Loop Quantum Gravity

Quantum Mechanics

• Study of the very small

• Matter and energy quantized

• Discrete packets – “quanta”

The Problem

• Nothing about the structure of matter

• Nothing about how gravity is generated

• Global not local• Black holes, the big

bang

Loop Quantum Gravity

• Attempts to reconciles QM, GR• Alternative to string theory• Quantum space is granular, 10-35 meters • Spacetime links connecting these chunks

Loops

• Links form braided loops

• Loops are elementary particles

Twists determine charge

• Each twist 1/3 electron charge

• Clockwise negative

• Counter-clockwise positive

• Electron 3 clockwise twists

• Positron complement

The Universe

• Turbulent, fluctuates 10-44 seconds

• A giant quantum computer

• The chunks are qubits• Qubits preserve

braids

Space does not exist

• Space is a web of information

• Humans are mere tangles

• No fundamental building blocks

• Matter emerges as network of relationships

• Loops not in space, loops are space

• Requires new quantum theory without background

Names

• Abhay Ashtekar http://cgpg.gravity.psu.edu• Lee Smolin http://www.qgravity.org/• Carlo Rovelli http://www.cpt.univ-mrs.fr/~rovelli/• Sundance Bilson-Thompson • Fotini Markopoulou• David Kribs http://www.uoguelph.ca/~dkribs/