The experiment you refer to involved a tethered satellite. It was performed on February 25, 1996, and as miles of tether were unrolled, the dynamo current grew just as predicted. The tether was almost entirely unrolled when it broke near the shuttle's end, whipping off into the void. The shuttle crew tracked the satellite by radio for several minutes, then lost contact.
After the mission, the tether was examined on Earth, and was found to have been melted through. Turns out the core of the cable was a porous material that had atmospheric-pressure air trapped in it during manufacture. The air leaked out through pinholes in the outer insulation and was quickly converted, by the high voltage (~3500V) of the tether, to a plasma far denser and more conductive than the surrounding ionosphere. Instruments indicated that the plasma diverted a full ampere of current (at 3500 volts) through the insulator pinholes, enough to melt through the cable.
That's why they don't let astronauts EVA any more without gloves.
OffTopic: That last line was a feeble joke, similar to the one in my original post. That post was modded up three points (by those who took "regenerative aerobraking" seriously) before being modded down five (by those who take mismoderation seriously). Is there a record for the number of mod points, both up and down, assigned to a single comment?
There's obviously no such thing as "regenerative aerobraking." My comment was mainly about the fact that by using aerobraking, they cut a few million off the launch costs. That's going to be invaluable in the future, as science budgets continue to be stripped to the bone.
Why anyone took the incredibly dry witticism at the end seriously is beyond me. Perhaps I should have used more vermouth.
By using the atmosphere of Mars to slow down the spacecraft in its orbit rather than firing its engine or thrusters, Odyssey was able to save more than 200 kilograms (440 pounds) of propellant. This reduction in spacecraft weight enabled the mission to be launched on a Delta II 7925 launch vehicle, rather than a larger, more expensive launcher.
No small feat, there. Too bad they didn't use regenerative aerobraking—we might have gotten the spacecraft back.
Sorry, billybob. I've got no excuse for adding 48 characters to your HTML download of this story, except that I was in a hurry when I submitted. Thankfully, your clever post has pointed out the error of my ways. Please feel free to bill me for the (48chars/yourcps) seconds which I cost you.
Then again, after looking at your posting history, perhaps it would be more fair if we billed you.
Oh, and I didn't include the link in order to demonstrate superiority (which I assume was the purpose of your dubious post), but for the simple convenience of the reader. I don't generally type unnecessarily—which is why I'll just link to this rather than waste more time on you myself.
News for nerds? Can a STORY be modded Offtopic?
on
Review: Orange County
·
· Score: 2, Offtopic
I really don't want this to sound like a troll, and I really love Slashdot, and I read it every day, and Linux is a great operating system, and open source is The Way, and I've really enjoyed all of Jack Black's movies, BUT...
Is this really a Slashdot news story? I mean, I'd never submit a non-tech movie review to/., much less expect it to be posted, and I don't think I personally know anyone who would.
Perhaps the editors could do the same thing we lowly grunts do—post stories like this in your journal.
This is the 50th/. story about Lessig since the first one three years ago. As court appointed master in the MS-DOJ case, he'd sworn that he had no personal bias or prejudice, even though he'd sent an email to a lawyer friend at Netscape saying that having installed IE was equivalent to selling his soul. An appellate court kicked him off the case shortly thereafter.
He continues to be a voice of reason and intelligent debate in an arena where both are often sorely lacking. Our community is richer for his presence.
As with all other song information on the iPod, the artist information comes from the MP3's ID3 tags, which it pulls and stores in a database for easy access.
Am I the only one whose ID3 tag info is sorely lacking across his entire collection? Either I've got a lot of work ahead of me before I'm iPod-ready, or some benevolent/.'er will reply with info about a tool that will automate this process, thus radically simplifying my purchasing rationalization^H^H^H^H^H^H^H^H^H^H^H^H^H^H^H decision.
I suppose they must have done some market research and discovered that only a small percentage of children were actually eschewing real Crayons and turning to a KDE menu option for their coloring needs. Their colored-wax-stick market share is safe.
Suppose companies start distributing video using the CPTWG encoder (whatever they might call it) to mark it as nondistributable. What's to keep folk from sending the video output to a DV device, then reading it back and re-encoding it to whatever 'open' format they choose? This isn't the easiest way to accomplish it, I'm sure, but if media can be played, can't it be re-recorded and converted?
It seems to me that whenever the powers-that-wanna-be try to establish total control of digital media, they lose whatever control or influence they already had. Why not redirect efforts toward better fair-use policies, reasonable licensing schemes, and accept that somebody will copy your work no matter what you do?
I think the real trick will be to improve Joe Random's perception of the recording industry to the point that he feels guilty about having media he hasn't paid for. Their current tactics will never accomplish that, and in fact will tend to perpetuate the Robin Hood fantasy that Napsterites currently enjoy.
"The more you tighten your grip, Valente, the more encoding systems will slip
through your fingers." -- Princess RIAA
I hate spammers as much as the next person, but I've also sent my resume out using a nifty little script I bru'd up to a hundred or so companies.
Really? Try these versions out:
"I hate crackers as much as the next person, but I've also sent my DDoS client out using a nifty little script I bru'd up to a hundred or so companies."
"I hate RIAA lawyers as much as the next person, but I've also sent my subpoenas out using a nifty little script I bru'd up to a hundred or so companies."
Remember, if you aren't part of the solution, you're part of the SPAM.
I'd have thought that someone would have brought up SpamCop by now. Is there a better service that I don't know about?
Anytime I get a spam, I hit the link that I received when I registered with SpamCop, and paste the email (complete with header) into the provided textbox. SpamCop processes the email, compiles a report of the offending spam, computes the appropriate reporting addresses, and delivers a copy to each one.
It even allows you to add text to the beginning of the report. I always add this:
The electronic mail message referenced in this report was transmitted to a user or users of an electronic mail service based in the state of Tennessee, USA, in direct violation of Tennessee Code Title 47, Chapter 18, Part 25: "Unsolicited Advertising by Electronic Means." See http://www.spamlaws.com/state/tn.html for the complete text of this law.
Does that make me a bad person?
-- Tsar's Hypothesis: As the population of the Earth increases, the sum of human intelligence remains constant.
I thought the Long Now Foundation's 10,000-year clock was an optimistic project. Why would anyone, especially learned men of the Royal Society, postulate that human life will exist in its present climate-dependent position even a million years from now?
We have gone from living at the mercy of the elements to building living environments in space in the span of only a few millennia, with the bulk of the technology being developed only in the last century. And now we stand poised to rewrite our own genome. Does anyone expect that, if mankind still exists five billion years hence, that it will be limited to this puny ball of rock, entirely dependent on this one yellow dwarf? Or that we will even resemble our current selves, either physically or intellectually?
Mankind may indeed pass through many cycles of near-extinction before the next million years pass. Look at our current speculative fiction. Scarcely anyone attempts to write about the future beyond a few thousand years, because we know it is beyond imagination.
Perhaps it would be best to say of stories such as this, that the Sun is still expected to continue, without substantial changes, for any conceivable lifespan of the human race as we now know it. Beyond that, we're whistling in the solar wind, for only God can know.
Imagining a satellite around a moon around a planet around a sun is a little out there.
Tough to imagine, eh? How about visualizing something closer to home--an electron in your wristwatch's second hand.
It's orbiting the nucleus of an iron atom,
which every 60 seconds circles the axis of your wristwatch,
which every 24 hours circles the axis of the Earth,
which every 365.242 days orbits the Sun,
which every 200 million years orbits the center of the Galaxy,
which every 150 billion years or so orbits the center of the Local Group,
which every few trillion years orbits the center of the Virgo supercluster.
I suppose those last two are somewhat optimistic predictions, especially considering that I have no first-hand knowledge of your wristwatch.
Re:Yet Another Bug? Story Submission History Gone!
on
Slashdot Code Update
·
· Score: 2
Oops, I just noticed that the blackened piece of umbilical cord that used to be attached to my belly button is gone, too! These bugs are more widespread than I thought!
That's my way of saying that I spoke too quickly about the submission history 'bug.' Apparently, Slash is wired to make those listings go away after a fortnight. Duh.
I think you're missing a very important detail -- I was making a joke. But let's go ahead and apply this to the shuttle. Here's how far you have to make your acceleration track in order to reach 7,814 m/sec (minimum orbital velocity) at various G-forces:
3112 gees............ 1.0 km
100 gees............ 31.1 km
15 gees............ 207.5 km
8 gees (comfy?).... 389.0 km
Think about how long you watch a shuttle launch, and that it's accelerating for that entire time. It takes a long, long track to pull this off. Better to build short, fast ones and use them for launching construction materials into orbit.
[O]nce you pay for the construction all that is left is electricity and maintence.
The same could be said for New York City. The devil is in the details, my friend. Folks thought the Shuttle would open up cheap access to space, since we'd get to reuse the orbiters. Ha ha.
[To avoid dangerously high acceleration, manned flights] will be launched off of a gradually ascending slope spanning a couple of kilometers.
Sorry, but that's still way too short. To achieve a minimum orbital velocity in a 2-kilometer run, you'd have to accelerate at a little more than 1500 gees. Splat.
Even with a 100-kilometer ramp, you'd be dealing with an average acceleration greater than 31 gees. It appears that, as far as space projects go, this will only ever be useful as an initial-stage boost, or for boosting raw materials into space for orbital construction projects.
Of course, it would still make a nice high-tech catapult for lobbing massive conventional weapons hundreds of miles, but of course no one in the Pentagon is thinking of THAT possibility...
let's hope that the Navy research gets us a step closer to not burning all that Oxygen and Hydrogen to get to space...
Yes, we must reduce emissions of deadly Dihydrogen Monoxide! It's already filling our rivers, streams and oceans, and has been found even in the ice of Antarctica! The time to act is now, people! Before our wells are full of this dangerous chemical!
Yet Another Bug? Story Submission History Gone!
on
Slashdot Code Update
·
· Score: 2
This is apparently unrelated, but I guess since it showed up just now, it probably is. Until a few hours ago, I had the following bit of info on my User Info page:
And now it's gone. Did anyone else experience this with their pages?
<BELLYACHE> Suggestions for improvements...
on
Slashdot Code Update
·
· Score: 5, Interesting
If this feature takes off, I'd like to see a "distributed affinity" system implemented, similar to Google's PageRank system. If I call a particular poster a friend, then anyone whom they call a friend gets an X% boost in my ranking, anyone they call a friend gets an X/100 boost, and so on.
That way, after I've picked a certain number of people (100/X, actually) as friends, and they all like another poster I've never noticed before, he'll automagically have the same status with me that they all do.
Foe rankings would work the same way, but is the foe of my friend necessarily my foe, and is the foe of my foe necessarily my friend? Automatically assigning points based on those assumptions would probably not be useful.
Interested readers seeking background information on this subject may enjoy this 30-page excerpt from Questioned Documents: A Lawyer's Handbook by Jay Levinson, from Academic Press.
Slashdot Mirror
Of the Future SUV site? It hosts such massive concept vehicles as the Kenworth Pilgrimage, the Grand Dominator, the Eliminator (a new version of last year's Fornicator), and the ever-popular Peterbuilt Crusader All-Sport Denali Outback Eddie Bauer 5.9 Limited.
If this were equipped with 802.11a (not b) networking, could a traffic jam of these things become an ad-hoc Beowulf cluster?
Also, did anyone else notice that the domain's admin contact is Bran Ferren of Disney Imagineering? This may be more imagination than engineering...
The experiment you refer to involved a tethered satellite. It was performed on February 25, 1996, and as miles of tether were unrolled, the dynamo current grew just as predicted. The tether was almost entirely unrolled when it broke near the shuttle's end, whipping off into the void. The shuttle crew tracked the satellite by radio for several minutes, then lost contact.
After the mission, the tether was examined on Earth, and was found to have been melted through. Turns out the core of the cable was a porous material that had atmospheric-pressure air trapped in it during manufacture. The air leaked out through pinholes in the outer insulation and was quickly converted, by the high voltage (~3500V) of the tether, to a plasma far denser and more conductive than the surrounding ionosphere. Instruments indicated that the plasma diverted a full ampere of current (at 3500 volts) through the insulator pinholes, enough to melt through the cable.
That's why they don't let astronauts EVA any more without gloves.
OffTopic: That last line was a feeble joke, similar to the one in my original post. That post was modded up three points (by those who took "regenerative aerobraking" seriously) before being modded down five (by those who take mismoderation seriously). Is there a record for the number of mod points, both up and down, assigned to a single comment?
There's obviously no such thing as "regenerative aerobraking." My comment was mainly about the fact that by using aerobraking, they cut a few million off the launch costs. That's going to be invaluable in the future, as science budgets continue to be stripped to the bone.
Why anyone took the incredibly dry witticism at the end seriously is beyond me. Perhaps I should have used more vermouth.
By using the atmosphere of Mars to slow down the spacecraft in its orbit rather than firing its engine or thrusters, Odyssey was able to save more than 200 kilograms (440 pounds) of propellant. This reduction in spacecraft weight enabled the mission to be launched on a Delta II 7925 launch vehicle, rather than a larger, more expensive launcher.
No small feat, there. Too bad they didn't use regenerative aerobraking—we might have gotten the spacecraft back.
Sorry, billybob. I've got no excuse for adding 48 characters to your HTML download of this story, except that I was in a hurry when I submitted. Thankfully, your clever post has pointed out the error of my ways. Please feel free to bill me for the (48chars/yourcps) seconds which I cost you.
Then again, after looking at your posting history, perhaps it would be more fair if we billed you.
Oh, and I didn't include the link in order to demonstrate superiority (which I assume was the purpose of your dubious post), but for the simple convenience of the reader. I don't generally type unnecessarily—which is why I'll just link to this rather than waste more time on you myself.
I really don't want this to sound like a troll, and I really love Slashdot, and I read it every day, and Linux is a great operating system, and open source is The Way, and I've really enjoyed all of Jack Black's movies, BUT...
/., much less expect it to be posted, and I don't think I personally know anyone who would.
Is this really a Slashdot news story? I mean, I'd never submit a non-tech movie review to
Perhaps the editors could do the same thing we lowly grunts do—post stories like this in your journal.
This is the 50th /. story about Lessig since the first one [slashdot.org] three years ago.
Oops, sorry, that was four years ago. (2002 - 1998 = 4, right?)
I'm still not used to 2K2 math.
This is the 50th /. story about Lessig since the first one three years ago. As court appointed master in the MS-DOJ case, he'd sworn that he had no personal bias or prejudice, even though he'd sent an email to a lawyer friend at Netscape saying that having installed IE was equivalent to selling his soul. An appellate court kicked him off the case shortly thereafter.
He continues to be a voice of reason and intelligent debate in an arena where both are often sorely lacking. Our community is richer for his presence.
As with all other song information on the iPod, the artist information comes from the MP3's ID3 tags, which it pulls and stores in a database for easy access.
/.'er will reply with info about a tool that will automate this process, thus radically simplifying my purchasing rationalization^H^H^H^H^H^H^H^H^H^H^H^H^H^H^H decision.
...Anyone?
Am I the only one whose ID3 tag info is sorely lacking across his entire collection? Either I've got a lot of work ahead of me before I'm iPod-ready, or some benevolent
I suppose they must have done some market research and discovered that only a small percentage of children were actually eschewing real Crayons and turning to a KDE menu option for their coloring needs. Their colored-wax-stick market share is safe.
Suppose companies start distributing video using the CPTWG encoder (whatever they might call it) to mark it as nondistributable. What's to keep folk from sending the video output to a DV device, then reading it back and re-encoding it to whatever 'open' format they choose? This isn't the easiest way to accomplish it, I'm sure, but if media can be played, can't it be re-recorded and converted?
It seems to me that whenever the powers-that-wanna-be try to establish total control of digital media, they lose whatever control or influence they already had. Why not redirect efforts toward better fair-use policies, reasonable licensing schemes, and accept that somebody will copy your work no matter what you do?
I think the real trick will be to improve Joe Random's perception of the recording industry to the point that he feels guilty about having media he hasn't paid for. Their current tactics will never accomplish that, and in fact will tend to perpetuate the Robin Hood fantasy that Napsterites currently enjoy.
"The more you tighten your grip, Valente, the more encoding systems will slip through your fingers." -- Princess RIAA
Really? Try these versions out:
-
"I hate crackers as much as the next person, but I've also sent my DDoS client out using a nifty little script I bru'd up to a hundred or so companies."
- "I hate RIAA lawyers as much as the next person, but I've also sent my subpoenas out using a nifty little script I bru'd up to a hundred or so companies."
Remember, if you aren't part of the solution, you're part of the SPAM.Anytime I get a spam, I hit the link that I received when I registered with SpamCop, and paste the email (complete with header) into the provided textbox. SpamCop processes the email, compiles a report of the offending spam, computes the appropriate reporting addresses, and delivers a copy to each one.
It even allows you to add text to the beginning of the report. I always add this: Does that make me a bad person?
--
Tsar's Hypothesis: As the population of the Earth increases, the sum of human intelligence remains constant.
I thought the Long Now Foundation's 10,000-year clock was an optimistic project. Why would anyone, especially learned men of the Royal Society, postulate that human life will exist in its present climate-dependent position even a million years from now?
We have gone from living at the mercy of the elements to building living environments in space in the span of only a few millennia, with the bulk of the technology being developed only in the last century. And now we stand poised to rewrite our own genome. Does anyone expect that, if mankind still exists five billion years hence, that it will be limited to this puny ball of rock, entirely dependent on this one yellow dwarf? Or that we will even resemble our current selves, either physically or intellectually?
Mankind may indeed pass through many cycles of near-extinction before the next million years pass. Look at our current speculative fiction. Scarcely anyone attempts to write about the future beyond a few thousand years, because we know it is beyond imagination.
Perhaps it would be best to say of stories such as this, that the Sun is still expected to continue, without substantial changes, for any conceivable lifespan of the human race as we now know it. Beyond that, we're whistling in the solar wind, for only God can know.
Small expensive things are always bad.
That's exactly how I explained it to my fiancé—she didn't buy it either.
--
Imagine a Beowulf cluster of these! You could fit 80GB into the space of a... oh, never mind.
Imagining a satellite around a moon around a planet around a sun is a little out there.
Tough to imagine, eh? How about visualizing something closer to home--an electron in your wristwatch's second hand.
It's orbiting the nucleus of an iron atom,
which every 60 seconds circles the axis of your wristwatch,
which every 24 hours circles the axis of the Earth,
which every 365.242 days orbits the Sun,
which every 200 million years orbits the center of the Galaxy,
which every 150 billion years or so orbits the center of the Local Group,
which every few trillion years orbits the center of the Virgo supercluster.
I suppose those last two are somewhat optimistic predictions, especially considering that I have no first-hand knowledge of your wristwatch.
Oops, I just noticed that the blackened piece of umbilical cord that used to be attached to my belly button is gone, too! These bugs are more widespread than I thought!
That's my way of saying that I spoke too quickly about the submission history 'bug.' Apparently, Slash is wired to make those listings go away after a fortnight. Duh.
Sorry for crying [beo]wulf.
I think you're missing a very important detail -- I was making a joke. But let's go ahead and apply this to the shuttle. Here's how far you have to make your acceleration track in order to reach 7,814 m/sec (minimum orbital velocity) at various G-forces:
............ 1.0 km ............ 31.1 km ............ 207.5 km .... 389.0 km
3112 gees
100 gees
15 gees
8 gees (comfy?)
Think about how long you watch a shuttle launch, and that it's accelerating for that entire time. It takes a long, long track to pull this off. Better to build short, fast ones and use them for launching construction materials into orbit.
[O]nce you pay for the construction all that is left is electricity and maintence.
The same could be said for New York City. The devil is in the details, my friend. Folks thought the Shuttle would open up cheap access to space, since we'd get to reuse the orbiters. Ha ha.
[To avoid dangerously high acceleration, manned flights] will be launched off of a gradually ascending slope spanning a couple of kilometers.
Sorry, but that's still way too short. To achieve a minimum orbital velocity in a 2-kilometer run, you'd have to accelerate at a little more than 1500 gees. Splat.
Even with a 100-kilometer ramp, you'd be dealing with an average acceleration greater than 31 gees. It appears that, as far as space projects go, this will only ever be useful as an initial-stage boost, or for boosting raw materials into space for orbital construction projects.
Of course, it would still make a nice high-tech catapult for lobbing massive conventional weapons hundreds of miles, but of course no one in the Pentagon is thinking of THAT possibility...
let's hope that the Navy research gets us a step closer to not burning all that Oxygen and Hydrogen to get to space...
Yes, we must reduce emissions of deadly Dihydrogen Monoxide! It's already filling our rivers, streams and oceans, and has been found even in the ice of Antarctica! The time to act is now, people! Before our wells are full of this dangerous chemical!
If this feature takes off, I'd like to see a "distributed affinity" system implemented, similar to Google's PageRank system. If I call a particular poster a friend, then anyone whom they call a friend gets an X% boost in my ranking, anyone they call a friend gets an X/100 boost, and so on.
That way, after I've picked a certain number of people (100/X, actually) as friends, and they all like another poster I've never noticed before, he'll automagically have the same status with me that they all do.
Foe rankings would work the same way, but is the foe of my friend necessarily my foe, and is the foe of my foe necessarily my friend? Automatically assigning points based on those assumptions would probably not be useful.
Interested readers seeking background information on this subject may enjoy this 30-page excerpt from Questioned Documents: A Lawyer's Handbook by Jay Levinson, from Academic Press.