Planck Force (Hijacked from Why do forces Exist?)

[TrappedLight]

Planck forces?

 

"it is believed" by whom?

 

And to use the limit, you then have to explain why c and G have the values they do.

 

 

 

That limit is theorized in unified field theories of gravity. It is the origin of the Planck forces and of black hole physics.

 

As for,

 

''then you have to explain why c and G have their values''

 

this is true. The origin of the forces can be given by the quantity I gave, but the question you raise is like asking why the fine structure constant has the value it has. We don't know why these field strengths exist, but we may actually already know their origin.

[ajb]

I think it may just be a unit of force, something similar to natural or geometric units. Right TrappedLight?

[TrappedLight]

What are the Planck forces?

 

 

The Planck forces, or rather Planck force is the upper field strength of the gravitational and electromagnetic fields.

I think it may just be a unit of force, something similar to natural or geometric units. Right TrappedLight?

The origin of the Planck scale may be attributed to as

[math]\frac{c^4}{G}[/math]

It is the classical or upper limit of both the gravitational and electromagnetic force, it is the grand unified force of black hole physics.

[math]F_P = \frac{c^4}{G} = 1.21027 \times 10^{44} N[/math]

[swansont]

Oh, this. http://en.wikipedia.org/wiki/Planck_force

 

It's not a limit, it's a scale. A value for force on a scale where you will need a quantum theory of gravity. Nothing really to do with what I was talking about.

[TrappedLight]

Oh, this. http://en.wikipedia.org/wiki/Planck_force

 

It's not a limit, it's a scale. A value for force on a scale where you will need a quantum theory of gravity. Nothing really to do with what I was talking about.

 

 

It is a limit and it is a lot deeper than what that article gets into.

[ajb]

The Planck forces, or rather Planck force is the upper field strength of the gravitational and electromagnetic fields.

Okay, so it is a unit of force. It looks similar to the notion of Planck mass and Planck length. I am not sure how this has much to do with the opening post.

[TrappedLight]

This article explains it better.

 

http://en.wikiversity.org/wiki/Strong_gravitational_constant

Okay, so it is a unit of force. It looks similar to the notion of Planck mass and Planck length. I am not sure how this has much to do with the opening post.

 

 

it's important because Planck physics ruled the beginning of the universe. Therefore, you can expect the upper/classical limit to be an important quantity when asking why forces exist.

Swansont argued it wasn't a limit but a scale. But it is actually also a limit.

[ajb]

it's important because Planck physics ruled the beginning of the universe. Therefore, you can expect the upper/classical limit to be an important quantity when asking why forces exist.

The interpretation of Planck force, as with the other Planck units is that it gives us a scale at which we would expect the effects of quantum gravity to be important. It probably indicated that forces are not quite the right language at that scale. Indeed, modern particle and gravitational physics actually tends not talk about forces rather fields and their interactions. So I am not really sure how much significance it should be given.

 

The Planck energy to me, seems a better thing to use, though they are of course all tied together.

[TrappedLight]

The interpretation of Planck force, as with the other Planck units is that it gives us a scale at which we would expect the effects of quantum gravity to be important. It probably indicated that forces are not quite the right language at that scale. Indeed, modern particle and gravitational physics actually tends not talk about forces rather fields and their interactions. So I am not really sure how much significance it should be given.

 

The Planck energy to me, seems a better thing to use, though they are of course all tied together.

 

 

The Planck Force may be attributed to all the field strengths since we assume that all quantum fields where actually unified - equal in their magnitude. When we speak of the quantity [math]\frac{c^4}{G}[/math], we are talking about the origin of the Planck Scale; this should include the Planck energy. Indeed, it should cover as you spoke about, all Planck parameters.

[ajb]

The Planck Force may be attributed to all the field strengths since we assume that all quantum fields where actually unified - equal in their magnitude.

"Hand-wavingly" okay. The GUT scale is far less than the Planck scale, so I don't really understand what the fields at this scale really. But okay.

[TrappedLight]

"Hand-wavingly" okay. The GUT scale is far less than the Planck scale, so I don't really understand what the fields at this scale really. But okay.

 

 

We may find out we cannot deal with the forces as we know it below the Planck Scale. In fact, as I understand it, physics generally breaks down at scales below the Planck origin.

With that said however, [math]\frac{c^4}{G}[/math] is an important scale as the origin of the classical upper limit.

[ajb]

We may find out we cannot deal with the forces as we know it below the Planck Scale. In fact, as I understand it, physics generally breaks down at scales below the Planck origin.

We know that we cannot deal with the forces in quite the same way as we usually do, that is via the standard model and GR near the Planck scale. By breaks down we mean that we cannot extend our existing theories to the energy scale near the Planck scale.

 

With that said however, [math]\frac{c^4}{G}[/math] is an important scale as the origin of the classical upper limit.

Right it gives us a scale.

 

Anyway, this is getting off topic. You could start another thread about the interpretation of Planck units if you wish.

Edited September 15, 2013 by ajb