> > at 0.99999999996c, you can cross the galaxy in > > 12 years of your own time
> Umm - the Milky Way galaxy is 150,000 light years > across. [Pause] Oh shit! You are from the Milky > Way, right?
Uh, time dilation.
Re:how do you stop the damn thing...
on
Antimatter Space Drive
·
· Score: 3, Informative
I think the idea is this: for short journeys, you accelerate until you're half way there, then you turn the ship around and decelerate. This has the added advantage of providing you with some sort of gravity (how much depends on your acceleration) for the duration of trip (aside from when you're flipping over). For longer trips, you'll accelerate until you're cruising along nicely, then turn the engines off. You'll have to flip over and decelerate for the same amount of time you spent accelerating tho...
You very quickly pile up speed too. If you accelerate at 1g for a year, you get rather close to c. If you ever want to return home tho, you'll have to be careful: at 0.99999999996c, you can cross the galaxy in 12 years of your own time, but 113 000 years will pass for us back here.
Firstly, you are aware of the difference between nuclear rockets and anti-matter propulsion, right? Nuclear rockets are basically nuclear reactors with their outputs attached to rocket engines instead of turbines.
Anti-matter drives are not going to be used inside the atmosphere. Using any sort of nuclear rocket inside the atmosphere is retarded. How safe do you want it to be? What are the consequences of a rocket full of uranium exploding over a populated area? Anyhow, chemical boosters work fine (and could work even better if people put their mind to it) for getting stuff into orbit. Getting stuff into orbit is a political problem these days, not so much a technical one.
Anti-matter propulsion canes all of these tho for energy density; you're getting down into the guts of physics here. No more `let's make this hydrogen and oxygen go boom!' engines, nor `let's use this decaying uranium to heat up some water! w00t!' engines, you're getting matter to convert directly and completely into energy.
So, yeah, no one's going to use nuclear rockets, nor anti-matter rockets inside the atmosphere. Long term, anti-matter looks to be the way to go; it's got the energy density we need and it ain't going to be expensive forever.
...At least to provide thrust for a vessel of any kind since it costs more energy (incredibly more, with current technology) to produce than it actually stores.
Hehe, I'd certainly hope so. The point of using anti-matter for propulsion is the enormous energy density, no energy efficency.
Getting around in space is hard. It takes piles of energy to get to a reasonable speed (especially if you want to get anywhere outside the solar system). The problem isn't the lack of energy around. How many gazillions of joules do you think the sun pumps out each second? The problem is concentrating it and putting it to use. Say we set up an anti-matter factory in space. Nothing too fancy, just a huge solar array, an accelerator and the magnetic trapping stuff needed to stop the whole thing annihilating itself. Leave it there for a few years, patiently producing anti-protons from the sunlight and inter-planetary gas. Want to go visit Alpha Centauri? Cruise up and pick up a blob of anti-matter from the factory. You could instead build huge solar panels on your ship and use an ion drive or something, but the anti-matter route means that you just need to carry a small amount of fuel, instead of huge amounts of machinary to generate it.
It's just like ecosystems: plants concentrate solar energy, animals eat them, then I eat the animals. It's not particularily efficent, but it concentrates the energy into easy to use packages (a.k.a. steaks) and lets me spend more time wiping out species for sport and less time hunting for food:/
I don't think cost is going to be a long-term problem. Once we get a bit better at making it, we could just build a giant-ass accelerator in space, with a huge solar array pointing at the sun. It can sit up there for years, patiently using sunlight to amass anti-protons. It doesn't cost squat once it's up there, and the immense usefullness of it would repay any initial investment a thousand times over.
The US government relaxed crypto export laws a bit last year. IIRC, you can export open source software with strong crypto if you report it some government agency. Debian's solution for getting crypto into the main distribution is to have the archive software automatically email the export control agency when a new package is uploaded.
X installation has always been a bitch for me irregardless of the distribution Linux or BSD. It seems that it's something that always needs tinkering. I did get this going fairly quick after some help from my BSD admin guru--thank the Gods for buddies!
Little known fact: if you install mdetect, discover and read-edid before X, then it will automatically detect your monitor your video card and your mouse. It's documented in the install docs somewhere...
I still don't have sound working, but I haven't given it the one two punch!
Have you added yourself to the `audio' group? That's one of the most common issues people seem to have on IRC.
I probably haven't looked in the right place or good documentation doesn't exist. And I'm lazy?:S
apm worked fine for me out of the box. apt-get install apmd.
Let's face it, I think that once most people get their configuration working they don't think about giving back to the community. Something that should definately be reconsidered.
Aggravating. I don't want to sit and select then download and install 200M of software after I get it installed, but I DO want an easy way to get back to package management once I hastily exit out if it. I want my cake and I want to eat it too.
Then quit from dselect and let it install just the base system. If you want to add packages later, then run aptitude or dselect. Easy.
Kangaroo and rats? WTF? Have any Americans every actually seen a kangaroo?
Don't you guys know anything? They're big and friendly, and they bounce up and down the main street of any major city here in Australia. If you give them a carrot, you can ride in their pouch.
Public domain != GPL. If there was no copyright, then I could sell you my new fandoozy version of Emacs, and refuse to give you the source. The GPL, depending on your point of view, thus gives you more rights than even a copyright-free society would give you.
I would argue that the only way of acheiving this is to have Free software from the firmware level up. I would trust thousands of geeks with nothing to gain by screwing me, over MS, with everything to gain from locking up the world, anyday of the week.
Re:Read a great story about this [Kinda OT]
on
Downloading The Mind
·
· Score: 2
Found it!
The story is called `Learning to be me', by Greg Egan. I read it in an anthology called MetaWorlds, but you can find it in his collection called Axiomatic.
Certainly well worth a read, if you can find it.
Re:Read a great story about this [Kinda OT]
on
Downloading The Mind
·
· Score: 2
Nope, neither of those. It was a short story in an anthology of Australian science fiction, and it had a giant flying platypus on the cover, IIRC.
Re:Not Version Bloat.
on
Linux 3.0
·
· Score: 5, Informative
ALSA is defintely in, as is things like USB2, Access Control Lists, new NTFS support (it doesn't completely trash partitions now!), hot pluggable CPUs, software suspend (hit a key combo and save the whole system state to the harddrive), support for drives >2TB, and a whole lot more.
BTW, I have to love a community where this sort of thing is discussed on a site called KernelNewbies:)
Read a great story about this [Kinda OT]
on
Downloading The Mind
·
· Score: 3, Informative
I read this great science fiction story by some Australian guy (can't remember who or when) that went something like this:
In the future, everyone has a `jewel' implanted in their brain at birth. It's an optical computer that receives all your sensory data, then tries to replicate the external results of your brain activity. When you're young, it's way off, but it trains itself to match the responses of your real brain. One day, in your thirties, when your real brain is going down hill, you go to the hospital. They hook you up to another computer that keeps an eye on how well the outputs of the jewel match the outputs of your organic brain. If they match up, then they scrape out your meatware, and replace it with non-sentient tissue that consumes just as much blood, glucose, etc as your original brain, and can produce hormones for the rest of your body, while hooking up the jewel to the rest of your body. At that point, `you' are the jewel.
The cool part of this is that there's no discontinuity between `me' and `it'; the jewel will think the same thoughts as me, it will be me; in fact, it will even worry about dying when the organic brain is killed, since it thinks it is the original.
The ending was quite a cool twist, which I won't spoil here. It was a really good story tho, hopefully someone will remember it and post details.
IIRC, you run the program through once, and the kernel stores all the priveleged calls in the policy file. This defines the set of allowed operations. During subsequent runs, the kernel checks this file to see if each priveleged operation is allowed.
Uh, `leaving things to the market' has lead to this situation: within a few months I will not be able to buy a consumer-level IDE drive with a warranty > one year.
The french TGV (the fastest - 515 km/h that's 320 miles per hour) the track, it's a smoooooth gentle nicely laid ribbon of steel, designed to be travelled at speeds up to 250 miles per hour.
Er...sounds like hitch hiking is the safest way to get around France:-)
Slashdot Mirror
> > at 0.99999999996c, you can cross the galaxy in > > 12 years of your own time
> Umm - the Milky Way galaxy is 150,000 light years > across. [Pause] Oh shit! You are from the Milky
> Way, right?
Uh, time dilation.
I think the idea is this: for short journeys, you accelerate until you're half way there, then you turn the ship around and decelerate. This has the added advantage of providing you with some sort of gravity (how much depends on your acceleration) for the duration of trip (aside from when you're flipping over). For longer trips, you'll accelerate until you're cruising along nicely, then turn the engines off. You'll have to flip over and decelerate for the same amount of time you spent accelerating tho...
You very quickly pile up speed too. If you accelerate at 1g for a year, you get rather close to c. If you ever want to return home tho, you'll have to be careful: at 0.99999999996c, you can cross the galaxy in 12 years of your own time, but 113 000 years will pass for us back here.
Firstly, you are aware of the difference between nuclear rockets and anti-matter propulsion, right? Nuclear rockets are basically nuclear reactors with their outputs attached to rocket engines instead of turbines.
Anti-matter drives are not going to be used inside the atmosphere. Using any sort of nuclear rocket inside the atmosphere is retarded. How safe do you want it to be? What are the consequences of a rocket full of uranium exploding over a populated area? Anyhow, chemical boosters work fine (and could work even better if people put their mind to it) for getting stuff into orbit. Getting stuff into orbit is a political problem these days, not so much a technical one.
Moving things around in inter-planetary space is another story. There's all sorts of cool methods: ion rockets, nuclear rockets and laser/solar sails.
Anti-matter propulsion canes all of these tho for energy density; you're getting down into the guts of physics here. No more `let's make this hydrogen and oxygen go boom!' engines, nor `let's use this decaying uranium to heat up some water! w00t!' engines, you're getting matter to convert directly and completely into energy.
So, yeah, no one's going to use nuclear rockets, nor anti-matter rockets inside the atmosphere. Long term, anti-matter looks to be the way to go; it's got the energy density we need and it ain't going to be expensive forever.
Hehe, I'd certainly hope so. The point of using anti-matter for propulsion is the enormous energy density, no energy efficency.
Getting around in space is hard. It takes piles of energy to get to a reasonable speed (especially if you want to get anywhere outside the solar system). The problem isn't the lack of energy around. How many gazillions of joules do you think the sun pumps out each second? The problem is concentrating it and putting it to use. Say we set up an anti-matter factory in space. Nothing too fancy, just a huge solar array, an accelerator and the magnetic trapping stuff needed to stop the whole thing annihilating itself. Leave it there for a few years, patiently producing anti-protons from the sunlight and inter-planetary gas. Want to go visit Alpha Centauri? Cruise up and pick up a blob of anti-matter from the factory. You could instead build huge solar panels on your ship and use an ion drive or something, but the anti-matter route means that you just need to carry a small amount of fuel, instead of huge amounts of machinary to generate it.
It's just like ecosystems: plants concentrate solar energy, animals eat them, then I eat the animals. It's not particularily efficent, but it concentrates the energy into easy to use packages (a.k.a. steaks) and lets me spend more time wiping out species for sport and less time hunting for food:/
I don't think cost is going to be a long-term problem. Once we get a bit better at making it, we could just build a giant-ass accelerator in space, with a huge solar array pointing at the sun. It can sit up there for years, patiently using sunlight to amass anti-protons. It doesn't cost squat once it's up there, and the immense usefullness of it would repay any initial investment a thousand times over.
The US government relaxed crypto export laws a bit last year. IIRC, you can export open source software with strong crypto if you report it some government agency. Debian's solution for getting crypto into the main distribution is to have the archive software automatically email the export control agency when a new package is uploaded.
X installation has always been a bitch for me irregardless of the distribution Linux or BSD. It seems that it's something that always needs tinkering. I did get this going fairly quick after some help from my BSD admin guru--thank the Gods for buddies!
:S
Little known fact: if you install mdetect, discover and read-edid before X, then it will automatically detect your monitor your video card and your mouse. It's documented in the install docs somewhere...
I still don't have sound working, but I haven't given it the one two punch!
Have you added yourself to the `audio' group? That's one of the most common issues people seem to have on IRC.
I probably haven't looked in the right place or good documentation doesn't exist. And I'm lazy?
apm worked fine for me out of the box. apt-get install apmd.
Let's face it, I think that once most people get their configuration working they don't think about giving back to the community. Something that should definately be reconsidered.
Have a look at both Debian QuickReference and the NewbieDoc guides. I've heard good things about them.
Aggravating. I don't want to sit and select then download and install 200M of software after I get it installed, but I DO want an easy way to get back to package management once I hastily exit out if it. I want my cake and I want to eat it too.
Then quit from dselect and let it install just the base system. If you want to add packages later, then run aptitude or dselect. Easy.
Kangaroo and rats? WTF? Have any Americans every actually seen a kangaroo?
Don't you guys know anything? They're big and friendly, and they bounce up and down the main street of any major city here in Australia. If you give them a carrot, you can ride in their pouch.
a simple back-of-the-envelope calculation tells us that it has to be at least 8 times as fast as the current devices
You needed an envelope to calculate 8x=8x? Geez, schools these days. Back in my day...:)
Public domain != GPL. If there was no copyright, then I could sell you my new fandoozy version of Emacs, and refuse to give you the source. The GPL, depending on your point of view, thus gives you more rights than even a copyright-free society would give you.
I would argue that the only way of acheiving this is to have Free software from the firmware level up. I would trust thousands of geeks with nothing to gain by screwing me, over MS, with everything to gain from locking up the world, anyday of the week.
I tried to reply, but the lameness filter hates me.
Found it!
The story is called `Learning to be me', by Greg Egan. I read it in an anthology called MetaWorlds, but you can find it in his collection called Axiomatic.
Certainly well worth a read, if you can find it.
Nope, neither of those. It was a short story in an anthology of Australian science fiction, and it had a giant flying platypus on the cover, IIRC.
ALSA is defintely in, as is things like USB2, Access Control Lists, new NTFS support (it doesn't completely trash partitions now!), hot pluggable CPUs, software suspend (hit a key combo and save the whole system state to the harddrive), support for drives >2TB, and a whole lot more.
BTW, I have to love a community where this sort of thing is discussed on a site called KernelNewbies:)
I read this great science fiction story by some Australian guy (can't remember who or when) that went something like this:
In the future, everyone has a `jewel' implanted in their brain at birth. It's an optical computer that receives all your sensory data, then tries to replicate the external results of your brain activity. When you're young, it's way off, but it trains itself to match the responses of your real brain. One day, in your thirties, when your real brain is going down hill, you go to the hospital. They hook you up to another computer that keeps an eye on how well the outputs of the jewel match the outputs of your organic brain. If they match up, then they scrape out your meatware, and replace it with non-sentient tissue that consumes just as much blood, glucose, etc as your original brain, and can produce hormones for the rest of your body, while hooking up the jewel to the rest of your body. At that point, `you' are the jewel.
The cool part of this is that there's no discontinuity between `me' and `it'; the jewel will think the same thoughts as me, it will be me; in fact, it will even worry about dying when the organic brain is killed, since it thinks it is the original.
The ending was quite a cool twist, which I won't spoil here. It was a really good story tho, hopefully someone will remember it and post details.
Tips for all the people churning out crappy PDFs from LaTeX: here
pay the director to wave his right for his movie
Er, `wave his rights' is what he would do when his rights drive away in the back of a van, on a trip to the beach for a day.
'waive his rights', on the other hand, is what the people of the world do when governments start ranting about terrorists.
This post is the best reason for increasing the mod cap up from 5 that I have seen in years.
It's one of those things you never believe until it happens to you. This machine right here is a testament to me ignoring good advice.
The standard IP stack implementations reserve port numbers under 1000 for these well-known services
Uh, 1024, of course. 2^10, after all.
IIRC, you run the program through once, and the kernel stores all the priveleged calls in the policy file. This defines the set of allowed operations. During subsequent runs, the kernel checks this file to see if each priveleged operation is allowed.
Uh, `leaving things to the market' has lead to this situation: within a few months I will not be able to buy a consumer-level IDE drive with a warranty > one year.
Yah for the free market!
Put it in your prefs.js file instead. Moz will leave it alone.
The french TGV (the fastest - 515 km/h that's 320 miles per hour)
the track, it's a smoooooth gentle nicely laid ribbon of steel, designed to be travelled at speeds up to 250 miles per hour.
Er...sounds like hitch hiking is the safest way to get around France:-)