Is there REALLY anything wrong with Fission power?
on
Mine The Moon For Helium-3
·
· Score: 5, Insightful
I mean come on. We can't even get one watt of positive energy flow out of Fusion and they already want to mine the moon for it. Let's spend our time developing better fission reactors, including ones for space engines. Then we can use them to get our scientists to the moon so they can play with Helium-3 and Fusion all they want.
Not quite. ISPs have something called "Carrier Status" which basically means that due to the amount of traffic, they can't be held responsible for what their users do. However, they can lose their carrier status if they fail to take action when informed of improper use of the system.
That's not entirely true. Apparently there's been some success in using more exotic materials such as plastics. NASA actually has a website on the subject.
Dear Lord. Don't you think the court already has to deal with these types of problems? It will be up to the prosecutor to prove that you were the one using Kazaa at the time of the incident AND that the actions you were taking were indeed done in an illegal fashion (i.e. You lacked the proper rights to commit the actions you did). If the prosecution has difficulty proving that it wasn't your neighbor, they may try to implicate you by showing that you took insufficient precautions to protect your identity and thus can be held as an accomplice. It's a bit hard to make stick, but it might be enough to keep you in court for quite a long time.
Tis true. Although it reminds me a lot of working with older machines where the text didn't blow by so fast that you couldn't even scroll lock it. I always assumed that Sun had slowed the console down on purpose.:-)
But it is pretty.:)
Isn't it? Last time I was working on developing an Operating System for fun (Intel GDT/LDT/IDTs SUCK), I spent a lot of time trying to get the text mode to start in that nice pure white with black text. I figured out that while there was pure white text, there were no pure white background colors. The only way I was going to get what I wanted was to use the protected mode VESA hooks. Of course, that sucks almost as much as Intel's real mode -> protected mode jump.
Maybe someday I'll modify FreeBSD to do what I want.:-)
I've been considering, but since the machine acts as the backend database and J2EE server for a recipes database I developed for my wife, I'm a bit hesitant to go monkeying around with the hardware.
I just got into the OpenBoot PROM (hold down Apple+Option+o+f as you turn the machine on; the o+f stands for "open firmware", get it?) and it still doesn't look right. I have a tiny black font on a grey background. Not to mention that the firmware is just about as non-friendly as it gets:
> help help on not found > ? Illegal memory access (gives some debug info) > boot -s
(At this point I get an empty grey screen with a crossed through circle in the middle. Must have caused some sort of error.)
In comparison, my Ultra 10 boots up into a nice pure white with large, easy to read fonts. Stop+A gets me into OpenBOOT where "help" or "?" gives me a very nice list of possible instructions. Perhaps you're misremembering the Sun text mode? The black on grey fonts are better than PC style, but a far cry from Sun's beautiful anti-aliased text mode.
No, OpenBoot is Sun's proprietary version that they licensed to Apple. OpenFirmware is the open standard upon which just about every non-pc computer uses for firmware.
The interesting thing, however, is that modern Macs use OpenBoot as well.
I knew that Apple licensed it from Sun, but why doesn't Darwin use the same fonts? If you log into an OS X machine with username ">console" and no password you'll get a standard (read: ugly) white on black shell prompt. Perhaps there's some way to change this?
Different models. My Ultra 10 is of an older design than the line that my Ultra 5 was from. Thus my Ultra 5 had a PGX24 (I think) while my Ultra 10 has a PGX8.
Choosing between 800x600 with 24 bit color or 1024x768 with 8 bit color sucks. On the bright side, it does its job as a server quite well.
It's a Known Fact (TM) that on that level of hardware, Linux spanks Solaris.
You may want to recheck your "known facts". About that time, Linux was crapping out on running Netscape. Sure, "modern" Linux may do better, but if we're talking about the actual time period, Linux was a very poor performer compared to Solaris.
It's also not ALL PC hardware. For example, the UltraSparc processors assist in the multitasking power of these machines. Can anyone say "superscalar done right"? Intel superscalar designs were a joke. Other hardware and ROMS have been similarly configured for better multiprocess performance.
Of course, it's a bit frustrating when even a modern Windows or Linux machine hangs while loading a large program or doing some other system intensive task. FreeBSD 4.x is pretty good about this, but 5.x brought in the Linuxish hangs.
BTW, I forgot to mention that PIIs of the time would outperform Ultras on one point: Games. The Intel architecture is designed around single threaded speed. The Sun architectures are designed around scaling up to as many threads/processes as possible. As a serious workstation Suns win. As a gaming machine PCs win.
An old Pentium II will run circles around most Sun boxes you could buy under $500 and you can pick the PII out of the trash.
Bull. I had my first Ultra 5 when PIIs were shiny and new. At that time not a single PII could keep up with my Ultra 5. I had StarOffice, Netscape, Furi, GCC, etc. all running or loading simultaneously. The PCs would usually crap out after only a couple of those programs. My Ultra 5 just kept chugging. Sure, every program would make the next one take that much longer to load, but the system stayed responsive no matter what the load. THAT is the kind of engineering I have NEVER seen in the PC world.
Who needs a frame buffer? Sparc console mode has *got* to be the prettiest thing I've ever seen on any machine. Who wants white text on black with 8x8 fonts? I'd rather have black on white with anti-aliased fonts. It's so nice, it's almost a shame to remotely administrate the system.
I think your problem is resolution. I hooked my first Ultra 5 up to a cheapo ViewSonic monitor and (predictably) it didn't work. After learning about Stop+A, I booted into single user and changed the default resolution from 1600x1200 to a more reasonable 1024x768. I then rebooted and no longer had any problems.
*sniff* I miss that Ultra 5. My current Ultra 10 has more power but much poorer video support.
On a more serious note, I wonder if this stuff has any radiation shielding properties? When they fired particles into the gel, they were very quickly stopped. And placing the gel against a bunsen burner doesn't even phase it. If it protects against radiation just as well, its light weight may make it the perfect space ship shielding material.
I stand corrected. A bit of googling produces the following formula:
Energy = mass * (velocity^2) Kinetic Energy = (1/2)mass * (velocity^2)
I'm not sure what the difference is in the two equations, but my hunch is that the kinetic energy is taking into account the reaction energy. i.e. Every action has an opposite and equal reaction. Thus, half the energy expenditure goes to the action and half to the reaction.
A bit of consideration on the formula makes one notice how close it is to the E=mc^2 equation. The only difference between the two is that c is a constant representing the speed of light. As to whether the speed of light is used because it is the maximum attainable energy state or not is another thing I should find out.
In any case, my point still holds. If we want to make our engines more efficient, we have to produce more velocity in the thrust. Since velocity is a much "heavier" part of the equation, we can equal performance with significantly less mass by a much smaller increase in the velocity of the exhaust. Thus a nuclear rocket that can throw the same exhaust mass at a higher velocity than a chemical rocket will produce far greater thrust.
By extension, a higher Isp rocket will assume a higher thrust as long as the amount of mass remains constant. The problem with technologies such as nuclear electric propulsion is that they trade far too significant a mass for their high propulsive effects. While the use of a larger power source (such as a nuclear reactor) can boost their mass throw significantly, it is still far less than is necessary to produce enough constant thrust to overcome the Earth's gravitational and atmospheric friction vectors.
If we continue down that train of thought, it becomes apparent that an electric rocket such as the ION drive is completely ineffective unless first boosted to a stable velocity (in this case orbital velocity) by more traditional means.
Hmm... I guess my old boss was right. Communication does complete thought.:-) Ok, I'm done thinking out loud now. You can all come down on me for what I got wrong.
Re:One question.
on
Mice In Space
·
· Score: 2, Interesting
It *would* be worth it if they were testing Nuclear Propulsion. At least that way they could measure the REM dosage that the mice received. If everything goes as planned, the mice would receive very little from the craft and land on Mars in a condition to begin other experiments.
s it the shock that you have received all that you have asked, or is it just your hate for the man that is causing this current most peculiar of backlashes?
My guess is that it's the later. Many Slashdotters are liberals who, as a matter of principle, must hate Bush. However, Bush has done more to give them what they want and need than Clinton *ever* did. Thus they're stuck in a position of wanting what Bush is offering, but feeling like they're violating their principles if they take it. The end result is that they're acting like a bunch of skeptics who secretly hope that their heckling will help be a driving force for Bush.
An RTG is NOT a fission pile. It simply takes the heat from the plutonium and converts that into electricity. The most current RTGs get about 75W per 2.5 pounds of Plutonium.
As for Fusion, there are quite a few good ideas on using it for propulsion (such as firing small fusible pellets in front of a pusher plate and causing fusion by way of high powered lasers). However, fusion as an electricity source is not only far away, but would probably be bulkier than an equivalent fission reactor.
Sorry, but you're confusing Nuclear Electric Propulsion with Nuclear Thermal Propulsion. The later can throw just as much mass as chemical rockets, but at a lot higher velocities. (force = mass * velocity2)
Slashdot Mirror
I mean come on. We can't even get one watt of positive energy flow out of Fusion and they already want to mine the moon for it. Let's spend our time developing better fission reactors, including ones for space engines. Then we can use them to get our scientists to the moon so they can play with Helium-3 and Fusion all they want.
Not quite. ISPs have something called "Carrier Status" which basically means that due to the amount of traffic, they can't be held responsible for what their users do. However, they can lose their carrier status if they fail to take action when informed of improper use of the system.
All right, it's official. You suck. "Proxima"? An Ultra 60 with 1024 megs of RAM? And Creator 3D graphics no less? GRRRR....
yeah, I think it is. :)
;-)
That's what I thought. Thanks for the confirmation. Now if someone could just tell BSDTroll that.
ISN'T THAT WHAT I SAID?!
They have to convince a judge. It entirely depends on how skeptical the judge is.
That's not entirely true. Apparently there's been some success in using more exotic materials such as plastics. NASA actually has a website on the subject.
Dear Lord. Don't you think the court already has to deal with these types of problems? It will be up to the prosecutor to prove that you were the one using Kazaa at the time of the incident AND that the actions you were taking were indeed done in an illegal fashion (i.e. You lacked the proper rights to commit the actions you did). If the prosecution has difficulty proving that it wasn't your neighbor, they may try to implicate you by showing that you took insufficient precautions to protect your identity and thus can be held as an accomplice. It's a bit hard to make stick, but it might be enough to keep you in court for quite a long time.
Pretty, but godawful slow.
:-)
:)
:-)
Tis true. Although it reminds me a lot of working with older machines where the text didn't blow by so fast that you couldn't even scroll lock it. I always assumed that Sun had slowed the console down on purpose.
But it is pretty.
Isn't it? Last time I was working on developing an Operating System for fun (Intel GDT/LDT/IDTs SUCK), I spent a lot of time trying to get the text mode to start in that nice pure white with black text. I figured out that while there was pure white text, there were no pure white background colors. The only way I was going to get what I wanted was to use the protected mode VESA hooks. Of course, that sucks almost as much as Intel's real mode -> protected mode jump.
Maybe someday I'll modify FreeBSD to do what I want.
I've been considering, but since the machine acts as the backend database and J2EE server for a recipes database I developed for my wife, I'm a bit hesitant to go monkeying around with the hardware.
I just got into the OpenBoot PROM (hold down Apple+Option+o+f as you turn the machine on; the o+f stands for "open firmware", get it?) and it still doesn't look right. I have a tiny black font on a grey background. Not to mention that the firmware is just about as non-friendly as it gets:
> help help on not found
> ?
Illegal memory access
(gives some debug info)
> boot -s
(At this point I get an empty grey screen with a crossed through circle in the middle. Must have caused some sort of error.)
In comparison, my Ultra 10 boots up into a nice pure white with large, easy to read fonts. Stop+A gets me into OpenBOOT where "help" or "?" gives me a very nice list of possible instructions. Perhaps you're misremembering the Sun text mode? The black on grey fonts are better than PC style, but a far cry from Sun's beautiful anti-aliased text mode.
No, OpenBoot is Sun's proprietary version that they licensed to Apple. OpenFirmware is the open standard upon which just about every non-pc computer uses for firmware.
The interesting thing, however, is that modern Macs use OpenBoot as well.
I knew that Apple licensed it from Sun, but why doesn't Darwin use the same fonts? If you log into an OS X machine with username ">console" and no password you'll get a standard (read: ugly) white on black shell prompt. Perhaps there's some way to change this?
Different models. My Ultra 10 is of an older design than the line that my Ultra 5 was from. Thus my Ultra 5 had a PGX24 (I think) while my Ultra 10 has a PGX8.
Choosing between 800x600 with 24 bit color or 1024x768 with 8 bit color sucks. On the bright side, it does its job as a server quite well.
It's a Known Fact (TM) that on that level of hardware, Linux spanks Solaris.
You may want to recheck your "known facts". About that time, Linux was crapping out on running Netscape. Sure, "modern" Linux may do better, but if we're talking about the actual time period, Linux was a very poor performer compared to Solaris.
It's also not ALL PC hardware. For example, the UltraSparc processors assist in the multitasking power of these machines. Can anyone say "superscalar done right"? Intel superscalar designs were a joke. Other hardware and ROMS have been similarly configured for better multiprocess performance.
Of course, it's a bit frustrating when even a modern Windows or Linux machine hangs while loading a large program or doing some other system intensive task. FreeBSD 4.x is pretty good about this, but 5.x brought in the Linuxish hangs.
BTW, I forgot to mention that PIIs of the time would outperform Ultras on one point: Games. The Intel architecture is designed around single threaded speed. The Sun architectures are designed around scaling up to as many threads/processes as possible. As a serious workstation Suns win. As a gaming machine PCs win.
An old Pentium II will run circles around most Sun boxes you could buy under $500 and you can pick the PII out of the trash.
Bull. I had my first Ultra 5 when PIIs were shiny and new. At that time not a single PII could keep up with my Ultra 5. I had StarOffice, Netscape, Furi, GCC, etc. all running or loading simultaneously. The PCs would usually crap out after only a couple of those programs. My Ultra 5 just kept chugging. Sure, every program would make the next one take that much longer to load, but the system stayed responsive no matter what the load. THAT is the kind of engineering I have NEVER seen in the PC world.
Only thing that's slow is their frame buffers.
Who needs a frame buffer? Sparc console mode has *got* to be the prettiest thing I've ever seen on any machine. Who wants white text on black with 8x8 fonts? I'd rather have black on white with anti-aliased fonts. It's so nice, it's almost a shame to remotely administrate the system.
I think your problem is resolution. I hooked my first Ultra 5 up to a cheapo ViewSonic monitor and (predictably) it didn't work. After learning about Stop+A, I booted into single user and changed the default resolution from 1600x1200 to a more reasonable 1024x768. I then rebooted and no longer had any problems.
*sniff* I miss that Ultra 5. My current Ultra 10 has more power but much poorer video support.
On a more serious note, I wonder if this stuff has any radiation shielding properties? When they fired particles into the gel, they were very quickly stopped. And placing the gel against a bunsen burner doesn't even phase it. If it protects against radiation just as well, its light weight may make it the perfect space ship shielding material.
#$^@#%$ high school physics!
:-) Ok, I'm done thinking out loud now. You can all come down on me for what I got wrong.
I stand corrected. A bit of googling produces the following formula:
Energy = mass * (velocity^2)
Kinetic Energy = (1/2)mass * (velocity^2)
I'm not sure what the difference is in the two equations, but my hunch is that the kinetic energy is taking into account the reaction energy. i.e. Every action has an opposite and equal reaction. Thus, half the energy expenditure goes to the action and half to the reaction.
A bit of consideration on the formula makes one notice how close it is to the E=mc^2 equation. The only difference between the two is that c is a constant representing the speed of light. As to whether the speed of light is used because it is the maximum attainable energy state or not is another thing I should find out.
In any case, my point still holds. If we want to make our engines more efficient, we have to produce more velocity in the thrust. Since velocity is a much "heavier" part of the equation, we can equal performance with significantly less mass by a much smaller increase in the velocity of the exhaust. Thus a nuclear rocket that can throw the same exhaust mass at a higher velocity than a chemical rocket will produce far greater thrust.
By extension, a higher Isp rocket will assume a higher thrust as long as the amount of mass remains constant. The problem with technologies such as nuclear electric propulsion is that they trade far too significant a mass for their high propulsive effects. While the use of a larger power source (such as a nuclear reactor) can boost their mass throw significantly, it is still far less than is necessary to produce enough constant thrust to overcome the Earth's gravitational and atmospheric friction vectors.
If we continue down that train of thought, it becomes apparent that an electric rocket such as the ION drive is completely ineffective unless first boosted to a stable velocity (in this case orbital velocity) by more traditional means.
Hmm... I guess my old boss was right. Communication does complete thought.
It *would* be worth it if they were testing Nuclear Propulsion. At least that way they could measure the REM dosage that the mice received. If everything goes as planned, the mice would receive very little from the craft and land on Mars in a condition to begin other experiments.
At least now we know where the Biker Mice from Mars came from!
s it the shock that you have received all that you have asked, or is it just your hate for the man that is causing this current most peculiar of backlashes?
My guess is that it's the later. Many Slashdotters are liberals who, as a matter of principle, must hate Bush. However, Bush has done more to give them what they want and need than Clinton *ever* did. Thus they're stuck in a position of wanting what Bush is offering, but feeling like they're violating their principles if they take it. The end result is that they're acting like a bunch of skeptics who secretly hope that their heckling will help be a driving force for Bush.
An RTG is NOT a fission pile. It simply takes the heat from the plutonium and converts that into electricity. The most current RTGs get about 75W per 2.5 pounds of Plutonium.
As for Fusion, there are quite a few good ideas on using it for propulsion (such as firing small fusible pellets in front of a pusher plate and causing fusion by way of high powered lasers). However, fusion as an electricity source is not only far away, but would probably be bulkier than an equivalent fission reactor.
Sorry, but you're confusing Nuclear Electric Propulsion with Nuclear Thermal Propulsion. The later can throw just as much mass as chemical rockets, but at a lot higher velocities. (force = mass * velocity2)
An actually physicist was kind enough to give an easy to understand explanation of the differences.