So, this is a really cool concept and I look forward to the determination if it is true or testable.<p>I find the "double copy of other forces" verbiage to be difficult to follow. Walking through a formula example would be helpful, and formaluae exist to communicate exactly this kind of clumpy-wumpy-lumpy-timey-wimey awkwardness language clods through in its quest to communicate mathematical structures.
This probably isn't the right place for this question. But the right kind of people will be reading this thread so I will ask it.<p>In college physics my teacher insisted that, despite gravity being popularly referred to as a force, it is <i>not</i> a force. Weight is indeed a force, but gravity is more like a field. I understood it like this: Say you have a point mass in an isolated system. There is certainly gravity all around that mass, but there are no forces anywhere in the system. Not until another mass is introduced into the system do you have any forces. It is apparent from the formula for force since then you have that new mass times the acceleration of gravity.<p>Or is this just being pedantic and does it even matter?
> Most theorists assume that gravity actually pushes us around through particles<p>Is this true, and if so, why? The interpretation of gravity as something that warps spacetime very elegantly yields its “gravitational force” via its effect on the action integral, and is easily understood using a path integral style framework. It seems like a particle-based framework would necessarily be a lot more complicated, although maybe it’s necessary for some reason I don’t know.
Someone needs to do a better visual explanation of these particle interactions. If you can describe it mathematically then surely you can create a computer simulation.
Anybody here know if this double copy technique is related to the cobordism property found in Donaldson's Theory [1]. From wiki:<p>> Donaldson was able to show that in specific circumstances (when the intersection form is definite) the moduli space of ASD instantons on a smooth, compact, oriented, simply-connected four-manifold X gives a cobordism between a copy of the manifold itself, and a disjoint union of copies of the complex projective plane CP^2.<p>[1] <a href="https://en.wikipedia.org/wiki/Yang%E2%80%93Mills_equations#Donaldson's_theorem" rel="nofollow">https://en.wikipedia.org/wiki/Yang%E2%80%93Mills_equations#D...</a>
sorry for this daft question<p>I imagine a very very slow moving rock in space - going at 1 m/s (relative to earth) in a straight line, the earths mass causes spacetime to bend making the rock head towards earth, but then the rock starts to accelerate<p>the bit I don't understand is why does the rock accelerate towards mass? Why does the bending of spacetime make it not carry on at 1 m/s towards earth<p>and since this rock has increased its speed due to accelation, where has this extra energy come from?
I’d like to learn more about this symmetry. Does anyone recommend a good article (or paper) about this?<p>> <i>Researchers note that electromagnetism, the weak force and the strong force each follow directly from a specific kind of symmetry — a change that doesn’t change anything overall (the way rotating a square by 90 degrees gives us back the same square).</i>
I don't know much about physics, but I always wondered if gravity is like a shadow.<p>Appearently shadows can move faster than light, breaking with the rest of physic knowledge, but when you look into the details, they adhere the laws of physics no problem.<p>Maybe, gravity is like that, not really a physical force, but the shadow of physical forces.
If this is related to string theory then the claims of any usefulness should be taken with a grain of salt. I remember all the ADS/CTF people claiming that they could provide huge insights into condense matter which later turned out to be very underwhelming.