Mysterious -270° C signal

Welcome back cosmoplorer!!! Before beginning our next adventure , let me tell you a story.

It starts with the quest of two humans , Robert Wilson and Arno Penzias , to open a new channel for satellite communication for "American Telephone and Telegraph" company. Some 60 years back (* here "years" are taken ONLY with respect to "earthians", if you are reading from some different planet or galaxy , make sure to convert it into your time scale ). SO, ahhhhhhhhhhhhh.....waiiiiiiiiiiiiittttttttttt, where was I??🤔 ahhhhhhhhhhmmmmmmmm........OH YES! I'm so Sorry........ I keep forgetting things due to some weird gases in my atmosphere that are warming me up. But you never mind, let's continue!!
Back in 1964, humans KNEW what microwaves were , BUT these radiations weren't practically used much. However , Wilson and Penzias, saw in them, whole new possibilities!!! So...... they made a massive horn-shaped antenna to detect and use the channel which no one had ever used before for communication (*again, here "no one" refers to "no earthian") .

CREDIT: NASA IMAGES

But , before transmitting or receiving a signal , one needs to know the natural sources of noise in it. Therefore, they pointed their antenna towards a part of sky aaannnndddd GOT A LOT OF NOISE.

"Well , okay , maybe there is some very strong source in this direction...... let's move it a bit away. Let's point it in this direction. " "Very Well !" "Ahmm, no better." Eliminating the radiations from all the possible sources they could think of , there still remained a VERY STRONG source , giving radiations from EVERY direction they pointed to. "Oh man, what the hell is wrong with this......wait , this pattern is not changing with direction....aaahhh.....maaayyyyybeeee......this noise is due to the antenna itself!!!"

This brought new hope for them and they climbed up the antenna to find "A WHITE DIELECTRIC MATERIAL" (more commonly known as pigeon poop) on the surface , which they thought may have been causing this unexplained interference. So they scrubbed the material off hoping to get much better results thereafter.

Video credit : World Science Festival 2014

Alas! The noise still persisted and was independent of direction or seasonal changes......"What are we gonna do now ? Where are we wrong? Maybe this whole experiment is faulty. :( "

Fortunately , at nearby Princeton University , researchers were devising a method to look for exactly this noise. So when Wilson and Penzias reported these strange signals , Robert Dicke and Dave Wilkinson precisely knew what they have recorded.

Being more of technical people, they didn't knew how big their discovery was. They had inadvertently detected the VERY FIRST LIGHT OF THE COSMOS!!. They...had...found the signals.....which humans were looking for , SINCE 1940s!!!!

This background radiation is E.V.E.R.Y.W.H.E.R.E!!! It's passing through me , through you , through everyone!!!! Get ready for a secret of this universe.....Believe it or not ........WE ARE LIVING IN A MICROWAVE OVEN !! Yes!! seriously!! But luckily , this energy is not high enough to bake you up 😅.

This background radiation is called COSMIC MICROWAVE BACKGROUND (CMB). If we could "see" microwaves with our eyes , we would see our universe glowing in EVERY DIRECTION!!

From the observations of Wilson and Penzias , it was found that this light has a very UNIFORM nature with a temperature of -273 °C or 3 K.

Source : NASA

However , as technology advanced , these humans could built much better observatories and were able to look more back in time and much more clearly.

Map of CMB by ESA's Planck observatory

source: ESA images

But why study CMB at all?? Let me tell you . It's a common phrase among astronomers , " The more farther you look in the sky , the more back you are looking in time" . How do I know what humans are talking about ? Can you keep a secret ?...... Come close..... *whispering* I occasionally eavesdrop them...You know , it's kind of fun 😁....But plllleeeeeaaaaaassseee don't report this to my godfather Jupiter😟. He'd be very angry.

OK , back to the topic . So the farther we' ll look , the more back we' ll see in time . Studying CMB is crucial to know what the cosmos looked like in the very beginning.

The fluctuations you see in the more resolved map of CMB is the non uniform density of baby cosmos. At places where , due to quantum fluctuations, matter was more , it resulted in generation of higher gravitational field than the surroundings , which then attracted more matter towards itself , hence forming the first known galaxies.

Robert Wilson and Arno Penzias were awarded the Nobel prize in physics in 1978 for detecting CMB.