Spinfoam idea for energy source (Louis Crane-FQXi)

[marcus]

Spinfoam idea for energy source (Louis Crane--FQXi)

FQXi recently announced the award of research grants to investigate especially interesting ideas bearing on profound questions.
for instance Garrett got one (a model putting matter and spacetime together in a different way that might work)

Look at this!

LOUIS CRANE co-author of the Barrett-Crane spinfoam model.
He is going to take a look at using BC spinfoam to model small black holes! A better understanding of how to make and use small black holes could have useful consequences.

====quote from Louis Crane abstract===
Dr. Louis Crane
Kansas State University

Project Title:
A New Approach To Quantum Gravity, With Possible Applications To The Origin And Future Of Life

Summary:
In this project, I will complete the interpretation of a model for quantum gravity I helped develop (the BC model) by finding expressions for its classical histories. This will make it possible to compute quantum effects for experiments involving gravity.

This technique will be applied to small black holes to see how their formation, radiation and interaction with matter differs from the semiclassical predictions. This information will be used to study the feasibility of using small artificial black holes as sources of energy and as propulsion methods for starships. The BC model can be extended to include singular points in the space-time, which have interesting similarities to ordinary matter. These are referred to as conical matter. Calculations using the classical states for the BC model will be used to explore the behavior of conical matter, and its interactions with black holes. A more distant goal is to explore the Evolutionary Universe hypothesis, which explains the fine-tuning of the laws of Physics for life by means of an evolution of baby universes.
===endquote===
http://www.fqxi.org/aw-crane.html

I've read some Louis Crane papers. high respect. very very smart but more than that----genuinely creative, invents things. The last time I posted notice of a Louis Crane paper, someone here replied in a one or two word post: "madness". Yeah. They could have said "edge".
probably what it takes.

 

[marcus]

there is a second page, with a TECHNICAL ABSTRACT.
the first thing I quoted was called a general summary

http://www.fqxi.org/aw-crane2.html
===quote===
Project Title:
A New Approach To Quantum Gravity, With Possible Applications To The Origin And Future Of Life

Technical Abstract:
The Barrett-Crane model is a finite candidate for a quantum theory of gravity. Unfortunately, its interpretation is difficult because it is not a path integram, but a summation over quantum states for subsystems.

The first goal of the proposal is to find the classical histories for the model using the decoherent histories approach. This work requires two stages. In the first we will apply microlocal analysis to the phase spaces of "large" regions to find wavepacket states with sharp geometric variables. In the second, we will use a Brownian motion approximation to compute the decoherence of the large histories due to their interaction with the "small" internal geometry.

We will then use these results to formulate descriptions of experiments in order to find quantum corrections to gravitational processes. We will apply this to black hole solutions to look for corrections to Hawking radiation superradiance and black hole evaporation. We will also attempt to estimate the significance of our results for black hole power sources and propulsion systems.

===endquote===

 

[Sauron]

Er, I just can see the abstract but not actually any paper with detailled calculations. Am I missing somthing or simply they are not available?

It would be interesting to compare the crane results with ones obtained using canonical LQG and "minisuperspace" techniques which state that there is a minimal mass for the formation of black holes due to the repulsive behaviour of gravity at very small scales.

 

[marcus]

Er, I just can see the abstract but not actually any paper with detailled calculations. Am I missing somthing or simply they are not available?

It would be interesting to compare the crane results with ones obtained using canonical LQG and "minisuperspace" techniques which state that there is a minimal mass for the formation of black holes due to the repulsive behaviour of gravity at very small scales.

You are not missing anything that I know of, Sauron. I think what one sees at the FQXI site is an abstract of proposed research.

Maybe one could get some clue by looking at earlier papers of Louis Crane, maybe some would point in the direction of this. Also Kea has spoken about this IIRC. But I don't know anything more.

I would not expect Crane's theory of small black holes to agree with what we read in papers of Bojowald and others, using LQG and minisuperspace (symmetry reduced) methods.

To my mind, Crane is a risky "long shot" thinker. I can't even judge the odds.

 

[Kea]

...someone here replied in a one or two word post: "madness". Yeah. They could have said "edge". probably what it takes.

Hi Marcus

Yeah. This world has no idea what is about to hit it.