How constant is the Hubble constant with professor Geraint Lewis (195)

Ninety years ago we first measured the rate of our expanding Universe. Today our accuracy is better but the new techniques are producing different numbers. Are there gremlins in our measurements or is it the Universe travelling in unexpected ways ? Dr Karl and Prof Geraint Lewis discuss this huge question. http://www.physics.usyd.edu.au/~gfl/ http://drkarl.com