Recently I tweeted this comment (are you following me on Twitter? @astrostephenson):
“Have you ever thought about who applies meaning to things? For instance, the shade of a tree on a hot summer day is meaningless unless there is someone there to enjoy it. Even the universe has meaning only because we are here to ascribe meaning to it. The cows in the field may enjoy the shade of the tree but they do NOT ponder the meaning of the universe. That’s up to us.”
This passage comes from the opening of chapter 12 in my recently published book Beyond the Classroom. I wrote it because as an astronomy teacher, one of my greatest challenges is to make my students, who’s modern day psyche is often tenuous at best, feel good about their purpose and meaning in a seemingly infinite universe. This is not an easy task!
However, I point out to them that we know as much as we do about the universe because we as a species are very smart. Humanity has demonstrated it’s ability to process the signals of light from very distant places and decipher it’s encrypted message. We didn’t need to go to the stars, because they came to us, in the form of their light. From this messenger we call the photon, we know the composition of stars, the distance between the galaxies and the dynamic nature of the universe, that being an expansion that doesn’t seem to slow.
Meaning and purpose are important to young people today. So much so that if they see meaning in the lesson, they will lean in to the material. They are very quick to distinguish between a lesson that is simply part of an ad infinitum checklist with no particular relevance. I try to stay away from such lessons, and largely because I don’t enjoy them either.
Let’s consider the universe though. What in fact do we know about it and how did we figure out such a large entity? And if I can explain that, does it have purpose and relevance to a 21st century teen? Well, you decide.
You see, at the turn of the last century, all of science believed that the universe was static and unchanging. It was called the Steady State model and even Einstein was a firm supporter. But along came an otherwise unknown young scientist named Edwin Hubble who set out to determine what these faint, whispy clouds of light were, seen in the darkest of skies. Training the 100” Hooker Telescope on many of these, Hubble took long exposure images of these nebulae and analyzed the light. He found that when it was passed through a spectroscope which splits the light into it’s constituent “rainbow”, he saw the spectrum of hydrogen. Thus he determined the chemical composition of the stars.
Yet there was more to it than just that! He also noticed that the spectra were in a different part of the scale than hydrogen analyzed in the lab. It had shifted to the longer end of the spectrum, the red end. It was indeed red-shifted. This, according to the well understood Doppler effect (that odd flat tone of a speeding siren as it goes by you) meant that the galaxies were moving “away”. Of course, away from what was yet to be understood. But certainly the space between the galaxies was increasing and the universe was clearly bigger today than it was yesterday, last year or a million years ago.
Some wondered if there was a time that the universe was a singularity, a point of infinite heat and density. Other’s scoffed at this idea. And then in the mid-60s, two researchers named Penzias and Wilson, accidentally discovered the remnant heat of that scenario, heat that had been theorized to exist simply because energy can’t be destroyed. If it was hot like that at the beginning of time, then that heat must still exist somewhere.
Turns out, it does. It exists everywhere in the universe and it’s called the Cosmic Background Microwave Radiation (CMBR). When this was discovered, it firmed up the notion that we live in a Big Bang universe. The entirety of the cosmos revealed itself through it’s light. And from our lonely place on Earth, this tiny and pale, blue dot, we have peered out into the universe and figured all this out! To me, that makes us very special.
It’s sort of like this. The unknown can be scary and intimidating. The universe to most is unknown. But with a little time and perhaps a teacher, what was unknown can become known and the fear turns into curiosity and challenge. For instance, what else can we know? What else are we capable of? How smart are we really?
I feel that Team Humanity, flying through space on Spaceship Earth, is a fun team to be on. It’s more fun to play for the winning team, and astronomy, the great unifying science, is full of great victories. We’ve figured out the cosmos, for Pete’s sake! That’s pretty darn impressive. So celebrate your part on this team. Chip in whenever you get a chance. Cheer on the process and join in the parade. To me, and hopefully to you, there is purpose in all of this.
Have questions on this? Send me a note and then check out my podcast Science360 on all major platforms, including this website!