One of the advantages of being retired is that I can dip my toes into areas of study that would be impractical if I was still working. Then, focusing on learning things I needed to know was more important. Any leisure time was spent with family and on a few creative hobbies, with both add-ons necessary to keep me sane and centered.
Free time isn’t free; it is a gift that can be utilized or squandered. It was so foreign that it took me several post-retirement years to adjust to it fully.
When I am inclined, I like to explore esoteric areas. Most recently, I have been studying the cosmos- the most gigantic structure we humans are aware of, and balancing that information with quantum mechanics and quantum wave theory, which are concerned with the smallest particles in nature.
I must admit that my knowledge of either field is primitive, and even at my minuscule level of understanding, these topics are complicated and overwhelming.
Our observable universe has trillions of galaxies; each has billions of star systems with planets. However, the actual universe is larger than our observable universe as the cosmos expanded at a speed greater than the speed of light at its inception. Because of this, some distant star’s light will never reach us. You are probably thinking, “But I thought nothing could go faster than the speed of light. Isn’t that what Einstein said in his theory of special relativity?” The speed of light is a fundamental constant in nature, but natural laws did not exist at the dawn of our universe. Those laws were established once light and matter came into being.
At the dawn of the universe, there were no long-lived elemental particles and certainty no atoms. The emerging universe was too hot to allow the creation of such things. As the universe cooled, subatomic particles formed that could join together to create hydrogen atoms, and with such formations, matter, as we know it, came into being. At the beginning of the universe, there was likely only one or two fundamental forces of nature that eventually separated into the four fundamental forces that govern the cosmos: electromagnetic, strong, weak, and gravitational. Physicists have been able to work backward and mathematically to join the electromagnetic, weak, and strong forces together. Still, they have yet to figure out how the gravitational force is part of a single elementary force model.
The values of any of these forces could have been different when the universe was forming. If any of these value was even slightly altered, the universe and everything in it as we know it would not exist. That is an amazing realization. How did we get the perfect values necessary for matter and, in turn, for life to exist? There is no current way to determine this. Some may say that an all-powerful intelligence designed the universe; others may state that there have been infinite universes, and ours just happened to be the lucky one where the numbers worked out. This is where science breaks down into philosophy, at least for now.
The universe is expanding, but we don’t know what it is expanding into. As our scientific tools become more sophisticated, more questions arise. Galaxies are spinning much faster than they should be, and the overall speed of the universe expanding is faster than what is calculable based on our measurements of the known matter and energy present in the universe. Something else is speeding things up. Physicists call these forces dark matter and dark energy, two things we can’t see or measure with our current technology. However, we believe they are present based on how they impact things we can see and measure. Further, we can determine that both exist in much greater quantity than the matter we can see and the energy we can measure. The majority of the universe is, therefore, invisible to us.
The idea that the universe is full of invisible things isn’t as far-fetched as it seems. Neutrinos are proven to be the most abundant particle in the universe (we can measure them), but they barely react with classic matter, so they pass through it. About 100 trillion neutrinos pass through your body every second, and you are completely unaware of it.
At the beginning of the universe, there was only energy. The universe rapidly expanded, and in the process, it cooled enough to form elementary particles, such as quarks, leptons, and gluons. As it cooled further, these elementary particles combined to form hydrogen atoms that served as stars’ fuel. In turn, the incredible energy and pressure of the stars formed helium and the other naturally occurring elements that make up our universe. These elements make up our oceans, skies, and land. It is amazing to realize that they also make up us. Why are we living while mountains are not? Another mystery.
The greatest scientist who ever lived was thought to be Sir Isaac Newton. His recognition of universal gravitation and his laws of motion became the foundation of physics. His formulas developed in the 1600s were accurate enough to guide Apollo 11 to the moon. However, they were incomplete as they couldn’t accurately explain the movement of some things we could observe in nature.
It was possible to correctly model the orbits of all known planets in our solar system using Newton’s classical equations, except for the planet Mercury. A patent clerk named Albert Einstein solved this conundrum in the early 1900s. He developed theories that went beyond Sir Isaac Newton’s observational equations. It turns out that Newton’s equations are correct, but they only work in certain situations. In reality, they are a subset of Einstein’s broader concepts. Newton’s equations are not accurate when dealing with the extreme. Among Einstein’s brilliant ideas are his special and general theories of relativity. One concept from these discoveries is the concept of space-time. Space (as measured by height, width, and depth) and time are joined together. Time is not a constant but varies. An accurate clock in a satellite experiences time faster than an accurate clock on earth. Time is moving faster in your head than in your feet (as your head is farther away from the earth’s gravity). So your head is aging faster. However, this difference is so tiny that you would never know it. These theories are hard to conceptualize, but they have been proven to be correct many times in experiments.
So why couldn’t classical physics (Newton’s equations) predict the orbit of Mercury? Huge objects, like the sun, can significantly warp space-time. Since Mercury is close to our massive sun, it is impacted more by this warping. That warping impacts Mercury’s orbit in a way not predicted by Newtonian (classic) physics, but it is perfectly calculated by Einstein’s equations. If an object has enough mass, it can even warp the path of light, even though light has no mass on its own. This has also been proven many times and is an accepted fact. Black holes warp space-time so much that massless light can’t escape a black hole, which is why they appear black. When it comes to how very large objects interact or things (like light) that move incredibly fast, our observable understanding of how things work (classical physics) fails, but Einstein’s theories on general and special relativity prevail.
What about things that are on a very tiny scale? Enter the world of quantum mechanics, which is even more bizarre than relativity. The quantum world operates by rules very different from the macro world. The quantum world behaves so strangely that Einstein felt that parts of quantum mechanics couldn’t be true. He sarcastically referred to one aspect of quantum mechanics as “spooky.” However, he was wrong, and quantum theory has been proven both mathematically and through scientific experiments.
It is difficult to understand basic quantum mechanics because things react differently than what we experience in our macro world. We know that electrons circle the nucleus of an atom, but quantum theory says that we have no way of knowing exactly where an electron is as it can be everywhere and nowhere at any time. Its position only exists when we measure it as if measuring it pulls the electron into existence. Quantum theory also embraces the concept of entanglement. Let’s say two electrons were created together simultaneously as a pair. They will always react instantly to each other, no matter how far apart. If one is spinning to the right, the other will spin to the left even if the universe separates the electrons. Relativity says that nothing can travel faster than the speed of light, so entanglement must be connecting these electrons by some other method beyond our comprehension.
In high school physics, we are taught that light can act as a wave (electromagnetic wave) and a particle (a photon). Quantum mechanics says this is also true for particles: particles (electrons) can act as a wave. It all sounds pretty crazy, but quantum mechanics is one of the most proven theories in physics. Eventually, even Einstein had to admit that quantum mechanics was correct. Quantum mechanics has real uses too. Quantum mechanics makes possible many practical things, from lasers to solar cells. Scientists are developing computers based on quantum mechanics, and some experimental prototypes exist. A fully functioning quantum computer could perform complicated tasks exponentially faster than our current computers that rely on classical principles.
Large objects can be defined by general relativity (including Newton’s classic laws), and quantum mechanics defines tiny objects like atoms. Both disciplines work very well for their respective purpose. However, they are not compatible with each other. In other words, the two theories are not unified. Many physicists have tried to join these theories into a theory of everything but failed.
In addition, there are some situations where quantum mechanics breaks down. For instance, when a particle is approaching the speed of light. No consideration for speed in quantum mechanic equations makes this theory incomplete.
Other theories try to address the above problems. One is quantum field theory (different from quantum mechanics), which says that various fields exist everywhere. These fields can have local areas of disturbance, and those peaks are what we observe as subatomic particles. Remember that subatomic particles form atoms, and atoms form everything in our known universe.
Another theory is string theory and its cousin, M theory, where strings of vibrating energy create matter as we know it. For string theory to work, our universe must have other dimensions (beyond height, width, and depth- or X, Y, and Z axes). However, as humans, we can’t conceptualize such things as our world as an X, Y, Z world, not one with ten or more dimensions.
The ontology of these two theories is different, but they explain the same thing. The problem with them is that they are not provable by any of our current methods of observation, so they are more philosophical rather than scientific. However, conceptually they are very interesting. We know that matter and energy are related by Einstein’s famous E =MC2 equation. The detonation of the atom bomb demonstrated that mass could be converted into energy. However, quantum wave and string theories suggest that energy can be converted into matter. In other words, everything we think of as matter is just fluctuating quantum fields or strings of energy (depending on what you ascribe to). Matter is just energy in a different form. Crazy, I know.
This brings to mind the movie, “The Matrix,” where people live in a synthetic computer-generated world so that machines can draw on human energy for their own nefarious reasons. Of course, that is science fiction. However, it is reasonable to think that all living things and the universe around us are just fluctuations in energy. Think about the complexity of that! It also implies that we are all joined together in some way which could explain certain phenomena that exists but doesn’t fit into a classic scientific model. How did all of this happen? God? Chance? Other? I’ll leave that for you to ponder.