What does time weigh ?

[GOD]

I just saw an interview where they explained about black holes . They said a black hole can slow time down . To me that means that time must have a weight and / or an electromagnetic charge . Has anyone got any theorys ? Can anyone explain ?

 

[Forkbender]

I reckon it has something to do with space curvature. But I wouldn't know the specifics.

 

[Meduzz]

Yes it has to do with space time curvature. Gravity does not only work in 3 but 4 dimensions (perhaps ALL dimensions).

I don't know very much about it but here's my two cents:
Time can be interpreted mathematically as a line (just like the other 3 dimensions). Let's put 2 points (A and B) on the line. The distance bewteen these points is "d". If you curve the line of time, more piece of line is between AB (d being a constant).
The increase of time-line between A and B means more events can be put between them => time is slower.
d is the length of the timeline between A and B if it is not curved but straight.

 

[st.bot.32]

"Weight" is the result of gravitational attraction between two objects that have mass.

But something doesn't have to have mass to be affected by gravity. Photons are massless, but light still bends due to the curvature of space caused by the gravity of large objects.

This was actually predicted by general relativity and was confirmed in early experiments:

http://physics.ucr.edu/~wudka/Physics7/ ... de100.html

Interesting info, meduzz..

 

[Meduzz]

But something doesn't have to have mass to be affected by gravity. Photons are massless, but light still bends due to the curvature of space caused by the gravity of large objects.

But photons do have a relativistic mass.

From wiki:
"The mass of the photon is believed to be exactly zero, based on experiment and theoretical considerations described in the article. Some sources also refer to the "relativistic mass" concept, which is just the energy scaled to units of mass. For a photon with wavelength ? or energy E, this is h/?c or E/c2. This usage for the term "mass" is no longer common in scientific literature."

 

[st.bot.32]

Fair enough. But relativistic mass isn't really mass in the typical sense though, it's just used to measure the interaction between photons and matter... By the very nature of relativistic mass a photon has to be traveling at C, whereas any matter traveling at C would have infinite mass.

 

[Meduzz]

Depends on the definition of mass. People used gravity for ages to determine mass. Then it changed to "the amount of matter", but photon's arent matter, but they are affected by gravity.

gravity: G*m1*m2/r^2
Yes, mass

 

[st.bot.32]

Yes, mass

Time weighs 150 microgrammes.

 

[GOD]

Time and space dont exist individualy , they exist as a pair = time space . = Time is another dimension of space .

""Weight" is the result of gravitational attraction between two objects that have mass. "

So time space is an object that has mass = weight ? If a black hole can bend space space must have a weight and / or an electromagnetic charge .

 

[Meduzz]

So time space is an object that has mass = weight ?

Not with the definition that mass = amount of matter (current definition)

If a black hole can bend space space must have a weight and / or an electromagnetic charge .

Yes, a black hole is very very heavy in all meanings of the word mass.
The huge gravity is a direct consequence of mass being very dense in a black hole. The inside of a black hole has so much pressure there are even new particles formed called "strange particles"

 

[Guest]

there are even new particles formed called "strange particles"

Now that's what I call inspiration.

 

[GOD]

"Not with the definition that mass = amount of matter (current definition) "

Then how can a black hole effect space /time ? If "Weight" is the result of gravitational attraction between two objects that have mass. " and the effect black holes have on space are caused by gravity = space / time must be an object and must have a mass .

 

[Meduzz]

Then how can a black hole effect space /time ?

Well the answer to that gave Einstein a noble price, so I gues it's not able to be explained in one post :wink:

 

[GOD]

Try .

 

[Meduzz]

How does a black hole affect space and time?
How it affects space is clear by "simple" Newtonian physics.

Now how does it affect time? Maybe time stays the same and space is altered? After all, only the relation between time and space is of importance, if both are altered in the same way (so the relation is constant) we wouldn't notice.
Perhaps it bends space and time stays linear? Giving the impression that time is bent?

Just some loose thoughts though...

 

[GOD]

"How it affects space is clear by "simple" Newtonian physics. "

Explain and please stop talking about time or space . They are parts of the same thing = time space . Wich should mean nothing can effect one without effecting the other .

"Perhaps it bends space and time stays linear? Giving the impression that time is bent?"

The physisist said black holes can slow time down . Not our impression of it .


Where is Drugless ????

 

[Horrigan]

What is weird with time is that when you slow it down, you also accelerate it.

I mean, if on location B time flows at a rate of 2 seconds every second whereas it flows at a rate of 1 second every second on location A, time flows 2x faster on location B but it's also true to say it flows 2x faster on location A because one second ONLY takes 1 second on A whereas it takes 2 seconds on B.

So how to define time ?

 

[GOD]

No it takes half a second .

 

[Meduzz]

"Perhaps it bends space and time stays linear? Giving the impression that time is bent?"
The physisist said black holes can slow time down . Not our impression of it.

THATS what relativity is all about. Compare to Horrigan's post.
I'm not going to explain any more as it is hard enough for me to construct these posts. In science you have to leave the trivial meaning of a word and just follow the intuition of that word in context of the theory. Example: impression; I meant "point of view", you read "human emotion".

And as english isn't my native language (neither is it yours) it's very hard for me to explain. So please use some abstraction and try to ask yourself "why?" first.

 

[Meduzz]

No it takes half a second .

How would you know? The devices to measure time are also bound by the speed time goes in the place they are used.