Mokele

Ok, so without too much background, my sister and I were discussing our various writing projects and how much "sci" should be in "sci-fi", and we got onto a question I have about a particular villain I'm writing. Basically, the villain has the power to warp spacetime into a small massless singularity (warping space without having any mass in there to do it - 'how' is never explained or known), in effect creating a black hole, and has the rather unfortunate tendency of doing this on inhabited worlds, leading to predictable results. I want to check several things about this scenario: 1) Assuming someone *is* able to do this, and the 'pseudo-black-hole' begins sucking in mass, will it eventually reach a point where sufficient mass has been sucked in to make the hole self-sustaining (the mass generates the singularity and not the villain's space-bending powers)? 2) If one of these 'pseudo-black-holes' is stopped before consuming enough mass, what happens? Will the already-compacted mass explode now that nothing is compressing it? Or will it just sit there like a super-dense lump? 3) What would this even look like? Would there be enough material in sea-level air to produce a noticable ecretion disk? Would it be an ecretion disk or sphere, and would the 'black hole' be visible as a black sphere? 4) Not specifically black-hole related, but assuming the villain did something like "warp" spacetime in a highly concentrated area (such as within some poor bastard's chest), this would kill them, right? Probably in an exceptionally gruesome manner? Mokele

Ahh, this probably relates to muscle fiber types. ~350W/kg is the maximum, the that's also for 'fast twitch' fiber types, the sort you often use in martial arts. 'Slow twitch' fibers, which are more commonly used in endurance sports like running (as well as for everyday activities like walking) have a lower peak power, though how much lower is dependent upon precise molecular differences. Also, speaking from martial arts experience, a LOT of it is technique. Doing moves 'right' allows you to use muscles more optimally, allows you avoid wasting effort, and allows you to even recruit additional muscles that would otherwise not be used, to add power. Whenever they say 'put your hips into it', what they're actually saying is to use your large leg muscles to provide additional power.

I think he's against those who simply conclude they know what the trick is, without confirmation, rather than those who simply say it's insufficient evidence because of any of several *possible* tricks.

How are you assessing muscle size, though? Some humans may have an illusion of more muscle due to having subcutaneous fat deposits, as well as fat deposits between and around muscles, while others with less fat may appear to have smaller muscles but actually have larger real muscle area. There's also possible variations within a muscle in the percent of cross-sectional area used for non-contractile stuff like blood vessels, sarcoplasmic reticulum, and mitochondria.

Vibrations, transmitted through the table to the pin that the pinwheel is mounted on?

CDarwin is correct - jumpers often have very long legs, with elongated, fused leg bones. Compare the galago skeleton in his post with this frog skeleton - same elongated limb bones, long ankle bones, etc. It also holds true for kangaroos and locusts. The main reason for this all comes back to muscles. If your muscles contract in conditions optimal for power generation (~30% of maximum shortening velocity), your final kinetic energy when you leave the ground will be Power x jump duration. Increasing the leg length means you exert that maximal power over a longer time, and thus achieve a higher final velocity.

Could this have something to do with why the videos like this always use paper, rather than aluminum foil or other materials? Are there specific, common frequencies paper is especially good at absorbing?

Interesting, I hadn't heard about the latter of those molecular findings. Fiber type is still an interesting area, in part because it's controversial whether it actually affects force output at the molecular level or force differences are a result of slow twich fibers having more extraneous 'stuff' around them, like blood vessels and mitochondria, thereby reducing the percentage of actual contractile machinery per unit cross-sectional area. I think the best way to test it is to do single-fiber muscle experiments - wait until they have to put a chimp under for some unrelated surgery, then excise a single muscle fiber and do in-vitro tests to determine its properties. We already have such data for humans, IIRC. The chimp might have a sore arm for a day or two, but nothing serious.

Honestly, I think zoology should be required for bio majors. The way I've heard some people talk, it's like the only animals that even exist are the model systems like Drosophila and mice.

He always points the hairdryer down. If there's a gap between the bowl and the table, the lip of the bowl would prevent the hairdryer from moving it, but a person located some distance away could blow on it or use a fan. Notice you can't see his face or anything outside of the very narrow area.

It's pushes out hot, burnt fuel products. If the gas pushes in all directions, the rocket doesn't move, because the forces are equal. Because there's a hole in one end, the forces are unequal. Take a soda can, shake it up, and it doesn't move. Poke a hole in it, and it zips across the floor, propelled by the ejected liquid and unequal pressures. And small masses can indeed move big ones, if their momentum is high enough. Even fire a powerful gun? Same thing - the mass of the bullet is tiny, but has such high velocity that it means you move back appreciably.

But remember that evolution isn't the only constraint - there's developmental constraints. You can't just *make* a tree with a plug in it, you have to *grow* it, from a seed, and there are certain limits to what the developmental system can and cannot do. Of course, it's possible to alter the developmental system too, but that comes under the 'cytochrome C' example, especially for very old, important systems, like HOX genes.

The increase in muscle radius necessary to explain that difference is less than 50%, and that doesn't take into account postural differences, differences in muscle origin/insertions, which muscles were used when, etc. Leg use would be especially important in a task like that, as well as center of gravity. Our legs are runner's legs, not made for exerting great forces, and the in-lever/out-lever ratios suck compared to a chimp. Interesting, but considering that the fact that muscle properties are pretty well conserved from worms to insects to fish to humans, I'm very skeptical of any claims of different muscle properties, especially of that magnitude, without excised-muscle experiments. Several problems are immediately apparent, most notably the lack of 3-D kinematics, and the poor quality of kinematics in general due to lack of even simple joint markers. The authors assume no 'rockbacks' or other pre-jump stretching, but without direct (and invasive) measurements, that's simply not possible to confirm. Honestly, such poor data does not support such a gradiose conclusion. Diameter is actually the sole determinant of baseline force (though the muscle and have increased or decreased force from baseline due to loading conditions). Leverage, however, is also very important, for the obvious physical reasons of in-lever/out-lever ratios. From what I understand, chimps generally have an advantage in leverage, particularly at the shoulder joint and hips. Mokele

(fair warning: this thread is really long, so I'm just going to jump in) IMHO, the most important point is simply that we don't know enough about how the genome works yet. We don't fully understand all the metabolic pathways and their roles in development, and we're only just beginning to understand how gene regulation works. Of course, technically nature doesn't "know" anything, but over the millennia, it's selected against non-viable phenotypes. So, basically, natural selection isn't really "smarter" or "dumber", but rather it's functional, and until we actually know a lot more than we do now, it's probably best to be cautious in any tinkering we do. However, molcular biology advances very, very fast, so it may not be too long.

The strength of chimps is due to several things, first and foremost a lifestyle that doesn't involve TV and Whoppers. Theirs is a very rough-and-tumble life, so in comparing strength, it would be most apt to compare them to very athletic humans. Basic muscle physiology counts for a lot, too. Muscles have limits on the amount of force they can produce, work (force x distance) they can do, and power they can produce. Force is dependent upon cross-sectional area of the muscle, and as you can imagine, a slight change in perceptible muscle size (such as diameter), would have a large effect on maximal force. Double diameter means 4x the force. Chimps are very muscular animals, thus, lots of force. Another issue is work, force x distance. Those long arms mean long muscles, so even if a chimp biceps was no bigger around than a human's, the extra length would mean extra energy is imparted to the distal limb segment. And that energy can go directly into injuring unwary keepers. Both of these combine to explain why I expressed power in W/kg. If force is dependent on cross section, and work depends on force and length, therefore work depends on total muscle volume (and muscle has a fairly consistent density of about 1.1 g/cm^3). Power is just the rate of work done, thus also depends on muscle mass (it also depends on shortening velocity, but that's not really applicable to this question, though it is to jumping). So basically, chimps are so strong because they have bigger muscles, and even slight differences in muscle mass can have effects on force and power an animal can produce.

It's the very first post in this thread, and the basis for this entire discussion.

Actually, the highest reported vertical jump is 2.25m. There's actually a whole paper on it, here, and this is actually my precise field of expertise. Basically, what limits jumping performance is power - muscles can produce a maximum of ~350W/kg at optimal conditions, simply due to muscle physiology. In order to circumvent this limit, a variety of animals (frogs, bushbabies, locusts) use tendons as springs, allowing them to store energy in the tendon & release it in a sudden contraction with much higher power output. Imagine how far you can throw a rock. Then put the rock in a slingshot, and it goes much farther. You're added the same amount of energy to the rock via your muscles, but a rubber of the slingshot stores that energy & releases it all at once.

By the logic of everyone in this thread who's been using the DOW as a metric of Obama's success, bascule is 100% correct.

As already mentioned, we've closed the Religion forum, and not just so the same threads could crop up elsewhere. Closed.

I think the conversation over it is still around in the suggestions forum, but basically it was a nightmare of flame-bait, trolling, and bitter axe-grinding.

Interesting - have we actually sent down ROVs to check on the former dump sites and assessed the local ecosystems? It does sort of make sense, since it's metabolically inert and there seems to be very little flow of nutrients & organisms up from the bottom. Do you know a reference for this?

Did I blink and miss the point where we re-opened the long-closed Religion forum?

It's a journal of nothing but review papers, which tend to get cited highly as they synthesize large amounts of research. The same thing goes for other journals - more review papers = higher impact factor. It's just one of the many deep flaws in the concept of 'impact factor'.

One problem with that is transport of the waste over the ocean, and more specifically, what happens in the case of a shipwreck. It would also require moving huge quantities of waste through large port cities on each end (which I'm sure the citizens will be happy about). Finally, who drives the ship? You can't put enough shielding on the ship to protect them without sinking it. I think it'd be a good idea to just keep any waste on the continent it was made on. Aus can use the desert, Europe and Asia can use the vast siberian wastelands, and North America can use the Canadian Shield (AFAIK, there are no nuclear power plants in South America or Africa).

You've seen the movies. I just wanna wreck Tokyo, but one stupid earthquake later and it's nothing but battling giant moths and 3-headed dragon-monsters all day long! Why assume it is? Is there any credible evidence that the decision was made to score political points, rather than out of legitimate concerns over the safety and cost of the site? Why assume one way or the other, without evidence?