Philosophy

What is general relativity vs. quantum mechanics incompatible? Is it possible to unite the four forces with the subatomic particles?  The predictions of relativity, which deal with phenomena on the massive, universal scale, break down when applied to the subatomic level of quantum mechanics. Uniting quantum mechanics and relativity is one of the great challenges to establishing a complete theory of the universe. Keep reading to learn about the general relativity vs. quantum mechanics dilemma.

Is the universe finite or infinite? Does the cosmos extend forever or does it have a boundary? The universe is always in the state of expansion but it cannot be infinite. In an infinite (and static) universe, every point of observation would arrive at a star (because there would be an infinite number of stars), but this is clearly not the case (this is known as Olbers’ paradox or the “dark night sky paradox”).  Here is why our universe cannot be infinite.

Does theoretical physics allow for time travel? And if so, under what conditions could traveling through time be possible? Believe it or not, there may be some scenarios under which traveling through time is theoretically possible. Specifically, it’d possible if it could be shown that parts of the universe exist where there is negative curvature, which is actually in the realm of possibility as far as theoretical physics is concerned. Here is why time travel is (theoretically) possible yet extremely unlikely.

What is string theory? What conundrum does string theory attempt to resolve? In physics, string theory states that the fundamental building blocks of the universe are one-dimensional strings as opposed to point-like particles. String theory attempts to solve one of the toughest stumbling blocks of physics—that is the difficulty of uniting the uncertainty principle with the predictions of general relativity. Keep reading to learn about string theory, explained in simple terms.

What is absolute time? How does the location of the observer affect the speed of time? Originally coined by Isaac Newton, the concept of absolute time refers to the idea that time flows without regard for anything external, progressing at a consistent speed throughout the universe. As it turned out, Newton was wrong. Albert Einstein established that time is relative, that is, it moves at different speeds for different observers. Keep reading to understand why time is not absolute, but relative.

What is the uncertainty principle? Why is it impossible to measure both the position and the velocity of a subatomic particle simultaneously? The uncertainty principle states that it is impossible to determine both particle velocity and position with certainty. In order to gauge the position and speed of a subatomic particle, we’d need to expose it to light, but doing that would alter both properties. Keep reading to understand the uncertainty principle and its implications for the study of our universe.