This is the Introduction section of my book, Unraveling the Universe’s Mysteries. Enjoy!
The strides that science made in the Twentieth and early part of the Twenty-First Century are astounding. At the beginning of the Twentieth Century, science held three theories as universal truths, namely:
- Time was an absolute, independent of distance and movement of observers relative to an event.
- The universe consisted of the Milky Way galaxy.
- The universe was eternal and static.
However, the strongly held theories of the greatest scientific minds of the time proved to be false. I will briefly examine each theory and the empirical evidence that caused its demise.
First, the science community up to the early part of the Twentieth Century believed that time was an absolute. This meant time was independent of the position and movement of an observer relative to an event. This almost self-evident theory about time was about to be shattered. In 1905, a young Albert Einstein developed his special theory of relativity. It is termed “special” because it applied only to inertial frames of reference. An inertial frame of reference is one that is at either rest or moving with a constant velocity.
The special theory of relativity offered two hypotheses. 1) The laws of physics are the same in all inertial frames of reference. 2) The speed of light is a constant in a vacuum—independent of the movement of the emission source in all inertial frames. To understand the second hypothesis, consider this example. If you are in an open-top convertible car that is traveling down the highway at sixty miles per hour, you are in an inertial frame of reference. If you throw a ball in the same direction that the car is going, the total speed of the ball will be equal to the speed of the car plus the speed of ball as it leaves your hand. If you are able to throw the ball at thirty miles per hour, the total speed of the ball as it leaves your hand is ninety miles per hour. We get this speed by adding the speed of the car to the speed you are able to throw the ball. Now, let’s pretend you have a flashlight, an emission source, and an observer is able to measure the speed of light as it leaves the flashlight. The result the observer would measure is that the speed of light would independent of the car’s speed. In effect, the speed of the car does not make the light go faster. Even if the car stops, the speed of light from the flashlight would equal the speed of light of the moving car. For this example, I have ignored atmospheric effects and considered the observer stationary. This is counter intuitive, but true. The speed of light is the same regardless of the speed of the car (inertial frame). The implications of special relativity became enormous. One significant implication demonstrated that time was highly dependent on the relative motion of both the observer and the event. This discovery eventually led to the development of space-time as a coordinate system. The special theory of relativity and the general theory of relativity, two highly successful theories of modern science, use space-time as a coordinate system.
A second theory that the science community held about the universe related to its size. Until the 1917 completion of the 100-inch Hooker Telescope at the Mount Wilson Observatory, science had no way of knowing other galaxies existed. Therefore, the scientific community held that the universe consisted of the Milky Way galaxy, and nothing else. In fact, this is what they taught our grandparents as schoolchildren.
Surprisingly, the German philosopher Immanuel Kant (1724-1804), using reasoning, suggested a hundred years earlier that our galaxy was one of numerous “island universes.” Unfortunately, Kant’s view would have to wait more than a hundred years for telescope technology to prove him right. Even when early astronomers saw the faint lights of other galaxies in their crude telescopes, they believed the observed phenomena to be part of the Milky Way. That view of the universe was about to dramatically change.
In 1919, a young astronomer, Edwin Hubble, arrived at the Mount Wilson Observatory in California. As chance would have it, his arrival coincided with the completion of the Hooker Telescope. At the time, it was the world’s largest telescope, and the only one able to observe other galaxies beyond the Milky Way. In 1924, Edwin Hubble, using the 100-inch telescope at Mt. Wilson, discovered the Andromeda galaxy, a sister galaxy similar to our own Milky Way. This completely shattered another strongly held scientific belief. The universe was larger than previously thought. In fact, today we know that the universe has billions of galaxies.
Lastly, science held that the universe was eternal and static. This meant it had no beginning. Nor would it ever end. In other words, the universe was in “steady state.” At the beginning of the Twentieth Century, as I mentioned above, telescopes were crude and unable to focus on other galaxies. In addition, no theories of the universe were causing science to doubt the current dogma of a steady-state universe. All of that was about to change.
In 1916, Albert Einstein developed his general theory of relativity. It was termed “general” because it applied to all frames of reference, not only frames at rest or moving at a constant velocity (inertial frames). The general theory of relativity predicted that the universe was either expanding or contracting. This should have been a pivotal clue that the current scientific view of the universe as eternal and static might be wrong. However, Einstein’s paradigm of an eternal and static universe was so strong, he disregarded his own results. He quickly reformulated the equations incorporating a “cosmological constant.” With this new mathematical expression plugged into the equations, the equations of general relativity yielded the answer Einstein believed was right. The universe was in a steady-state. This means it was neither expanding nor contracting. The world of science accepted this, and continued entrenched in its belief of a steady-state universe. However, as telescopes began to improve, this scientific theory was destined to be shattered.
In 1929, Edwin Hubble, using the new Mt. Wilson 100-inch telescope, discovered the universe was expanding. In time, other astronomers confirmed Hubble’s discovery. This forced Einstein to call the cosmological constant his “greatest blunder.” This completely shattered the steady-state theory of the universe. In fact, this discovery was going to pave the way to an even greater discovery, the Big Bang theory, but more about that later.
In 1900, and for centuries before that, the greatest scientific minds of the time held the above three theories sacred. However, each theory crumbled as measurement techniques improved, and new theories evolved. This is a pivotal point. Science is rapidly evolving, and scientific knowledge doubles about every 10 years. We are constantly gathering new data that challenges our understanding of science, and that often leads to new mysteries. As soon as we become confident and comfortable in our grasp of reality, a new discovery turns our world upside down. For example, until 1998, every cosmologist knew the universe was expanding, but commonly held the belief that gravity would eventually slow down the expansion, and cause the universe to contract in a “Big Crunch.” The Big Crunch would result in an infinitely dense energy point similar to the infinitely dense energy point that existed at the instant before the Big Bang. In effect, the commonly held view was the universe would first expand, via the Big Bang, and then gravity would eventually cause it to contract, via the Big Crunch, to the infinitely dense energy point just prior to the expansion. Their confidence in this view abounded, and three scientists, Saul Perlmutter, Brian P. Schmidt, and Adam G. Riess, decided to measure it. To the scientific world’s astonishment, they discovered the universe was not only expanding, but the expansion was accelerating. In 2011, these three received the Nobel Prize for this remarkable discovery.
Stay tuned for part 2.
