How hot was the cosmic microwave background? Do gravitational waves travel at the speed of light? How do we understand cosmological redshift?

How hot was the cosmic microwave background? Do gravitational waves travel at the speed of light? How do we understand cosmological redshift?
Building the advances in technologies for today’s experiments & detectors. More on this discussion by @awesomeastropod & Barry Barish
Dr Brad Cenko discusses the recent discovery of a Kilonova event from the collision of two neutron stars.
Neutron stars find each other, promptly blow up, the new importance of gravitational wave astronomy!