CCWilson

Elf, this may well be beyond my mathematical abilities, but what are the necessary assumptions, and how could one be sure that compression to that degree is even possible?

As a layman, this is something I've wondered about. I understand that an object larger than around three solar masses will shrink to a black hole. That amount of mass is necessary for the force that keeps electrons in their quantum areas of probability to be overcome. So those electrons' fields collapse and they join the protons and essentially create a neutron star. How do scientists know what happens at that point? How do they know what forces allow neutrons or perhaps quarks or leptons to maintain their size and shape? How do they know that there isn't some force, presumably undiscovered, which prevents them from collapsing to zero size? I think I've read that many physicists nowadays are unsure of the singularity theory, expressing the fact that nobody knows what happens under black hole conditions. Is this the kind of question that has prompted such thinking?

How can you calculate how fast oxygen levels will fall and carbon dioxide will rise per person in a sealed room of a certain volume, and what levels of each will likely cause death?

There are some diving dry suits which might be adequate for thermal protection, especially if we added 7V electric undergarments, as suggested. There's still the issue of how to supply oxygen. There's oxygen in the atmosphere, but it would be way too cold to breathe directly. Compressed air scuba tanks, superinsulated, could work, but for a limited time only. Ideally you'd have something almost like a snorkel inside the headgear where you breathe in air from the outside world which is somehow preheated before it reaches your mask, then you exhale through the snorkel's exit valve to the outside. Also, there wouldn't be any water vapor in the atmosphere, having frozen long before. Any ideas on how to heat the inspired air and maybe add humidity?

In a novel I've started, the Earth is slung out of solar orbit. But we are given several years' warning that we will be losing the sun as an energy source. Would it be possible for a scientific-minded individual to build a space suit to protect him for a few hours, at least, from temperatures down to say -150 degrees Celsius, when he ventures out from his underground bunker? At that point we would still have a decent atmosphere - although water vapor, carbon dioxide, and several other gases would have frozen out - so the issue wouldn't be atmospheric pressure, it would be protection from the cold plus oxygen supply. Thanks.

I wonder if the temperature would drop as quickly as you'd think. So much energy stored within the Earth that even out in space the core would take millions of years to cool down to base temperature, so there would be heat from the ground radiating out to the atmosphere for a long time, and the greenhouse gases would hold a lot of that in. So it would be damn cold, but a long time before oxygen and nitrogen froze. Carbon dioxide, too, but that would freeze a lot sooner than oxygen and nitrogen.

If our planet was slung out of solar orbit by a passing star or black hole, what would happen to its atmosphere? With no Sun to warm us, and no life to generate O2 or CO2, would some gases freeze and precipitate out? Would some be slowly lost into space or elsewhere? Would the atmosphere become thick or even solid? Would there be layering of some gases?

I agree. No one can consciously decide what turns him on, which sex he prefers to be intimate with. But he can indeed choose who to have sex with. I'm sure that many men with homosexual orientation in the past did confine themselves to sex with women - ugh! Now that homosexuality is more socially acceptable, we'll probably have more homosexual sex - but the desires and preferences will likely be much as always. Those who are halfway between homosexuality and heterosexuality in desire can choose to swing either way, or both ways, and godspeed.

Sure. And my guess is for the same reason - genetic diversity.

I think teenage rebellion is built into our species somehow. When those hormones kick in, our parents, who seemed so wise and wonderful before, suddenly don't have a clue, and are almost evil in trying to control us. Now maybe this isn't related directly to evolution, maybe it's just some side effects of necessary changes, but on the other hand maybe evolution pushed the disatisfaction because it was useful. In what ways might it be useful? One would be to encourage breaking away from the family's ways of doing things, to try new solutions, to be creative rather than accepting the conventional way of doing things. Another would be to spread genetic diversity - which is very important - by encouraging the teenager to leave the family and seek fame and fortune, thus cutting down on inbreeding. I think there probably are innate psychological aversions to inbreeding, but I think it happens a lot in some families and communities, and if you're a horny brother, sister might be awfully tempting. I know that it happened frequently in some royal families. So the idea that teenage rebelliion might have come about because it was good for the species is just a guess on my part, but it makes sense. To be honest, most of the theory of evolution is based on guesswork and logic, in the absence of much solid scientific evidence. We can see evolution in action in bacteria and other simple organisms, but for homo sapiens most evolution happened long before science began, and we have to make educated guesses, supplemented currently by DNA studies, as to how things got to this point.

I'm aware of that article by Steven Pinker, and the subsequent attack on E.O.Wilson's book, which promotes group selection, by Richard Dawkins. I haven't read Wilson's book - though I plan to - so I don't know which variety of group selection he believes in - but I'm a firm believer in a particular version of group selection, myself - though since I'm a layman, don't put too much stock in that. E.O.Wilson is a prominent biologist, so it's still an open question, although I think most evolution scientists don't accept group selection. Charles Darwin did, however.

Actually, I'm not aware of any solid evidence that there are gay genes. I believe that periodically somebody announces such things, and then it turns out to be false. I'm certainly willing to change my opinion if there's substantial evidence of a gay gene. For me, it's illogical - but in science often the illogical turns out to be true, and a different logic makes sense of it. Thanks for a thoughtful scenario. I don't doubt that having extra caregivers - and maybe more important, extra warrriors - could be of benefit to the survival of a family group. It's just that the balance between the benefit of having extra bodies in a family or group, which would perhaps indirectly carry some of the homosexual's genes forward, and the detriment to the homosexual's individual genetic legacy seems to me to be pretty heavily biased in favor of the genetic loss of any gay genes. If a couple has two or three sons, and they all are gay, their entire genetic heritage could be lost. Incidentally, this argument mainly concerns men; I don't know that women, at the time these evolutionary changes were occurring, had much choice in avoiding pregnancy.

Those are good points. But the whole basis for evolution is that he who sends his seed forward, wins. The fill-in's genes go into the next generation, and the homosexual's don't, in comparison. Some genetic crossover between the homosexual and his generous fill-in if a relative, perhaps .. but only if a relative. My argument is that most likely there aren't gay genes, that it's an error in the development of sexual preference, which must be very complicated to accomplish, perhaps by hormonal or other inconsistencies in the womb. Regardless, I don't think anyone has a choice in the matter of which body parts turn him or her on. I understand that. Of course with ants and bees, the DNA of all individuals is so closely matched that evolution works differently than it does in most species. In humans, once you have a group of people, bonded together by empathy as well as self-interest, they will work out their own arrangements, and some of the participants will be those who for whatever reason are non-reproducers. Not every social arrangement is codified in our DNA; I think that a lot of general personality traits are set in our brains, and various versions of social interactions spring from that. For example, I doubt that communication by email and texting and cell phones is specified in our DNA. Remember, not every couple is fertile; evolution isn't perfect in getting the plumbing exactly right in all of us. In the case of sexual preference, which presumably is hard wired in the brain and must be even more difficult to get right than the physical structure of our pee-pees, mistakes are going to be made from time to time.

Personally I believe that group selection is the driver behind sociality, which is based largely on empathy and its offshoots. I know that group selection is not generally accepted but one version of it makes perfect sense to me.