The " I always wondered" thread

[Skanky Burns]

We would probably be shipping heavy metals to earth (or water or something from asteroids) so the weight difference wouldn't be as much.

[Urban Ranger]

Originally posted by Japher
Just to note that if someone is traveling at 0.99c there is no time dialation, this only occurs during times of acceleration. Thus, compared to someone else, at a different relative we could be traveling 0.99c right now!

No. Time dilation is caused by velocity, not acceleration. Besides, acceleration "breaks" relativity anyway, since you can tell who is moving and who isn't.

[Urban Ranger]

Originally posted by Ramo
The thing is, I don't think slightly stronger and slightly smarter people than average would be selected out of the population, and neither would slightly stronger weaker and slightly dumber people. I don't think the differences are significant enough. Selective pressures only come in when the differences become important.

Selection works on two levels, upon a species, and upon individuals. I don't see any selection pressure against Homo Sapiens Sapiens now (other than what we created ourselves, such as overpopulation and pollution), but there might still be some selection against dumber people.

[Urban Ranger]

Originally posted by Starchild
Remove it from the Earth. A mix of space based solar energy collectors beaming energy to powernetworks supplemented by local wind/tide/hydro plants would be ideal. Most energy would of course go into the electrolysis of water to provide hydrogen.

It's a lot more energy efficient to extract hydrogen from methane, which comes mainly from natural gas, but it could be produced by a number of renewable ways too. You get twice as much hydrogen, and the C-H bond is easier to break than the O-H bond.

[Ramo]

Also... if time slows down with the speed of light, if we fell into a black hole, would we ever get there? I mean, if we keep accelerating, we'd keep slowing time down... and eventually, we would be stuck in time due to our high speed and be frozen... right?

Depends on the observer. If you're on the ship, you'll face some serious acceleration and fall into the singularity almost instantenously. If some guys at NASA are watching the approach, the ship will appear to slow down as the ship approaches the event horizon and appear to be frozen there due to time dialation from the gravitational field as well as her velocity; further, the photons will come to NASA further and further apart in time as the coordinate speed of lights slows, and so for all intents and purposes they would stop receiving light from the ship as the ship approaches the event horizon.

Selection works on two levels, upon a species, and upon individuals. I don't see any selection pressure against Homo Sapiens Sapiens now (other than what we created ourselves, such as overpopulation and pollution), but there might still be some selection against dumber people.

There are certainly selective pressures in hunter-gatherer societies. If someone is exceptionally weak/dumb/wasteful/etc., he wouldn't have as many offspring. As for civilized societies, the main selective pressure would be resistance to disease.

[Urban Ranger]

Originally posted by Ramo
Depends on the observer. If you're on the ship, you'll face some serious acceleration and fall into the singularity instantenously.

I am always facinated by the possible existence of a naked singularity. That would be just mind boggling.

[Ramo]

Yeah, but also incredibly unlikely.

[Guest]

"I meant if there's any criteria as for which equations are solvable algebraically and which are only numerically solvable ones.

x (sin x) = 26 is only solvable numerically for instance, but does it exist a set of rules to quickly determine which are and which are not? Or does the nature of each specific case have to be determined independently?"

There are no general criteria. Some families are known to be solvable algebraicaly while some others are known not to be.
Its hard to even describe in all generality what you mean by an equation in a way too.

[Sikander]

Originally posted by DAVOUT


Just a few guesses for the tortoise (knowing that the 200 years is probably not the average life expectancy, and by far):
- considering the enormous losses due to predators of the eggs and young tortoises,
- and considering also the necessity that the descent result from many different mates (tortoises make eggs once a year ?)
it could take that kind of duration to be sure to get a viable descent.

The idea is identical for the trees, with a reproduction system more complex in that it demands the help of elements outside the trees such as winds or insects, and therefore still more time.

Why do we have to break down ?

Life is a replication system; any living form, once it has replicated enough to ensure the transmission of its genes, is designed to break down and die through degeneration. That process makes room and material for more life.

One reason that we break down is to secure our genes. The longer something lives the more likely that its genetic material is damaged by radiation etc. If everything could live indefinitely, there would be very little viable genetic material passed on as time elapsed.

[Sikander]

Originally posted by dejon
Why is common sense so uncommon?

For example, everyone finds it annoying to have to walk around people who are standing still (talking on their cellphone, chatting with someone they ran into) in a high density area. Yet almost everyone does this very thing at some point. If I meet someone I'd like to chat with in a public place, I suggest we "pull aside", so as not to become an obstruction.

There are countless other situations like this, both minor and major in impact. I really think the phrase should be renamed "uncommon sense".

Basic training in the Army is a geat way to break this habit for good. Anyone who stops in a doorway or other chokepoint is immediately chewed out by the Drill Instructors.

[Sikander]

Originally posted by Urban Ranger


You will experience time dilation, even though you cannot measure it, but that's not the cause. The cause is your "ruler" has shortened in the direction of your travel.

So my penis isn't actually short, it's just that I'm so damned fast. I like it!

[Sikander]

Originally posted by LulThyme
..... For example the general quintic is unsolvable by radicals.

Heh heh. Stupid Radicals!

[Kropotkin]

Originally posted by Urban Ranger
You can throw organic stuff (probably not bones though) such as bits and pieces you peel off when preparing a meal down the sink, then turn on the grinder with water running so all that stuff you thrown down won't clog up the drainage.

Isn't it easier to just throw it in the trash can? Instead of having some sort of machinery that can stop working or turn you fingers to kebab if you're not careful (when trying to fix it). And of cource the hole in the sink shouldn't be so big that pieces can pass trough.

[Ramo]

If you're cleaning dishes and have to scrub 'em with soap and water to get some of the food off, a grinder can be useful.

[Urban Ranger]

Krop,

It depends. If you have, say, spoilt oxtail soup, it'd be easier to just pick out the bones, then chuck the whole thing down the drain.