titel the oldest memory: the echo of the big bang
TRANSCRIPT
What is the oldest memory?
•First question: What is the start of time?
•Creation of the universe – The Big Bang!
•Is there any „memory“ of this event?
What is the CMB?•Universe is expanding (Hubble flow)- Doppler Effect:
•Expanding blackbody: Still a blackbody, but cooler
•CMB: The cooled down blackbody named Universe
Universe started in a hot, dense state
CMB is „The Echo“ of this Big Bang
(This was already predicted by Gamov in the 40‘s)
Static source Moving source
What to learn from the CMB?
•Anisotropies are caused by slight inhomogenities
•Inhomogenities interact with sound speed
•Cosmic expansion decouples light from matter CMB shows „last scattering surface“
•Results in length scale allows to measure the geometry of the universe
•Geometry related to fundamental parameters