> It's easy to move the shuttle, much harder to use the shuttle as a tugboat.
Simple question: What happens if they spot a piece of junk heading at them when a shuttle isn't docked?
Obviously they would have this covered. The options I can think of are:
One of the Russian modules has a propultion device, but can it fire when there's stuff docked to its rear end?
The Soyuz lifeboat has engines, but does it have enough fuel to haul the station around and still return safely to Earth? Besides, the Soyuz is often docked at right angles to the V-bar, meaning it's engines would just make the station pinwheel.
There is often a Progress cargo delivery ship docked, maybe it can tap into the Russian module's fuel and burn it useing its own engines?
Google aren't idiots. Don't be so quick to post about how this will be a huge failure and how easy it will be to defeat the system.
Think about it. According to the article, the system is currently just collecting information, it isn't affecting rankings -- yet. So in a couple of weeks Google will look at this new data, look at the corresponding pages, then figure out what should be done. Why are we assuming that they will just do a linar mapping between the number of happy faces and relevance?
I wouldn't put it past them to dynamically map relevance with a far more complicated function. User rankings are another non-random data stream. All information (even negative information) is useful. Just as long as one strips it from its labels, and looks at it blindly. Can you say neural networks?
> I thought that getting rid of the (now useless) mass from the heavy boosters also had something to do with it?
Not really. When you drop a stage, what exactly are you saving? You aren't dropping any payload. You aren't dropping any fuel. You are dropping a very heavy set of engines, but that's a complete waste since if you only had a single stage you wouldn't have a redundant set of engines to drop in the first place. The only thing you are able to drop is an empty fuel tank (aluminum cans are very light, no big savings). Splitting a rocket into stages isn't done to save weight (the extra engines weigh more than the tanks). The only reason to stage is to swap out the engine bells with ones that are more suitable to the current atmospheric pressure.
That is what was so exciting about the (now cancelled) aerospike engine was that its geometry was perfect for any altitude.
> In any case the energy savings by lifting the payload to 20km are minimal at best. Most of the advantage comes from being weather independant, due to being above the clouds.
Nice point. However, I'd think that there are more important saveings than a 20km lift and weather independance:
Equator. You get to launch exactly on the equator, instead of having to burn fuel in dog-leg maneuvers to get there.
Horizontal speed. An old German V2 can get to space, but it can't get to orbit. A launch is a little bit of up, and a whole lot of sideways. If you dump the rocket out of the plane while traveling at Mach 0.75, that's 3% of your velocity taken care of.
Engines. The real reason rockets stage is to swap out engine nozels. The bells that work at sealevel are ill-suited to vacuum operation. By launching above most of the atmosphere you can just use a single stage.
Friction. A good portion (numbers anyone?) of the energy of a lunch is devoted to plowing through the air. Something that's not an issue when you start 20km up.
Moderators, that was most certainly *not* offtopic.
I would be very much interested in a comparison between the Ice Cube and SNO. My guess is that the Ice Cube is a lot cheaper, but that the SNO is a lot more accurate.
What technology? Guy walks into a plane, shoots pilots, and turns the yoke. These events could have happened at any time since the towers were first constructed 30 years ago. What is this rant about technology for?
> Where has it gone? $1000 floppy disks? 50 person full-time ground crew?
In order to communicate the probe you need to rent time on the Deep Space Network. This network is currently running at capacity, so getting time on it is rather expensive.
But an even bigger expense is the mission software. Modifications to the programming of the probe need to be codded. Then the code has to be proved to be mathematically perfect. You cannot afford to compile it, upload it, and get a message back saying "stack overflow, press any key to continue". The software must be proven to be 100% bug free before it goes up.
It takes a lot of people to manage a space mission correctly. Cut corners, and your mission fails because of something stupid (e.g. metric vs imperial).
> Reminds me of that story about pens in space. [...] The russians, facing the same problem, used a pencil.
For goodness sake, will people stop posting this trolling story? As has been said before this is misleading.
For the first few missions, the Soviets did use pencils. Then the Soviets went to Fisher (the American company that made the pens) and bought several cases. The reason is that pencils produce a lot of graphite dust. When you are locked in a room the size of a telephone booth for a week, you don't want graphite dust floating around, getting into your lungs, eyes and your equipment.
> Facing the same problem, the Soviets used pencils.
For the first few missions, yes. Then the Soviets went to Fisher (the American company that made the pens) and bought several cases. The reason is that pencils produce a lot of graphite dust. When you are locked in a room the size of a telephone booth for a week, you don't want graphite dust floating around, getting into your lungs, eyes and your equipment.
>In the United States, there is a presumption of innocence. Face-recognition systems assume the opposite: you are a wanted criminal and only a null result on their database search proves you are NOT, in fact, a criminal.
Ok, lets throw some pseudocode at this and prove this statement to be false:
innocent = true
for criminal in criminal_db() {
if you == criminal {
innocent = false
}
}
As you can clearly see, you can easilly code a matching system so that you are presumed innocent until found otherwise.
[...] stars cans be made to explode into supernova. [...] Your signal can be detected from any point around the supernova & traces last for some time.
Blowing up a star to say "Hello there!" (or "First post!", or "All your base...") seems like a rather expensive way to communicate. Plus you then have to travel to another star to send your next message.
Green Peace would have a cow if we started blowing up neighbouring stars for fun. --
Re:optical detection sounds hard
on
Optical SETI
·
· Score: 2
>If they've just got a huge laser on the top of their local Everest-sized mountain & are relying on their planet's rotation to turn it into a beacon we have a better chance of spotting it.
Erm, no. First of all, that laser beam would only sweep a circle, not a sphere. So unless we just happened to be exactly on the plane of their planet's rotation, we'd miss it. Secondly, even if we did happen to be lined up perfectly, we'd never notice it since the beam's path (not the photons) would sweep past Earth at a velocity far exceeding the speed of light. Consider that if they are 100 light years from us, then their laser would be painting a circle that is 2*Pi*100ly in circumference every one of their days. Assuming their day is the same as hours (24 hours), that would mean that at our distance their beam would be sweeping 70,000,000,000km a second. How long would Earth stay in such a beam? Not long enough for your detector to see more than a single photon. And that's assuming we just happen to be lined up.
No, the only way that laser communication would work is if it is directed straight at us. --
The New Scientist had an article about this back in May. They took a slightly different angle on it -- pointing out its "spy-proof" features. Although the article appears to be gone, Google still has a copy of it. --
> > or all of us will pay the price sooner or later
>
> How so? What are the negative consequences for the rest of us in just letting evolution take its course in Africa?
Very interesting question. Anyone want to help out in answering it?
Three things that come to mind (don't know if they are valid or not):
War. Poverty breeds war, and if Africa decends into a war, history shows that western nations will eventually get sucked in.
Disease. Ebola and AIDS both came from Africa. Diseases don't respect borders, so it would be advantageous for the West to help Africa medically. Who knows what's next.
Environment. There are a lot of people in Africa, yet they currently don't have a large per capita impact on the environment. This will change as the standard of living improves. There would be global consequences if all the African rain forests are logged, and every household starts buring coal.
>When does something stop being 'security through obscurity'? Depending on how you look at it, all forms of security, (or at least most of the ones employed over the internet) are based on picking access tokens that are really hard to guess.
Thanks for qualifying this as security on the Internet. Note that there are a whole range of other forms of security. For instance a guard holding an M16 is a particularly effective form of security that has no secret component at all. An entirely different method is the "security camera". And a third is Mutually Assured Destruction.
None of these three methods of security are prevalent on the Internet. Are there any others? Could any of these be used in place of traditional usernames and passwords?
--
>1) Lag time. Radio travels at speed of light, so you are going to incur some delay. Say a half second of delay round trip. Is this a problem? Could be. Also, when the ISS is on the otherside of the earth, you can't send it a signal (unless you have more then one transmitter, of course)
All communication to and from ISS, Shuttles, Hubble, and a number of other NASA vehicles is routed through the TDRS system of three massive satellites in geosynchornous orbit. Unlike the Russian system, Nasa doesn't have to wait for their missions to pass over their ground stations. The lag incurred by TDRS is identical to that you hear on a transoceanic telephone call.
>2) Repair. Can't fix the bot from the ground. You will have to train the crew to fix the bot (which you would have to do anyway).
I would imagine that a shuttle would bring up a half-dozen balls. This would allow you to bring several of them online during busy times. It would also allow you to discard ones that break (to be replaced by the next shuttle flight). After all, the goal is to relieve the astronauts of work, not burden them with more things to fix. --
Slashdot Mirror
Simple question: What happens if they spot a piece of junk heading at them when a shuttle isn't docked?
Obviously they would have this covered. The options I can think of are:
Think about it. According to the article, the system is currently just collecting information, it isn't affecting rankings -- yet. So in a couple of weeks Google will look at this new data, look at the corresponding pages, then figure out what should be done. Why are we assuming that they will just do a linar mapping between the number of happy faces and relevance?
I wouldn't put it past them to dynamically map relevance with a far more complicated function. User rankings are another non-random data stream. All information (even negative information) is useful. Just as long as one strips it from its labels, and looks at it blindly. Can you say neural networks?
Not really. When you drop a stage, what exactly are you saving? You aren't dropping any payload. You aren't dropping any fuel. You are dropping a very heavy set of engines, but that's a complete waste since if you only had a single stage you wouldn't have a redundant set of engines to drop in the first place. The only thing you are able to drop is an empty fuel tank (aluminum cans are very light, no big savings). Splitting a rocket into stages isn't done to save weight (the extra engines weigh more than the tanks). The only reason to stage is to swap out the engine bells with ones that are more suitable to the current atmospheric pressure.
That is what was so exciting about the (now cancelled) aerospike engine was that its geometry was perfect for any altitude.
I'm convinced Slashdot is dropping vowels. :-) It's a conspiracy I tell you!
Nice point. However, I'd think that there are more important saveings than a 20km lift and weather independance:
Sorry Hemos, Michael beat you to it in the update to this story.
Moderators, that was most certainly *not* offtopic.
I would be very much interested in a comparison between the Ice Cube and SNO. My guess is that the Ice Cube is a lot cheaper, but that the SNO is a lot more accurate.
> I think we'd have trouble getting astronauts to
> volunteer. Or did you have someone specific in mind?
As long as "one way" != "suicide", I would jump at the opportunity to go to Mars. And I'm not alone.
Yes, I completely agree that when we go to Mars, we should go to stay. Planting a flag then leaving doesn't seem productive.
Does the buyer have to pay for the postage?
What technology? Guy walks into a plane, shoots pilots, and turns the yoke. These events could have happened at any time since the towers were first constructed 30 years ago. What is this rant about technology for?
In order to communicate the probe you need to rent time on the Deep Space Network. This network is currently running at capacity, so getting time on it is rather expensive.
But an even bigger expense is the mission software. Modifications to the programming of the probe need to be codded. Then the code has to be proved to be mathematically perfect. You cannot afford to compile it, upload it, and get a message back saying "stack overflow, press any key to continue". The software must be proven to be 100% bug free before it goes up.
It takes a lot of people to manage a space mission correctly. Cut corners, and your mission fails because of something stupid (e.g. metric vs imperial).
For goodness sake, will people stop posting this trolling story? As has been said before this is misleading.
For the first few missions, the Soviets did use pencils. Then the Soviets went to Fisher (the American company that made the pens) and bought several cases. The reason is that pencils produce a lot of graphite dust. When you are locked in a room the size of a telephone booth for a week, you don't want graphite dust floating around, getting into your lungs, eyes and your equipment.
'Mentally'? With these replicators you'd be well armed physically.
"What do you need?" ... Lots of guns."
"Guns
> [...]
> Facing the same problem, the Soviets used pencils.
For the first few missions, yes. Then the Soviets went to Fisher (the American company that made the pens) and bought several cases. The reason is that pencils produce a lot of graphite dust. When you are locked in a room the size of a telephone booth for a week, you don't want graphite dust floating around, getting into your lungs, eyes and your equipment.
Ok, lets throw some pseudocode at this and prove this statement to be false:
innocent = true
for criminal in criminal_db() {
if you == criminal {
innocent = false
}
}
As you can clearly see, you can easilly code a matching system so that you are presumed innocent until found otherwise.
The quoted story is over a year and a half old. Things move rather quickly in the tech field.
You haven't lived until you've seen Xena Warrior Princess die in a terrible grill fire while Sculley flails her arms in terror.
Sounds like an acceptable plot...
--
Blowing up a star to say "Hello there!" (or "First post!", or "All your base...") seems like a rather expensive way to communicate. Plus you then have to travel to another star to send your next message.
Green Peace would have a cow if we started blowing up neighbouring stars for fun.
--
Erm, no. First of all, that laser beam would only sweep a circle, not a sphere. So unless we just happened to be exactly on the plane of their planet's rotation, we'd miss it. Secondly, even if we did happen to be lined up perfectly, we'd never notice it since the beam's path (not the photons) would sweep past Earth at a velocity far exceeding the speed of light. Consider that if they are 100 light years from us, then their laser would be painting a circle that is 2*Pi*100ly in circumference every one of their days. Assuming their day is the same as hours (24 hours), that would mean that at our distance their beam would be sweeping 70,000,000,000km a second. How long would Earth stay in such a beam? Not long enough for your detector to see more than a single photon. And that's assuming we just happen to be lined up.
No, the only way that laser communication would work is if it is directed straight at us.
--
Aha, found the original New Scientist article. They've moved it here.
--
Not the same graphic, but really close.
--
The New Scientist had an article about this back in May. They took a slightly different angle on it -- pointing out its "spy-proof" features. Although the article appears to be gone, Google still has a copy of it.
--
>
> How so? What are the negative consequences for the rest of us in just letting evolution take its course in Africa?
Very interesting question. Anyone want to help out in answering it?
Three things that come to mind (don't know if they are valid or not):
--
Thanks for qualifying this as security on the Internet. Note that there are a whole range of other forms of security. For instance a guard holding an M16 is a particularly effective form of security that has no secret component at all. An entirely different method is the "security camera". And a third is Mutually Assured Destruction.
None of these three methods of security are prevalent on the Internet. Are there any others? Could any of these be used in place of traditional usernames and passwords?
--
All communication to and from ISS, Shuttles, Hubble, and a number of other NASA vehicles is routed through the TDRS system of three massive satellites in geosynchornous orbit. Unlike the Russian system, Nasa doesn't have to wait for their missions to pass over their ground stations. The lag incurred by TDRS is identical to that you hear on a transoceanic telephone call.
>2) Repair. Can't fix the bot from the ground. You will have to train the crew to fix the bot (which you would have to do anyway).
I would imagine that a shuttle would bring up a half-dozen balls. This would allow you to bring several of them online during busy times. It would also allow you to discard ones that break (to be replaced by the next shuttle flight). After all, the goal is to relieve the astronauts of work, not burden them with more things to fix.
--