The aim of /v/Physics is to build a subverse frequented by physicists, scientists, and those with a passion for physics. Papers from physics journals (free or otherwise) are encouraged. Posts should be pertinent, meme-free, and generate a discussion about physics. Please report trolls and intentionally misleading comments.
At this early stage /v/physics is open to any physics related question or comment. Including physics homework problems, physics GRE problems or questions, or questions about jobs in physics.
Sort: Top
[–] SwiftLion 0 points 10 points 10 points (+10|-0) ago
"Explained" is a strong word. The other three forces have been UNIFIED.
Ultimately, we have this guess about the way the universe should be. It's maybe better described as a prejudice: humans appreciate elegance and simplicity. We believe that theories with fewer "moving parts", or simpler components, are "more true" or "better". Of course, this isn't the only test that exists--I can tell you, "the whole universe is made up of little tiny T-shaped bar magnets", and that theory may be very simple, but if it doesn't make correct predictions about how stars work, it'll be thrown out.
Matter as an Example of Simplification as you Drill Down
To be fair, it's true that things seem to become simpler as we "drill down". If you start off by trying to categorize "substances", you have billions and billions and billions of options. We even have neural networks that try to figure out the properties of various new substances to identify ones we like. But, what's more elegant than that? Elements. With only about a hundred or so entries, you can categorize all of those billions of substances as "arising from" elements. We actually thought, for a long time, that a correct "theory of the universe" involved around a hundred different kinds of "atoms". We called them "atoms" because we thought they couldn't be subdivided. Then, after that, we found out how to smash those apart, and discovered that ultimately, they're made of only three kinds of things: electrons, protons and neutrons.
Strangely, when you smash THOSE apart, you get quarks, which are weird--we step up from only three types of particles for the "elementary particles", to a much larger spectrum for quarks. You have the six flavors ( up, down, top, bottom, charm, strange ) and then three 'colors', but whatever.
Fundamental Forces
We should take just a second and clarify what we mean when we say "explain", too. Nobody can actually tell us WHY the electroweak force exists. We can only talk about 'what' it is. Right now, we have the 'Grand Unified Theory', which describes charge. The only thing is, it actually doesn't predict the existence of gravity.
Because we value elegance and simplicity, the idea that there are two, completely unrelated forces seems irksome to us. And that's the reason we say gravity is "unexplained": we EXPECT, we HOPE, that there is a way to describe charge so that gravity arises naturally as an aspect of it. This would be called a 'Theory of Everything', because it would explain a fundamental feature of the universe: "Here is what 'force' is". Then, all the forces we observe in our daily lives could be described as "aspects" of the fundamental force.
It may turn out that we have "explained" gravity just as well as it's gonna be explained. Maybe it turns out that there's not gonna be a unification at all, and the universe DOES just have two fundamental forces: charge, and gravity! But we just have a suspicion that it isn't quite so, and that there IS an explanation for gravity as an aspect of charge. And so, we call gravity "unexplained".
[–] 475677 0 points 2 points 2 points (+2|-0) ago
The one time I dropped acid I got in a huge fight with gravity and although I was tripping it became clear as day to me that it doesn't actually exist as something that can really be measured. What I saw was energy with space inside of it rotating which dragged the outside space around with it into a whirlpool of space that went in every direction. The more energy the more space spun which attracted things around it like it was falling into it until the forces evened out and settled either into place or in orbit.
So to me it was like what I perceived to be weight was merely how much space bent making that object fall into a greater mass of energy that was spinning space around it into basically lines of attraction. I then had the feeling that being in orbit where I was traveling at a great enough speed to ride one of those waves essentially cancelling the force out and because it was cancelled out it was only the things around me that were having an influence which since they were tiny compared to the earth gave me super human strength compared to when I would be on the ground.
I'm half retarded and was tripping major balls at the time though so chances are I'm wrong but that's how I picture gravity anyway.
[–] ramultyleveachan [S] ago
Are you from the US?
[–] 475677 ago
Nah mate, Ausfag here.
[–] klobos ago
Have done LSD, can confirm.
[–] goatboy 0 points 1 point 1 point (+1|-0) ago (edited ago)
The other fundamental forces have observed exchange particles for the transfer of information. Gravity does not have an observed transfer particle or graviton. If it exists the graviton would cover infinite distances, which seems to violate or be the inverse of the r-square law.
However, the D-Wave quantum computers indicate possible information transfer with alternate universes. If that is indeed the case, then it is possible that gravitons don't exist in this universe at all.
The other component of gravity is time dilation due to acceleration around large mass.
It is possible our entire universe is on the inside surface of an ultra massive black hole and the blackhole's event horizon which is constantly and everywhere behind us is itself the graviton field.