Paul Steinhardt

Paul Joseph Steinhardt (born December 25, 1952) is an American theoretical physicist and cosmologist who is currently the Albert Einstein Professor in Science at Princeton University. In addition, Steinhardt co-founded and is the current Director of the Princeton Center for Theoretical Science.

Paul Steinhardt in 2015

Quotes

• ... the inflationary paradigm is so flexible that it is immune to experimental and observational tests. First, inflation is driven by a hypothetical scalar field, the inflaton, which has properties that can be adjusted to produce effectively any outcome. Second, inflation does not end with a universe with uniform properties, but almost inevitably leads to a multiverse with an infinite number of bubbles, in which the cosmic and physical properties vary from bubble to bubble. The part of the multiverse that we observe corresponds to a piece of just one such bubble. Scanning over over all possible bubbles in the multiverse, everything that can physically happen does happen an infinite number of times. No experiment can rule out a theory that allows for all possible outcomes. Hence, the paradigm of inflation is unfalsifiable.
  • (5 June 2014)"Big Bang blunder bursts the multiverse bubble". Nature 510 (7503): 9. DOI:10.1038/510009a.

• String theory suggested that we should have a whole new set of particles called "supersymmetric partners" that were supposed to be observed at the Large Hadron Collider at CERN — we don't see those.
• (June 2, 2022)"Impossible Matter! Stuff that shouldn't exist in nature...but does! Paul Steinhardt". Dr Brian Keating, YouTube. (quote at 33:07 of 49:06)

Quotes about Steinhardt

• I know of no other scientist, no other theoretical physicist alive who has a clearer focus on whether our theories and ideas are relevant to the real world. And that's always what he's after.
  • Neil Turok, Perimeter Institute Graduation Ceremony (2015).