All origin stories sound crazy, but very few have supporting evidence. That’s where cosmic background radiation comes into play. As a warning, this stuff is confusing, especially for those of us who spend most of our time watching Netflix and TikTok videos.
Credits
Obviously, someone like me can’t write about this material without help—a lot of it. These are the sources I used:
- A Short History of Nearly Everything by Bill Bryson
- Origins: Fourteen Billion Years of Cosmic Evolution by Neil deGrasse Tyson and Donald Goldsmith
- Astrophysics for People in a Hurry by Neil deGrasse Tyson
- This New York Times article
A Quick Definition
Cosmic background radiation refers to the faint electromagnetic radiation that fills the universe, a remnant of the photons present at the time of the Big Bang some 13.8 billion years ago.
Lost? Same here. Let’s take a deeper look.
A Deeper Look
Back in 1927, the Belgian astronomer-priest Georges Lemaître—under the influence of beer, chocolate, and waffles—proposed a concept that would ultimately lead to the famed Big Bang theory (the actual theory, not the TV show).
The basic idea is that everything in the universe was contained in an inconceivably small singularity that subsequently underwent a sudden and vast expansion that continues to this day.
What that means is that near the beginning—say, as above, 13.8 billion years ago—the universe was literally a hot mess, an opaque soup of subatomic stuff like photons, protons, electrons, and so on. A photon couldn’t travel far without colliding with an electron, impeding the former’s progress and preventing the latter from entering into any sort of partnership.
With each passing moment, the young universe became bigger, cooler, and dimmer, allowing protons and electrons the opportunity to get together and form atoms (specifically hydrogen atoms). This also allowed photons to move along unimpeded, sending electromagnetic radiation (like visible light) to the far reaches of the expanding universe.
In the 1940s, other really smart people hypothesized that if all this really happened, those photons would have been “stretched” by the ongoing expansion, evolving from the visible part of the electromagnetic spectrum to something with longer wavelengths—microwaves.
Fast forward to the 1960s, and two young scientists working at Bell Laboratories—Arno Penzias and Robert Wilson—set out to use microwaves for the purpose of measuring the brightness of galaxies. The tool at their disposal was an antenna located in Holmdel, New Jersey, a bedroom community of New York City. Their plans, however, were foiled by an annoying and persistent background signal coming from all directions at all times of the day and year.
Puzzled, they contacted Robert Dicke, a Princeton physicist who knew exactly what they had stumbled upon—cosmic background radiation.
In 1978, Penzias and Wilson received the Nobel Prize in physics. Their serendipitous discovery, after all, had served as crucial evidence in support of the Big Bang. As for the antenna, it might be displaced by a senior housing development. (It’s expected that the real estate developer will be hailed as a God-fearing hero, run for public office, and cut funding for research.)
A Few Final Tidbits
Cosmic background radiation is sometimes referred to as cosmic microwave background (CMB) or cosmic microwave background radiation. Of course, as the universe continues to expand, the microwaves will morph into radio-waves (which have a longer wavelength), meaning that billions of years from now, the terminology could change to cosmic radio-wave background.
More recent research, including that provided by the Cosmic Background Explorer satellite (COBE), has shown that cosmic background radiation is not spread perfectly evenly, going hand in hand with the fact that parts of the universe contain galaxies and galaxy clusters while others are relatively empty.
And finally, you might have interacted with cosmic background radiation without even knowing it. A small percentage of the static on televisions and walkie-talkies comes from you know what.
Don’t worry. Next week, we’ll be back to TikTok level.
