Peering Back to the Big Bang: The Quest to Detect Cosmic Inflation

This class will take place on May 9, 2:30-4:30p.m., on Zoom, with renowned physicist Gary Sanders. Although you can sign up separately, we encourage you to also take Gary’s class Listening to the Universe Vibrate on May 2!

The Big Bang is considered to be the starting point of our observable universe. The Big Bang initiated in the vacuum of space-time, as we describe it in everyday language. How can that happen? Was it a start of time and space? Was it a quantum fluctuation in the prior vacuum? We don’t know. As the universe expanded and cooled to the point that atoms could form and emit light that could travel finite distances, the universe became luminous. This happened about 380,000 years after the Big Bang. This first light can be seen in any direction of the sky as a very uniform bath of microwaves. This Cosmic Microwave Background (CMB) will be described.

The nearly smooth distribution of brightness of these microwaves, in every direction, is a surprise. How did the very early universe get so smooth? The prevailing theory describes a short violent expansion of the fledgling universe, faster than the speed of light, that smoothed the universe with imperfections caused only by quantum fluctuations. These imperfections provided the means, much later, for the rich features we see in the observable universe such as stars and galaxies. But cosmic inflation happened before the first light. How can we see it or discount it? The search for signatures of cosmic inflation in the CMB, in space, Antarctica and at 17000 feet in Chile, will be summarized.

Topics covered will include:

• Intuitive physics, nothingness, the vacuum, Heisenberg Uncertainty and quantum aspects of the vacuum, space-time
• The time progression of the universe from the Big Bang to today
• First light in the universe, the Cosmic Microwave Background (CMB), the 1964 discovery as a surprising static
• What happened before this first light to make the universe so smooth? Cosmic “Inflation”?
• Quantum fluctuations yield primordial gravitational waves
• The birth trauma of searches for cosmic inflation
• The ongoing quest to see through the CMB back to inflation
• What we are about to do with the Simons Observatory at 17000 feet in Chile

Suggested Reading: