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.

An extra caregiver in a family is going to give a big boost in survival? Really? Come on, now! And on the other side of the equation, significantly reduced intersex copulation and offspring. And teenagers are programmed by evolution to rebel, most likely to prevent inbreeding, so many of them tend to leave the comforts of home and seek new adventures and new possibly like-minded friends, so you can't count on the family staying together. If you are Mr. Evolution Designer, taking all that into account, does homosexuality sound like a good idea? Um, let's see. This isn't a close call. It isn't a matter of morality, or whether homosexuality is a good thing today, it's just that all evolution is concerned with is the propogation of an individual's genes into future generations, and on that score homosexuality fails.

In humans, you have mental suffering if you know you're going to die, because you have a concept of death. Animals avoid death by instinct and possibly fear of pain, but they don't suffer mental anguish from fear of death as we do. So again I don't have any moral objection to killing livestock, as long as its done as painlessly as possible, because then there would be no suffering. What sort of death would you prefer, when the time comes? Me, I'd like for it to be quick and painless and unexpected, not a lingering death in hospital. Of course we don't get to choose.

That's true, if recessive, but you have to admit that having an extra caregiver is pretty small potatoes with regard to survival, compared with having fewer (or no) children. To me that sounds like a major stretch. And who's to say that homosexuals, at the time this was theoretically getting evolved, stayed with their family consistently enough to have much effect? Creative, I'll give them that, whoever came up with that theory, but it doesn't pass the smell test.

I've seen that suggestion before, and don't buy it. One the one hand you have that pretty nebulous family advantage for homosexuality, and on the other hand you have the fact that homosexual men will almost surely have fewer offspring than straights will. Which is stronger? Remember, if you don't have children, your genes don't get carried forward. If you are gay and have fewer children than straights, the chances are that the genes of straights will come to predominate. And if you are postulating that the family's survivability would be increased by having more caregivers, remember that it's the gay person who has the "gay gene", not the rest of the family, presumably, so it would still be lost.

The decision to spend gazillions on this kind of research is not made strictly on the basis of utility; it's made because of the intense curiosity of scientists who are able to convince moneyed people of its importance. Certainly the desire for knowledge of how the universe works is a beautiful thing; without that burning curiosity we wouldn't have an industrial and technological society. I think the chances are good that this money - and that invested in string theory research - is wasted. But that's just a guess. It's possible that a better understanding of the underpinnings of the universe will result in fabulous new inventions. But there is a dividing line - hard to define - between what makes sense and what's wasteful of resources. We don't want to spend a large fraction of our national wealth on things that have an extremely poor likelihood of being of any practical benefit to anyone except the amusement and ego satisfaction of those few scientists with the brains to understand this stuff.

At puberty for most of us men there was a rather sudden and quite overwhelming sexual preference for the opposite sex. It wasn't a matter of conscious thought, no logical thinking was going on, we just became aroused by the sight or thought of girls. Presumably homosexual men have a similar sexual preference for those of the same sex, and it's probably just as automatic and uncontrollable as it is for straight men. Anybody who thinks that our sexual orientation is a matter of choice is frankly not too bright, unless they themselves are not strongly sexed in preference, in which case perhaps they can indeed swing one way or the other. Women's sexual preference is a different case, characterized by less intense reactions to pornography and nude dancing and for most of them casual sex - and that's probably because evolution favored men - but not women - who spread their seed widely. With regard to a gay gene, certainly any gene promoting homosexuality should logically be weeded out easily by evolution, because evolution always favors individuals who have the most progeny; that's how evolution works. But like most personality traits, I assume that a number of genes are involved in sexual preference, and surely some individuals are more strongly pushed in the direction of heterosexuality than others. Think for a minute about how genetics could imprint sexual preference in the brain. Not an easy thing to accomplish, I would think. Is there an image of female body parts that's connected to a sexual preference center? Or is there some representation of the newborn's mother that gets imprinted? Since each sex likes others of the same sex as friends, it has to be complicated to separate that out from sexual stimulation in the developing brain. So my theory is that sexual preference is so difficult to codify that evolution came up with the best scheme it could to insure heterosexuality, which is obviously best for sending genes forward, but not a perfect one, so that it gets it right 90% of the time. There is a complicated dance of hormones in the womb that result in proper sexual physical equipment, and things sometimes go wrong there, so something like sexual preference, which is much more complicated to accomplish, is subject to errors, too - maybe partially due to differences in hormone levels. The study mentioned above about boys being more likely to be homosexual the more older brothers they have - that could have a hormonal basis; maybe mother's hormones for use in gestation get partially depleted.

What's hard to get our minds around is that when scientists say that the universe is bounded (has limits), what they mean is that spacetime is bounded, not that the three dimensional universe is bounded. If you just consider three dimensions, there would always be empty space outside any boundaries specified. Since we cannot really visualize more than our usual three spatial dimensions - we didn't evolve to need more than that - if we want to sort of visualize it, we have to replace one of the spatial dimensions with a time dimension. Then if you think of the surface of a sphere as spacetime, with the two dimensions we see there representing the three dimensions in our world, and nothing allowed outside that surface (just as in our world nothing is allowed our three dimensions), that's what they mean by "bounded". Theoretically I think that means that if we sent out a beam of light and it didn't hit an obstruction, it could eventually find its way back to our position. Whether there would still be anyone here to observe it, doubtful. The concept of multiverses can have several forms. The one which is postulated to explain quantum weirdness is that every time any quantum event occurs, a new universe branches off. That's too weird to even contemplate. The one which sounds plausible is that our universe could have sprung from a mother universe, maybe from a black hole in that mother universe; think of our universe as an expanding sphere as described above, with its own version of time, completely cut off from all other universes - unless it collides with one. Also possible that new universes could spring from black holes in our universe, somehow, on and on, backward and forward. That could explain how our universe began, since it wouldn't have come from nothing, but of course it doesn't explain how the mother universe - the first one - originated. All speculation, and probably no way to confirm or deny, ever. I'm not a physicist, and this stuff requires a lot of very hard thinking to even approach understanding it, so if there's a professional here who can comment, great.

The question "Why is there anything?" is the most profound question there is. My guess is that the answer is so complicated that our human brains are not adequate to the task. Here are some deep thoughts. The old argument was that if you go back in time, eventually you'll get to a point where there was nothing. The problem with that idea is that time as we know it is specific to our universe. If there was indeed a singularity or near-singularity that preceded the big bang, time had essentially stopped under the effect of gravity. So there was nothing that occurred before that in our universe, since time had stopped. But that particular version of time is only applicable to our universe. If there is stuff outside our universe, we have no idea if time exists there, or if it does, it's like ours. Some people believe that the universe wasn't created - that it has always existed. But that doesn't help in understanding how it came to be here. Ours may not be the only universe. There might be a mother universe from which we sprang. There could be new universes being created all the time. Maybe every time mass in a black hole reaches a certain number, a big bang creates a new universe, each of which is isolated from (but could conceivably collide with) all the other universes. Our universe could be creating new universes. Our mother universe could be a daughter of its mother universe, on and on. No way to confirm or deny any of this but it's certainly possible. Some scientists believe that our universe originated as a quantum fluctuation out of absolute nothingness. That doesn't make sense because there would have to be some sort of framework with physical laws that allowed that to happen, in my opinion - and if so, where did that framework come from? The truth is that we will probably never figure this out. We just don't have the brainpower, in my opinion; we didn't need to be smarter than we are for evolution's purposes. It's possible that some Einstein-level brain will come along and his insights will make it clear, but I doubt it. The one chance I envision is if we someday are able to make computers of some sort that not only have reasoning power like ours but also the ability to improvet their intelligence each generation to the point that they could figure this puzzle out and then explain it to our poor brains in language we can understand. So the question is whether this unsolvable question means that there may be a God. The truth is that it seems so weird that we can't rule anything out. I doubt that an intelligent entity created all this but it's all so incomprehensible that it's not impossible. One thing we can be damn certain of; if an intelligence did create the universe, it has zero in common with anything that organized religion believes it to be.

Since cows do not - as far as we know - ruminate on death and what happens after they're gone, fear of death doesn't come into it, as it does for humans. Cows presumably worry about the prospect of pain, but not death, which is a complex concept. So if your main concern is that we should avoid suffering, as mine is, then as long as the cow dies quickly and relatively painlessly, there should be no ethical objection.

My guess is, not much. It was his "natural selection" concept that was most important, not the specific mechanism behind it. But as smart as Darwin was, he might well have added fresh nsights based on Mendel's ideas.

The fewer the colonists, and the more closely related they are, the more likely you'd be to see changes. If the state controlled who was allowed to have babies, selecting only the brightest and most beautiful for the settlement's benefit, evolutionary changes could be rapid. Most importantly, if there occurred some natural disaster that killed a good percentage of the settlers or made them sterile, there could easily be significant changes in 1000 years; those with mutations, new or existing, that made survival or reproduction easier would come to predominate in the population. If there was a new mutation that spread, other characterstics of the individual who introduced the mutation, including those unrelated to survival, would spread as well. The appearance of the subspecies after 1000 years might also be subtly different from those on Earth. The reason that you can easily distinguish Europeans from Africans from Asians from South Sea Islanders from American Indians by their appearance is that evolution occurred in each of those reproductively isolated groups, including changes in facial features that probably were the result of genetic drift and/or differences in the originators of the races rather than in anything related to survival or reproduction.