Gravity Emerges from Quantum Information, Say Physicists

Technology Review ^ | 3/26/10

[Fiddlstix]

BTTT

[chrisser]

I don’t get it.

If gravity is a force of entropy, why does gravity cause things to be attracted to each other - that seems less entropic rather than more.

[BipolarBob]

why does gravity cause things to be attracted to each other

I don't think attraction is the correct term. I think in terms of "weight". The earth is not pulling you towards it but rather space is pushing you down towards its cog.

[vbmoneyspender]

universe starts as singularity - more entropy - less gravity - things move apart - universe expands.

[FairWitness]

"Some physicists are convinced that the properties of information do not come from the behaviour of information carriers such as photons and electrons but the other way round. They think that information itself is the ghostly bedrock on which our universe is built."

Why did the phrase, "In the beginning was the Word - - -", suddenly come to mind?

[quintr]

I would love to see and hear these physicists debate global warming with Al Gore, just to see himself sputter into the pool of his noninformation and inconvenience.

[Louis Foxwell]

Agreed. Pardon my illiteracy, but, what is meant by “information”?

[Sherman Logan]

They think that information itself is the ghostly bedrock on which our universe is built.

Which brings up the potential to "hack into" the transmission of the information and by definition control everything.

I'm not entirely sure this would be a good thing. I can think of a number of people who I don't want to have such control.

[UnbelievingScumOnTheOtherSide]

I think the universe still is a singularity.
It only appears not to be so by those who are in it.
That is why every particle is at the center of the Big Bang,just as they were at the Big Bang.
They are separated by time and momentum but have never reall moved relative to the universe’s event horizon.

[stripes1776]

universe starts as singularity - more entropy - less gravity - things move apart - universe expands.

That explanation is not based on physics. Gravity is an acceleration: the rate of distance per time squared. The only way an object can accelerate is by a force acting upon it such as gravity.

An object moving through space at a constant velocity has no acceleration. Therefore no force is acting upon it. To change its velocity, there must be an acceleration. To get that acceleration, a force must act upon the moving object.

The velocity at which the universe is expanding is increasing. That means there is an increase in acceleration. That increase can only come about due to a force.

[UnbelievingScumOnTheOtherSide]

Pardon my illiteracy, but, what is meant by “information”?

http://en.wikipedia.org/wiki/Physical_information

[vbmoneyspender]

I thought Einstein’s General Theory of Relativity proposed that gravity isn’t a force but a distortion of space-time caused by the mass of an object that resides in space-time.

[vbmoneyspender]

I thought Einstein’s General Theory of Relativity proposed that gravity isn’t a force but a distortion of space-time caused by the mass of an object that resides in space-time.

[Species8472]

I would love to see and hear these physicists debate global warming with Al Gore, just to see himself sputter into the pool of his noninformation and inconvenience.

Gore can't even understand the simple concept of equilibrium, he would blow a fuse trying to understand entropy.

[The_Reader_David]

You are assuming that the expansion of the universe consists in matter moving further apart in pre-existing empty space.

Rather it consists in the volume of space increasing over time. It’s hard to imagine it with space being three-dimensional, but down a dimension, space should be thought of not as 3-dimensional analog of an infinite plane, but of a closed surface (for simplicity, the surface of a sphere, say), which is increasing in area (volume in the 3D case) over time (like a balloon being blown up). What you say about accelerations and forces is about dynamics of matter within space (on the surface of the sphere in the dimension reduced analog) not about the dynamics of space itself.

[AceMineral]

In the beginning was Will and Idea.

[stripes1776]

I thought Einstein’s General Theory of Relativity proposed that gravity isn’t a force but a distortion of space-time caused by the mass of an object that resides in space-time.

The geometry of space due to gravity still results in an acceleration of mass. You can still use the formula for convenience: F = mg, where the force is F, the mass is m, and the acceleration g is gravity.

But let's not loose sight of the big picture. The universe is expanding at an increasing velocity. That means some force is accelerating it.

[Brilliant]

Quantum physics is the obstacle to the theory of everything. It’s sort of like a modern day flat Earth.

[stripes1776]

You are assuming that the expansion of the universe consists in matter moving further apart in pre-existing empty space.

That is an inference you made. Conceive of space however you want. That doesn't change the facts of observation. The universe is expanding at an increasing velocity. That means a force is accelerating it. Hence the need to theorize the existence of dark matter and dark energy.