Astronomers Deal Blow To Quantum Theories Of Time, Space, Gravity

Space Daily ^ | Huntsville - Mar 28, 2003 | Editorial Staff

[vannrox]

Astronomers Deal Blow To Quantum Theories Of Time, Space, Gravity

Huntsville - Mar 28, 2003

For the second time in as many months, images gathered by the Hubble Space Telescope (HST) are raising questions about the structures of time and gravity, and the fabric of space.Using two HST images, astronomers from Italy and Germany looked for but did not find evidence supporting a prevailing scientific theory that says time, space and gravity are composed of tiny quantum bits.

Using existing theories, the team led by Dr. Roberto Ragazzoni from the Astrophysical Observatory of Arcetri, Italy, and the Max Planck Institute for Astronomy in Heidelberg, Germany, calculated that infinitesimally small quantum-scale variations in space time would blur images of galaxies seen from vast distances across the universe.

Instead, when they looked at both diffraction patterns from a supernova and the raw image of a second galaxy more than five billion light years from Earth, they saw images much sharper than should be possible if quantum-scale phenomenon operated as previously supposed. Their research is scheduled to be published in the April 10, 2003, edition of Astrophysical Research - Letters.

"The basic idea is that space time should fluctuate," said Ragazzoni. "If you are looking at light from a huge distance, this light passing through space time would be subject to this fluctuation in space time. They should give a distorted image of the far universe, like a blurring.

"But you don't see a universe that is blurred. If you take any Hubble Space Telescope deep field image you see sharp images, which is enough to tell us that the light has not been distorted or perturbed by fluctuations in space time from the source to the observer. This observation is enough to rule out this effect on the quantum scale.

"You can say," said Ragazzoni, "that this measurement constrains the quantum gravity theory to certain parameters."

This report comes a month after physicists at The University of Alabama in Huntsville (UAH) announced their unsuccessful attempt to use an image from an HST interferometer to find evidence of Planck-scale effects. Taken together, the independent research findings might force physicists to reexamine the scientific underpinnings of the quantum theories of gravity, time and space.

To look for the quantum blurring effect the European team used a parameter from optics, the Strehl ratio, to calculate how sharply the telescope should be able to resolve an image of the distant light source and its first Airy ring - a signature of the interference of the rays of light entering a telescope.

If the popular quantum theories were correct, space-time effects should blur light from distant sources beyond the telescope's ability to resolve them.

They didn't.

"Without a theory to describe this, I think it's hard not to agree that it is time to start to consider theories that do not require this Planck scale, at least not like it is now," said Ragazzoni. "From an experimental point of view, there is no establishment. We are proud to have established in as rigorous a manner as possible the parameters of this quantum effect."

The Planck-scale quantum theories of time, space and gravity were derived from attempts to calculate the theoretical limits to electromagnetic energy, according to a UAH physicist, Dr. Richard Lieu.

By inverting Albert Einstein's theory of relativity (E=mc2 becomes m=E/c2), physicists could calculate how much mass should be added to a photon as it gains energy. Using that, they calculated a theoretical limit to how much energy a photon might contain before gaining so much mass it would collapse into a photon-sized black hole.

That theoretical upper limit was then used to set theoretical limits on time. One cycle of a photon carrying that much energy would last 5 x 10-44 seconds, an interval called Planck time. As the shortest potentially-measurable interval of time, theorists speculated that time moves is Planck time-sized quantum bits.

In his theory of general relativity, Einstein theorized that time, space and gravity are different manifestations of the same phenomenon, much as light and thunder are signatures of the electrical discharge in lightning. If time is made up of quantum bits, that would also mean space and gravity should also be composed of quantum units.

Since the expected blurring "signature" of quantum space time isn't seen, however, it might mean that time isn't made of quantum bits, and neither are space or gravity.

[patton]

Define universe. How many dimensions?

From "out there", we are a line, or a point.

Proves the existense of G_D, don't you think?

[Windcatcher]

I was under the impression that the uncertainty didn't so much arise from random fluctuations, as from the statistical nature of Bosons. It's been ten years sine grad school but I remember a long derivation with Boson statistics where we found that the dxdp>=h/2 was fundamental to the way such particles behaved. Simply put, their nature made certain things unknowable.

[TheLion]

Wow!....you really cleared that up!....just kidding. Now I am even more confused. Guess I should leave this to those that have a clue.....still, I don't see how it can be guaranteed that light will blur.

[patton]

But does the cat exist?

[IGOTMINE]

I'm still trying to understand quantum checkbook balancing.

[Doctor Stochastic]

The Heisenberg relations are a consequence of Fourier transforms. Once it is determined that elementary particles have a wave structure, these relations are a natural consequence.

[Doctor Stochastic]

Erwin, was hast mit der Katze getan? Sie scheint, beinahe tot zu sein!

[AMDG&BVMH]

Re:"uncertainty didn't so much arise from random fluctuations, as from the statistical nature . . ."

That is the basis of the problem, I think. "Statistical nature" and "behave" imply something "real" about the individual bosons themselves. In reality, the statistical view is a way we can compute the behavior/positions of many of them, and really doesn't tell us what an individual one really "does" according to its real nature in reality. Because we can't measure it accurately, ala Heisenberg.

This is where Einstein and Schroedinger were coming from. Those particles out there are real and behaving according to some causal principle -- even if we don't know what it is and even if we can't know what it is because of the fundamental level of uncertainty. We can certainly view them as statistical for computational efficiency. That does not mean that their "behavior" is random in the sense of not caused by some law of physics unknown to us . . .

[Windcatcher]

A gedanken experiment:

Let's postulate that space is "frothy" and constantly produces pairs of electrons and positrons (anti-electrons) that spontaneously appear, move a tiny distance, and annihilate when their angular momentum causes them to come together again. Both of these particles have mass. Just as really heavy things like the Earth, the Sun, and black holes bend light, these particles can bend light by a teeny, tiny bit. Because these particles are appearing *randomly*, they would, over billions of light years, cause a ray of light to blur in a similarly random fashion.

Now let's postulate that the universe doesn't produce such particles that carry mass, but only *massless* particles (light is made of photons, which are massless particles--all massless particles move *only* at the speed of light; it's an easy calculation. There are other massless particles as well). Particles with no mass don't exert a gravitational force and wouldn't bend any light passing nearby.

[patton]

The moment it was created, actually

[Windcatcher]

Like I said, it's been a long time. I dimly remember something like that, though. I remember for a fact that we did that derivation in our grad E&M class, but for the life of me I can't remember what exactly we were studying.

[AMDG&BVMH]

Re: "But does the cat exist?"

Schroedinger certainly thought so. In fact, he developed that Gedankenexperiment to show how preposterous the idea was that the cat could be alive and not alive in some complex formula . . . After all, we can look in the box and see the cat and determine the state of its existence; and BYW, he did not think that his looking in the box would change the state of the cat!

[plusone]

I love that logic!!!

[Windcatcher]

But opening the box collapses the wavefuntion :)

[patton]

Ich bin unschuldig dafuer....!

[EternalVigilance]

You are one brilliant dude, and I believe correct.

[EternalVigilance]

Time is caused by the fact that things don't all happen at once. Space is caused by the fact that some things are over here, and other things are over there. These scientists who insist on making things complicated just kill me.

You have probably made more sense than anyone else on this thread. ;-)

[patton]

But it did change the state of the cat - from "I dunno" to "live/dead cat"

[AMDG&BVMH]

Re: "But opening the box collapses the wavefuntion :)"

Conveniently -- for that interpretation of what QM means. :)

"Common sense" (not to mention the laws of pbysics as they pertain to reality as we actually experience it) tells us the cat is in the same state (alive OR dead, not some complex combineation of the two) the instant we open the box as it was the nano-second before we opened the box.

[AMDG&BVMH]

Re: "But it did change the state of the cat - from "I dunno" to "live/dead cat""

No, the state of the cat did not change by your looking at it. Your knowledge of the state of the cat changed from "dunno" to "live or dead cat". :)