As I mentioned in a previous blog post I’ve been thinking about launching a second blog. The topic would be facts, or insights that are widely disputed or misunderstood amongst the public, yet important and known to be true. However, I am also thinking about adding another aspect to the blog and that is facts, or insights that are highly surprising to people, yet important and known to be true. Curious or strange facts if you will. Not strange trivia but important stuff. People wouldn’t necessarily dispute these facts, well they might, but they may appear unintuitive to a lot of people. So, the true facts that people are disputing would be “cluster-A” and the facts that just would seem strange, ponderous, or counter intuitive would be “cluster-B”. I will post about both.
This particular blog post gives an example of a cluster B fact. To express myself a little bit simplistic, science does not know everything (otherwise it would stop), but it knows a lot. By studying the light from a distant star, we can determine what elements it is composed of. The star may be composed of 71% hydrogen, 27% helium, 1% Lithium, and 1% other elements, and we can know that just from its light. We can determine the distance to the star, how it is moving compared to us, its temperature, roughly its age and longevity, and more. 150 years ago, we could not have dreamed of this capability.
Yet we know that there are things we can never know, no matter how advanced science becomes. Infinite experimentation, super intelligence, a quintillion super genius, infinite time, cannot breach some knowledge. The universe itself forbids some knowledge. It also means that the statement “nothing is impossible” is false. My natural reaction to such a claim is, “come on you can’t say that with certainty”, and I expect many others will feel the same. However, the reason some knowledge will never be attainable is that physical laws as well as mathematics and logic forbid some knowledge. Some things are not meant to be known. I will explain in the four sections below: the event horizon, the Heisenberg uncertainty principle, beyond the observable Universe, and Gödels incompleteness theorem.
I should say in my future blog I will explore each of the four examples below more in depth, and put them in their own blog posts, and I might add or remove examples as I learn more.
The Event Horizon of a Black Hole
A black hole is a region of spacetime where gravity is so strong that nothing, including light, can escape it. The boundary of no escape is called the event horizon. If you pass the event horizon you cannot come back out no matter how much energy, you expand. Nothing can escape, no matter, no radiation, not light or other electromagnetic radiation, and no information. Nothing at all can escape. The curvature of time and space itself forbids it. I should add that right at the event horizon, there is so called Hawking radiation, but without complicating things it is not the same thing as escaping a black hole.
Some black holes are formed when large stars die and collapse. These black holes are estimated to have a mass of five to several tens of solar masses. However, there are also super massive black holes that reside in the center of galaxies. The super massive black hole at the center of our galaxy, the Milky Way, is called Sagittarius A* and is estimated to have a mass of four million times the mass of our sun. The largest known supermassive black hole TON 618 is 66 billion times more massive than our sun. There are an estimated 100 million black holes in our own galaxy, the Milky Way. One interesting fact is that celestial objects can orbit a black hole, just like planets orbit the sun, but as you get too close you will rush, at the speed of light, into the depths of the black hole You are “poff and gone”.
The fact that nothing, including information, can escape a black hole means that we can never observe what is on the inside. You can venture inside and be lost. You can extrapolate from physical laws what might be inside, but you can never observe and report what is inside to planet Earth.
The Heisenberg uncertainty principle
The Heisenberg uncertainty principle states that it’s not possible to know the position and momentum of an object with perfect accuracy at the same time. Another way of saying that is that we cannot know both the position and speed of a particle, such as a photon or electron, with perfect accuracy. The formula is: dX * dP >= h/4pi , uncertainty in position (dX) times uncertainty in momentum (dP) is larger than half of Planck’s constant, which is very small. There is also an energy and time precision : dT * dE >= h/4pi. It basically means that there are no perfectly exact measurements or knowledge. Everything is a bit fuzzy. Planck’s constant is very small, so Heisenberg uncertainty principle does not matter for everyday objects, but it matters when sizes are very small (positions, energies, etc.) Note, Heisenberg uncertainty principle is not regarding a limitation of our equipment, but a limit set by a law of physics. It is a limitation set by the Universe.
Beyond the observable Universe
The observable universe is a ball-shaped region of the universe consisting of all matter that currently can be observed from Earth or its space-based telescopes. The radius of the observable universe is 46.6 billion light-years. The size of the observable universe is growing. Unfortunately, at those distances, space itself is stretching/expanding faster than the speed of light. Since no signal or information can travel faster than the speed of light we are losing, not gaining, celestial objects from the observable universe. Further, in the past we’ve lost many galaxies this way. I can add that the universe may be infinite. Since the expansion is accelerating, we will keep losing more galaxies beyond the boundary of the universe and some galaxies were always lost (with respect to observation).
If we are wrong about the fact that the expansion of the universe is accelerating, then perhaps we can observe more galaxies in the future. But if not, then there are galaxies that we have never observed, galaxies that we can never observe, and there are galaxies that will become unobservable in the future. Depending on the size of the universe we may never be able to observe more than an infinitesimally small portion of the universe. Again, the universe is stopping us from knowing something.
Gödels incompleteness theorem(s)
The theorem states that in any reasonable mathematical system there will always be true statements that cannot be proved. In other words, to find a complete and consistent set of axioms for all mathematics is impossible. There are forever hidden truths in mathematics. For the case of natural numbers this means that there will always be statements about natural numbers that are true, but that are unprovable. I can add that there is also a second incompleteness theorem that states that a formal system cannot prove that the system itself is consistent. Basically, there are limits to mathematics set by logic.
I have a book on Gödels incompleteness theorem, which I have not read, but I will read it before I make a post about it.
Some other topics for strange yet important facts
- Light speed in vacuum is a Universal Constant.
- Time is relative (deeper explanation).
- Non-simultaneity and simultaneity are relative.
- The strange double slit experiment.
- Quantum Tunneling.
- Quantum entanglement.
- The Monty-game-door trick, 3-doors.
- The butterfly effect.
- Mandela effect.
What do you think about mixing in some very strange but important facts in my future blog about facts people dispute even though they are known to be true?
Leonberger Life 