Seems like a black body surface treatment would be better.
Um, why?
Now that I think about it I remember those little evacuated glass bulbs with the a small turnstile with small paddles - one paddle is black and the other is white. When placed in the sun they turn. That should be enough to prove the concept.
No, because these radiometers do not contain a very good vacuum, and that is why they work. The black side heats up, the air nearby expands, and that's what drives the propeller. There's not enough gas in space for that to work.
Won't it only be useful for travel away from the sun?
No, just regular real sail boats can travel upwind.
I think it's even easier in the case of solar sails: all you need to do is angle your mirror 45 degrees to the sun (reflecting the solar wind toward your direction of travel) and gravity will do the work for you. You'll slow down into an elliptical transfer orbit that will take you closer to the sun.
magazines are insanely priced here in Japan. A general purpose one (say, equiv to cosmo) would be 700 yen (think 6 dollars). A specialty one, say an hobby related RC magazine is a whopping 1,800 yen (about 15 dollars)
That's about twice what they cost in the US, right? Does that really qualify as "insanely priced"?
Golf is insanely priced in Japan. Magazines seem fairly reasonable, given the cost of living in Japan in the first place.
In other news, the thousand-man LAN party was a great success last night, as the sole attendee played Quake all by himself. Organizers were delighted with the success of the event.
After rent/mortgage, food, car, and everything else, most people probably have about 20-40 days' worth of disposable income to spend every year. If you want to toss that away one day's worth at a time, be my guest, but don't be surprised if someone finds 1 day's pay to be a significant amount to worry about.
Also, you're talking about end-customers that will be buying just one of these things. But your quote was about Intel (who will sell millions of them) and mobo manufacturers (who will buy millions of them). Now you're talking some fraction of a billion dollars. Is that enough to worry about yet?
Wow, that statement is so ridiculous, I don't even know where to begin.
You armchair computer scientists need to give the researchers just a little credit, and benefit of the doubt, especially if you haven't read the paper.
You're right, equality only works in very restricted circumstances. To say it's "just fine" is a big overstatement.
If you do IEEE 754 math with fractions with power-of-two denominators (like 13/256 + 7/64), and you stay within the mantissa's range, then you'll get exact results, and equality comparison will work. In practical terms, this never happens, so yes, you can't rely on the equality operator.
Maybe it would be nice if FP computations came with built-in error bars, and equality were defined with could-be-equal semantics.
Yep, people do use floats for money. I have seen it.
And it's not about the equality comparison operator either (which, by the way, is just fine if you use it right). It's because there is no finite binary representation for 0.01, so all your dollars-and-cents values will have rounding error, as will your percent-interest values, and all the other things that use decimal fractions.
Sheesh. Not everything you disagree with is a troll. Do you find it really so inconceivable that I actually believe what I'm saying?
I'm sure you're aware that a "cup" is 8 "ounces", and that an "ounce" is 28.2 of your precious metric "grams". I should know better than to not RTFA, but this is/. after all. I'm sure the guy's just pointing out reasons why metric isn't as logical as many of the eurosheep think it is. And trust me, there ARE such reasons.
You don't need to read it. I quoted the relevant parts.
And a metric cup is 250ml, so you can still ask for a cup of coffee and get what you're expecting.
Metric has no basis in reality. Inches are about the distance from the tip to the first knuckle of an adult human's thumb, give or take.
So what? A metre is 1/10000 the distance from the equator to the pole, give or take. Who cares? For that matter, a metre is the distance from your hips to your heels, give or take. Does it matter?
...if you don't have a measuring tool, with metric measurements, you can't make one easily. That was the guy's point.
No, the guy's point was that you can't accurately divide a ruler into fifths. He was wrong.
Scientists are probably better off using metric, but not Joe carpenter building your house. You'd probably rather have your house fit human measurements, rather than be correct to metric measurements.
Actually, I'd prefer my carpenter to use a ruler, rather than his thumb or his foot, thank you very much.
And another fact, numerically: a foot can be divided into inches without fractional or irrational result by 1, 2, 3, 4, 5, and 6.
Nope. You can't do 5. Besides, again I say, who cares? Who ever needs to do this?
Beyond that, a foot can be divided into fractional, but not irrational, inches with 8, 9, and 10. Only 7 and 11 give unwieldy numbers. Again, decimeters aren't as flexible.
Wrong again. No fraction produces an irrational result, so decimetres are equally "flexible" by this criterion.
So keep doing your simple geometry and using your metric system. Just don't force it down our throats.
I never said you should use it. I only said the arguments against it are bogus.
I'll take a *cup* of coffee over 236.666666667 mL of coffee any day.
And I'll take a metric cup of coffee, and relish my extra 13ml.:-)
First of all, when you say "everything we know about number theory", I presume that's the theory that lots of things divide 12 and 60 evenly. Well so what? That's only one small advantage to an otherwise baroque, arcane system.
Second, that essay sucks. For instance, a pint is not 250ml, but 568ml. The reason people order pints of beer instead of 568ml (or even a half-litre) is mostly historical, but it's also because it's handy to have a nice short name for a measure you use often. If they had used metric for beer all along, then people would have needed a short nickname for a half-litre, and perhaps they would have called it a pint. It's the same way we call kilometres "clicks", and it has nothing to do with base 10, or fractions, or "number theory" as you say.
This guy goes on to say:
We change everything into metric, then
people find it more useful to use fractions, and then they give names
to these fractions, and before you know it, we're back where we
started from!
No, we are most certainly not back where we started from. If you like to give a name to 3/7 of a metre, that's your business, but I like the fact that I can do mental math in metric, and convert units just by sliding the decimal point.
For example, if I'm travelling at 31km/h, what is that in metres per second? It turns out the hardest part of that calculation is converting hours into seconds, which involves dividing by 3.6. As far as mental arithmetic goes, it doesn't get much harder than that. There's your precious number threory for you. And it only gets worse if you try to turn 31mph into feet per second.
In contrast, if my car uses 7.3 litres of fuel per 100km, what is that in millilitres per km? It's 73. It's so simple you can do it in your head, and get your answer with as much precision as you want, so long as you are capable of sliding the decimal point properly for each unit conversion.
Later, we find this demented little nugget:
So then I go to my mother-in-law-to-be, and I say, "Hey, these
recipes call for cup of something, how much is that exactly?" And
she pulls out her cup that she drinks coffee from to show me, and I
say,"Yeah, but aren't different cups sometimes different sizes?"
And then she said, "Ja zeker!" And she took me to her china cabinet
and showed me all the different cups she has and all the different
sizes there are. And then I said, "Yeah but Francine, doesn't this
like, ever become a problem in knowing exactly how much to use?" and
she shrugged her shoulders and nodded!
So that means the European kitchens are less precise than American
and English. They just take any old cup, any old spoon! So where
is the advantage of being metric?
The problem here, if you'll take a moment to think about it, is that the authors of these cookbooks are not using the metric system. If they were, the problem would disappear. (In fact, if they would use any consistent system, the problem would disappear.)
How the author manages to blame this on the metric system is beyond my comprehension.
The best part comes next. I think my whole attitude on this "essay" can be focused on this one small quote:
So we have this friend who is a carpenter, and I see him, and I say,
"Hey, Freddie, when you have a board a meter long, how do you divide
it into 3?" And he sortof gives me a funny look, and says why would
he want to do that. And I say, well, How does that work? Because in
the metric system, a third of a meter isn't marked on your ruler so
what do you do? don't you ever have a board of one meter that you
have to divide by three? And he says No.
You don't need to read anything else in this essay---even the rest of this paragraph, where he goes on to say that people buy wood in 120cm lengths---because it's all here. Nobody cares if you can't divide a metre into 3, just like nobody cares if you can'
Slashdot Mirror
I think it's even easier in the case of solar sails: all you need to do is angle your mirror 45 degrees to the sun (reflecting the solar wind toward your direction of travel) and gravity will do the work for you. You'll slow down into an elliptical transfer orbit that will take you closer to the sun.
The article is bogus.
Golf is insanely priced in Japan. Magazines seem fairly reasonable, given the cost of living in Japan in the first place.
Wow, nice user id.
All I meant was that the FSF's complaints about painting all Free software with the same brush, and about confusing Linux with GNU, no longer apply.
Dude, what I'm trying to say is that 1/3 is not an irrational number.
In other news, the thousand-man LAN party was a great success last night, as the sole attendee played Quake all by himself. Organizers were delighted with the success of the event.
Also, you're talking about end-customers that will be buying just one of these things. But your quote was about Intel (who will sell millions of them) and mobo manufacturers (who will buy millions of them). Now you're talking some fraction of a billion dollars. Is that enough to worry about yet?
Ok, now that's more like it. :-)
Honestly, yours is not a bad idea, but it's totally unrelated to the paper.
Someone give the man some mod points.
You armchair computer scientists need to give the researchers just a little credit, and benefit of the doubt, especially if you haven't read the paper.
I don't understand. What part of the problem would hashing solve? (Did you read the paper?)
If you do IEEE 754 math with fractions with power-of-two denominators (like 13/256 + 7/64), and you stay within the mantissa's range, then you'll get exact results, and equality comparison will work. In practical terms, this never happens, so yes, you can't rely on the equality operator.
Maybe it would be nice if FP computations came with built-in error bars, and equality were defined with could-be-equal semantics.
And it's not about the equality comparison operator either (which, by the way, is just fine if you use it right). It's because there is no finite binary representation for 0.01, so all your dollars-and-cents values will have rounding error, as will your percent-interest values, and all the other things that use decimal fractions.
And a metric cup is 250ml, so you can still ask for a cup of coffee and get what you're expecting.
So what? A metre is 1/10000 the distance from the equator to the pole, give or take. Who cares? For that matter, a metre is the distance from your hips to your heels, give or take. Does it matter? No, the guy's point was that you can't accurately divide a ruler into fifths. He was wrong. Actually, I'd prefer my carpenter to use a ruler, rather than his thumb or his foot, thank you very much. Nope. You can't do 5. Besides, again I say, who cares? Who ever needs to do this? Wrong again. No fraction produces an irrational result, so decimetres are equally "flexible" by this criterion. I never said you should use it. I only said the arguments against it are bogus. And I'll take a metric cup of coffee, and relish my extra 13ml.I think my own little mutants will use hexadecimal. Then, thousands of years hence, when they invent computers, everything will come naturally.
Second, that essay sucks. For instance, a pint is not 250ml, but 568ml. The reason people order pints of beer instead of 568ml (or even a half-litre) is mostly historical, but it's also because it's handy to have a nice short name for a measure you use often. If they had used metric for beer all along, then people would have needed a short nickname for a half-litre, and perhaps they would have called it a pint. It's the same way we call kilometres "clicks", and it has nothing to do with base 10, or fractions, or "number theory" as you say.
This guy goes on to say:
No, we are most certainly not back where we started from. If you like to give a name to 3/7 of a metre, that's your business, but I like the fact that I can do mental math in metric, and convert units just by sliding the decimal point.
For example, if I'm travelling at 31km/h, what is that in metres per second? It turns out the hardest part of that calculation is converting hours into seconds, which involves dividing by 3.6. As far as mental arithmetic goes, it doesn't get much harder than that. There's your precious number threory for you. And it only gets worse if you try to turn 31mph into feet per second.
In contrast, if my car uses 7.3 litres of fuel per 100km, what is that in millilitres per km? It's 73. It's so simple you can do it in your head, and get your answer with as much precision as you want, so long as you are capable of sliding the decimal point properly for each unit conversion.
Later, we find this demented little nugget:
The problem here, if you'll take a moment to think about it, is that the authors of these cookbooks are not using the metric system. If they were, the problem would disappear. (In fact, if they would use any consistent system, the problem would disappear.)
How the author manages to blame this on the metric system is beyond my comprehension.
The best part comes next. I think my whole attitude on this "essay" can be focused on this one small quote:
You don't need to read anything else in this essay---even the rest of this paragraph, where he goes on to say that people buy wood in 120cm lengths---because it's all here. Nobody cares if you can't divide a metre into 3, just like nobody cares if you can'
Ok, I'm sorry. We're having a heat wave here in Toronto and it's making me grumpy.
Have you really read all these comments and still not understood the difference between an OS and a kernel?
It's time to enter the '90s.
John? Is that you?