Sisyphus

I've seen enough cops on power trips (and covering for each other), and enough people freaking out at them for trying to do their jobs, that really either version of events is totally plausible. (Yeah, yelling at a cop is a good way to get arrested for disorderly conduct no matter whether it's justified or not. Whether that is right or wrong is a larger issue than whatever happened in this case.) I really doubt race had much to do with it, but I don't think it's an unreasonable suspicion, either. We'll never know exactly what happened, and it doesn't really matter: all charges have been dropped. As for the subject of this thread, Obama's reaction, I agree with Pangloss. I was disappointed that he, apparently on impulse, called them "stupid" without knowing the facts. He shouldn't even have commented on something like that (but hey, he was asked about it). However, as far as I'm concerned, he set it right. A genuine, non-squirmy apology, and an invitation to civil dialogue. That's a classy way to handle it.

That's correct. There does not need to be anything for the universe to "expand into," because the expansion is not motion. It is simply an increase of distances.

Eric, your post has messed up formatting and is hard to read, but it seems like you're pretty much saying the same thing over and over again: a living thing cannot be made up of nonliving parts, because nothing is more than the sum of its parts. This is demonstrably false. In fact, almost the exact opposite is true. Everything there is can be broken down into a handful of homogeneuous elementary particles, yet there is a limitless variety of things and properties of things in the universe, all based on how these fundamental things are arranged and interact on a large scale. So too, is the difference between a living human and a dead human quite physical. First of all, death is not like some switch being turned off. It is a process, not an event, in which the body breaks down beyond a critical point where it can no longer maintain its basic biological functions, most importantly the metabolism of the brain. You also seem to be making a big deal out of the use of pronouns. I refer to myself as "I." So what? I refer to the chair I'm sitting on as "a chair," even though it's made up of the exact same fundamental particles I am, just arranged differently. This pile of stuff possesses no additional special "chairhood force." There are no "chair particles." The fact that iit makes a good place to sit for an upright-walking ape is an emergent property. A human brain, too, has emergent properties, although a human brain is billions of times as complicated as the chair, and so its emergent properties are a good deal more impressive. Specifically, it can think.

Fanghur, you're talking about the same situation as a rocket with a maximum exhaust velocity of 0.5C. The rocket's maximum velocity is not limited to 0.5C. A single projectile with no means of independent propulsion, sure, but not a universal law applicable to all objects. Again, a simple example: You start at rest, and have three projectiles with you, each equal to to your own mass. You fire two at once at 0.5C away from you, in the positive direction. Because of Newton's third law, you (and the third projectile) are now also moving at 0.5C, in the negative direction (as the fired projectiles were half your total mass). Now fire the third, also at 0.5C (relative to you, obviously), in the postive direction. The third projectile now has zero velocity (-0.5C+0.5C=0), and because of Newton's third law, you are now moving at C (-0.5C-0.5C=-C). "Speed limit" exceeded.

I removed it for you. Mod powers activate!

That makes assumptions about the value of it, though, which is exactly what is in question. Sickle-cell disease could actually be a good analogy. It could work if one copy of a gene gives some very subtle advantage, but two gives some major disadvantage, or some similar situation. The sickle-cell gene continues to exist despite the disadvantage but without becoming dominant in the population as a whole despite the advantage, and except for special circumstances (exposure to malaria) you would never even know about it. More generally, any kind of persistent diversity puts a lie to the proposition that any trait is either absolutely beneficial (and will therefore quickly become dominant) or absolutely detrimental (and will therefore quickly die out).

There is no "wrt itself."

It doesn't matter whether it's running off batteries or fuel. The charge going to the battery must be less than the extra energy either motor is using to overcome the extra drag. You're better off just charging the battery with the fuel-driven motor directly, which is in fact how it works. Heat of exhaust is indeed waste, as is engine noise and vibration. You could try to harness them, but it would be more efficient to just try to reduce them in the first place. If you really want to see some efficiency optimization, check out this car being developed called the Aptera: http://www.aptera.com

Not only would it not disintegrate, but there would be no way to determine how fast its going. This is because there's no such thing as "absolute velocity," only velocity relative to other things. If you pour all the energy in the universe into accelerating your spaceship, you won't feel any different, and you won't be any closer to the speed of light. You turn your headlights on, the beams still recede away from you at C. Your velocity will, however, be C minus only a tiny fraction different from your original velocity.

The energy output is always going to be less than the added drag. Otherwise you've created energy from nothing, which is impossible.

So why does God hate Mars?

Far more objects hit the Earth than the Moon. The difference is that the vast majority of them burn up or explode in the upper atmosphere. The Moon, on the other hand, basically has no atmosphere, so everything makes it to the surface.

Why would you lose the ability to push back?

Ah, that makes sense. So the reason they're still somehow associated today even in America is just evidence that we were never totally serious about the whole "classless society" thing. Still, though, once upon a time it was only "gentlemen scholars" who would have been doing the work now done by "scientists." But I guess that was never actually a profession, per se, just a hobby nobody got paid for.

Seriously, though, what does doctorin' have to do with lawyerin', that they always seem to be associated? Does anyone actually know?

That's not really the same thing as "imagining" it, though. You have to distort them in some way to represent them, usually by distorting the angles. You can, however, take a series of undistorted 3D "slices."

I don't even understand why law and medicine are always grouped together.

I don't get what you mean. You don't need to throw it back at more than C. Throw an equal weight back at C to move at C. Throw half the remainder back at C (meaning it's now at zero velocity) and you've got 2C.

A light source (or anything except light itself) cannot be moving at C. And nothing is ever 2C. Light moves at C relative to you no matter how fast you are moving relative to anything else. I don't really follow your question, but is it still a problem if the source is moving at less than C?

There are two kinds of differences each might observe in the other. A difference in the rate at which the other's clocks tick, and a difference in what those clocks say. The rate will be different if they have a nonzero velocity relative to one another. The clocks will give different readings (i.e., more time will have passed for one or the other), even if they rejoin the same reference frame, depending on how much each has accelerated in the past.

...failed! You're right that you couldn't get something to move faster than C away from you by, say, shooting a laser at it. You could, however, move yourself at faster than C by using good old Newton's third law of motion. You weigh 100kg. You have 1000kg worth of additional mass, all of which you accelerate away from you to C/2. How fast are you now going?

With a chain pump, you are also lifting it the same height. However, the way they actually do it, they don't have to lift it. They just replace it with water.

It's not balanced. Empty bucket goes down, bucket full of oil comes up. Oil is not weightless. It is, in fact, less efficient than other types of pumps, but any pump has to lift the weight of what it's pumping. You can't get energy from nothing. However, if you just pour water into the hole, the oil, which is lighter than water, will come to the surface, with no energy used. (Or rather, you're just using the potential energy of the weight of water decreasing in height.)

What you've got there is a chain pump, at least 2700 years old. I don't think that copyright is going to hold up in court, seeing as there's prior art in the Hanging Gardens of Babylon.

Technically, any species whose last surviving member was eaten by a predator was "completely wiped out" by a single animal.