NASA's Kepler Mission Announces Largest Collection of Planets Ever Discovered

[Ripster42]

Ah so the speed of light in a vacuum that reflects on a particle (back and forth) is at 186,000 mps.
In a non vacuum without interaction of a particle it can bounce off on it is unlimited?

No, it's not unlimited, it's slower. I think this is you not understanding reference frames and what speed does to different reference frames' perception of time.

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IF you are sufficiently close to the speed of light from your point of view...maybe. From the view point of everyone you left behind....Days month, years decades or more.

Yes, he mentions that on the first page. Paraphrasing: It'll take seconds for you, but the earth might not be around when you get back.

[Barael]

https://en.wikipedia.org/wiki/Relativistic_rocket

http://math.ucr.edu/home/baez/physic...et/rocket.html

Essentially, all I need is a rocket that can indefinitely accelerate at 1g and I can reach Andromeda (2 million lightyears) in 28 years. This is, as noted before, BECAUSE relativity, not in spite of it.

The key word is length contraction and it's not any "theoretical" consideration of relativity but is easy to observe in our own atmosphere:



In short, muons created in our upper atmosphere have too short of a lifetime to reach the surface from OUR point of view but due to their high velocity, the distance is contracted for THEM and they do in fact reach the surface.

[Uzkin]

If a rocket is moving nearly at c towards a star 4 light years away, an Earth-based observer will measure that the trip took a bit more than 4 years. The Earth-based observer will also see that the clocks on board the rocket tick very very slowly and therefore those clocks (and the passengers) won't age much during the trip, lets say only one week (= time dilation).

The observers on board the rocket will see the star approaching them nearly at c and the distance between Earth and the star to be massively contracted; the distance in their reference frame would be only about one light-week (= length contraction). Thus in their frame they would reach the star (or rather, the star would reach them) in only one week. Both the Earth-based and rocket-based observers agree that the passengers only aged one week during the trip.

This according to Special Relativity. Here the times and distances refer to their "true" values once the visual signal travel times etc. have been accounted for.

[Gheld]

Another issue to overcome is the fact that relative to the traveler the universe begins to emit electromagnetic radiation of ever increasing temperature.

Close to the speed of light you'd essentially get roasted to death.

[Ulmita]

Man NASA should be sponsored by the whole globe. They are doing quite some work there.

[-Nurot]

From an external reference frame.

Well for all purposes intended, we couldn't send out a manned mission to check for habitable planets with the human race on the brink of destruction, for example, and send them 100 light years out.

Good news the planet is atmosphere friendly and filled with flora. Bad news is there was a nuclear winter in the 200 years you were gone and you're services aren't needed anymore.

[Ripster42]

The key word is length contraction and it's not any "theoretical" consideration of relativity but is easy to observe in our own atmosphere:

https://www.youtube.com/watch?v=ejcaz7wXawY

In short, muons created in our upper atmosphere have too short of a lifetime to reach the surface from OUR point of view but due to their high velocity, the distance is contracted for THEM and they do in fact reach the surface.

I had to rewind a few times. At first I thought that guy had a mu tatooed on his eyeball when they showed it. Turns out it's just blood vessels that look vaguely like it.

[Mifuyne]

My apologies to Holas :P

[Holas]

My apologies to Holas :P

No problem dude - it surprised me as well when I first figured this out as it was against everything I thought (and it was years after taking my undergrade courses in basic private relativity). Nice of you to write this though. I should have explained my point and not just give the final result.

I am happy some people understand this better now as I think it could have pretty insane applications.

[Grimbold21]

Looks like the thread forgot about the planets as quickly as they were discovered :P

[Holas]

Looks like the thread forgot about the planets as quickly as they were discovered :P

My first comment was that this isn't really exciting or even news - it seems like a summary of the mission. The more exciting papers/science from kepler these days are about special interesting systems.

[Gadion]

No problem dude - it surprised me as well when I first figured this out as it was against everything I thought (and it was years after taking my undergrade courses in basic private relativity). Nice of you to write this though. I should have explained my point and not just give the final result.

I am happy some people understand this better now as I think it could have pretty insane applications.

I would actually like to take you up on that explanation... it seems I require the For-Dummies version. I'm reading on this on the Wikipedia, but am trouble relating to it. Perhaps it has something to do with my being incapable of thinking about time as something that exists and can be altered :s

I'll reserve my apology for when it's not just a hollow statement and I actually understand what you're trying to say.

[Deletedaccount1]

You can't travel faster than light (probably) but you don't need to. All you need is to travel close to light speed and then you could reach any spot in the universe in a matter of seconds.

post of the year

[Holas]

post of the year

Sigh.......
Edit: Hehe I even got a signature out of it. Please do keep it though after you understand its actually correct.

[Deletedaccount1]

Sigh.......

dude you are my new sig, you should be happy.

[Ripster42]

I would actually like to take you up on that explanation... it seems I require the For-Dummies version. I'm reading on this on the Wikipedia, but am trouble relating to it. Perhaps it has something to do with my being incapable of thinking about time as something that exists and can be altered :s

I'll reserve my apology for when it's not just a hollow statement and I actually understand what you're trying to say.

It's a concept that can be difficult to internalize because it's not something you really ever experience viscerally.

Say you have two people. One standing still, one running at 0.5c (he's a hell of an athlete) compared to the stationary guy. Right when the running guy passed the stationary guy a photon of light is released in the same direction the guy is running in. To both people, the light is moving at the same speed. It's not moving at 0.5c for the guy running, it's still moving at c. The only way to reconcile this is for time to be moving slower for the running guy.

[Voidism]

At least people in the thread knows that spacetime is a thing and don't subscribe to the Newton world view of gravity as a force like most people in the world.

If I was travelling at the speed of light I'd experience the process of going to our nearest star (4 light years away) as instant. People on the Earth would see me doing 4 years of travelling.

My time goes slower compared. I'm almost frozen in time and experience those 4 years compared to the Earth as almost instant.

It's all relative to what you compare it with.
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OnT:

Cool! I hope we'll see aliens soon. Would make people think about bigger things.

[Barael]

Say you have two people. One standing still, one running at 0.5c (he's a hell of an athlete) compared to the stationary guy. Right when the running guy passed the stationary guy a photon of light is released in the same direction the guy is running in. To both people, the light is moving at the same speed. It's not moving at 0.5c for the guy running, it's still moving at c. The only way to reconcile this is for time to be moving slower for the running guy.

What's more interesting to think about is what it would mean if this DIDN'T happen (ie. if relativity was wrong). Not only would the "moving" could get completely different results from almost any physical experiment (since most of them depend on the value of c in some, however remote, way) but the "moving" guy wouldn't even get consistent results in regards to himself, since he would measure the speed of light to be two different things depending on the direction. Also, there would have to be some preferred reference frame in the Universe against which all movement would be measured.

If anyone ever thinks that (Special) Relativity is weird, the facts is things would be a LOT weirder, as in 1+1=3 levels of weird if it wasn't true.

[Gadion]

It's a concept that can be difficult to internalize because it's not something you really ever experience viscerally.

Say you have two people. One standing still, one running at 0.5c (he's a hell of an athlete) compared to the stationary guy. Right when the running guy passed the stationary guy a photon of light is released in the same direction the guy is running in. To both people, the light is moving at the same speed. It's not moving at 0.5c for the guy running, it's still moving at c. The only way to reconcile this is for time to be moving slower for the running guy.

I'm sorry if I don't respond to this, and I really appreciate the effort of helping me to understand. I'm trying to process this.

At least people in the thread knows that spacetime is a thing and don't subscribe to the Newton world view of gravity as a force like most people in the world.

If I was travelling at the speed of light I'd experience the process of going to our nearest star (4 light years away) as instant. People on the Earth would see me doing 4 years of travelling.

My time goes slower compared. I'm almost frozen in time and experience those 4 years compared to the Earth as almost instant.

It's all relative to what you compare it with.

I'm afraid I appear to still be in the Renaissance.

[Voidism]

I'm afraid I appear to still be in the Renaissance.

It's not like I understood everything the first time I heard about it. It IS difficult and easy to forget that I wasn't born with the knowledge. I certainly wasn't.
Don't worry, after a while it will feel relatively natural. You can view spacetime as two glasses. If you fill the space one with speed you need to take away speed from the time glass. You have only a specific amount of speed that you switch between the glasses. If it's almost empty you are "frozen" in space or time depending on the glass and very quick in the other glass. Quick space travelling means slow time travelling. It's not linear though. At our human speeds it doesn't practically feel any difference.