If the universe started 15 million years ago with the Big Bang, what preceded it? Nothing, according to the late Stephen Hawking. However, no one can know for sure; any events that happened before the universe came into existence are without “observational consequence,” as Hawking out it, so “we might as well cut them out of the theory, and say that time began at the Big Bang.”
2. What is Dark Matter?
Everyone and everything is made up of baryonic matter: protons, electrons, and neutrons. Up until about three decades ago, astronomers believed that the universe followed the same pattern. However, scientists have since found that only 5% of the universe is composed of baryonic matter – and they can’t even detect the other 95%. Scientists believe that some 25% consists of dark matter, but nobody can say definitely what dark matter actually is or what it’s made of.
Gravity poses a vexing paradox that can be summed up with this one question: Why can a mere fridge magnet defy an entire planet’s gravitational pull? Some scientists believe that gravity may well be as strong as the other fundamental forces, but its influence is decreased because it leaks into extra dimensions.
4. How Big is the Universe?
If scientists know that the universe is expanding, then it must mean that they have a rough idea as to how big it is, right? Unfortunately, they don’t. They would have to know the universe’s shape and rate of expansion, among other things – and those are all mysteries as well.
If the universe is compelled to repeat itself – to be part of a multiverse – could there be another version of you? According to Space.com, if you look far enough, you would encounter another version of you – in fact, infinite versions of you. Some of these twins will be doing exactly what you’re doing right now, while others will have put on different sweaters this morning, and will have made vastly different career and life choices.
6. How did the Moon Form?
The moon’s gravitational pull is responsible for the rise and fall of the tides, but how did it come into being? After all, it took 100 million years after the solar system and its planets began to form before the moon actually came into existence. A number of theories exist, none of which are even close to being proven. Meanwhile, one potential key to figuring out this mystery is to understand why Venus doesn’t have one.
We all take it for granted that life on Earth began here – but this isn’t accurate. Scientists are finding evidence that life on this planet may have actually have come from Mars and was brought to Earth by a meteorite.
8. Is There Alien Life?
Since the early 1960s, scientists have theorized that it’s extremely likely that intelligent life exists outside this planet. However, the trouble is that we have no scientific evidence. In fact, we have no evidence that any life exists outside of earth, at least so far.
9. Who’s in Charge Here?
Did someone or something start the whole process that has led to you reading this article on an electronic screen? Or is everything that has happened in the history of ever simply the result of a process guided by the laws of science? While many notable scientific thinks say that God doesn’t exist, not all scientists are atheists. This is one we’re unlikely to solve – at least during our lifetime.