What makes anyone think that a manned mission of such unprecendented length will go off without a hitch?
Mir. If the Russians can manage to keep people alive for months at a time with their inadequate budgets, why can't a Mars ship? I don't doubt there are considerable problems, but I can't see that the life-support issues are the intractable ones.
Surely a ship can be assembled in earth orbit.
Assembling things in orbit is an extremely slow and expensive proposition. It's much easier to screw bits together on Earth, where you can just get a technician to hit things with a hammer if they won't fit together:)
Seriously, having to design things to screw together in orbit adds significantly to the cost and complexity - though I suppose that the US, Europe and Russia are spending $60 billion or so to make their mistakes with the ISS.
Lots of redundency. We can't, for example rely on having a single ship (fueled by one of these proposed fuel `factories') at the other end ready to come back. It is too large a single point of failure. We'll need to send at least two of everything and three of some things.
As soon as the crew launches, you have a single point of failure - what if the shuttle/launch vehicle blows up? Seriously though, it might be a good idea to do that. Why not put the Earth Return Vehicles a couple of hundred kilometres apart, and equip the lander with a couple of cars with enough range to travel to either one? That way, you get the redundancy, and an extra bonus of another base you can use for exploration purposes.
Propulsion. It'll need to be done as quickly as possible, which means propulsion. This in turn means Nuclear (either directly or more likely powering a plasma drive or something).
As I understand it, the way the orbital mechanics work out, you can't do much better than a 180-day trip, regardless of the power source, until you can get something that can maintain a continuous acceleration for the whole trip (which would require fusion power or something similarly exotic). Of course, if you can do that, the whole gravity question becomes irrelevant:)
Finally, food? Are you serious? Ever heard of that remarkably complex technology known as "the freezer"? Ever seen the freeze-dried food bushwalkers eat (devised during the Apollo program, if I recall correctly)? Sure, they'll take along a few seeds to see whether the can make them grow in the Mars "soil", but they'll definitely be bringing their food with them using a combination of 19th-century and 1960's technology.
Compared with the difficulty of 100% reliably intercepting ICBM's with another missile, Mars is easy. The greatest problem, in my view, is one you *haven't* touched on, the risk of a solar storm.
Get some perspective, please. European settlement of Australia was performed, in the beginning, by a bunch of second-rate soldiers, and (mostly) petty criminals, who were cooped up in hugely overcrowded cabins for six months, with terrible food and not that much water, to be dumped in a location as isolated as Mars was at the time, for the rest of their lives. They survived, set up a society, and after a long struggle the colony survived and prospered, becoming self-sufficent in all basic needs. Exploration trips were routinely conducted , often by relatively small parties away for months at a time - the exploration of Australia's south-eastern coast was performed in a boat little bigger than a modern sailing dinghy.
Compare that to the slightly cramped, but well-equipped communcation-and-entertainment-equipment-laden (oh dear, it might take as much as *twenty minutes or so* for email to get through . ..) Mars explorer of the future, with a highly-trained and motivated crew knowing that immortality and fortune awaits on their return to Earth.
Draw your own conclusions.
Unfortunately, I don't know whether it's possible to do hard sci-fi on TV. It's only been done on film a few times (2001, Contact, Metropolis, a couple of 50's classics that somehow sneaked in between the shlock). Aside from the fact that getting the science right often gets in the way of a good story (realistic orbital mechanics and and photogenic space combat don't go particularly well together), the audience that could potentially understand and appreciate the difference between it and Star Trek is pretty bloody small.
I very much doubt those programs that run on the graphics card are ever going to work on anything but Nvidia chipsets. If games start to use them( and it appears the effects possible with it are really something) doesn't that create the same
lock on the game hardware market that 3DFX had with Glide?
I used them so that students could teach each other.
But what if you've got students who are not only weak, but are only in the course to get the subject points and only want a bare pass? Inflicting this kind of person on people who are either a) very strong in the subject, or b) not so inherently strong but are working very hard, is an unfair burden.
As a TA, I dealt with situations like this all the time. The subject was the second semester of CS, and taken by a lot of engineers who couldn't code to save themselves. The pain and suffering they put their group partners through convinced the department that group projects were *not* a good idea until later on in the course.
If anybody has or knows where to locate an archive of this magazine, it should be possible to add a bunch of Australian listings.
Actually, it wasn't a bad read - it had fairly eclectic columns on things like the Forth language and the like, and it was written by obvious computer enthusiasts rather than journos turning their hand to something they had no affinity with.
I'm unaware of the situation in the US, but one of my old lecturers was involved in a fascinating case that provides much of the software copyright case law here in Australia.
IIRC, the proprietary software company concerned copy-protected its software with a parallel-port dongle. Some bright young hacker monitored the parallel port and figured out that if a certain sequence was sent to the dongle, a 128-bit sequence was sent back. He developed a small device which would do the same, and sold it for $500 - appoximately 1/10th the cost of the software.
Now, as it turned out, that sequence of bits was generated as the output of a small collection of flip-flops and the like on a custom chip - it was hardware. However, the software that checked the dongle stored the sequence directly. The hacker's device also stored the sequence directly as software.
And, after several appeals, the crux of the matter turned out to be that the arrangement of flip-flops and the like could be legitimately reverse-engineered, so if the hacker had have simply wired up some transistors that would have been legal. However, because the device contained the bit sequence - which was a piece of a copyrighted software program - the device was ruled to be infringing copyright law. So, at least in Australia, 16 bytes is enough to infringe copyright.
Whether that would extend to a 40-bit DVD key is, of course, open to question, but it would have been very interesting as to how Jon Johansen and his unknown colleagues would have fared in front of an Australian court . . .:)
After all that (and several other fascinating court cases as a technical expert), it was interesting that my lecturer took the view that software IP laws are a disaster area.
If that's what you wanted, that's great. I'm glad you use the BSD license for your code. However, I have had BSD license advocates suggest that the GPL is unnecessary, because people will always contribute back their improvements as free software anyway, without the compulsion provided by the GPL. That's BS, and this is an example.
So, no, Apple are not doing anything wrong, but I wouldn't want them using the code I write in that manner. Hence the GPL/LGPL suits me fine in most circumstances.
To pull this off, I would think that they are going to rely on favourable wind conditions. With a maximum airspeed of 45 mph, even a 15-knot headwind (which not much more than a breeze, particularly at 2000 feet on the open ocean) halves their ground speed and thus halves their range.
IIRC, there is a prevailing wind that should ensure them a good chance of tailwinds for this trip - the same prevailing winds that people use for Atlantic balloon crossings.
From my undergraduate-level compiler design course (which every CS person should take, IMHO), there are many problems in optimizing compilers that are NP-complete. For instance, the favoured method of allocating variables to registers is NP-hard for exact answers, but a heuristic is used that works very well, provided you have more than about 16 registers (one of the main reasons why modern architectures all have 32 or more registers).
Anyway, there is no such thing as the "perfect optimizing compiler". To be verifiably optimal, as well as knowing everything there is to know about the machine's internal architecture, it would have to have complete knowledge about the dataset that the program to be compiled is to be run on - if that is not available, if there is a tradeoff to be made the compiler has to make a choice that will be suboptimal
To take a simple example, the compiler might choose functions to be placed in a certain order in the object file so that functions called repeatedly in sequence can all fit in the cache at once. Running the program with a different dataset could produce different call patterns, and thus the optimal layout of functions in the object file might be different.
So, your program, and any non-trivial program, could only ever be truly "optimized" for one input dataset. Anything else is a compromise.
It's because the Australian government makes a lot of money through auctioning off bits of the radio spectrum, so they like to create an artificial scarcity of it to bump up the price.
However, the assumption that the masses will all start listening to "quality" - whatever that is - if exposed to it is just crap. From all that we've heard, the overwhelming majority of Napster users just want their Britney Spears and Offspring MP3's.
However, that still doesn't alter the fact that many more frequencies could and should be made available, so that if you want a station that specialises in, say, 60's Motown, or big band music, or whatever's getting played in the edgier local pubs, you can find one.
Yes, published papers tend to be reasonably well-written and logically constructed. Notwithstanding the gifts of the people that write them, there is a very good reason why that's the case, though - time and effort. A scientific paper takes many times longer to write, per word, than a slashdot comment.
Additionally, even before they enter the formal peer review process, if the research is collaborative everybody who is listed as an author will have contributed to improving the paper, which picks up many errors and help ensure clarity of expression.
Not to mention the routine practice in *some* Muslim countries of mutilating women's genitals in such a way as to make it impossible to obtain any physical pleasure from sex. Or the practice of marrying girls off at ridiculously young ages.
Go you big red fire engine!
Plenty of targets already available
on
First Arcology?
·
· Score: 4
I used to live near a large dam. If somebody took made a sufficiently large hole, it would have taken approximately 5 minutes for the water to flood much of a town of about 70,000 people. The floods could then potentially devastate many, many communities along Australia's only significant inland waterway, and cut the water supply of Adelaide (a city of ~1 million people) in half until the dam could be repaired.
If terrorists want to kill thousands of people and wreak havoc, it's not all that hard. My guess is the only thing that stops it is that, as well as the efforts of the intelligence services, is those with the brains to plan such a thing realize that it's not not a particularly productive tactic.
Go you big red fire engine!
Home reactors ain't gunna happen
on
Fission in a Box
·
· Score: 2
for the obvious reason - if you're selling enriched uranium at the friendly local corner store, you've just made life a heck of a lot easier for your friendly local terrorists to build a nuclear weapon. Yes, I am aware that there's more to it than that (for instance, you need an enrichment plant to produce near-pure U235, quite a bit of knowledge about conventional explosives to trigger it, particularly if you're going to use an implosion design, etc. etc. etc.), but having a supply of uranium is a necessary prerequisite, and it's something that is currently at least somewhat difficult to obtain.
Go you big red fire engine!
Russia seems to be going back to totalitarianism
on
User-friendly Freenet
·
· Score: 2
I dunno whether people have noticed, but the Russian government is busy shutting down all of Russia's independent media at the moment, mainly by getting state-owned enterprises to buy it. So, yes, Russians are going to be in need of independent ways of sharing information shortly. Whether Freenet really meets those needs is unclear at best (if you're a totalitarian government, make posessing Freenet-type software a criminal offence and enforce compulsory government software audits for all computers), but they sure need it.
However, what's really interesting is that the Russian people seem to be quite happy to let this happen at the moment. Maybe their memories are either shorter or more selective than we might think.
Could somebody correct me if I'm wrong here, but as I understand it we *can't* meet our existing, let alone projected, energy needs with our known uranium reserves, for more than 30-40 years.
The only way to sustainably use fission is to make plutonium in breeder reactors and then use that, isn't it? Additionally, isn't plutonium about the nastiest stuff you can ever deal with?
Go you big red fire engine!
Re:Great Movie, maybe not for Americans
on
Review: The Dish
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· Score: 1
Cease and decist all Paul Hogan exports or face the consequences. You have been warned.
Well, it seems that America doesn't like him, Australia doesn't like him very much (he reminds us just how dorky Australia was back in the 1970's), there's only one thing to do . . .
Send him to Britain to join Clive James and Rolf Harris. Better still, we'll have Clive James back if they'll take Hoges off our hands . . .
Go you big red fire engine!
If you like this, you'll love . . .
on
Virtual Skydive
·
· Score: 2
Powers of Ten, a short film made in 1968 that does a zoom all the way from the edges of the known universe to individual atoms.
What's really interesting is that the film, made by Ray Eames, was originally commissioned by IBM! Fancy that - IBM, the world's least exciting technology monolith (no pun intended) produces one of the best science films, and best short films, ever made . . .:)
BTW, we already make internal combustion engines almost that small - model aircraft engines are tiny. These things are undoubtedly smaller and simpler again, and I can think of a large variety of applications, but . . .
How do you dissipate the heat? Laptops already have heat problems.
Won't the exhaust fumes smell kinda bad - not to mention be a safety risk in enclosed environments?
What's the total mass when you throw in a generator?
How much would a model big enough to power a laptop weigh?
How much space and weight does the total system (generator, engine, and fuel) take up?
This might be a goer in certain applications (a portable drill, particularly if combined with a small high-current battery or capacitor, for instance), but I can't see it replacing a laptop battery. A micro-sized fuel cell might be a different story, though:)
What's really needed is for someone to fix or denigrate Java so that applets never crash in runing states.
What's the difference between a Java applet stuck in a non-terminating loop chewing CPU, and one that's, say, searching the key space for a distributed code-cracking problem? As far as the Java runtime environment, nothing that it can identify.
If I understand you correctly, the problem that you are suggesting that Java should solve is a variant of the halting problem, which is practically undecidable (it's theoretically possible for storage-limited machines, but not in any practical sense). In other words, it can't be done.
Java can be faulted for many things, but this doesn't appear to be one of them.
Just remember, these cameras are not used to spy, and never will be. They are used by the police, who are famous around the world for fairness and correct, brotherly behaviour.
Perhaps you need to read Geoffery Robertson's The Justice Game. This guy is perhaps Britain's most well-known lawyer (and perhaps the world's most famous human-rights lawyer) and is certainly not a crackpot, and check the scant respect the police held for human rights (or fair trials) at times throughout his career.
However, you're probably not interested because you're trolling. Unfriendly to business interests, my arse! Perhaps you should explain that to Bernie Eccelstone when he donated millions to Labour and just by coincidence restrictions of tobacco sponsorship of Formula One teams were delayed.
In any case, why do you bother trolling Yanks about socialism? It's not even fun anymore, it's like shooting cows in a paddock, something you Poms should be getting pretty expert in by now . . .
GNU stow - manages your/usr/local hierachy with ease.
You install your programs into/usr/local/stow/foo/*, and then from/usr/local/stow type stow foo, which then creates symlinks into the/usr/local hierachy. To remove the symlinks, simply cd/usr/local/stow and stow --delete foo, and then you can safely remove/usr/local/stow/foo.
Slashdot Mirror
Yeah. I bought a special hole-puncher just for the job. worked a treat :)
Go you big red fire engine!
Mir. If the Russians can manage to keep people alive for months at a time with their inadequate budgets, why can't a Mars ship? I don't doubt there are considerable problems, but I can't see that the life-support issues are the intractable ones.
Assembling things in orbit is an extremely slow and expensive proposition. It's much easier to screw bits together on Earth, where you can just get a technician to hit things with a hammer if they won't fit together :)
Seriously, having to design things to screw together in orbit adds significantly to the cost and complexity - though I suppose that the US, Europe and Russia are spending $60 billion or so to make their mistakes with the ISS.
As soon as the crew launches, you have a single point of failure - what if the shuttle/launch vehicle blows up? Seriously though, it might be a good idea to do that. Why not put the Earth Return Vehicles a couple of hundred kilometres apart, and equip the lander with a couple of cars with enough range to travel to either one? That way, you get the redundancy, and an extra bonus of another base you can use for exploration purposes.
As I understand it, the way the orbital mechanics work out, you can't do much better than a 180-day trip, regardless of the power source, until you can get something that can maintain a continuous acceleration for the whole trip (which would require fusion power or something similarly exotic). Of course, if you can do that, the whole gravity question becomes irrelevant :)
Finally, food? Are you serious? Ever heard of that remarkably complex technology known as "the freezer"? Ever seen the freeze-dried food bushwalkers eat (devised during the Apollo program, if I recall correctly)? Sure, they'll take along a few seeds to see whether the can make them grow in the Mars "soil", but they'll definitely be bringing their food with them using a combination of 19th-century and 1960's technology.
Compared with the difficulty of 100% reliably intercepting ICBM's with another missile, Mars is easy. The greatest problem, in my view, is one you *haven't* touched on, the risk of a solar storm.
Go you big red fire engine!
Compare that to the slightly cramped, but well-equipped communcation-and-entertainment-equipment-laden (oh dear, it might take as much as *twenty minutes or so* for email to get through . . .) Mars explorer of the future, with a highly-trained and motivated crew knowing that immortality and fortune awaits on their return to Earth.
Draw your own conclusions.
Go you big red fire engine!
Unfortunately, I don't know whether it's possible to do hard sci-fi on TV. It's only been done on film a few times (2001, Contact, Metropolis, a couple of 50's classics that somehow sneaked in between the shlock). Aside from the fact that getting the science right often gets in the way of a good story (realistic orbital mechanics and and photogenic space combat don't go particularly well together), the audience that could potentially understand and appreciate the difference between it and Star Trek is pretty bloody small.
Go you big red fire engine!
Doesn't that worry you just a bit?
Go you big red fire engine!
But what if you've got students who are not only weak, but are only in the course to get the subject points and only want a bare pass? Inflicting this kind of person on people who are either a) very strong in the subject, or b) not so inherently strong but are working very hard, is an unfair burden.
As a TA, I dealt with situations like this all the time. The subject was the second semester of CS, and taken by a lot of engineers who couldn't code to save themselves. The pain and suffering they put their group partners through convinced the department that group projects were *not* a good idea until later on in the course.
Go you big red fire engine!
The reference is wrong. According to this page, both British and Australian computers had been used for playing music at least six years previously.
The music of CSIRAC, the first Australian computer, has recently been recreated using an emulator and rebuilt hardware, and a CD has been released.
Go you big red fire engine!
Actually, it wasn't a bad read - it had fairly eclectic columns on things like the Forth language and the like, and it was written by obvious computer enthusiasts rather than journos turning their hand to something they had no affinity with.
Go you big red fire engine!
IIRC, the proprietary software company concerned copy-protected its software with a parallel-port dongle. Some bright young hacker monitored the parallel port and figured out that if a certain sequence was sent to the dongle, a 128-bit sequence was sent back. He developed a small device which would do the same, and sold it for $500 - appoximately 1/10th the cost of the software.
Now, as it turned out, that sequence of bits was generated as the output of a small collection of flip-flops and the like on a custom chip - it was hardware. However, the software that checked the dongle stored the sequence directly. The hacker's device also stored the sequence directly as software.
And, after several appeals, the crux of the matter turned out to be that the arrangement of flip-flops and the like could be legitimately reverse-engineered, so if the hacker had have simply wired up some transistors that would have been legal. However, because the device contained the bit sequence - which was a piece of a copyrighted software program - the device was ruled to be infringing copyright law. So, at least in Australia, 16 bytes is enough to infringe copyright.
Whether that would extend to a 40-bit DVD key is, of course, open to question, but it would have been very interesting as to how Jon Johansen and his unknown colleagues would have fared in front of an Australian court . . . :)
After all that (and several other fascinating court cases as a technical expert), it was interesting that my lecturer took the view that software IP laws are a disaster area.
Go you big red fire engine!
So, no, Apple are not doing anything wrong, but I wouldn't want them using the code I write in that manner. Hence the GPL/LGPL suits me fine in most circumstances.
Go you big red fire engine!
IIRC, there is a prevailing wind that should ensure them a good chance of tailwinds for this trip - the same prevailing winds that people use for Atlantic balloon crossings.
Go you big red fire engine!
Anyway, there is no such thing as the "perfect optimizing compiler". To be verifiably optimal, as well as knowing everything there is to know about the machine's internal architecture, it would have to have complete knowledge about the dataset that the program to be compiled is to be run on - if that is not available, if there is a tradeoff to be made the compiler has to make a choice that will be suboptimal
To take a simple example, the compiler might choose functions to be placed in a certain order in the object file so that functions called repeatedly in sequence can all fit in the cache at once. Running the program with a different dataset could produce different call patterns, and thus the optimal layout of functions in the object file might be different.
So, your program, and any non-trivial program, could only ever be truly "optimized" for one input dataset. Anything else is a compromise.
Go you big red fire engine!
However, the assumption that the masses will all start listening to "quality" - whatever that is - if exposed to it is just crap. From all that we've heard, the overwhelming majority of Napster users just want their Britney Spears and Offspring MP3's.
However, that still doesn't alter the fact that many more frequencies could and should be made available, so that if you want a station that specialises in, say, 60's Motown, or big band music, or whatever's getting played in the edgier local pubs, you can find one.
Go you big red fire engine!
Additionally, even before they enter the formal peer review process, if the research is collaborative everybody who is listed as an author will have contributed to improving the paper, which picks up many errors and help ensure clarity of expression.
Go you big red fire engine!
Not to mention the routine practice in *some* Muslim countries of mutilating women's genitals in such a way as to make it impossible to obtain any physical pleasure from sex. Or the practice of marrying girls off at ridiculously young ages.
Go you big red fire engine!
If terrorists want to kill thousands of people and wreak havoc, it's not all that hard. My guess is the only thing that stops it is that, as well as the efforts of the intelligence services, is those with the brains to plan such a thing realize that it's not not a particularly productive tactic.
Go you big red fire engine!
for the obvious reason - if you're selling enriched uranium at the friendly local corner store, you've just made life a heck of a lot easier for your friendly local terrorists to build a nuclear weapon. Yes, I am aware that there's more to it than that (for instance, you need an enrichment plant to produce near-pure U235, quite a bit of knowledge about conventional explosives to trigger it, particularly if you're going to use an implosion design, etc. etc. etc.), but having a supply of uranium is a necessary prerequisite, and it's something that is currently at least somewhat difficult to obtain.
Go you big red fire engine!
However, what's really interesting is that the Russian people seem to be quite happy to let this happen at the moment. Maybe their memories are either shorter or more selective than we might think.
Go you big red fire engine!
The only way to sustainably use fission is to make plutonium in breeder reactors and then use that, isn't it? Additionally, isn't plutonium about the nastiest stuff you can ever deal with?
Go you big red fire engine!
Send him to Britain to join Clive James and Rolf Harris. Better still, we'll have Clive James back if they'll take Hoges off our hands . . .
Go you big red fire engine!
What's really interesting is that the film, made by Ray Eames, was originally commissioned by IBM! Fancy that - IBM, the world's least exciting technology monolith (no pun intended) produces one of the best science films, and best short films, ever made . . . :)
Go you big red fire engine!
This might be a goer in certain applications (a portable drill, particularly if combined with a small high-current battery or capacitor, for instance), but I can't see it replacing a laptop battery. A micro-sized fuel cell might be a different story, though :)
Go you big red fire engine!
What's the difference between a Java applet stuck in a non-terminating loop chewing CPU, and one that's, say, searching the key space for a distributed code-cracking problem? As far as the Java runtime environment, nothing that it can identify.
If I understand you correctly, the problem that you are suggesting that Java should solve is a variant of the halting problem, which is practically undecidable (it's theoretically possible for storage-limited machines, but not in any practical sense). In other words, it can't be done.
Java can be faulted for many things, but this doesn't appear to be one of them.
Go you big red fire engine!
However, you're probably not interested because you're trolling. Unfriendly to business interests, my arse! Perhaps you should explain that to Bernie Eccelstone when he donated millions to Labour and just by coincidence restrictions of tobacco sponsorship of Formula One teams were delayed.
In any case, why do you bother trolling Yanks about socialism? It's not even fun anymore, it's like shooting cows in a paddock, something you Poms should be getting pretty expert in by now . . .
Go you big red fire engine!
You install your programs into /usr/local/stow/foo/*, and then from /usr/local/stow type stow foo, which then creates symlinks into the /usr/local hierachy. To remove the symlinks, simply cd /usr/local/stow and stow --delete foo, and then you can safely remove /usr/local/stow/foo.
Very simple, very effective.
Go you big red fire engine!