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Time

Just finished reading A Brief History of Time by Stephen Hawking and I have a newfound fascination with time. One of the concepts he discusses is the relativity of time and gravity’s effect on it. As in, time moves slower near large masses due to their gravitational forces. Taken to the extreme, if I were to travel close to a black hole, time would slow down significantly and seconds for me would be hours on Earth for instance (just making up the scale but like in the movie, Interstellar).

It makes sense theoretically, but when I try to think about it practically, I’m having a hard time fathoming it. Would this potentially be a way to “time travel”? As in, travel to a distant planet 10x the mass of Earth, live there a year and return to Earth for it to be 10 years in the future (assuming linear scaling and a host of other assumptions of course). Thoughts? Any recommendations for other books on the topic? (just ordered The Order of Time)

Hey Hamilton, have a holly jolly Christmas.

The Order of Time is a phenomenal book that will blow your mind. Rovelli has a way with words that takes concepts one should already know if they have been exposed to General or Special Relativity, but he couches them in a way that really makes it hit home why those are important paradoxes (the one about communicating with a person on Proxima Centauri b really caused a sense of wonder in me).

Time travel forward from the perspective of the traveler via time dilation is a well-understood and accepted phenomenon that has been established since Einstein’s day (in fact your GPS devices work because of calculation corrections baked into the computers which compensate for the gravitational effects of the Earth). You can get to time dilation either through acceleration or gravitational differentials. The real problem for physicists has always been figuring out how to prove you can go backwards along the same timeline without doing a paradox-avoiding leap into a parallel universe. 

"When what I'm doing isn't working, that's when I'll take your criticisms." -- Me, some time ago

Good to hear - looking forward to reading it.

Thought experiment (ignore current technological and physical limitations): if someone flew near a black hole and was able to stream a live feed of themselves back to Earth, would we be viewing them in slow motion? And if they could see a live stream of Earth, would they be viewing us in fast forward?

Hey Hamilton, have a holly jolly Christmas.

I wish AF would go back in time.#FreeTurd #FreeCVM #RessurectJDV

Regarding going forward in time relative to someone on earth, it’d be much more practical to get a fast ship and zip around the galaxy for a while rather than hang out near an object that would crush you.

Velocity and time are inversely related (kinda like gravity). So, if you are able to travel at 99.99% of the speed of light, time would essentially stop for you while ticking normally back home. Taken to the extreme, a photon (light particle) traveling in a vacuum is moving at the speed of light. Since it’s moving at 100%, time stops completely for the photon. This means the light from a star 10 billion light years away hit the earth instantaneously upon its creation. From the photon’s perspective, no time passed in the 10 billion years it took to travel the universe to reach us. Let that sink in. Crazy stuff out there.

Read some Brian Greene too. He does a great job of illustrating these points for us armchair astrophysicists that are interested but can’t do the math. 

Now, going backwards in time is a real mind bender…

Can someone explain why in the end of Interstellar, Matthew Mcounoughy was able to steal one of the fighter jets to go look for Anne Hathaway? Does this mean that they could have been looking for her this whole time but just didn’t bother? What a bunch of mofos.

“Visit the Water Cooler forum on Analyst Forum. It is the best forum.”
- Everyone

who is jdv? any greatest hits?

I love my cheese. I got to have my cheddar.

Nerdyblop wrote:

who is jdv? any greatest hits?

Like S2000 but more pretentious and a total asshole. He helped a ton of people pass the exams. Very active on the CFA boards, answering tons of questions, etc. So, people really liked him. Plus, there’s no doubt the guy is extremely smart. According to him, the smartest person on AF.

Then he left for a bit, came back a couple years later to announce he was going to work on Obama’s economic council (which wasn’t met with the cheers I think he was expecting), and hung out in the WC for a few months before leaving again. 

Seeing as he was a Krugman-loving economist, he and I didn’t really get along. There’s no denying his positive impact on AF and he undoubtedly helped dozens of people pass the exams. He was just socially retarded, imo.

^mess with the best, die like the restttttttttt

I love my cheese. I got to have my cheddar.

So let’s say I set a timer on Earth for 1 minute and, at the same time, someone else sets another timer for 1 minute on a planet with twice the gravity. Once the full “Earth minute” has passed, the other timer would read 30 seconds remaining correct? (assuming linearity between gravity and time for simplicity’s sake)

If that’s the case, has the same amount of “moments” passed for the other person even though it was in half the time? As in, did the ticking clock just move at half the speed for the other person as he experienced the same number of “moments” as I did? Or did his clock tick at the same rate as mine from his perspective, but his actual passage of time was just at half the speed? As in, he was essentially living in slow motion relative to me and half the amount of “moments” had passed.

I guess I’m trying to reconcile the movement of time according to a watch versus the ACTUAL passage of time. Am I making any sense?

Hey Hamilton, have a holly jolly Christmas.

IsThereAny wrote:

So let’s say I set a timer on Earth for 1 minute and, at the same time, someone else sets another timer for 1 minute on a planet with twice the gravity. Once the full “Earth minute” has passed, the other timer would read 30 seconds remaining correct? (assuming linearity between gravity and time for simplicity’s sake)

If that’s the case, has the same amount of “moments” passed for the other person even though it was in half the time? As in, did the ticking clock just move at half the speed for the other person as he experienced the same number of “moments” as I did? Or did his clock tick at the same rate as mine from his perspective, but his actual passage of time was just at half the speed? As in, he was essentially living in slow motion relative to me and half the amount of “moments” had passed.

I guess I’m trying to reconcile the movement of time according to a watch versus the ACTUAL passage of time. Am I making any sense?

Is it true that you age slower in space? So if you lived on a spaceship and everything else were the same as compared to the situation down on earth, you’d live longer because time moves slower in space? Heard this once but I find it very hard to believe. 

If you're the first out the door, that's not called panicking

The greatest asset is time. So if I can live longer in space I would do it. So that when I come back to earth, I’m one rich mother****er.

I love my cheese. I got to have my cheddar.

Nerdyblop wrote:

The greatest asset is time. So if I can live longer in space I would do it. So that when I come back to earth, I’m one rich mother****er.

Yeah you’d be loaded, unless you went long those 5x sp500s. But you could be the same age as your kids or even grandkids, which would make Thanksgivings a pretty awkward gathering.  

If you're the first out the door, that's not called panicking

Ud have to factor the cost of the trip and the amount of money you have invested. Plus how much time you are spending while at space. Anyways I remember reading Enders game and they talked about that idea. 

I love my cheese. I got to have my cheddar.

True. I think space life could make a dent on your cash. 

What a great read. I read that book and realized afterwards that there’s like a series of 10 books that you should read before reading ender’s game or something. I was pissed. 

If you're the first out the door, that's not called panicking

Iike a prequel? I thought there were only sequels. 

I love my cheese. I got to have my cheddar.

Nerdyblop wrote:

Iike a prequel? I thought there were only sequels. 

Yeah, the dude first wrote Ender’s game but afterwards wrote a whole series leading up to it or something like that. So Ender’s game is the last book in a series, IMO. I’m not 100% sure though. 

If you're the first out the door, that's not called panicking

https://en.wikipedia.org/wiki/Ender%27s_Game_(series)

books are pretty new. enders game was a required reading in hs, but i loved the book. his older brother peter was my favorite character. enders a lame ass fool.

I love my cheese. I got to have my cheddar.

****ing bonzo

“Visit the Water Cooler forum on Analyst Forum. It is the best forum.”
- Everyone