Emma is one of my regular guest bloggers. I feel really thrilled about the possibility to post one educating post of this great blogger once a month over the next couple of months. Thank you so much, Emma, for sharing these great posts with us! If you would like to check out the previous guest posts, this amazing blogger wrote for me, head over here.
Space is the final frontier of astronomy. Space consists of material bodies so much larger than anything in our experience that we struggle to wrap our minds around the sheer size of their numbers. Floating through the yet undiscovered space of our universe are countless planets, stars, solar systems, galaxies, black holes, and many other things, including some that thus far remain undiscovered. But perhaps the greatest mysteries of astronomy lie not in the extraordinarily large, but in the extraordinarily small. If we are to learn how our universe originated and piece together the puzzle of how we got here, we must study matter—or “stuff”—at the very smallest level possible.
You may have heard of elements, the most basic forms of matter. But there are particles even smaller. Atoms, responsible for the composition of every body containing mass in existence, are only the beginning. Within an atom is a nucleus consisting of protons and neutrons, and orbited by a cloud of electrons whizzing around at extremely high speeds. You think we’ve gotten to the smallest pieces yet? Not even close. Within protons and electrons are quarks, even smaller. And within quarks are the smallest pieces of all—yep, we’ve found them—the gluon.
Gluons are the glue that binds us. Without gluons, there would be no universe. There would be no binding together of particles, no coalescing into larger chunks. Elements could not form. Thus, neither could molecules, dust particles, dirt balls, rocks, iron chunks, boulders, asteroids, planetesimals, planets, brown dwarfs, stars, white dwarfs, red giants, supergiants, supernovae, neutron stars, black holes, or anything else we may not know about yet. But that sounds so certain. If gluons are the final frontier, then what don’t we know about them?
The answer is: just about everything. The mass of quarks accounts for only 2% of the mass of protons and neutrons. We think that the other 98% comes from the actions of gluons. But here’s the quandary: gluons are literally massless. What does that mean? They have no stuff in them. The physical properties that make a table a table, and not a gap of empty space, do not apply to gluons. As far as physical, readily comprehendible existence goes, gluons are essentially nothing. So how does “nothing” make up for 98% of the physical stuff—mass—in our universe? How does “nothing” literally comprise your desk, your computer, and even the words on the page you’re reading right now?
Like so many other aspects of science, we don’t know. There are many quandaries surrounding gluons and the quarks they comprise. Supposedly, the laws of quantum mechanics should explain gluons. Gluons are responsible for the strong force, one of four fundamental forces in nature (the strong force, gravitation, electromagnetism, and the weak force). The strong force is the force that binds the nucleus of the atom together. A very strong force is required to do so, hence the name, because of the enormous electromagnetic repulsion between like-charged protons in the nucleus. According to the laws of most forces in nature, the strength of the force should grow stronger the smaller the distance between the attractive particles. That’s how gravity works—we can’t jump very high in the air, but the moon manages to orbit far away without crashing down to Earth’s surface. That’s how electromagnetism works. But the strong force? No. It would figure that if it has to do with gluons, it’s complicated. The strong force seems to increase in strength as distance increases. Its workings also imply that gluons, compared to the other particles of the atom, are huge in mass. As mentioned above, that is not the case—rather, gluons have no mass.
We have yet to answer these questions, But that’s what drives us to discover. Who knows—once we figure out gluons, an entirely new concept may be presented to us for us to digest. Such is the nature of our universe. The times when it seems to conspire against us are also the times when we can find ourselves learning the most about our world. Patterns are easy to decipher. But these mysteries, seemingly beyond our comprehension? They present us with a worthwhile challenge and dare us forth. I often wonder, where would we be without the questions in science?