Delta1212

QM isn't really illogical, just counter-intuitive.

Be aware, memory is extremely malleable to the point where it is quite easy to have memories of things that never happened or new information inserted into old memories without being able to distinguish what is original memory and what isn't. Rather than suddenly remembering that you've seen something before in detail immediately after it happens, it's quite possible that a memory storage error got the new information mixed up with an older memory and suddenly you "remember" the new memory as having happened before even though it didn't. The effect can range from a vague feeling of familiarity to being able to full on visualize stuff that never actually appeared in the original memory as if it had always been there.

From the perspective of the sun. If you have two observers moving in opposite directions with respect to the sun, the sun is most definitely moving as seen by one or both observers.

The Planck length is, theoretically, the smallest distinguishable distance between two points. We aren't even close to being able to detect things that small (for reference, the radius of an electron is about 10,000,000,000 times the Planck length) so what physical significance the Planck length actually has is, at this point, purely theoretical. That said, it's been mathematically proven that pi doesn't have an end decimal place.

Well, maybe-ish. It's very difficult to make qualitative statements about the subjective experience of sensory input that we can't process in the same way an animal does.

There isn't really a center of the universe as far as we can tell.

Universal expansion means that everything is moving away from us. So light emitted 13 billion years ago from an object 13 billion ly away reaches us after 13 billion years, during which time the distance has increased to 46 billion ly.

It's not saying that we can't see as far as we theoretically could. It's saying that we could not, even in theory, see any farther than we do. It's like saying that the fastest we can theoretically communicate over any distance is the speed of light. We frequently do communicate at that speed, but the importance of noting it as a theoretical limit is conveying that it's impossible to do any better, not that it's a limit we think we can reach but haven't.

Something to consider: the most common number one fear of young men as self-reported in research surveys is being perceived to be gay. The easiest way for someone who is afraid of being seen as gay to "prove" they aren't is to act visibly disgusted at homosexual acts. This doesn't mean that anyone who says they are disgusted or acts disgusted definitely isn't disgusted, nor does it mean that they are really gay, but it does mean that it's fairly likely that any show of disgust is going to be somewhat exaggerated from the true reaction of the person in a significant percentage of people simply because it's how they think they're supposed to react and they don't want the social stigma involved in people thinking they weren't disgusted enough, which does still exist in a lot of places even as wider acceptance of homosexuality has come about.

It's really not anyone's job, although Mike seems to have provided a pretty detailed answer anyway.

Where classical mechanics predicts a horse, QM instead finds a zebra and pop sci writers everywhere announce the discovery of a unicorn.

It's not rotting. It's fermenting into something more fun.

When did the population of Great Britain die off, exactly?

By all means, question everything. Questioning is how we learn, but just because you've thought of a question you don't know the answer to doesn't mean there isn't an answer, and someone else answering the question is not suppressing your ability to question things; it just means other people thought of those questions before you and figured out what the answers were. To find a flaw or gap in current knowledge of a subject, you have to find a new question.

Hyperspace is a cheat used in science fiction to circumvent some inconvenient physical laws, but it usually ignores the fact that if you could travel faster than light, you'd wind up going backwards in time and arrive at your destination before you left.

As stuff falls into a black hole, the black hole gets bigger. This black hole is at the center of a whole galaxy where the density of stars and other matter goes up as you move toward the center. That's a lot of stuff that can, and does, fall into the black hole.

Nothing with mass can travel at the speed of light. You can only approach it. You also experience time dilation traveling at any speed, but it's too little to notice unless you're going at a significant fraction of light speed for a measurable period of time. The closer you get to the speed of light, the more time dilation you experience.

Yes, but eventually you'd run out of those chemicals that release energy. Saying that they'd be re-formed by an endothermic reaction using the ambient heat (that they released) is a bit like building an elevator that goes up by dropping a counter-weight, and then raises the counter-weight back up by dropping the elevator. In that case, no weight is leaving the system, but your ability to use that weight to lift things decreases. It's the same with energy. It takes more energy than is released by a chemical reaction to store that energy again in the same form. You will always wind up with less usable energy at the end than when you started. That doesn't mean that the energy has left the system, it just means you can't use it to do work. Eventually, your bubble will run out of energy that can do work and that resource will be "used up" even though the total energy in the bubble remains unchanged.

Earth's frame is being used because it's the one where they are brought back together for comparison. If, instead of turning around, the traveling twin continued on his path away from Earth, and, after some years, the twin on Earth blasted off and caught up with the traveling twin, the twin who had been on Earth initially would be younger. He'd also be the one who traveled away from the other twin (along with the Earth) and then turned around and came back.

One experiences time dilation for 10 seconds (Earth time). The other experiences time dilation for 50 years (Earth time). The fact that they don't have the same difference in aging isn't particularly surprising.

B will be younger than C if B leaves with C, returns to Earth, again leaves Earth, catches up with C and then returns with him. This wasn't the scenario swansont was responding to.

I don't see where anything I said contradicts swansont.

Are you asking whether, if two twins leave Earth together, one turns around and goes back, then turns back around, catches up to the other and they bo return together, the twin who first turned back will have aged more slowly? If so, then yes.

There are two events: the twins separating, and the twins coming back together to compare ages. These two events are separated in spacetime. The longer the path through space you take from one to the other, the shorter your path through time. The shorter your path through space, the longer your path through time. The separation and final comparison both take place at rest with respect to the twin who stays behind. In this frame, the twin never moved and therefore experienced the maximum amount of time. According to this frame, the twin that leaves and returns traveled some distance, and this means he experienced proportionately less time. While the twin is initially traveling, he can say that he is the one at rest and the other twin is moving. At this point, both twins will say that the other has aged less, but this isn't a problem because you can only compare clocks if they are co-located. However, once the twin turns around, he can no longer say that he spent the whole time at rest while the other twin traveled because there is no inertial path that goes from the twins separating through the turnaround point and then to the return where the clocks are compared. To answer your question: If 50 years pass on Earth during which one twin is traveling out and back at 99% of the speed of light, that twin will age 7 years. If, during that time, the other twin takes a ten second trip out and back at 90% of the speed of light, that twin will be about 6 seconds younger than he would have been if he'd stayed on Earth the whole time. So their ages would be, if they started when they were first born, 7 years old and 49 years, 364 days, 23 hours, 59 minutes and 54 seconds, respectively, after 50 years as measured on Earth.

Nothing is ever finished evolving until it's extinct.