The theories in which modern science rest heavily upon were presented hundreds of years ago by the scientists we have grown to learn about and love. Their theories have yet to be disproved, and that is why those theories are the platform on which modern science now rests. It is a strong platform, but as it ages, we must fill in the cracks. That’s where we are at in this day and age, filling in the cracks of an old foundation. Gravity is the most fundamental force in the universe, yet it is a very weak force. The series of posts I am about to share rely heavily on our concept of Gravity, so it’s important to get the basics down first.
We will start with Galileo. In a uniform gravitational field, Galileo believed that all objects fall identically-irrespective to their mass. To prove his theory, he climbed up the Leaning Tower of Pisa where he dropped various masses. In doing so, he proved that when an object is in free fall, it will not experience a force in relation to it’s mass and that all objects, regardless of their mass will move in the same direction, at the same time. Think of an elevator- your head and shoes will “fall” at the same time, even though your head is heavier than your shoes. Galileo gave us the understanding of inertia; where an object that is set into motion stays in motion until it is acted upon by some external force.
Aristotle believed that the Earth did not move because if you threw a ball straight up in the air it would come straight back down, instead of going to the left/right etc. Galileo argued this idea giving an example of the cabin of a ship. Inside the cabin, if there are no windows, there is no way to tell if the ship is moving or not. Galileo concluded that the laws of physics are identical in all Galilean (intertial) reference frames, providing us with our first encounter with relativity.
Next, Sir Isaac Newton comes along to explain the force that acts upon all objects. Newton’s first law of motion is essentially Galileo’s concept of intertia. The second law of motion tells us that the force needed to act upon an object depends on it’s mass and acceleration. If you have a large mass with a large acceleration, you will need a large force to act upon it and so on. Finally, Newton’s third law of motion state’s that for every action, there is an equal but opposite reaction.
Newton’s laws gave us a better understanding of the physical world around us. Einstein decided to apply his idea’s to the entire universe. On November 25th, 1915 Einstein
published his Theory of Special Relativity. This theory has provided us a profound understanding of our universe, and much of what we know has been found using Einstein’s theories. Special Relativity tells us that the speed of light is the same in all constantly moving frames and that Time slows down the faster you travel and vice versa.
To better understand the idea of special relativity, I will provide an analogy from the book “Hyperspace” by Michio Kaku: Continue reading “The Implications of Gravity in Spacetime”