Planckian

Assuming an interaction between both kinds of matter which becomes important at Planckian densities, it is found that the universe undergoes a periodic cycle of contraction and expansion.

May 16th, 2006 2006

This would include: the formation and decay of (nonsupersymmetric) black holes; graviton scattering at hyper-Planckian energies; physically continuous transitions from one topology, through a quantum state with no geometric interpretation, to a different topology; states where a submanifold of spacetime has a noncommutative geometry; states with a variety of apparent geometric singularities, where the physics is nonsingular.

Guest Post: Joe Polchinski on Science or Sociology? Sean 2007

However, I didn´t press to ask the following natural question: would a generic collapsing spacetime (which has growing entropy, in the classical regime) also become low-entropy as it enters the Planckian regime?

Against Bounces Sean 2007

Even though the Planck scale was still just as inaccessible, string theory was so good that it became reasonable to hope that we could figure it all out just by using brainpower, even without Planckian accelerators.

Arguments For Things I Don’t Believe, 1: Research on String Theory is Largely a Waste of Time Sean 2007

If inhomogeneities are not magically suppressed, then there is no way they can be neglected when the universe reaches the Planckian densities characteristic of the bounce.

Against Bounces Sean 2007

[6] The ones that came to mind were modifications of the gravitational force law on laboratory scales, strings, black holes, and extra dimensions at particle accelerators, cosmic superstrings, and trans-Planckian corrections to the CMB.

Guest Blogger: Joe Polchinski on the String Debates Sean 2006

“Therefore, whether real black holes emit Hawking radiation remains an open question and could give non-trivial information about Planckian physics.”

The BBC on the LHC Mark 2006

Later, Richard Easther gave a talk entitled “Trans-Planckian Physics and Cosmology”, but I had another meeting to go to and so could not attend.

SuperCosmologists Think Out of the Box cjohnson 2005

As, according to Planck, the quantum of energy is the product of the number of light vibrations with the Planckian constant, which is denoted by the letter h, it is possible to calculate the number of vibrations which corresponds to a given passing from one orbit to another.

Nobel Prize in Physics 1922 - Presentation Speech 1965

And indeed Bohr succeeded, in his first treatise on this question, in calculating the Rydberg constant from other known magnitudes, namely the weight of an atom of hydrogen, the Planckian constant, and the value of the electric unit of charge.

Nobel Prize in Physics 1922 - Presentation Speech 1965