Sisyphus

One of the main reasons I don't expect that we'll ever have meaningful communication with an extraterrestrial lifeform is that even on our own planet, where all life probably has common ancestry, the kind of intelligence needed for that sort of communication is basically limited to only one species (us), and even that arising out of some pretty big coincidences.

However, many species seem to be on the verge of such capability. As one would expect, several of these are our closest relatives: apes. Our chances of encountering intelligent life would seem more promising if we saw such intelligence arising more independently here on Earth, i.e. in species for which our most recent common ancestor was as unsophisticated as possible. For example, dolphins are more encouraging than chimps, ravens more than dolphins, and octopi more than ravens. Of course, none of those species appear to have their own radio telescopes...

I don't really expect a definitive answer, as we essentially have a statistical model of 1 (our own planet), but what are your thoughts on the chances of the kind of intelligence we could have any communication with arising independently, either here on Earth or otherwise?

Why does society = not instinct? We're social animals, are we not? Unless you think fish swim in schools because of cultural values passed on through oral tradition.

Also, it may be wildly inappropriate today, but it also seems likely such hymen inquiries were all part of the mating process for most of our history. It might even help explain its presence: a woman able to unambiguously demonstrate her virginity would be more desirable.

you still have to have some empirical data for those to predict anything.

I guess that's just indicative of how little we understand about it. Presumably, it must be theoretically possible to construct a model such that given a hypothetical substance, its behavior under given conditions would be entirely predictable.

it isn't very apparent physically as to wheather a woman is a virgin.

You mean besides the hymen? In any case, you could still be instinctively more attracted to someone you think is a virgin. Entirely plausible, as I don't expect there are many secrets in a society of nomadic hunter-gatherers...

It would also help explain the persistent double standard between the sexes. It is almost always more socially acceptable for a man to have previous partners than a woman.

Me, I am of the opinion that 2 + 2 in fact equals 5.

The main target of angry rhetoric, maybe. Whether they would actually use a nuclear weapon is a question of whether or not Iran's leaders are willing to sacrifice the lives of every single Iranian and the Palestinians they claim to support, as well as destroy their own Holy Land, all to prove a point.

It's still humiliating to be invaded and propped up by forgeigners, particularly if those foreigners happen to be arrogant, condescending asses. I doubt there will ever be a great deal of gratitude among the Iraqis.

Then again, Japan and West Germany became our close allies after reconstruction. But in those cases we had a common enemy (the Soviets), and we had Truman and Eisenhower instead of Bush and Rove. Also, nobody was telling Germans or Japanese they had a religious necessity to fight at any cost, at least not once the "official" war was over.

Assuming you're talking about the U.S. and not SFN, and considering that hardly anyone is still saying that the U.S. should have invaded Iraq in the first place, and them with increasing strain in their voices, I'd say it's not going to happen. In any case, it can't happen - at least not for a long time. They simply don't have the resources to fight the same kind of war in Iran that they're fighting in Iraq, and Bush would get lynched if he tried.

Luckily, I happen to think that Iran is basically harmless. Any weapons they are trying to develop are almost certainly not for offensive purposes. If they get nukes, they'll tell the world, because the best use for them is to deter an invasion. That's why N. Korea has them, anyway. Anti-Israeli and anti-American rhetoric is perhaps heartfelt but ultimately political and toothless, since actually using a nuclear bomb would only ensure their own catastrophic destruction. Plus, as I understand it, there is a strong and growing dissatisfaction within Iran about their extreme Islamist government, especially among the youth. If that's true, then there will be radical self-reform within a generation's time, anyway.

But the pressure at a given temperature for a given substance at a given outside pressure is always the same, apparently. The percentage of vaporizing molecules is predictable. That's why I think it's so strange that there isn't some known law that determines that percentage, that we just have to observe it and fit it to some approximate function. What that tells me is that there is no way to actually predict what that pressure will be for some known substance without actually trying it. Is nobody else bothered by that?

It's well known and easy to demonstrate that the gravity inside the sphere, exerted by the sphere, would be zero at any point whatsoever. You don't get pulled towards the center, you don't get pulled towards the nearest edge (even if you're right next to it), it doesn't matter how big the sphere is or how thick its walls are. It doesn't matter if it's 50 billion miles across with 10 thousand mile thick lead walls that you're right next to. The net force is exactly zero. Always.

So nobody actually knows, then. And here I was, trying to figure it out...

I understand that. I just mean, is there any explanation for why a given substance is a given pressure at a given temperature?

Any particular explanation for why that is?

I was wondering something today. Given a simple liquid barometer, the idea is to have two connected surfaces of a fluid, one exposed to vacuum, the other to air. The weight of the air column above the air-exposed surface forces the other upwards until the weight of the difference in height is equal to the air pressure. Right? Right. Now what I'm wondering is, won't there always be vapor in the vacuum chamber as some of the liquid boils when exposed to vacuum? If so, how negligible is the pressure exerted by said vapor, and how does it relate to the exterior air pressure? Does it in any way depend on the liquid used?

Not sure what you were expecting really: the number of mathematicians reading this site is negligible' date=' and the number of those who've done enough optimization to know what max-flow/min-cut is must be, oh, about 3.

 

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Hey! I'm not a mathematician, but I knew what he was talking about. I just figured my bumbling attempts would be less valuable than what Google would turn up for "Hall's theorem Konig's theorem logical equivalence" or some variation thereof.

The affect of CO2 aside, it's still very much in our own best interest (by just about any measure you want) to get more serious about regulating our own environmental impact, regardless of whether the rest of the world does so as well. Global warming is merely the scariest of the potential consequences of short-sightedness, and curbing CO2 emmisions appears to be how we can slow it down the most for the least effort. We do need a better Kyoto pact, though, if only because it's useless if it isn't even implemented...

I don't think they're claiming to have found the genetic basis for intelligence, just that they've found something that actually makes a difference. Not on its own, since it doesn't affect anything in females, but apparently some interaction between this gene and something on the Y chromosome can have adverse effects on intelligence. Interesting, but not all that significant, I don't think. It's already obvious that genetics plays a major role in intelligence (however you want to quantify it), since smart parents tend to have smart kids. Notice I say tend.

Oh, and ecoli: I have friends at Harvard. They're not nearly as smart as you might think...

The net pull is zero inside a sphere. It's not terribly difficult to show with calculus, if you realize that for any location within the sphere, there is an axis which passes through it, and that the force from a given point on the sphere can be divided into forces along the axis and perpendicular to it. The perpendicular forces obviously cancel out (for every point pulling you one way, there is a corresponding point pulling you exactly as much in the other direction), and so you are left with the forces along the axis, which vary as the sine of the angle between perpendicular and point divided by the square of its distance. The integral of this function will always equal zero in a given sphere

One step closer to a space elevator. Still, the wait is unbearable...

The universe wouldn't be destroyed, but you have to admit it would be pretty strange.

Sorry...

You've conveniently defined innocent to include anyone who doesn't qualify as an operator.

Actually I think he means innocent in the sense of having nothing to do with it. It's entirely indiscriminate. Unless you think simply being a Palestinian is enough to convict you of supporting terrorism, which I think is called racism. The fact that it's (for the most part) merely psychological makes it not nearly as bad as if they were just indiscriminately bombing, but it's still pretty clearly wrong. I mean, there are terrorists living in every country of the world; are we going to shatter everyone's windows until they do something about it? No. That's ridiculous.

Not only that, but it's a stupid tactic. What effect could something like this possibly have but encourage yet more hatred for Israel among Palestinians, and turn people who WERE innocent into terrorists and terrorist-supporters? Yeah, good work, guys. Stop terrorism by making them as angry as possible. I'm sure that will work...

why can't a solar system be sent into space as close to the sun as possible.....

At first I thought you were talking about moving the Earth closer to the sun...

On a related note, try googling "Dyson spheres." The logical extension of what you're talking about.

What is life? Self-replicating patterns. I'd imagine that's possible in just about any scenario you could come up with.

Yeah, I would imagine any trait at all that allowed creatures to push the boundaries of the biosphere and move towards the essentially competition-free land would reproduce like mad... if you could maneuver and respirate at all outside of water, you'd be home free, genetically speaking...

The author says T^4 = L/(D^2), where T is planetary temperature, L is solar luminosity, and D is orbital radius. This is more or less what I think you want, already. Rearrange to get D = sqrt[L/(T^4)], or D = sqrt(L)/T^2, if it helps. Thus you have radius as a function of temperature. Plug in the upper and lower extremes for temperature to get the inner and outer radii for the limits of the habitable zone. (Diameters, obviously, are just twice the radii.)