Sisyphus

Well, +1 for Americans vs. British in category: accurate representations of friction in cliched similes. USA! USA!

I've never heard that expression. Rubber has plenty of friction with glass, though. Or dry glass, at least. Why not get a window wet and try rubbing a sneaker on it?

To be fair, I'm quite ready to believe that "something very significant" will happen within 63 million years of 2012.

Just going by Wikipedia, it looks like there have been about a dozen supernovae visible to the naked eye, although only five have actually been confirmed by identifying the predicted remnants. The earliest was in 185AD, and the most recent was in 1604. Kepler wrote a book about it. The one in 185 would have been only about 3000ly away, and there is one claimed remnant only about 700ly away, although it should have been visible from Earth around 1250AD, and there are no records of it. The others are all farther. So yeah, it would be a rare and amazing event.

I don't think the reaction is as universal as you think...

Wow, that would really be something. Has there ever even been one that close in recorded history?

We have software that automatically takes posts that it deems probable spam and keeps them invisible until a moderator either lets them through or deletes them. It actually works quite well, catching probably 95%, with only the occasional false positive like this one.

Again: The measurement you make is the "distance" (time elapsed in the original, or vertical height in the analogy) AA1. You then calculate AB.

No you wouldn't be measuring the hypotenuse. To make an analogy where you replace the time in that graph with another axis of distance: You want to know the length of AB. You have a physical wedge of a known angle*, angle A-B-A1. You lay it down across AB, pointy side at A. You measure the vertical height of the wedge at B, i.e. length BB1. What you have then is angle-angle-side, and from that you can calculate length AB. However, thank you for finally stating what you're trying to get at, Minkowski diagrams. That's not going to make any sense without general relativity, and there's not going to be any point if you're only dealing with one reference frame. *Or to more closely parallel velocity as distance/time, "height gained per unit width"

http://en.wikipedia.org/wiki/Persistence_of_vision I don't know if that's the whole explanation, but it's definitely part of it.

Didn't you just say what you measured?

In this particular experiment, yes. Not as a rule. Here you're calculating distance based on known velocity and measured time.

The diagonal is just an artifact of how you drew your graph, which is arbitrary. Just because you happen to draw it so that a second and a meter are represented by the same distance on a piece of paper (in orthogonal directions), doesn't mean they are directly comparable, let alone equal. So yes, you are measuring two things. Time in seconds, and then distance in meters.

There isn't a difference, though. I made that comment when I thought both axes were spatial.

Ok. Since B hasn't moved relative to A between time 2 and time 0, there is nothing to calculate. The distance is observed as 6*10^8m, and it is 6*10^8m.

True, I didn't realize the Y axis was time. That doesn't make any sense.

I don't understand why you're calling it a "space part" and a "time part." That is just needlessly confusing. It's a calculation of spatial distance, full stop. Yes, there is a difference between the observed location and the present location. So what?

What counts as an "interstellar ship?" You're effectively saying that no space colony of any kind can ever be self-sufficient. That seems like an extraordinary and unsupported assertion. As for history, I was just poking fun for getting your monarchs mixed up. There wasn't a "King George" until 1714. And there was a Church of England, of which the monarch was in fact the head, since Henry VIII in 1534. And there was an official English translation of the Bible since 1538, though various unofficial ones predated it. And of course this didn't set off the Protestant Reformation, which started decades earlier. But none of this really seems relevant to planet-moving.

You would need about half as much energy if you were utilizing current orbital velocity.

Zero useable energy. I should have pointed this out earlier, but there were a lot of different issues going on. You can get energy from burning hydrogen, but you will always get less than you used to separate it out in the first place. How? Merged post follows: Consecutive posts merged For the planet itself. Not for the human species. I take it it's been a long time since history class, eh?

If I understand you, you're wondering if maybe cosmic expansion is really tidal ripping inside a black hole. Right? I don't think that would work. Cosmic expansion is equal in all directions, in proportion to distance. Surely that wouldn't be the case inside an event horizon?

We haven't directly observed a black hole (and we couldn't directly observe the inside of one even if we found one), but you can observe the curving of space due to mass: http://en.wikipedia.org/wiki/Tests_of_general_relativity Theories evolve and obviously there is much we don't know, but calling something that has made so many accurate predictions mere "guesswork" is not really fair. The "slowing light down" thing is off topic, but for what it's worth, it's actually not slowing light down. When light "travels" through a fluid, it's really photons being absorbed by the material, than other photons being emitted and reabsorbed, etc. in a chain reaction. This causes a delay every time, and so overall the light appears to be travelling "slower." Sometimes a lot slower, as in that case. However, individual photons are still all traveling as fast as they always do.

To elaborate, inside the event horizon of a black hole, space is bent so much that any straight line (and thus any path that light can take) just leads elsewhere inside the event horizon, and never outside. That's why nothing can escape, because there is literally no direction that is "out." Photons do not have mass. The confusion probably stems from the fact that they do have momentum, which is confusing if you're used to thinking of momentum as just mass*velocity.

So, to review the actual facts: 1) A calendar invented by "Mayanists" (not Maya) has a period of about 63 million years. 2) A couple of physicists have noticed elevated extinction rates at around 62 million year intervals, roughly. They don't know why. 3) One among the many proposed hypotheses is that it has something to do with galactic cycles, though there's no actual evidence for this. Why is this supposed to convince me that 2012 will be a very significant year?

Right, they just divert all power to the plot hole compensators.