Beyond space and time

Marc Lachièze-Rey
Scientific Café: November 24. 2005

Cosmology — universe in its globality
cosmic properties (not stars nor glaxies nor clusters)

General relativity — birth of scientific cosmology
Plato, Aristotle: small, restricted to solar system
100 billions of stars in our galaxy
100 billions of galaxies

1687 Newton Principiae
XIXe nebulae (inside or outside our galaxy)
American scientist: Vesto Slipher — measured their speed
1924 Edwin Hubble (distance of Andromeda, farther than the size of our galaxy) speed of galaxies 100s or 1000s of km/s; most of them going away, the farther, the faster
1929 Hubble law
1916 curvature == gravity
1930 meeting in Cambridge — problem
Georges Lemaître — letter to Eddington
1927 Solution to the expansion — Big Bang (1960)
Cosmic dilution — cooling. In the past: denser, hotter
Background microwave fossile radiation (1964 discovered)
Primordial soup (14 billions years ago) — various steps

Planck era — mixing of gravity of quantum effects at the beginning
Theories of quantum gravity (strings, etc.)

Dark matter — not a cosmological problem;
mass within galaxies too

Crisis of physics among students?

Leibniz: time doesn't exist — classification tool
Speed of expansion — faster than speed of light. Problem of definition of velocity (referential) — not a real velocity: only a redshift (exansion of the universe)
Symmetry — anti-time?

Hawking-Penrose: unavoidable singularity (without quantum gravity)
With quantum effects, no proof of singularity
Time and parity violations
Confirmations: repartition of the elements

Conférences ToC
Marc Girod
Last modified: Wed Nov 30 09:40:36 EET 2005