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Comment Re:Can't this be tested on a Cube Sat? (Score 1) 471 471

Delta-V of 1.8e-4m/s is not so tiny. If my calculations are correct, that means it will move away by 1 m from an identical satellite in a pseudo-parallel orbit in under an hour if the second craft switches on its EM drive in the other direction for the same duty cycle. Make the two take alternate cycles of acceleration direction and they should see-saw in orbit together. Make the see-saw cycle 100 m long (wait a few days between blasts) and you can even observe it from the ground.

Comment What benefit to announcing it? (Score 3, Insightful) 201 201

This group sounds like they acted reasonably and responsibly, letting Google know there was a problem, and submitting good patches to correct the issue.

If, now, there's some other fundamental impediment to distributing a correction to the bug that does not have to do with Google, but rather with the heaploads of cell phone manufacturers who use Google's code and who may or may not have the ability to distribute the fix, why should the vulnerability be made public? I don't see any apparent upside to the public good.

Comment Re:Potholes? (Score 4, Interesting) 183 183

I live in New England. We have lots of freeze-thaw cycles during the year. It's rare that you see a proper frost heave in a road (and you certainly know it when you see it). By FAR the most road damage is caused by inexpert patching of the asphalt where the surface needs to be cut for utility work. When inexpertly patched, the surface is no longer remotely planar, and the unevenness right at the (and caused by the) patch increases the wear exactly where it can do the most damage. So, shortly, the patch needs a patch. Which is inexpertly done, and the cycle continues until you get a stretch of crud for surface and the local municipality shells out big bucks to have the road re-surfaced entirely.

Compare this to Southern California (where I lived for a number of years) where the road patches after utility work are 100% as smooth as the original surface. With your eyes closed, you cannot tell that you've driven over a patch. The patch (and especially the transitions from original surface to patch, and back) receives no more or less force than the original road, so there's no focus of wear, and it lasts a very long time.

It baffles me why we can't make proper road patches in New England. It's clearly possible. And I really can't believe that the people working to patch roads in Southern California are that much more talented, so it's either a technology issue, lack of managerial directive, or an out-and-out conspiracy to have a never-ending amount of road resurfacing work.

Comment Re:No mention of Concorde (Score 1) 238 238

What, do they think the world has become globally amnesiac in the last ten years?

No, but the editors around here have.

[ta-dam, tzing!]

Thankyou, thankyou. I'll be here all week. Don't forget to tip your servers!

(Now who's going to mod this funny, and who's going to mod it insightful?)

Comment Re:Citizen of Belgium here (Score 1) 1307 1307

I wasn't alive during WWII but both of my parents were. My mother was fortunate enough to be evacuated to Canada with her brother and my grandmother while my grandfather stayed behind. Neither of those two then-children saw the war up-front. My grandfather never, ever spoke of the war.

My father, however, did experience it first-hand and did tell me about it. As a precocious young boy, he risked imprisonment and worse by illegally building and repairing radios during the Nazi occupation. I hope you understand the full implications of it being illegal to own radios (think if it being illegal to own a smart phone, a tablet, or any kind of computer). There was no such thing as free speech. The Axis occupation of Greece was horrific, with the Germans being responsible for the worst of the atrocities. 13% of the occupation of Greece was killed or starved to death. Nearly all of the infrastructure was destroyed. The hyperinflation was the 5th worst in history. There is very good reason that many Greeks still do not like Germans, and want war reparations, and it isn't too much of a stretch to view the recent bail out programs as exactly that.

Comment Bad for Business (Score 1) 33 33

On Kaspersky:

I have no idea if this was because of a corporate policy about it or what, but I found it singularly amazing that these experts would have so little interest in the [bad] actors who were so clearly operating under their noses.

Put the bad actors out of business, and the threat disappears. No threat, no need for their software. Perhaps they were not openly collusive, but it isn't so difficult to imagine that they look the other way at the hand that indirectly feeds them.

Comment Re:What was the command? (Score 2) 154 154

Indeed, you definitely do NOT want hundreds-to-thousands of servers doing an update all at the same time, or, worse, rebooting all at the same time. The first has the potential to saturate your network and bring the entire setup to its knees, and the second will blow your rack supplies. I speak from experience on the latter, having been the one who identified the issue with our weekly DB scrubbing procedure once the company I was working for grew to more than a half dozen servers.

You want to stagger things by a few 10s of seconds per server on each rack to avoid power supply issues.

Comment Electrons matter (Score 1) 67 67

Imagine if when you run a set of computations that not only information is processed but physical matter is algorithmically manipulated as well.

And here I thought the movement of electrons in normal computers was already the embodiment of algorithmic manipulation of physical matter. Silly me.

Comment Re:I know a lot of this is cutting edge... (Score 2) 41 41

I don't know how you can see much from the second video, as NASA has not released anything high-res yet.
could be the same problem as before, the feed is way too low-res to understand what went wrong.

Thanks for the links. I had another look and you may be right -- it may be the same failure mode. In fact, it might be that the most recent 'chute actually lasted longer than the first one.

Comment Re:I know a lot of this is cutting edge... (Score 5, Informative) 41 41

... but the parachute? Really? If you know the speed and the density of the atmosphere you're going to deploy it in then the rest is basic physics and engineering. Just make sure you make the damn thing strong enough!

You would think so, yes, except that no one has developed a parachute precisely (or even remotely) like this one before: it's the biggest super-sonic parachute ever (the ring portion of the 'chute deploys at over Mach 4 ... normal aerodynamics don't work there), AND, it has to be light enough to meet mission parameters for weight budget. While you might think it's basic physics, the empirical details are a bear to get right.

It's not just that this is, in fact, rocket science, but really, really hard, cutting-edge rocket science.

Having watched the NASA-released video, the failure mode appeared to be very different from the first test. The first test suffered from imperfect deployment that resulted in uneven loading and thus failure of the main 'chute. The droge (the first little 'chute) went out perfectly, but the main parasol failed to open. The second test failed more quickly, without even partial deployment of the main 'chute, as if it was immediately ripped apart. Watch the videos, they're fascinating!

Comment Re:Incredible (Score 1) 92 92

Funny, yes, but the scientists behind the research, at NASA, do use the term correctly. They do mean chaotic in the mathematical sense. I listened to the streamed press conference on the subject and, if you look beyond the egregious mis-pronouciation of Charon by the lead author on the work, someone who really should know better, they did a pretty good job of establishing a likely chaotic orientation for Hydra and Nix. Not "really messy and hard to predict but deterministic," but chaotic. With an N-body system, it turns out it isn't that hard to establish chaos.

And, of course, we know from simulation work done at MIT that the orbit of Pluto is likely chaotic, as published in Science some years ago: -- I've worked with some of the people who wrote that report, and they are among the best, and most careful scientists I know.

The fancy is indeed no other than a mode of memory emancipated from the order of space and time. -- Samuel Taylor Coleridge