Hawking radiation evidence

[outlaw]

is this evidence of hawking radiation?also is there any other evidence for it? http://blogs.discovermagazine.com/80bea ... radiation/

[neufer]

is this evidence of hawking radiation?
also is there any other evidence for it?
http://blogs.discovermagazine.com/80bea ... radiation/

1) probably not
2) no

[The Code]

is this evidence of hawking radiation?also is there any other evidence for it? http://blogs.discovermagazine.com/80bea ... radiation/

Didn't Roger Penrose win that battle ?

http://en.wikipedia.org/wiki/Cycles_of_Time_%28book%29

tc

[neufer]

is this evidence of hawking radiation?also is there any other evidence for it?
http://blogs.discovermagazine.com/80bea ... radiation/

Didn't Roger Penrose win that battle ?

http://en.wikipedia.org/wiki/Cycles_of_Time_%28book%29

Different issue.

[outlaw]

is this evidence of hawking radiation?
also is there any other evidence for it?
http://blogs.discovermagazine.com/80bea ... radiation/

1) probably not
2) no

what does the article talk about?

[Aescens]

The article first gives a little background on Hawking radiation. Then says that a team of researchers claims to have found another way to separate particle/anti-particle pairs without using black holes (because we cannot create ones to experiment with this). However their experiment is only a claim, it is not proven at all, only as an idea for now till it is evaluated and redone.

[outlaw]

The article first gives a little background on Hawking radiation. Then says that a team of researchers claims to have found another way to separate particle/anti-particle pairs without using black holes (because we cannot create ones to experiment with this). However their experiment is only a claim, it is not proven at all, only as an idea for now till it is evaluated and redone.

can hawking radiation be explained without virtual particles?

[neufer]

can hawking radiation be explained without virtual particles?

Of course.

The main advantage of virtual particles is in providing for simplified explanations.

[outlaw]

can hawking radiation be explained without virtual particles?

Of course.

The main advantage of virtual particles is in providing for simplified explanations.

how come all the information i get is connecting virtual particles with hawking radiation?

[neufer]

can hawking radiation be explained without virtual particles?

Of course.

The main advantage of virtual particles is in providing for simplified explanations.

how come all the information i get is connecting virtual particles with hawking radiation?

Probably because you wouldn't understand alternative explanations
(which are mathematically equivalent to virtual particle explanations anyway.)

[outlaw]

do virtual particles time travel?

[Aescens]

do virtual particles time travel?

What do you mean by time travel? The movie definition? Or relativistic and quantum effects?

[neufer]

do virtual particles time travel?

• You have no idea

[url=http://www.realmagick.com/path-integral-example/]Path Integral Example of a virtual outlaw[/url] :wink:

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[outlaw]

do virtual particles time travel?

• You have no idea

[url=http://www.realmagick.com/path-integral-example/]Path Integral Example of a virtual outlaw[/url] :wink:

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so they do time travel backwards?

[outlaw]

do virtual particles time travel?

What do you mean by time travel? The movie definition? Or relativistic and quantum effects?

what would be the difference?

[Chris Peterson]

What do you mean by time travel? The movie definition? Or relativistic and quantum effects?

what would be the difference?

The "movie definition" suggests something physically traveling backwards in time, carrying information. No particle does that, virtual or otherwise. But in quantum mechanics it is convenient to consider that particles can travel either forward or backward in time. They need not be virtual- positrons are typically treated as moving backwards in time. This does not violate relativity or causality, however, since no information is transported backwards in time.

[outlaw]

What do you mean by time travel? The movie definition? Or relativistic and quantum effects?

what would be the difference?

The "movie definition" suggests something physically traveling backwards in time, carrying information. No particle does that, virtual or otherwise. But in quantum mechanics it is convenient to consider that particles can travel either forward or backward in time. They need not be virtual- positrons are typically treated as moving backwards in time. This does not violate relativity or causality, however, since no information is transported backwards in time.

So virtual particles don't time travel backwards?

[Chris Peterson]

So virtual particles don't time travel backwards?

In the way you seem to intuit the meaning of traveling backwards in time, no, they don't. No particles travel backwards in time, although it is sometimes convenient to treat them that way mathematically, within the framework of current theory.

[outlaw]

So virtual particles don't time travel backwards?

In the way you seem to intuit the meaning of traveling backwards in time, no, they don't. No particles travel backwards in time, although it is sometimes convenient to treat them that way mathematically, within the framework of current theory.

On this article,maybe i reading it wrong if you scroll down to "faster than light?" it says they do travel backwards in time. http://en.wikipedia.org/wiki/Propagator

[Chris Peterson]

On this article,maybe i reading it wrong if you scroll down to "faster than light?" it says they do travel backwards in time. http://en.wikipedia.org/wiki/Propagator

You are reading it wrong. You are failing to distinguish between a mathematical (or even physical) equivalency to going faster than light or going backward in time, and what this means when stated in English (which is very imprecise for ideas like this).

If you want to envision some particles going backwards in time, do so. But since there is no information being conveyed in that direction, it's hard to see what difference it makes.

[outlaw]

On this article,maybe i reading it wrong if you scroll down to "faster than light?" it says they do travel backwards in time. http://en.wikipedia.org/wiki/Propagator

You are reading it wrong. You are failing to distinguish between a mathematical (or even physical) equivalency to going faster than light or going backward in time, and what this means when stated in English (which is very imprecise for ideas like this).

If you want to envision some particles going backwards in time, do so. But since there is no information being conveyed in that direction, it's hard to see what difference it makes.

if im reading relativity correct,please correct me if im wrong,if something were to travel faster than light in one frame it will travel backwards in time?

[Chris Peterson]

if im reading relativity correct,please correct me if im wrong,if something were to travel faster than light in one frame it will travel backwards in time?

If pigs could fly. The "if" in this case is physically meaningless. Since nothing physical can travel faster than c with respect to another physical thing in the same frame, nothing can travel backwards in time by that mechanism. Just because the math leads to that conclusion (i.e. if you plug in v>c you get -t) that doesn't mean there is any physical meaning to it. All sorts of theories are described by math that can lead to unphysical conclusions if you fail to take into considerations the conditions of validity for those theories. And one of those conditions in the case of relativity is that v<=c. Outside that boundary condition, the math that describes the theory is not valid.

[outlaw]

if im reading relativity correct,please correct me if im wrong,if something were to travel faster than light in one frame it will travel backwards in time?

If pigs could fly. The "if" in this case is physically meaningless. Since nothing physical can travel faster than c with respect to another physical thing in the same frame, nothing can travel backwards in time by that mechanism. Just because the math leads to that conclusion (i.e. if you plug in v>c you get -t) that doesn't mean there is any physical meaning to it. All sorts of theories are described by math that can lead to unphysical conclusions if you fail to take into considerations the conditions of validity for those theories. And one of those conditions in the case of relativity is that v<=c. Outside that boundary condition, the math that describes the theory is not valid.

I think this is the article that says virtual particles travel faster than light and even backwards in time. http://www.desy.de/user/projects/Physic ... icles.html

[Chris Peterson]

I think this is the article that says virtual particles travel faster than light and even backwards in time. http://www.desy.de/user/projects/Physic ... icles.html

I'm pretty sure you're just a poorly written computer program. A real person wouldn't keep asking the same question over and over after it had already been answered (many times).

[outlaw]

I think this is the article that says virtual particles travel faster than light and even backwards in time. http://www.desy.de/user/projects/Physic ... icles.html

I'm pretty sure you're just a poorly written computer program. A real person wouldn't keep asking the same question over and over after it had already been answered (many times).

Do we know of anything that travels back in time?