Why Antarctica to study Cosmic Microwave Background (CMB)?

Why Antarctica to study Cosmic Microwave Background (CMB)?

by Ju Boo Lim - Monday, 18 November 2019, 7:30 PM

Number of replies: 1

Q. Cosmologists have often studied the CMB with balloon-borne experiments, typically launched from Antarctica. What do you think the advantages of such an approach are? Share your ideas in this forum

A. I really do not know Dr. Grant Miller. My only wild guess is, if it had been in other highly populated areas on earth, especially in industrialized areas with high electronic and electrical technologies, the radiations and radio transmissions emitted in these places may interfere with the very feeble CMB.

The CMB is just 3 Kelvin above absolute zero, so it may also not be suitable to try to detect such low temperature in hot places like in cities and the deserts

Obviously the Antarctica, besides the Arctic being the coldest place on Earth would be the most suitable place to detect or study CMB.

 Even at sea level in the Antarctica may not be enough. Perhaps it is even colder at higher altitudes by using balloons

Maybe also at the poles charged particles from the Sun (solar winds) are deflected by the magnetosphere giving the region an almost a radiation-sterile environment

I do not know these or other reasons for sure.

What I am expressing here is just my personal thoughts and guesses

If I am wrong please correct me. This is one of the reasons I take up this course to learn new and interesting facts

Sorry for my ignorance on what is going on in the Antarctica.

In reply to Ju Boo Lim

Re: Why Antarctica to study CMB?

by Dr. Grant Miller - Tuesday, 19 November 2019, 2:14 PM

Hey Lim,

This is a brilliant question, and amazingly the paper on the BOOMERanG experiment doesn't even present their reasoning for choosing Antarctica! - https://arxiv.org/abs/astro-ph/0201137 (poor paper writing)

I think you may be absolutely right about them trying to limit other sources of radio frequency interference (RFI). It may also be down to the atmosphere over Antarctica. It is especially dry (fewer water molecules to absorb EM radiation), this is why it is used for a lot of Astronomy experiments (also because it points towards the galactic centre, but that's not important for CMB observations).

Cheers,

Grant

In reply to Dr. Grant Miller

Re: Why Antarctica to study CMB?

by Ju Boo Lim - Wednesday, 20 November 2019, 5:16 PM

Thank you Dr. Grant for your answer. I was only trying my level best to reason out the answer as you know I am not an astronomer, and hence I have never read any account on why they use the Antarctica for studying CMB

In fact I never even know they use the Antarctica for this purpose till your question came

Thanks for your enlightenment

lim jb