A new analysis of the South Pole-based telescope’s cosmic microwave background observations has all but ruled out several popular models of inflation.

Physicists looking for signs of primordial gravitational waves by sifting through the earliest light in the cosmos – the cosmic microwave background (CMB) – have reported their findings: still nothing.

But far from being a dud, the latest results from the BICEP3 experiment at the South Pole have tightened the bounds on models of cosmic inflation, a process that in theory explains several perplexing features of our universe and which should have produced gravitational waves shortly after the universe began.

Physicists are interested in the big questions like “Where did we come from?” and “What is all this stuff?”. But the answers to some of these questions, just lead to more questions.

Hosted by: Michael Aranda.

SciShow is on TikTok! Check us out at https://www.tiktok.com/@scishow.
———
Support SciShow by becoming a patron on Patreon: https://www.patreon.com/scishow.
———
Huge thanks go to the following Patreon supporters for helping us keep SciShow free for everyone forever:

Alisa Sherbow, Silas Emrys, Chris Peters, Adam Brainard, Dr. Melvin Sanicas, Melida Williams, Jeremy Mysliwiec, charles george, Tom Mosner, Christopher R Boucher, Alex Hackman, Piya Shedden, GrowingViolet, Nazara, Matt Curls, Ash, Eric Jensen, Jason A Saslow, Kevin Bealer, Sam Lutfi, James Knight, Christoph Schwanke, Bryan Cloer, Jeffrey Mckishen.

When we look into the night sky, we see the universe as it once was. We know that in the past, the universe was once warmer and denser than it is now. When we look deep enough into the sky, we see the microwave remnant of the big bang known as the cosmic microwave background. That marks the limit of what we can see. It marks the extent of the observable universe from our vantage point.

The cosmic background we observe comes from a time when the universe was already about 380,000 years old. We can’t directly observe what happened before that. Much of the earlier period is fairly well understood given what we know about physics, but the earliest moments of the big bang remain a bit of a mystery. According to the standard model, the earliest moments of the universe were so hot and dense that even the fundamental forces of the universe acted differently than they do now. To better understand the big bang, we need to better understand these forces.

One of the more difficult forces to understand is the weak force. Unlike more familiar forces such as gravity and electromagnetism, the weak is mostly seen through its effect of radioactive decay. So we can study the weak force by measuring the rate at which things decay. But there’s a problem when it comes to neutrons.

To check out any of the lectures available from Great Courses Plus go to http://ow.ly/Y8lm303oKJe.

SXSW Panel Picker Sign-up: https://panelpicker.sxsw.com/vote/68148

Get your own Space Time t­shirt at http://bit.ly/1QlzoBi.
Tweet at us! @pbsspacetime.
Facebook: facebook.com/pbsspacetime.
Email us! pbsspacetime [at] gmail [dot] com.
Comment on Reddit: http://www.reddit.com/r/pbsspacetime.
Support us on Patreon! http://www.patreon.com/pbsspacetime.

Help translate our videos! https://www.youtube.com/timedtext_cs_panel?tab=2&c=UC7_gcs09iThXybpVgjHZ_7g.