Human heads cover quite a small percentage of the earth's surface; it would be rather remarkable if the balloon hit a person.

Anyway, pretty neat. I thought at first they were talking about a rocket, which I thought must cost much more than $150 to get 20 miles up. But I guess a balloon gets you much higher for much cheaper. Not as cool as a rocket though. I think really big amateur rocket launches go about 10 miles up? There are some impressive videos on youtube.

If it proved predictive, yes. If not, no.

No, that's not the point. Of course if your standards for statistical significance are low enough you will find all sorts of nonsense "correlations." That is not the point. The point is that while there is a very strong correlation between the income of Massachusetts pastors and the price of rum, the pastors are neither financing the rum trade nor profiting off it.

A robot that notices and picks up coins when they are dropped is not beyond our capabilities. The important point, I feel, is that at one point (when you were very young) you couldn't have performed any of those steps, but now you can. It's the creation of a robot with this kind of ability to learn and grow that is beyond our capabilities.

Then the title should have been "Bacteria Used to Make Toxic Metals Inert."

I voted for world peace, and this was my reaction too. Perhaps it just says that /. readers are cynical geeks; I wonder what you'd get from polling a different population.

if the human race lasts long enough. I'd rank them like this in order of increasing likelihood of impossibility:

• World peace: this just requires (a) nice people or (b) a powerful enough superstate, which should happen eventually. If this hasn't happened within 1,000 years it will be because we destroyed ourselves; technology will be too powerful for war. I think world peace is much more likely than an apocalypse, though
• Human level AI: obviously possible through brute-force simulation of a brain, so this must happen eventually. Will probably happen within 1,000-10,000 years.
• Immortality: will probably happen eventually through the advance of medical science, say within 10,000 years.
• Aliens: surely they exist somewhere in the universe, but the fact that there's no evidence for them suggests that the closest (intelligent) ones are very far away. I estimate 10,000,000 to 100,000,000 million years to first contact. If there is nontechnological life in the galaxy, perhaps only 100,000 to 1,000,000 years till we find some.
• FTL: a good chance that this is impossible in principle, but there's some real research into warp drives and physics is incomplete, so the door is still open. Say within 100,000 years if it's possible.
• Time travel: very likely impossible. Nature seems to work very hard to prevent any scheme by which time travel might succeed.

Pretty sure no one's going to stop you from taking a glass jar onto a plane. What are they going to do, confiscate glass picture frames in people's carry-ons? Heaven forbid that some pickle juice should make it on, though.

Why do people voluntarily join the military? Some people are willing to die for a cause. Whether that disqualifies them from being sane is subjective, but if you say that no sane person would volunteer for a Mars trip it seems to me that you are also implying that no sane person would join the army.

I don't know why everyone needs to find something to whine about in this article; it's a pretty cool story. An amusing blend of modern and ancient technology to solve an interesting problem.

[citation needed]

There's a good argument that the choice of pi = (circumference / diameter) was unfortunate; it should have been (circumference / radius). In the light of modern mathematics it seems clear that the radius is more "fundamental" than the diameter; choosing pi = (circumference / radius) = 6.28... gives a number of nice things like:
A = (1/2)pi r^2, just as E = (1/2)m v^2 or d = (1/2)a t^2, and for the same reason.
In general, in the current convention, 2pi seems to show up a lot more than pi, e.g. there are 2pi radians in a circle, sin(x) has period 2pi, etc. All these would become simply pi with the (circumference / radius) convention

I don't think this is true. From what I've read, the ancient approximations for pi were 22/7 or 25/8. The surprisingly accurate approximate 355/113 wasn't found until 400 AD according to wikipedia. And anyway, we don't gain anything from the fact that 360 is close to the numerator of a rational approximation to pi, so this is even less likely to be the reason for using 360. I guess it helps you remember that the length of the circular arc subtended by one degree is a little less than 1/113th the diameter, but this is a fairly useless fact.

The sun sets approximately in the west... On the equinoxes (late March and September) I think it should set due west.