Well... erm... uhh... I've read a few web pages in the meantime, and I have to admit, you're right. "Sun sails" use the photon pressure effect. Sheesh, why did they have to use these misleading names in the first place, "solar wind", "solar sails"...
So, this sheds (to me) new light on this whole issue. From what I can say now, this technology seems really useful, because you don't have to accelerate the energy source and the fuel together with the spacecraft. This means, e.g. if you have a propulsion laser on our moon and one on Phobos or Deimos (the Mars' moons), you could actually travel really fast between those planets (using the destination station for braking), and you could carry more payload because the actual spaceship would be rid of the fuel and engines, which make up most of the mass of a conventional craft.
I'm aware of the fact that the spacecraft will not slow down. But once you're past Jupiter, you will need an energy source other than the sun anyway, because photovoltaic cells won't work anymore. For a long-term energy source, there's not much choice: it has to be a nuclear reactor of some sort (maybe fusion in the future). If you're carrying a nuclear reactor anyway, you could just as well use ion engines.
And once you get outside of the solar system (say one light year from the sun) you actually have the galactic wind exerting pressure towards our sun.
As for the radiation, yes the earth does a pretty good job. You could use an artificial magnetosphere to shield against the solar wind, but power failures do happen, and you still have cosmic radiation (which is the bigger problem). Our atmosphere is equivalent to 13 feet of concrete WRT shielding cosmic radiation.
One thing is clear: long-range manned spacecraft are going to be big and heavy.
OTOH, solar sails could make for very low-cost, light-weight probes (without chemical or ion engines and fuel tanks). And they could still be useful in giving an initial boost to manned ships.
... but first of all, this will only work really close to the sun, maybe within the five inner planets, as the wind pressure decreases with the inverse square of the distance to the sun. Second, it won't work with humans on board, because to protect people from the solar wind itself (electrons, protons and neutrons, so highly ionizing and not good for your health) and cosmic radiation, you need thick layers of absorbant material (water or rock), which would make the craft too heavy to be adequately accelerated by the solar wind.
So, it's maybe a good idea for low-cost space probes, but it won't work for manned spacecraft.
And I think before worrying about linguistic problems (space English and Earth English, WTF?), we should first find a way for humans to even survive for an extended period of time on our front porch, i.e. interplanetary space.
I found IBM's PC-DOS 2000 really nice. I didn't notice any incompatibilities, and it has a powerful builtin REXX and a nice editor:)
DOS is underrated
on
FreeDOS
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· Score: 5, Interesting
I guess what most people don't realize is that DOS is really a great way of running programs (note that I don't say OS), especially on very slow CPUs. DOS is real-time, and it has next to no memory or CPU overhead, so it's well suited for embedded real-time apps. Now that we have a free DOS we can build highly reliable embedded systems, because as DOS has a small code base, it's easy to audit, increasing reliability over (WRT that special task) bloated Unices.
Yeah, I built my model railroad controller with an embedded 386 and PC-DOS so I'm a bit biased, but DOS still has its place in today's world.
Oh, and to run a DOS PC without a graphics card, just enter (or put in autoxec.bat) ctty com1:. The serial port will be used as console (use mode to set parameters).
Where'd you get that? In 1939, Molotov became foreign minister and that same year, the Soviet Union invaded Finland. The Fins had an underequipped army and therefore had to improvise - inventing the Molotov cocktail. The fins were also very good friends with us Germans (I believe they still used the Swastika after WWII), so you're completely wrong in all points:)
Some time ago I had a Sony CRX120E CD Recorder which had problems with CD-Text. I called Sony support.
"Yes, it's a known problem. You need a firmware upgrade."
"Oh OK. Where can I download it?"
"You can't download the firmware. You have to send the device to a Sony service center and they will upgrade it for you. It will cost 50 DM."
"Lady, you can <censored> my <censored>."
I was pissed. I frantically searched the web for the firmware. The only thing I could find was the firmware for the CRX140E on the Dell website. The CRX140E is an 8x burner while the CRX120E is a 4x burner. I thought it was highly improbable that this would work, but what did I have to lose, I had to send the burner to Sony anyway.
I hacked the Dell flash program to work with the CRX120E and flashed the firmware. Naturally, it didn't work. The burner was dead. Wouldn't even respond to ATAPI commands. The next day, I sent it to the Sony service center.
A week later, I get an email from the Sony service center.
"We weren't able to flash the firmware. The burner doesn't show up on the IDE bus. We will have to replace the main board, which will cost <some ridiculous amount> DM."
OK, so these bozos can't flash the firmware in-circuit. Great "service center".
So I replied:
"Alright, send it back to me, maybe you could put the firmware on a diskette and put it with the burner, so I can flash it myself, after I've built my own freakin flash programmer?"
Response:
"Our policy is to not give out firmware. But we can dispose of the device for free if you want that. Otherwise we would charge you a <some ridiculous amount> return fee for P&P."
So, this was the last Sony product I've bought. Ever.
This one looks better!
on
Uplink
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· Score: 0, Offtopic
Parsec is non-commercial and will be free (as beer)! Finally a state of the art online action game that for Linux (and MacOS X). CS is dead, long live Parsec! Unfortunately it's not finished yet.
The reason is this: hydrogen can easily be converted to methane, using carbon dioxide from the air. So you could have cars running on fossil methane (organic gas is methane) today and methane made from solar power generated hydrogen in a few years. Oh, and methane doesn't need cryotanks like hydrogen. Much easier to handle.
I mean it's nice, but much too complicated and expensive. Why not use cheap, existing technology, i.e. combustion motors? They can be fueled by alcohol, methane and even hydrogen (BWM is already series-producing a hydrogen-fueled 750). We could have been driving on methane for decades, but the fact is, the oil companies have a lot to say in most governments, and without fuel, even the most high-tech car is useless.
No, it doesn't. CCFL (Cold Cathode Fluorescent) Lamps are glass tubes filled with mercury vapor and an additional inert gas (commonly Argon) to create a plasma when a sufficiently high voltage is applied to the electrodes. The tube is coated with a phosphor on the inside which 'converts' the UV radiated by the plasma to visible light. Are you saying Europeans are stupid?
Interestingly, the Ancient Greeks were more civilized than we are today. They slaughtered each other most of the time, but during the Olympics, they ceased all hostilities. No one would dare to disturb the Olympics.
... in space exploration policy, I would concentrate all efforts to building an observatory on the moon. The Hubble Telescope has a 2.6m mirror and revolutionized astronomy. Just imagine what an 8m telescope on the far side of the moon could discover. Also, radio astronmy is becoming more and more difficult, because of the "radio pollution" on earth. A radio telescope on the far side of the moon, screened from all man-made interference, could bring us a tremendous amount of new insights.
Just my $0.02...
I think you're wrong. n-tv.de has the same story, and they say that the actual shutdown will take place on March 5th, 2002, on which day the Link Level Protocol (LLP) will be deactivated.
Semi-important? Yeah, the news about the last TCP/IP connection being shut down will be semi-important too, when everyone uses mind transmitters, but it's still a part of history.
Sure, we completely agree on this. But the reason that they are not allowed to distribute their patch is that the files they are distributing contain copyrighted material, and not that the EULA prohibits it. E.g., a patch to remove the copy protection would be completely legal.
As I wrote in my other comment, it's not illegal to modify/disassemble apps in Germany. It's just that those guys are distributing a copyrighted text. In Germany, there are companies which make a living of removing copy protections (dongles, etc.) from commercial software.
Not in Germany. In the U.S., when you buy software, you actually buy a license to use that software, which allows the software company to impose all kinds of restrictions. In Germany, buying software is no different from buying a loaf of bread (from a legal point of view), so you can do with it anything you like.
The problem here seems to be that the text those guys are distributing is (c) Infogrames.
Slashdot Mirror
Yeah, but then Ug got pissed and captured a flatulent Pteranodon and crashed it into Og's cave ...
So, this sheds (to me) new light on this whole issue. From what I can say now, this technology seems really useful, because you don't have to accelerate the energy source and the fuel together with the spacecraft. This means, e.g. if you have a propulsion laser on our moon and one on Phobos or Deimos (the Mars' moons), you could actually travel really fast between those planets (using the destination station for braking), and you could carry more payload because the actual spaceship would be rid of the fuel and engines, which make up most of the mass of a conventional craft.
Anyway, thanks for clearing this up.
And once you get outside of the solar system (say one light year from the sun) you actually have the galactic wind exerting pressure towards our sun.
As for the radiation, yes the earth does a pretty good job. You could use an artificial magnetosphere to shield against the solar wind, but power failures do happen, and you still have cosmic radiation (which is the bigger problem). Our atmosphere is equivalent to 13 feet of concrete WRT shielding cosmic radiation.
One thing is clear: long-range manned spacecraft are going to be big and heavy.
OTOH, solar sails could make for very low-cost, light-weight probes (without chemical or ion engines and fuel tanks). And they could still be useful in giving an initial boost to manned ships.
So, it's maybe a good idea for low-cost space probes, but it won't work for manned spacecraft.
And I think before worrying about linguistic problems (space English and Earth English, WTF?), we should first find a way for humans to even survive for an extended period of time on our front porch, i.e. interplanetary space.
Hmm, makes no sense. Wait ... Always Where Under Where ... aaaahahahah always wear underwear ... heeheheheheh
Yeah I know.
I found IBM's PC-DOS 2000 really nice. I didn't notice any incompatibilities, and it has a powerful builtin REXX and a nice editor :)
Yeah, I built my model railroad controller with an embedded 386 and PC-DOS so I'm a bit biased, but DOS still has its place in today's world.
Oh, and to run a DOS PC without a graphics card, just enter (or put in autoxec.bat) ctty com1:. The serial port will be used as console (use mode to set parameters).
Cheers
Some time ago I had a Sony CRX120E CD Recorder which had problems with CD-Text. I called Sony support.
"Yes, it's a known problem. You need a firmware upgrade."
"Oh OK. Where can I download it?"
"You can't download the firmware. You have to send the device to a Sony service center and they will upgrade it for you. It will cost 50 DM."
"Lady, you can <censored> my <censored>."
I was pissed. I frantically searched the web for the firmware. The only thing I could find was the firmware for the CRX140E on the Dell website. The CRX140E is an 8x burner while the CRX120E is a 4x burner. I thought it was highly improbable that this would work, but what did I have to lose, I had to send the burner to Sony anyway.
I hacked the Dell flash program to work with the CRX120E and flashed the firmware. Naturally, it didn't work. The burner was dead. Wouldn't even respond to ATAPI commands. The next day, I sent it to the Sony service center.
A week later, I get an email from the Sony service center.
"We weren't able to flash the firmware. The burner doesn't show up on the IDE bus. We will have to replace the main board, which will cost <some ridiculous amount> DM."
OK, so these bozos can't flash the firmware in-circuit. Great "service center".
So I replied:
"Alright, send it back to me, maybe you could put the firmware on a diskette and put it with the burner, so I can flash it myself, after I've built my own freakin flash programmer?"
Response:
"Our policy is to not give out firmware. But we can dispose of the device for free if you want that. Otherwise we would charge you a <some ridiculous amount> return fee for P&P."
So, this was the last Sony product I've bought. Ever.
Like this.
"game for Linux" that is ... heh.
Parsec is non-commercial and will be free (as beer)! Finally a state of the art online action game that for Linux (and MacOS X). CS is dead, long live Parsec! Unfortunately it's not finished yet.
The reason is this: hydrogen can easily be converted to methane, using carbon dioxide from the air. So you could have cars running on fossil methane (organic gas is methane) today and methane made from solar power generated hydrogen in a few years. Oh, and methane doesn't need cryotanks like hydrogen. Much easier to handle.
I mean it's nice, but much too complicated and expensive. Why not use cheap, existing technology, i.e. combustion motors? They can be fueled by alcohol, methane and even hydrogen (BWM is already series-producing a hydrogen-fueled 750). We could have been driving on methane for decades, but the fact is, the oil companies have a lot to say in most governments, and without fuel, even the most high-tech car is useless.
No, it doesn't. CCFL (Cold Cathode Fluorescent) Lamps are glass tubes filled with mercury vapor and an additional inert gas (commonly Argon) to create a plasma when a sufficiently high voltage is applied to the electrodes. The tube is coated with a phosphor on the inside which 'converts' the UV radiated by the plasma to visible light. Are you saying Europeans are stupid?
Let's agree on pr0n, DivX and mp3s. But putting it on /. is no good idea, could bring the whole net down ...
Interestingly, the Ancient Greeks were more civilized than we are today. They slaughtered each other most of the time, but during the Olympics, they ceased all hostilities. No one would dare to disturb the Olympics.
The Ultimate Test
Fill the servers up with pr0n and serve it to the public, for free! If it withstands that, the Olympics will be a piece of cake.Hey, I'm serious ...
... in space exploration policy, I would concentrate all efforts to building an observatory on the moon. The Hubble Telescope has a 2.6m mirror and revolutionized astronomy. Just imagine what an 8m telescope on the far side of the moon could discover. Also, radio astronmy is becoming more and more difficult, because of the "radio pollution" on earth. A radio telescope on the far side of the moon, screened from all man-made interference, could bring us a tremendous amount of new insights. Just my $0.02 ...
Actually, I'm looking forward to manned missions to Uranus.
Semi-important? Yeah, the news about the last TCP/IP connection being shut down will be semi-important too, when everyone uses mind transmitters, but it's still a part of history.
Sure, we completely agree on this. But the reason that they are not allowed to distribute their patch is that the files they are distributing contain copyrighted material, and not that the EULA prohibits it. E.g., a patch to remove the copy protection would be completely legal.
As I wrote in my other comment, it's not illegal to modify/disassemble apps in Germany. It's just that those guys are distributing a copyrighted text. In Germany, there are companies which make a living of removing copy protections (dongles, etc.) from commercial software.
The problem here seems to be that the text those guys are distributing is (c) Infogrames.