BICEP & Gravitational Waves - Professor Joseph Silk

TL;DR

Scientists are searching for the highly elusive signal in the microwave background that would allow them to infer the initial conditions of the universe and confirm the inflation theory, but dust contamination and low sensitivity present major challenges.

Transcript

so here is the next challenge you've all experienced this effect I'm sure of having using polarized sunglasses maybe to reduce the glare etc because you know dust reflections basically polarized light and you can avoid some of the haze from dust but using polarizing sunglasses well there's a lot of dust in the Milky Way and that polarizes like to i... Read More

Key Insights

• 😎 Polarized sunglasses can serve as a tool to study the polarization of the microwave background caused by dust.
• 🙂 The inflation theory suggests that gravity waves left behind by the rapid expansion of the universe can be detected as a slight polarization in the radiation field.
• 🙂 Detecting the primordial signal of the universe's beginning would provide evidence for the inflation theory and shed light on the earliest moments after the Big Bang.
• 🕵️ The primordial signal is challenging to detect due to dust contamination and the need for extreme sensitivity on the nano degrees Kelvin scale.
• 📡 The bicep2 experiment initially claimed to have found the elusive signal but later discovered it was due to dust contamination, highlighting the challenges in detecting the true primordial signal.
• 🛰️ The Planck satellite has provided detailed images of dust in the galaxy, helping to identify regions with less contamination for future studies.
• 👨‍🔬 The search for the primordial signal is considered the holy grail of modern cosmology, as it would offer a glimpse into the earliest moments of the universe.

Questions & Answers

Q: Why do scientists use polarized sunglasses to study the microwave background?

Polarized sunglasses can reduce glare and haze caused by dust, which also polarizes the microwave background. By studying this polarization, scientists can learn more about the early universe.

Q: What is the inflation theory and how does it relate to the search for the beginning of the universe?

The inflation theory suggests that the universe expanded rapidly after the Big Bang. This expansion should have caused the universe to be jostled around, leaving gravity waves behind. Detecting these gravity waves would provide insights into the early moments of the universe.

Q: What challenges do scientists face in detecting the primordial signal of the universe's beginning?

Dust contamination and low sensitivity are major challenges in detecting the primordial signal. The signal is extremely faint, requiring sensitivity on the nano degrees Kelvin scale, which is a thousand million times more sensitive than current measurements.

Q: What did the bicep2 experiment discover and why was it later determined to be incorrect?

The bicep2 experiment initially claimed to have found the elusive signal of the universe's beginning. However, it was later determined that they were seeing dust contamination instead. This was unfortunate because they had chosen a region of the sky with strong dusting.

Summary & Key Takeaways

• Using polarized sunglasses, we can reduce glare and avoid haze from dust, but polarizing sunglasses can also polarize the microwave background.

• The inflation theory predicts that the universe should be jostled around due to rapid expansion, leaving behind gravity waves that can be detected as a very slight polarization in the radiation field.

• The primordial signal of the universe's beginning is difficult to detect due to dust contamination and the need for extreme sensitivity, but finding it would provide proof of the early moments after the Big Bang.