Why should I care about it? What difference does it make? It doesn’t make a difference for my cozy life in the comfort of mid-sized normalcy. I like it here but it’s fun to explore the extremes, no?
Our universe is unimaginably big and unimaginably small and when scientists look at the extreme’s things get strange. I’m going to start big, with the Cosmic Microwave Background (CMB).
The CMB is ubiquitous microwave radiation and the oldest remnant of our beginnings. Current thinking is it came about just when our universe cooled enough to go clear. Photons were then free to go wherever, no longer impeded by pervasive super-hot plasma. That happened around 380,000 years after the ‘big bang’ started things rolling. Those photons have been wandering the universe, their wavelength changing from short to longish (microwave) due to redshift as the universe expands.
Discovered in 1964, the CMB is like an archeological find, with clues seemingly inscrutable until someone discovers the translation. It’s the largest structure of our universe, it’s everywhere and appears a uniform 2.7 degrees kelvin, but we really weren’t sure what to do with it. We needed more data, and some translation.
One thing we are pretty sure of, the CMB radiation we currently measure is the photons freed way back then and they help determine the age of our universe.
Fast forward 45 years and we have lots more data, and weirdness. Rather than a predicted uniform temperature the CMB is split into two ‘hemispheres’, with one more uniform than the other. We don’t know what causes this. Even stranger is a big temperature anomaly called the cold spot in the more ‘wrinkled’ hemisphere. This cold spot is huge, spanning around 10 degrees on the sky and 70 micro-kelvins cooler than the surrounding CMB. To me 70 micro kelvins seems miniscule but on the CMB it is significant. More data please!
All the known universe is made up of matter, energy, and space. When we look closely at matter it starts to get weird at the atomic and subatomic level.
Atoms were thought to be like miniature solar systems with electrons going around the nucleus like planets going around the Sun. Not so simple. Currently the model is a cloud of possible electron positions and directions. Seems we can identify an electrons position or its direction, but not both. Apparently when we look at an electron its possibilities collapse into one result, either its position or its direction. This is the super small quantum world where the strong, weak, and electromagnetic forces live and possibly where gravity begins. Everything we know about is made up of this stuff.
What about dark matter and energy? It’s weird to begin with, I’ll bet it’s made of weird stuff too.
What’s in the Sky?
Venus sparkles in the southwest just after sunset.
Mars is in Scorpius, visible in the southeast an hour before sunrise.