A ribbon will actually end up perpendicular to the satellites orbit, due to tidal effects.
Actually that might be a good thing. I read somewhere about attempts to power satellites by dragging a long wire, the movement through the earth's magnetic field produces a current. The problem was that because of the magnetic drag, more fuel was required to keep the satellite in orbit.
So for an end-of-life satellite, simply releasing a long wire may be enough to de-orbit it without requiring more fuel. I think the wire had to be very long (but thin) so the mass wouldn't be too excessive. If it still takes a long time to de-orbit though, instead of chunks of metal in orbit you have chunks with long invisible wires hanging off them, which could be even more dangerous.
if you can get it elliptical enough you put the perigee inside Earth's atmosphere
Lovely, if you can have ALL items touching the atmosphere in the same zone, and they all line up in the same path.
However, the orbits will likely just be in every possible plane and have every possible center. As they approach Earth, they get accelerated by the smaller radius, and pretty soon there will be superspeed space junk everywhere coming from all directions.
No, the whole point of getting the pieces to touch the atmosphere is that atmospheric drag slows them down, lowering the orbit even more until they eventually burn up or crash (depending on the size).
Investigations of most disasters reveal not a single cause, but a combination of factors which lead to the disaster itself. Often, the absence of any one of those root causes may have avoided the disaster, or at least mitigated it to some degree. While I would not minimize the importance of the other factors which have already been acknowledged as key causes, identifying all the possible causes is critical to avoiding future repetition of the problem. If a computer-controlled alarm system was so faulty that its operators shut it down rather than endure its false alarms, we should give it due consideration as a potential contributing factor.
That makes it even more inexcusable though. There are so many systems and procedures in place to prevent such a disaster that they had to really make a continued effort of disabling safety devices and skipping procedures to blow up the rig.
This laser is 32kW, and it's already pushing the limits of solid state laser tech. 32MW laser is nowhere in sight for several decades, unless we make major breakthroughs in materials needed, not to even talk about power draw, which for current laser at 20% efficiency would be around 160MW for your suggested 32MW laser. And with increased power, the efficiency of laser installation is likely to decrease significantly.
You're gonna have some pretty hardcore power cabling, cooling system and a nuclear reactor to power that kind of a thing, not to even mention the epic size of a weapon. Cooling system alone will probably be bigger then a modern missile silo.
This replacing a small, localized and largely autonomous system that performs better in most conditions? I think not.
Comparing this to Sea Sparrows or any other ship based medium range SAM in any way other then augmentation is just plain foolish anyway. This caps at a few kilometers, depending on weather. It's a potential kinetic CIWS replacement (i.e. phalanx). It's in no way even a contender for SAM CIWS replacement. Not even because the tech isn't ready, but because the tech is unsuitable by default. Weather and fact that Earth is a sphere will make sure of this.
You are correct that there are issues, but they aren't as bad as you say. 1. This system is for a large ship eg aircraft carrier which already has nuclear reactors for power, if the engines aren't going max speed power is not an issue at all. 2. These ships are huuuge, so again size is not much of an issue. If the advantages are so great then room can be made. 3. As for the cooling system, it happens that ships usually sit in the ocean... an unlimited* supply of cold water.
*compared to any amount of possible usage by a ship.
A better analogy would be that the Lexus didn't come with a cup-holder, but you can purchase an after-market one for $30. It's not a show stopper because there is a workaround. If the iPhone antenna did not improve reception by adding a case, then it would be a show stopper.
No, a better analogy would be that the Lexus engine cuts out if you have too much pressure on the left half of the seat. Sure there is a work around, you just have to lean to the right while you drive. You would be fine with that I assume?
In order to ensure childres safety they are placed and encuraged stay in secuer safe 'creative' environments. Classic example, who here below tha age of 50 has every seen or even played with a 'real' chemistry set.
I'm 28 and had a chemistry set etc as a kid, but maybe you wouldn't call it "real" as the chemicals provided were not very exciting. Luckily I have an uncle who was a research chemist, and he provided me with more interesting chemicals and recipes.
These days though, making "touch powder" (a very unstable substance that explodes with the slightest touch) would probably get you arrested.
It sounds like this could be a treatment that (with some modification) could be used to treat folks with laser damage to their eyes (or any other damage caused by highly focused light.) In that case, the 'donut hole' would be fairly small. To some degree, I also wonder if defocusing an area that illuminates small blind spots might be advantageous - instrad of a blind spot, instead the person would have a blurry spot...
It's better to have a blind spot. After a while your brain filters it out and you don't notice it unless you really try to look at something with that area. With a blurry spot you would have an annoying blurred patch larger than the damaged area, which again may be filtered out by your brain, resulting in a larger "blind spot". And you would have a chunk of plastic sticking out of your eyeball.
In Japan they have a cool solution: the escalator ends up having two lines. The people on the left keep walking, and those on the right stand. I guess for that to become a custom you'd need escalators that are typically crowded, which most in the US are not.
Oddly, its stand on the left, walk on the right in Tokyo and the north/east side of japan but opposite in Kobe (and maybe other cities in that region?).
This only works well in a quite rigid society like Japan because everybody follows the unwritten rule. It only takes a very small percentage of people to break a system like this, which is why it doesn't work nearly as well in most western countries.
Can we assume that the media will always be stored at room temperature in 100 year period? My experience generally shows this is wishful thinking, because air conditioning breaks down, heating fails,...
You need air conditioning and heating to keep a room at room temperature? All the rooms in my house seem to stay at room temperature automatically...
Yes yes I know, they probably defined "room temperature" as 25 degrees C.
In most designs regenerative braking has to throw away power because you can't charge the packs fast enough. A battery that CHARGES faster would be useful not only for quick-charging but also for regenerative braking.
You don't need the full capacity to be of the fast-charge type though, it would be enough to have a smaller "buffer" battery to store energy from braking. The main pack could be topped up by the buffer pack at a slower rate, or the energy could be used directly from the buffer if braking is followed soon after by acceleration (which would often be the case).
Yeah, well... when we're arriving at wires being tens of atoms wide, I'm tending to believe we're at the limits of physics rather than process.
Well it's not exactly "shrink", but I expect chips will start going 3D next. So the 2D transistor density will still keep going up (thickness is negligible).
Does the right to bear arms cover arms which are for more awesome than ever conceived of by the writers of the constitution?
The 2nd amendment covers arms. If you use, or intend to use, this as a weapon, it's arms. So yes, it's covered.
If you intend to define this as a weapon, I believe blinding weapons are banned by the Geneva convention. There are also laws restricting the operation of high power lasers in public places. So either way, it is a bad idea to get one of these for anything except playing around at home in an enclosed area while wearing eye protection.
the inaccurate use of the word radar [wikipedia.org], meaning electromagnetic waves, not the two video cameras this system is using.
What makes you say cameras don't work on electromagnetic waves? After all, visible light consists of electromagnetic waves. Yes, most commercial radar systems use microwaves instead of visible light, but that's not a requirement for something to be called radar.
RAdio Detection And Ranging Radio = not visible light. It is in fact a requirement for something to be called radar, unless the person has no idea what they are talking about. That's why we have different words for SONAR and LIDAR.
How much additional heat would the 15-minute per day cell phone sessions plus the phone being in "Stand-By" 24/7 produce in the hive? My guess is it might increase the temperature a couple of degrees.
Bugger all. Does talking on the phone for 15mins heat your head up by a couple of degrees? No.
The problem is that you cannot use this mechanism to actually transmit information faster than light because you need some other kind of means to know when to observe your entangled photon. If Bob and Alice have entangled photons, Alice has no way of knowing if Bob has sent her a message using her photon because if she checks it to see if the superposition has collapsed then she will herself cause it to collapse if it hasn't already done so (thereby preventing Bob from sending a message at all).
This means that you're left using some alternative means of communication (radio, etc) which itself is limited by the speed of light. Bob will collapse his photon, send a message to Alice via normal means, at which time she can measure her photon and see the result of Bob's actions on his photon.
What if it was previously agreed to measure the entangled photons in order at specific intervals, starting from an agreed upon time? Is there then something else preventing the information to be sent FTL?
You'd think that the RIAA/MPAA/etc. would have noticed that the Free Software crowd has no problem with piracy, and would want to adopt their successful tactics. Anyone know why they don't?
I have seen a demo like that in a science museum in Japan. It was a large disk shape that could be spun by turning a handle, painted with a black and white pattern. When spun, coloured bands seem to appear. I have no idea how this works...
Slashdot Mirror
A ribbon will actually end up perpendicular to the satellites orbit, due to tidal effects.
Actually that might be a good thing. I read somewhere about attempts to power satellites by dragging a long wire, the movement through the earth's magnetic field produces a current. The problem was that because of the magnetic drag, more fuel was required to keep the satellite in orbit.
So for an end-of-life satellite, simply releasing a long wire may be enough to de-orbit it without requiring more fuel. I think the wire had to be very long (but thin) so the mass wouldn't be too excessive. If it still takes a long time to de-orbit though, instead of chunks of metal in orbit you have chunks with long invisible wires hanging off them, which could be even more dangerous.
if you can get it elliptical enough you put the perigee inside Earth's atmosphere
Lovely, if you can have ALL items touching the atmosphere in the same zone, and they all line up in the same path.
However, the orbits will likely just be in every possible plane and have every possible center. As they approach Earth, they get accelerated by the smaller radius, and pretty soon there will be superspeed space junk everywhere coming from all directions.
No, the whole point of getting the pieces to touch the atmosphere is that atmospheric drag slows them down, lowering the orbit even more until they eventually burn up or crash (depending on the size).
Investigations of most disasters reveal not a single cause, but a combination of factors which lead to the disaster itself. Often, the absence of any one of those root causes may have avoided the disaster, or at least mitigated it to some degree. While I would not minimize the importance of the other factors which have already been acknowledged as key causes, identifying all the possible causes is critical to avoiding future repetition of the problem. If a computer-controlled alarm system was so faulty that its operators shut it down rather than endure its false alarms, we should give it due consideration as a potential contributing factor.
That makes it even more inexcusable though. There are so many systems and procedures in place to prevent such a disaster that they had to really make a continued effort of disabling safety devices and skipping procedures to blow up the rig.
Yep, and to make mirrors you need........
... manufacturing facilites only during the construction.
After that, you're done.
With gas pipelines you need the pipelines to stay there, without holes, and with someone pumping gas in the other end.
This laser is 32kW, and it's already pushing the limits of solid state laser tech. 32MW laser is nowhere in sight for several decades, unless we make major breakthroughs in materials needed, not to even talk about power draw, which for current laser at 20% efficiency would be around 160MW for your suggested 32MW laser. And with increased power, the efficiency of laser installation is likely to decrease significantly.
You're gonna have some pretty hardcore power cabling, cooling system and a nuclear reactor to power that kind of a thing, not to even mention the epic size of a weapon. Cooling system alone will probably be bigger then a modern missile silo.
This replacing a small, localized and largely autonomous system that performs better in most conditions? I think not.
Comparing this to Sea Sparrows or any other ship based medium range SAM in any way other then augmentation is just plain foolish anyway. This caps at a few kilometers, depending on weather. It's a potential kinetic CIWS replacement (i.e. phalanx). It's in no way even a contender for SAM CIWS replacement. Not even because the tech isn't ready, but because the tech is unsuitable by default. Weather and fact that Earth is a sphere will make sure of this.
You are correct that there are issues, but they aren't as bad as you say.
1. This system is for a large ship eg aircraft carrier which already has nuclear reactors for power, if the engines aren't going max speed power is not an issue at all.
2. These ships are huuuge, so again size is not much of an issue. If the advantages are so great then room can be made.
3. As for the cooling system, it happens that ships usually sit in the ocean... an unlimited* supply of cold water.
*compared to any amount of possible usage by a ship.
A better analogy would be that the Lexus didn't come with a cup-holder, but you can purchase an after-market one for $30. It's not a show stopper because there is a workaround. If the iPhone antenna did not improve reception by adding a case, then it would be a show stopper.
No, a better analogy would be that the Lexus engine cuts out if you have too much pressure on the left half of the seat. Sure there is a work around, you just have to lean to the right while you drive. You would be fine with that I assume?
In order to ensure childres safety they are placed and encuraged stay in secuer safe 'creative' environments. Classic example, who here below tha age of 50 has every seen or even played with a 'real' chemistry set.
I'm 28 and had a chemistry set etc as a kid, but maybe you wouldn't call it "real" as the chemicals provided were not very exciting. Luckily I have an uncle who was a research chemist, and he provided me with more interesting chemicals and recipes.
These days though, making "touch powder" (a very unstable substance that explodes with the slightest touch) would probably get you arrested.
I'm able to see stupid people at work all the time. Does that count?
No, most people have the ability to see stupid people.
But some people are also able to see the limits of their own ability, a far rarer skill.
It sounds like this could be a treatment that (with some modification) could be used to treat folks with laser damage to their eyes (or any other damage caused by highly focused light.) In that case, the 'donut hole' would be fairly small. To some degree, I also wonder if defocusing an area that illuminates small blind spots might be advantageous - instrad of a blind spot, instead the person would have a blurry spot...
It's better to have a blind spot. After a while your brain filters it out and you don't notice it unless you really try to look at something with that area. With a blurry spot you would have an annoying blurred patch larger than the damaged area, which again may be filtered out by your brain, resulting in a larger "blind spot". And you would have a chunk of plastic sticking out of your eyeball.
For their partial punishment, they will have to pay the $/gallon price for their liters of gasoline. :-)
Many countries already pay the $/gallon price you have in the US for litres of gasoline.
In Japan they have a cool solution: the escalator ends up having two lines. The people on the left keep walking, and those on the right stand. I guess for that to become a custom you'd need escalators that are typically crowded, which most in the US are not.
Oddly, its stand on the left, walk on the right in Tokyo and the north/east side of japan but opposite in Kobe (and maybe other cities in that region?).
This only works well in a quite rigid society like Japan because everybody follows the unwritten rule. It only takes a very small percentage of people to break a system like this, which is why it doesn't work nearly as well in most western countries.
Is there some weird definition of "Alien" that I dont know of?
Hey I'm legally an "alien" according to the Japanese government.
I even have an official "alien registration card" to prove it!
Can we assume that the media will always be stored at room temperature in 100 year period? My experience generally shows this is wishful thinking, because air conditioning breaks down, heating fails, ...
You need air conditioning and heating to keep a room at room temperature?
All the rooms in my house seem to stay at room temperature automatically...
Yes yes I know, they probably defined "room temperature" as 25 degrees C.
The article seems misleading...
Seems like we've made a "news story" out of thin air. Slow news day?
One word: kdawson
In most designs regenerative braking has to throw away power because you can't charge the packs fast enough. A battery that CHARGES faster would be useful not only for quick-charging but also for regenerative braking.
You don't need the full capacity to be of the fast-charge type though, it would be enough to have a smaller "buffer" battery to store energy from braking. The main pack could be topped up by the buffer pack at a slower rate, or the energy could be used directly from the buffer if braking is followed soon after by acceleration (which would often be the case).
Yeah, well... when we're arriving at wires being tens of atoms wide, I'm tending to believe we're at the limits of physics rather than process.
Well it's not exactly "shrink", but I expect chips will start going 3D next. So the 2D transistor density will still keep going up (thickness is negligible).
OKI printers are really nice.
The one I am using now is a colour laser OKI 5900, and it works perfectly in Ubuntu 9.10 and 10.04.
The 2nd amendment covers arms. If you use, or intend to use, this as a weapon, it's arms. So yes, it's covered.
If you intend to define this as a weapon, I believe blinding weapons are banned by the Geneva convention.
There are also laws restricting the operation of high power lasers in public places.
So either way, it is a bad idea to get one of these for anything except playing around at home in an enclosed area while wearing eye protection.
the inaccurate use of the word radar [wikipedia.org], meaning electromagnetic waves, not the two video cameras this system is using.
What makes you say cameras don't work on electromagnetic waves? After all, visible light consists of electromagnetic waves. Yes, most commercial radar systems use microwaves instead of visible light, but that's not a requirement for something to be called radar.
RAdio Detection And Ranging
Radio = not visible light.
It is in fact a requirement for something to be called radar, unless the person has no idea what they are talking about. That's why we have different words for SONAR and LIDAR.
How much additional heat would the 15-minute per day cell phone sessions plus the phone being in "Stand-By" 24/7 produce in the hive? My guess is it might increase the temperature a couple of degrees.
Bugger all.
Does talking on the phone for 15mins heat your head up by a couple of degrees?
No.
The problem is that you cannot use this mechanism to actually transmit information faster than light because you need some other kind of means to know when to observe your entangled photon. If Bob and Alice have entangled photons, Alice has no way of knowing if Bob has sent her a message using her photon because if she checks it to see if the superposition has collapsed then she will herself cause it to collapse if it hasn't already done so (thereby preventing Bob from sending a message at all).
This means that you're left using some alternative means of communication (radio, etc) which itself is limited by the speed of light. Bob will collapse his photon, send a message to Alice via normal means, at which time she can measure her photon and see the result of Bob's actions on his photon.
What if it was previously agreed to measure the entangled photons in order at specific intervals, starting from an agreed upon time? Is there then something else preventing the information to be sent FTL?
a radius of 42000km
Wouldn't that generate an artificial gravity equal to that of the earth at 42000km of altitude?
no.
Earth's gravity is caused by its mass, the further away from the centre of mass the less you are affected.
Rotational "gravity" increases with distance (for the same rotation rate) as you are accelerated at a higher rate.
To a certain degree, the owners of Avatar owe it to the shared culture that allowed them to make this movie.
Ahem Pocahontas ...
You'd think that the RIAA/MPAA/etc. would have noticed that the Free Software crowd has no problem with piracy, and would want to adopt their successful tactics. Anyone know why they don't?
Umm yes... They want lots of money.
I have seen a demo like that in a science museum in Japan. It was a large disk shape that could be spun by turning a handle, painted with a black and white pattern. When spun, coloured bands seem to appear. I have no idea how this works...