IIRC the centre of mass of the earth-moon system is inside the earth, but not near the centre of the earth. It's pretty easy to calculate it if you have the masses and radii of the earth and moon to hand.
The real problem with using a nuclear reactor to power a vehicle is shielding. The nuclear reactions produce an extremely high flux of dangerous (lethal) neutrons and gamma rays. This is OK in a power station because you have pleny of room to build thick concrete walls and to line your reactor with thick steel. You can also do this on large submarines and surface ships. In something like a car, train or aeroplance, it's just not do-able.
The Americans actually built a nuclear powered aeroplane back in the 1950s. It was enormous and had to be flown over uninhabited ground because they couldn't put enough shielding around the reactor due to size and weight constraints.
This is wonderful news for China, the environment and nuclear scientists and engineers the world over.
China is showing that it is forward-thinking enough to look beyond fossil fuels for its electricity. This can only be good for the environment and global warming in particular.
I hope this reopens the nuclear power debate in the West. The USA and Europe should seriously consider comitting to new nuclear power plants for both economic and environmental reasons.
HP doesn't view itanium and opteron as an either/or proposition. Given their product porfolio, it's quite reasonable to use both. Itanium is fast and expensive, a good fit for a 128-way superdome.
itanium does OK on one or two specific benchmarks, but most people view it as an expensive turkey judging by the lack of sales.
Now, what they should have done was to abandon itanic when they got Alpha from DEC via Compaq and continue to develop that. It's been sad over the years watching HP commit suicide.
Or by someone who wants to eliminate your liberal vote, by claiming that you should waste your vote by giving it to someone that can't beat Bush.
This is the kind of simplistic reasoning that holds back political and societal progress.
I'm not American, but I hope you lot vote in a more clue-up president next time.
Suffice to say, they way I vote here in the UK is my own business, but if I used your logic I'd just be like the other millions of sheep who vote either Labour or Conservative.
Sometimes, a vote for another party with a differing point of view is worth it, whether that party is likely to win over-all or not. You see, by getting votes, they get to have their voice heard, and so have influence in the political debate, keeping the influx of new ideas going. This is especially valuable in the Western world today when many of the main politcal parties have converged on to some sort of conservative, introverted, stagnant mire of backwards-looking paranoia and ignorance.
They're not liberals, they're Communists. Big difference. However, you can't explain that to most Americans here because they've been so brainwashed by their own "education" system and mass media. And I should really stop arguing with Anonymous Cowards.
Not the dreaded "Windows Mainframe?" Is that the 32-way box that no one at all bought? The one that they only managed to get installed in one site (Abbey National)? Wasn't it an unmittigated disaster?
We all know that physically, x86 (intel to be specific) processors can be made to work together in greather that 4-way configurations (just roll your own glue logic), but the actual performance of such systems does not scale even remotely linearly with the number of processors. Programming the damned things for SMP isn't straight-forward at all past 4 or 8 processors (I forget the precise number).
I would submit that there aren't too many applications that require more CPU cycles than 4x 3-Ghz Xeons can spin, even with less than perfect efficiency--let's say in the neighborhood of %60-%80, which fits with my own experiences on Quad-Xeon boxes going back about two years.
You go on to say:
So for 99% of the world's problems, why do you need more than 4-way systems?
You fall into the same old trap as everone before you, namely "one size fits all."
I am old enough to remember wen 16-bit machines were giving way to 32-bit machines. I also remember when single-processor machines weren't going to be fast enough.
Well, 64-bit machines have been available (at the workstation level) for a decade now, and I can assure you that large multiprocessor machines are still very much in demand.
You see, the thing is, as hardware increases in power, peoples' demands of that hardware increases. There is always the demand for more power. That's what fuels competition and development.
Your 4-way Xeon may be good enough for you and 98 of your buddies, but I still need by 16-way 64-bit RISC SMP server. Yes, cost goes up, but for an awful lot of people, that cost is justified. You low-end people ultimiately win too as these technologies trickle downwards eventually. You just may have to wait 5 or 10 years.
So do I really care what the CPU in this box is, or how textbook perfect its architecture is? It's pretty much irrelevant.
To the low-end consumer, yes, it is pretty irrlelevant. But to the rest of us, how we got to where we are today is relevant, and especially when we look to the future, and when consumer-grade isn't enough. That is why we need to be aware of our CPU history and need to be aware of the options available to us when a 4-way Dell or HP 32-bit Xeon just doesn't cut the mustard - and why.
The biggest advantage of using x86 systems over anything else isn't that they're the fastest chips, cycle-for-cycle, or that they're a particularly elegant solution. It's that they're CHEAP and FAST ENOUGH.
Thanks to the ruthless intel vs. AMD competition of the last half decade, that is now the case, but it didn't used to be.
Back in the early '90s when the 64-bit RISC architectures were coming out, x86 was a joke. Now, Opteron is more or less a DEC Alpha with an x86 translation unit slapped on top and hypertransport, which made its way down from Cray, via the Sun E10k to the desktop.
If it hadn't been for these radical RISC architectures, and the intel vs. AMD fight, things would be very different.
Don't even think about multi-processor Xeon systems. The primitive bus architecture and interprocessor communications simply does not scale well at all past 2 processors. You can just about get away with 4 processors, but after that, you might as well just put space heaters in the box.
Slashdot Mirror
Because intel didn't invent it?
IIRC the centre of mass of the earth-moon system is inside the earth, but not near the centre of the earth. It's pretty easy to calculate it if you have the masses and radii of the earth and moon to hand.
This is the Central Scruitinizer speaking. Please have a doughnut and stick to Church-based social activities in future.
To all intents and puropses, it is.
The Americans actually built a nuclear powered aeroplane back in the 1950s. It was enormous and had to be flown over uninhabited ground because they couldn't put enough shielding around the reactor due to size and weight constraints.
You, sir, have a clue. I fear that means you will not be modded up.
Very witty I'm sure young man.
Nuclear waste is isolated from the environment, unlike the waste from fossil fuel power plants.
The boys responsible were caught and brought to justice and the tabloids got their hysteria. Jamie is still dead though.
China is showing that it is forward-thinking enough to look beyond fossil fuels for its electricity. This can only be good for the environment and global warming in particular.
I hope this reopens the nuclear power debate in the West. The USA and Europe should seriously consider comitting to new nuclear power plants for both economic and environmental reasons.
There was snow in Aberdeenshire in July.
itanium does OK on one or two specific benchmarks, but most people view it as an expensive turkey judging by the lack of sales.
Now, what they should have done was to abandon itanic when they got Alpha from DEC via Compaq and continue to develop that. It's been sad over the years watching HP commit suicide.
True, but compared to everything else of note on the market (and stuff available gratis) it still stinks.
No, this should be exposed and derided for what it is: the Emperor's New Clothes.
Microsoft is a corporation, not a fan club or a charity. It does not require our sycophancy in any way shape or form.
Like all large, powerful entities, it needs an enquiring Press, skepticism and competition to keep it in check.
There was me thinking that the Internet was designed from the outset to be resilient to attacks. Excuse me while I LART myself...
Perhaps it's targetted at Young Republicans and the Abstainers etc.?
This is the kind of simplistic reasoning that holds back political and societal progress.
I'm not American, but I hope you lot vote in a more clue-up president next time.
Suffice to say, they way I vote here in the UK is my own business, but if I used your logic I'd just be like the other millions of sheep who vote either Labour or Conservative.
Sometimes, a vote for another party with a differing point of view is worth it, whether that party is likely to win over-all or not. You see, by getting votes, they get to have their voice heard, and so have influence in the political debate, keeping the influx of new ideas going. This is especially valuable in the Western world today when many of the main politcal parties have converged on to some sort of conservative, introverted, stagnant mire of backwards-looking paranoia and ignorance.
They're not liberals, they're Communists. Big difference. However, you can't explain that to most Americans here because they've been so brainwashed by their own "education" system and mass media. And I should really stop arguing with Anonymous Cowards.
Traditionally, liberals have not been proponents of Eugenics.
So how long before the Conservatives discover that lefties have "defective brains" and start genetically-engineering them out of the population? :-)
Three dudes doesn't count. It has to involve at least two females. :-)
Tell us something we don't already know :-)
We all know that physically, x86 (intel to be specific) processors can be made to work together in greather that 4-way configurations (just roll your own glue logic), but the actual performance of such systems does not scale even remotely linearly with the number of processors. Programming the damned things for SMP isn't straight-forward at all past 4 or 8 processors (I forget the precise number).
You go on to say:
So for 99% of the world's problems, why do you need more than 4-way systems?
You fall into the same old trap as everone before you, namely "one size fits all."
I am old enough to remember wen 16-bit machines were giving way to 32-bit machines. I also remember when single-processor machines weren't going to be fast enough.
Well, 64-bit machines have been available (at the workstation level) for a decade now, and I can assure you that large multiprocessor machines are still very much in demand.
You see, the thing is, as hardware increases in power, peoples' demands of that hardware increases. There is always the demand for more power. That's what fuels competition and development.
Your 4-way Xeon may be good enough for you and 98 of your buddies, but I still need by 16-way 64-bit RISC SMP server. Yes, cost goes up, but for an awful lot of people, that cost is justified. You low-end people ultimiately win too as these technologies trickle downwards eventually. You just may have to wait 5 or 10 years.
To the low-end consumer, yes, it is pretty irrlelevant. But to the rest of us, how we got to where we are today is relevant, and especially when we look to the future, and when consumer-grade isn't enough. That is why we need to be aware of our CPU history and need to be aware of the options available to us when a 4-way Dell or HP 32-bit Xeon just doesn't cut the mustard - and why.
Thanks to the ruthless intel vs. AMD competition of the last half decade, that is now the case, but it didn't used to be.
Back in the early '90s when the 64-bit RISC architectures were coming out, x86 was a joke. Now, Opteron is more or less a DEC Alpha with an x86 translation unit slapped on top and hypertransport, which made its way down from Cray, via the Sun E10k to the desktop.
If it hadn't been for these radical RISC architectures, and the intel vs. AMD fight, things would be very different.
Don't even think about multi-processor Xeon systems. The primitive bus architecture and interprocessor communications simply does not scale well at all past 2 processors. You can just about get away with 4 processors, but after that, you might as well just put space heaters in the box.