Slashback: Iridium, Synthesis, Drives

Slashback tonight with word on the (groan) fate of Iridium, more Speak n' Spell modding, examples of Serial ATA oozing to market, the RIAA versus mandatory DRM, and more. Read on for the updates.

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."

Comments

For you proper Simpson's nuts -

[spaten-optimator]

"In this house, we obey the laws of thermodynamics!" Homer mutters this when Lisa, bored at being out of school, creates a perpetual motion machine.

Infinite speed gravity?

[Doctor Fishboy]

All general relativists (and for that matter, all physicists) I know think that gravity propagates at the speed of light. In the linked articles, the criticism is that they've measured the speed of light by virtue of the radio photons, not the speed of gravity, which they're claiming.

There's nothing about 'infinitely' fast gravity in the article that I can see, and of the two physicists claiming to disagree with the results, the one who says it is 'nonsense' then refuses to comment any further.

Dr Fish

Re:Hey Y'all

[Sloppy]

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.

Me fail GPS ? That's unpossible!

[OldMiner]

GPS is a passive system. It can't be overloaded.

Re:Iridium and GPS

[axjms]

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.

Can we turn gravity off?

[bleckywelcky]

I think the real problem with determining the speed of gravity if indeed it does have a speed is the fact that we can not turn gravity on and off. Some of the first very very very rough measurements of the speed of light were made by a light source standing away from an oberserver and being turned off and on in a way that an algorithm they designed would use the information to tell them the approximate time it took for the light to get to the observer from the source. The problem with gravity is that we can not turn it off and on. Perhaps even like we can with a magnetic field. Just get a wire, run some current through it and use a switch to open/close the circuit. We could then measure the speed of a magnetic field (if it has one). The inability to turn gravity off and on is the key inhibitor to any substantial calculations on its part. And, I'm sure that when we can turn gravity off and on we really won't care that much anymore about trying to determine how fast it travels :) (although we probably will have already).

Re:Iridium and GPS

[Russ Steffen]

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.

Iridium Flares

[FrostedWheat]

If you haven't already seen one, Iridium Flares are really quite impressive.

SCO is toast

[legLess]

My brother used to run a motorcycle courier service in LA, and the only bill higher than his liability insurance (think about it - what type of guy wants to be a motorcycle courier? how safe is he going to be?) was his SCO license. These folks have been squeezing blood out of the turnip for years, and now that people have abadonded their turnip (to further torture the analogy) SCO is looking for other vegetables.

They're toast, though, no matter what half-assed "intellectual property" scheme they come up with. I mean, really - who're you going to stay friends with? A girlfriend who gave you your toothbrush back and said, "Bye, and thanks for all the fish," or one who boiled your fucking cat alive? SCO is kicking its customers in the nuts while they walk out the door; they might squeeze a little cash out of them on the way, but they're only hastening the exit.

Chris Sontag, hired in October as senior vice-president of SCO's Operating Systems division, leads the intellectual property organization, sources said. Earlier in his career, Mr. Sontag led marketing and product development for Novell...

Did I mention that SCO is toast? That quote alone should get them on FC

Our Unix IP is a significant asset. And for several months, we have been holding internal discussions, exploring a wide range of possible strategies concerning this asset," the company said in a statement Monday. SCO hasn't decided how exactly to collect more Unix revenue, the company added.

Translation: "We're desperate and rudderless, checking under sofa cushions for spare change. Got any?"

Re:SCO is toast

[IntlHarvester]

Flame on, but read the article.

Sources said SCO plans to charge for use of two software "libraries," ... 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.

"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.

Argh!!!!!

[volsung]

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.

Re:Hey Y'all

[Otter]

Why Linux Isn't Ready For The Desktop: Chapter LXXIV

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.

Today's exercise in open source user-friendliness is making a major change to score display with no notice or explanation. After all, users can simply download the current Slash code from SourceForge CVS, grep for "No Karma Bonus", see what variable the checkbox sets and work back through the source to figure out why display seems to be broken. Oh! It's just a new preference that needs to be set!

Re:Iridium and GPS

[angst_ridden_hipster]

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.

.

Re:Okay, I'll try:

[glenebob]

"...would the Earth continue to hold its orbit for 8 or so minutes..."

There would be no clue that anything happened to the sun until 8 minutes after it happened. Or so the scientests are telling us. And if you think about it, it seems to make some sense when compared against other relativistic theories.

For one thing, if gravity was instananeous it could conceivably be used to send information anywhere in the universe with zero ping time. Imagine a gravity-wave wireless link that would enable us to communicate with civilizations in other galaxies. Imagine playing Q3 with an alien on a planet in M3 and still having a 20ms ping.

Now imagine sending energy via gravity waves. With the right technology you (in energy form) could be beamed, Star Trek style, to another galaxy. You could go visit your alien buddy for a lan party and be back in time for dinner.

Unfortunately, the notion of energy (and indirectly, matter) moving at infinite velocity seems to violate the entire theory of relativity. Moving you from here to another galaxy instantly certainly seems to violate the theory of relativity.

SATA benchmarks pretty useless thus far

[Tumbleweed]

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.

Speed of gravity paradox

[nebbian]

If the speed of gravity isn't infinite, then I think you get a paradox when two bodies are orbiting each other.

Let's say we have two bodies, body 1 and body 2, both orbiting a central point.

Both of them are getting pulled in towards the central point by the other one. Right?

But if the speed of gravity isn't infinite, each body will be pulled not exactly towards the center, but towards the point at which the other body used to be, a certain time ago.

Try this experiment: You will need:
1 friend
2 tennis balls
1 roundabout (the circular playground variety)

Stand on a point on the circumference of the roundabout, and get your friend to stand opposite you. Spin the roundabout so you are both orbiting the central point.

Now throw your tennis ball at your friend. Chances are you will miss, because your friend will have moved by the time the ball gets there. So now change your aim so that the ball actually hits your friend. Get your friend to do the same.

When you've got things sorted, you should get the tennis balls hitting you from slightly 'front-on' compared to the center of the roundabout.

So what this means is that if gravity has a speed, then each orbiting body will be pulled by the phantom ghost of the other one, which will appear to be slightly behind the center of rotation. Therefore, the two bodies will keep on accelerating, pulling themselves up by their shoelaces, until the orbits around the central point become so huge that the effect isn't very big at all.

In other words, orbits won't be stable if gravity has a speed.
If we assume that 2-body orbits are stable, then gravity must be instantaneous, but this introduces a communication paradox (as pointed out by many other posters).

So we have a paradox! If you were God, would you make gravity have a speed, or not? Or do you make it so friggin' hard to measure that people give up and argue over which physicist has the bigger reputation? :-)

Re:Speed of gravity paradox

[NanoProf]

I'm impressed. Very clever, but you've forgotten about the coordinate transformations of relativity. Assuming I remember my grad school E&M correctly, if one does a full calculation relativistically, the force arising from a body moving in a straight line at uniform speed does in fact appear to come from where the body would be predicted to be at the time that the signal is received, not the time that it is sent. Of course, if the body curves suddenly, this simple result breaks down (since own can't anticipate how it would curve). The situation with co-orbitting bodies is more complex, but the basic idea is the same: the full relativistic calculation with retardation effects (i.e. finite signal propagation) eliminates the naive nonphysical effects. One does, however, see things like precession of the perihelion from GR, which is absent in the Newtonian approximation.

Ok, this is what i think

[FS1]

I have seen alot of people here who say that gravity can't travel faster than the speed of light and usually back their response up with relativity. But mind you, relativity is still theory not law. Say for example gravity could travel faster than light, we will say that gravity waves travel at 2x the speed of light. Now say we have a way to measure the effect of gravity waves and not of gravity itself, just going to Heisenberg's uncertainty principle to say we can't measure the intensity of gravity waves unless we change their position. Because we would have to use light or energy or something that goes slower than light to measure the speed of the effects, that renders the results of any such attempt to send information or energy this way useless.

Now getting back to what someone asked earlier, what would happen if the sun were to be removed, would the earth spin off or stay in place for 8 minutes. To answer you question i use will use einstien's theory of gravity. He equated space to a 2-d surface, like a trampoline, gravity would warp that surface and create indentions. Ok say i put a bowling ball (sun) on the trampoline, and put a baseball (earth) in orbit of it. Now lets say i pick up the bowling ball quickly (almost instaneously), the baseball does just go off in a straight line, right?. What if i did it slowly?

Now saying that, you all know that you just simply can't move a mass such as the sun faster than the speed of light, heck you can't even make an bowling ball go faster than the speed of light, but the problem is relativity doesn't quite work for very large or very small objects. My theory is that gravity can move faster than the speed of light but the mass that generates it can't so you could never use it to create any paradox that was suggested.