At this time of year it’s not unusual to wonder, where does Santa Claus come from? Or the elves or even the raw materials to make all the toys? Where does it all come from? Or anything else here? Science suggests that what is on Earth, basically comes from the same place anything else here comes from – Earth. There are a few minor exceptions like rocks brought back from space and whatever meteorites find their way here, but generally the stuff we see here is from Earth. That would include Santa, his elves, and their toy-making materials. I’m assuming Santa and his various associates aren’t extraterrestrials. But where did Earth come from?
According to common scientific theory, Earth started to form about 4.5 billion years ago along with the other rocky planets.[1] Around that time, the solar system was largely a cloud of gas and dust, maybe with a young sun in the middle. The element hydrogen makes up most of a typical star for a large part of its lifetime. That’s not surprising when considering that light elements such as hydrogen were formed shortly after the Big Bang. The Big Bang is of course the hypothetical event that gave rise to our universe about 13.8 billion years ago.[2] All the matter and energy of the universe was in one place and then at some point it started rapidly “expanding” (maybe just another way of saying it was exploding).
But Earth is made up of more than just light elements. Uranium can be mined on Earth, and a uranium atom can be 238 times heavier than a hydrogen atom. So some elements on Earth are very heavy, as far as their atoms are concerned. You may know that a star “burns” hydrogen as its fuel. Stars actually convert hydrogen into the heavier element helium in a process called nuclear fusion. The same principle is used to make a hydrogen bomb explode with so much energy. Stars don’t have to stop with helium. Elements other than hydrogen can combine through nuclear fusion to create new heavier atoms. Unfortunately, for heavier elements, the payoff of energy is not as great as compared to the energy required. So a star can grow dimmer when mainly forming heavier elements, due to using up most of its hydrogen and other light elements.
Heavier elements happen to make up most of Earth’s mass. In fact, some simple arithmetic shows that about 61% of Earth’s mass is iron, silicon, and aluminum.[3] Clearly it’s not mostly hydrogen. Considering Earth has been here a while, maybe the sun is too young to have provided the heavier elements for the creation of Earth. So where did those heavier elements come from? Other stars, apparently. And how did they get here? Stars can explode at some point, depending on size and age.[4] Such explosions can push stellar material out at great speeds. Eventually, some of those heavier elements arrived where our solar system would form.
Back to the question of where people and stuff come from, is it all from Earth or not? Yes and no. Essentially the Big Bang and the explosion of stars provided all the matter that we take for granted on Earth. In a way, we are part star and part cosmic formation residue. But otherwise, yes, we and nearly everything we see on Earth are from Earth. That does kind of give new meaning to the question of “are you from around here.” With a year like 2020, regardless of whether distant explosions helped us to eventually come into existence, being here at all is like a cosmic Christmas miracle.
References
[1] https://phys.org/news/2014-12-earth.html
[2] https://earthsky.org/space/definition-what-is-the-big-bang
[3] https://en.wikipedia.org/wiki/Abundance_of_the_chemical_elements
[4] https://en.wikipedia.org/wiki/Stellar_evolution
(c) Copyright 2020 by Mike Ferrell
Odd STEM 