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Slashback: Iridium, Synthesis, Drives
In this household, we obey the laws of physics! Tuesday before last, we mentioned that two scientists had announced what they claim is the first accurate measure of the speed of gravity.
Now, Emperor_Alikar writes "In an article on Space.com, many physicists have criticized the current work on the speed of gravity, calling it 'nonsense' and 'simply incorrect.' Many of them still doubt the claims made by Fomalont and Kopeikin even before the results were even announced. Many of the physicists still hold on to the idea that gravity works instantaneously no matter what the distance, an idea that originated by Newton, but that was argued against by Einstein."
Back from the back from the back from the dead. Checkers writes "Spacedaily.com posted the following two stories about Iridium today. The first story is about the DoD committing the first of three renewal options that will use Iridium through 2005. The second story related story is about an agreement inked between Iridium and Harris Corp. that allows Iridium the right to use Harris' OS/COMET satellite command and control system for the life of the Iridium satellite network."
E.T. was also into this scene. In re: matt simpson writes "Another fantastic Speak & Spell modder is Dave Wright of the band "not breathing". You can check his work out, among other modifications to toys, at www.carrionsound.com Dave has made speak & spell/math/read for Nine Inch Nails, Meat Beat Manifesto, and many other bands. Figured you might be interested in other neat synth hackers :)"
Further evidence, never a good time to buy. SpinnerBait writes "It's seems like Serial ATA Controllers have been on the market forever but where have all the Serial ATA Hard Drives been? The wait seems to finally be over, as HotHardware shows with this review and showcase on a pair of new Seagate Barracuda V Serial ATA drives. This article covers benchmarks with the product in single drive configurations, as well as RAID 0. In addition, they show performance on two different SATA controllers, from Promise and Silicon Image. And oh, those nice thin neat little SATA cables! Gotta love 'em."
We've had a few articles about Serial ATA; I hope it lives up to its reputation.
Just to add to the confusion ... probejockey writes "A current article in the Globe and Mail claims SCO will start collecting licensing fees from some Linux users, not all Linux vendors as previously reported here."
Birds of a feather, separate rooms. Finally, Declan McCullagh sent in a few interesting links yesterday regarding the RIAA and its announced opposition to mandated DRM technologies:
"First, here are the photos from today's press conference.
Second, the supposed news of today's announcement was that the RIAA would no longer pursue mandatory-DRM technologies like the Hollings bill. But it was the MPAA that was behind Hollings from the beginning (September 2001). And when Hollings finally introduced his bill in March 2002, it was the MPAA that endorsed it, while the RIAA pointedly did not."
Thanks to Declan for the links.
Wasn't smart enough to get in, either ... Finally, thanks to the several readers who alerted me by email and in comments that the school variously rendered Cal Tech, CalTech and other things even worse is in fact properly spelled "Caltech."
Check your user preferences, messages. Readers decide how much the bonus is worth. Set it to 1 instead of the default, 0, and you'll see the old behavior.
As copyright owner of this comment, I authorize everyone to defeat any technological measure which limits access to it.
GPS is a passive system. It can't be overloaded.
You like splinters in your crotch? -Jon Caldara
I am not sure if you completely understand how the GPS system works. I am not sure if I do either for that matter but the GPS system is in very little danger of being "overloaded". It is the actual GPS device that does the triangulation calculations. All the sats do is keep track of their relative position to their peers and broadcast a unique signal. Doesn't matter if 1 device or 1 million devices are earthside it is just a broadcast.
It is not enough to succeed, others must fail. - Gore Vidal
GPS can never be overloaded like that. The SVs are broadcast only, they don't give a rat's arse how many things are using them.
And, GPS would never be the sole means of guidance for all weapons, by virtue of the fact that it only really works well against targets at known positions. Only laser and TV guidance work well against moving targets.
users can decide what the bonus is worth for themselves, so if you've got the bonus set to 0 it won't show up.
Username taken, please choose another one.
Of course, it's not that simple. The sun can't suddenly disappear.
It could explode. Assuming that it forms a sphere with all the mass at the outer edge, the gravity that the Earth feels wouldn't change at all until the mass reached the Earth's orbit, and then it would immediately drop to zero (I forget the law that tells us that the gravity of a spherical body is the same as if all the mass was contained at one point in the center.)
Unfortunately, the mass would come at the Earth at less than the speed of light, so this wouldn't be a good test. That, and it would kill us all, so if you do find a device to make the Sun blow up, I suggest not using it for this.
The Sun could be grabbed away by some massive force -- but the source of this `massive force' (super massive spaceship? God? Galacticus?) would have gravity too, and that would affect us. That, and the Sun couldn't leave at more than the speed of light, so even that's not a good test.
It's not easy to measure this :)
No, no, no! The contraversy over the results of the gravity measurement surrounds the MEASUREMENT TECHNIQUE, not the conclusion. You would have to look *really*, *really* hard to find a working physicist who thought that the influence of gravity was instantaneous. You'd have an easier time finding a "Pacifists for Bombing Iraq" organization to join.
actually, you CAN get a really long string from here to china. If you pull it however then each atom in the string will atract a nearby atom to 'stay close' and this information moves at best at the speed of light. So yes, your 'almost instantaneous' will turn out to be the speed of light.
Actually, if gravity is instantaneous, then you would percieve the sun as moving away from the earth instantaneously after it vanished due to the earth moving quickly out of orbit. The earth would fling off in a straight line from the sun as soon as it vanished at incredible speed, and the light from where the sun WAS would take longer to reach the earth as the earth moves away.
While you are correct in pointing out that we'd see the light for slightly longer than 8 minutes (with a slight accompanying redshift), the time (and distance) difference is very small.
The time between gravity shutoff and light shutoff is 8 minutes. The Earth's orbital period is about 526,000 minutes. That gives an angle of about 9.6e-5 radians. Over that small an angle, the Earth's orbit is close enough to being straight already that divergence from the path would be negligeable.
The problem with jamming GPS is that, to do that, you need to transmit a signal.
When you transmit a signal, you make yourself vulverable to things that can sense that signal; e.g., missiles that home in on radio transmissions.
So yes, you could jam a wave of GPS-guided weapons. But if the wave of attacks includes a handful of gravity bombs or other weapons that seek those frequencies, you couldn't do it twice...
Still, a smart jamming strategy might help protect a hardened target.
.
Eloi, Eloi, lema sabachtani?
www.fogbound.net
Out of every benchmark I've seen of the new Seagate Barracuda V S-ATA drives, _none_ of them benchmark against it's parallel ATA brother, but instead benchmark it against either an older generation drive, or a drive of another manufacturer completely.
Look, if you want to know how SATA performs, benching one of these 'cuda V drives against a western digital p-ata drive isn't going to tell you anything. Those drives from Seagate aren't all that fast compared to drives from Maxtor or WD (or IBM/Fujitsu).
Expecting SATA to speed anything up is pretty ridiculous - the drive mechanism is what determines performance in current hard drives - we're nowhere near ATA drives that can match even ATA100 speeds (even burst rates are only reaching ATA66 speeds, if that!).
SATA won't increase your speed, PERIOD. New generation drives with higher data density, etc., are what speed up drives. The interface doesn't matter in speed.
FYI.
In any case, lest we forget, I quoth the FAQ:
Karma is used to remove risky users from the moderator pool, and to assign a bonus point to users who have contributed positively to Slashdot in the past. It is not your IQ, dick length/cup size, value as a human being, or a score in a video game. It does not determine your worth as a Slashdot reader. It does not cure cancer or grant you a seat on the secret spaceship that will be traveling to Mars when the Krulls return to destroy the planet in 2012. Karma fluctuates dramatically as users post, moderate, and meta-moderate. Don't let it bother you. It's just a number in the database.
And I just always wanted to note that the focus on dick length (not girth?) and cup size (not shape?) certainly lends credence to the concept of computer geeks being male dominated and female unfriendly.
"She's a scientist and a lesbian. She's not going to let it slide." Orphan Black
Don't moderate at level 4, duh. Turn off the bonus while you're at it. Browse at -1. That's how it's supposed to work. Don't pay any attention to what other people set their post bonuses to. That's their problem. A worthy score 5 post needs to be a natural 5.
If you mod at 4, then you are the lazy mod you speak of. It's your duty to moderate correctly if you volunteered by checking the box.
First you say no one is testing PATA vs SATA,
then you say it won't make a difference anyway.
What exactly was your point? Everyone is ignoring the interface standard, and just testing like any other HDD, but with a nice cable.
BTW the reason no-one is testing the PATA vs the SATA versions of the same drives, is that the PATA version has a 2Mb buffer and the SATA has a 8Mb buffer (with a slightly lower access time). The drives are not comparable.
Doesn't a centrifuge, or something like that, that spins at a really high rate of speed, generate it's own gravitational force?
Nope. From the point of view of someone in the centrifuge it *seems* like there is a force pulling them outwards, away from the axis of rotation. It's important to emphasize that it only seems this way. There isn't any force pulling you outward at all.
Recall that things like to go (that is must go) in straight lines until they are messed with by something else. A centrifuge spins in a circle very quickly. You, standing in the centrifuge, are trying to move in a straight line (tangent to the circle) but the floor is moving in a circle, so it keeps getting in the way: thus pushing you back on the circular track. In fact, everything in the centrifuge is trying to move in a straight line, but the floor keeps getting in the way. So when you throw something, it goes in a perfectly straight line, but to you inside it seems like the object traced out a parabola and was pulled back to the floor. When in fact, it only looked that way because *you* were wizzing around this circle.
To someone outside the centrifuge, they don't feel anything at all. It's just a big spinning thing.
This is the same feeling you get when you turn a corner in your car. Your body wants to keep moving in the same direction it was (straight) but now the car is going off on the other street, in a completely different direction! So your body runs into the door which pushes you back into the right direction. That's why it seems like you are "pulled" to the left when you turn right. In fact you aren't pulled at all: you were traveling along just fine but the car runs into you from the left because it has changed direction.
Actually.. it's not a perpetual motion machine.. it keeps getting faster and faster !
Flame on, but read the article.
... A source said SCO libraries that accompany the SVR4 and OSR5 versions of Unix may be used with UnixWare and OpenServer, respectively, but using them in conjunction with Linux is prohibited by the software's licence.
Sources said SCO plans to charge for use of two software "libraries,"
"There's a little bit of ignorance on the part of some customers," a source familiar with the plan said. But at the same time, the source added, "there are customers using the libraries that know they're not supposed to be using them."
Using the libraries allows programs designed for SCO Unix to be run, unmodified, on Linux machines in conjunction with a package called Linux-ABI. That's a key step for companies moving servers from SCO Unix to Linux with minimum disruption.
For those who don't know, "Linux-ABI" used to be called IBCS -- "Intel Binary Compatibility Standard" -- and you can guess from the name that it was an (old) attempt to standardize the ABI between different x86 Unixes. A long time ago, Linux users needed this to run commercial software like Oracle or WordPerfect.
It sounds like either Linux-ABI steps on SCO patents, or certain customers are shipping SCO libraries to run on top of Linux-ABI (which is outright copyright violation). In either case, this only affects about 0.001% of Linux users.
In short, all 2000 posts eariler were probably a massive over reaction.
Business. Numbers. Money. People. Computer World.
OK... your wish is my command. See this article, written by a University of Toronto physicist, that explains in simplespeak the concept of relativistic simultaneity. To wit:
The article continues... Pretty interesting, no?The matter would become energy .. and energy doesn't create gravity .. so .....
According to general relativity, energy does make a contribution to gravitational effects. Einstein's field equations include the stress-energy tensor, which for each point in spacetime gives information about the energy (including mass-energy) density, momentum density, and stress (e.g. pressure) associated to all forms of matter and all non-gravitational fields [MTW].
The problem is that if you assume Einstein's field equations, you automatically get the assertion that gravity "travels" at c, the speed of light in a vacuum. Any alternative theory regarding speed would have to include some change in the field equations, which have made some very strongly verified predictions in the last 85 years. On the other hand, if you had some alternative theory that did not have the same dependence on the stress-energy tensor, and if it predicted a gravitational change from an annihilation event, then you might be able to test its validity using such an experiment.
"Your notation sucks!" -- Serge Lang (1927-2005)