manages to not know what positive predictive values are!

Learned is such a strong word. I teach evidence based medicine, including test evaluation to med students and residents. I also have to try and explain it to practicing physicians.