https://theconversation.com/evidence-of-brand-new-physics-at-cern-why-were-cautiously-optimistic-about-our-new-findings-157464
In: Physics
Just some misconceptions I’d like to clarify:
– Gravity is a force
Einstein’s general relativity says otherwise. Gravity is described by Einstein to be the warped space-time around heavy objects. This is why even light’s path is bent by gravity. Someone not in a gravity well will age more than someone in a gravity well. In theory, if you can survive falling into a black hole and look back at the universe, you can see the whole future of the universe happening very quickly.
So far this is the most widely accepted theory of gravity.
– Why can’t we add Gravity to the SM
Because of a very simple reason. Gravity seems to disappear when we get to small things. The SM deals with extremely small things, so to “add” gravity to it, means to describe gravity in the very small things. It’s very hard to create a theory of something when you can’t even measure it.
General relativity describes the physics of the big things. Quantum physics describes the very tiny things. These 2 theories are not compatible with each other. However, they are the best theories we have. This is why the world is waiting for a unification of general relativity and quantum physics. If we have a theory that describes everything, it would also describe gravity in the very small things too.
– How can we consider Earth a closed system when there are other things out there?
It’s just for practical reasons. For things such as thermal activities, it is good enough to consider the Earth a closed system. The medium between the Earth and the other things do transfer some heat, but extremely tiny to have a meaningful impact on anything. Simply dismissing it will simplify our lifes a lot.
It’s the same thing when you consider Newton’s laws of motion, if you hit a ball with a bat, the ball will have a force applied to it, and the bat will have an opposite force applied to it as well, as if they were in a closed system. In reality, there’s the muscles in your arms, the ground, the air molecules, etc, but those don’t really contribute much to the subject.
– Stars create matter so they are the opposite of black holes
Stars are matter clumped together due to gravity. They are not magical godlike beings that create matter out of nothing. A black hole is actually created from a very massive star after it’s death.
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