Sisyphus

I agreed that photons move at C, and said that objects moving faster than C and emitting photons make little physical sense. What is your point?

Even if everything else you said is true, how does this follow? Recording the incident just gives the people in charge of deciding if there was wrongdoing (i.e., his superiors, IA, a judge, not an angry mob) more information. If the officer didn't do anything wrong, then the video evidence should help him. Also, the public reaction is not the final say, but that doesn't mean it isn't important. If a bunch of people watch this on youtube and are pissed off, that doesn't mean they get to lynch the officer. It does mean, however, that the powers that be can't get away with simply ignoring incidents of actual wrongdoing. Flight data recorders are actually a good example, because if there is a plane crash, you can be confident that the FAA is going to very carefully review everything. In stark contrast, this guy's sergeant has every motive just to sweep complaints under the rug, and you'd have to be extremely naive not to realize that this happens all the time.

"Brutality?" I don't know. Probably not very. But then, I look like a yuppie, so my own impressions of police are probably a lot more positive than others. But abuse of power, in some form or another? I would say it's extremely prevalent. I think it's downright inevitable, given the dramatic power imbalance inherent to the system in pretty much all interactions with civilians, and the culture of "protect your own." You think cops ever get speeding tickets? I know cops who actually brag about helping each other avoid the rules. What we're talking about here is not interfering with cops doing their jobs. I would never ever taunt a cop arresting somebody, nor would I resist arrest myself. But you're damn right I would record the event. Making more information available only hurts those who are lying. Yes, it can be taken out of context. That's what we have a legal system for, to determine what is and is not sufficient evidence of wrongdoing.

So you're arguing what, exactly? That police should be above the law, because the only alternative is anarchy in the false dichotomy in the mind of Joe Sixpack?

But stuff continues to enter. Rivers only flow in one direction, but they're not empty (otherwise we'd call them valleys).

Huh? Post #20 is you.

I think the idea is that "seizure" would be an option only if BP fails in their responsibilities themselves. I don't see where the confusion is in this argument.

What event horizon? You mean near a black hole? Light can enter a black hole, it just can't leave.

I don't know how Wolfram Alpha does it, but pi will definitely be non-repeating in any base. Pi is an irrational number, which means it cannot be expressed as a ratio between two integers. There is nothing peculiar to base 10 about that.

They're not moving FTL relative to us, though, they are receding. We most definitely do not observe them moving FTL. The observations, if you want to get technical, are patterns of different shiny spots in the sky. Cosmic expansion scenarios are the only explanations that fit the observations and successfully predict others.

This is what I'm saying. So, to rewind: Could we observe an object moving away from us FTL? Invalid scenario. Can we currently observe any objects that are currently receding due to cosmic expansion FTL? Yes. Can we currently observe any objects that were receding due to cosmic expansion FTL when the light we're seeing was emitted? Yes. (But not light that was emitted after the first 5 billion years or so of the universe.) Will we observe light that is emitted now from any object receding due to cosmic expansion FTL? No. (Unless cosmic expansion stops accelerating.) Do we all agree?

I'm seeing a lot of questions here that seem to be intended as challengingly rhetorical, but actually have straightforward answers. (Gravity vs. magentism, radio vs. visible light, etc.) Not challenging cutting edge physics, but really basic stuff, in some cases first demonstrated centuries ago (and in a million different ways since then), that much of the technology we use today relies upon. What I'm getting at here is not just a way of saying "you're ignorant" (you are, but that in itself is nothing to be ashamed of - we're all ignorant in different fields), but that you lack the grounding to be critical, especially in such an accusatory tone. If you want to ask questions about what we know and how we know it, go right ahead (just do it in the appropriate subforums). And so too for the scientific method itself, which doesn't work the way you seem to think it does. This place is full of people who love explaining things to curious laymen. There is less tolerance for people coming in accusing us (as representatives of "science," I guess) of "persecuting" them for their "theory" that "obviously" the television is full of tiny people (else how how could you see them?). There really are good reasons to think otherwise, and a perfectly good alternative explanation. It's not just a guess as good as any other, I promise you.

And the photons that reach you would have infinite energy if moving towards you, and negative energy if moving away. And the object emitting them would be moving backwards in time, and violate causality. Ignoring most of relativity, though, you could have neat effects! For example, an object moving towards you would appear to be moving away, since the photons it emits last (when closest to you) would reach you first.

I'm amused by the image of OBAMA personally cleaning up the Gulf of Mexico, by himself.

Then sorry. I misunderstood. You did say "independent of any space expansion," which I interpreted to mean despite space expansion. I see now you simply meant disregarding it. Yes, totally correct. Which I would agree with, except that an object with a relative velocity >C doesn't really make much physical sense, at least not in terms of interaction with us.

The energy of a photon is proportional to its frequency, and inversely proportional to its wavelength. As the object you're viewing approaches the speed of light, the redshift approaches infinity, and hence the energy of the photons you receive approaches zero. And it is. No, it is not the result of a simple Galilean summation of speed. We're not talking about objects moving away from one another, we're talking about the amount of space in between them increasing, and the rate of that increase accelerating. A photon emitted from an object receding at FTL is indeed approaching us at exactly C. However, it will still never reach us. This is an effect that is not covered by special relativity, but it is not contradictory to it, either. No, it is not. Look: http://en.wikipedia.org/wiki/Hubble_volume The early universe is different, because the rate of expansion was decreasing (rapidly). In the intervening time, the Hubble sphere grew faster than the universe and overtook it. When the rate is constant or accelerating (as it is now and will continue to be AFAWK), it remains true that objects receding FTL will never be observed. What I should say is, anything emitted after the first ~ 5 billion years from an object receding FTL will never reach us.

I know, I just thought it might be possible to make physical sense of it anyway, as a hypothetical. But I'm thinking that might not be possible, since as Mr. Skeptic points out, an emitted photon would have "negative energy, whatever that means," which I guess means nothing. And I don't fully understand what a tachyon would actually be except in an abstract sense, and as a colored beam on Star Trek that solves time travel problems.

I don't think that's right. A photon that is emitted from an object receding FTL will never reach us. It is true that some of the light reaching us now is from objects that are currently receding FTL, but were not when that light was emitted.

An object moving away from us at FTL should still be visible, I think, though I'm not sure what we would actually see. A photon emitted from any particular location it has been would travel towards us at C in our reference frame, and reach us in a finite amount of time. An object receding from us via cosmic expansion at FTL would not be visible, as the distance the photon has to travel would increase faster that it does the traveling, and it would never reach us.

Of course. Everyone knows that to own something, you have to plant a flag in it.

That is absurd. Exactly the opposite of what the law ought to be, which is as much publicly available footage of law enforcement as possible.

What is it you eat now?

Wow, that is seriously awful. I can only imagine how violated and purely angry I would feel if that happened to me. I hope they catch them soon.

Yeah, that sounds about right.

My home page is Google News. I also browse the New York Times at least a few times a week, and I read through The Economist weekly. I also regularly browse blogs of various and disparate foci and ideologies, to see what stories people think are being ignored or misinterpreted by the "mainstream."