I have heard it explained multiple time by different science educators that what we feel as gravity is a really just a consequence of curvature of spacetime and no real force is being applied. Why do we need to make gravity work with the standard model, and why are we looking for gravitons if there is no actual force and it is just caused by the geometry of the universe?
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I’ll just leave this here
“It is wrong to think that ‘geometrization’ is something essential. It is only a kind of crutch [Eselsbrücke] for the finding of numerical laws. Whether one links ‘geometrical’ intuitions with a theory is a … private matter.” (Einstein to Reichenbach, 8 April 1926)
Einstein himself didn’t seem to read too much into this interpretation. But Einstein was also wrong about other things, so I guess he could be wrong about this.
The math of GR is firmly rooted in the math of curved surfaces. But this is an ontological question. Does the math *describe* the thing. Or *is it* the thing. Our *spacetime model* is described by curved surfaces, but are space and time in reality one and the same as our model? Who knows…..
The standard model is kind of like a set of dance moves for the universe. If we see certain moves, like the electric slide, we can predict what is going over there like ionization. There are also spins and flips which can tell us about how a particle and its partners are going to behave. They have still yet to find, identify and study a dance move to Get Down. We know stuff does get down all the time because we observe it in our everyday lives. We have just yet to see a dance move that actually does it.
Now, some people think of gravity as just the shape of the dance floor instead of a dance move. Which is fine, but we should still be able to figure out how stuff interacts with the dance floor. Which is still being figured out.
The standard model is kind of like a set of dance moves for the universe. If we see certain moves, like the electric slide, we can predict what is going over there like ionization. There are also spins and flips which can tell us about how a particle and its partners are going to behave. They have still yet to find, identify and study a dance move to Get Down. We know stuff does get down all the time because we observe it in our everyday lives. We have just yet to see a dance move that actually does it.
Now, some people think of gravity as just the shape of the dance floor instead of a dance move. Which is fine, but we should still be able to figure out how stuff interacts with the dance floor. Which is still being figured out.
The standard model is kind of like a set of dance moves for the universe. If we see certain moves, like the electric slide, we can predict what is going over there like ionization. There are also spins and flips which can tell us about how a particle and its partners are going to behave. They have still yet to find, identify and study a dance move to Get Down. We know stuff does get down all the time because we observe it in our everyday lives. We have just yet to see a dance move that actually does it.
Now, some people think of gravity as just the shape of the dance floor instead of a dance move. Which is fine, but we should still be able to figure out how stuff interacts with the dance floor. Which is still being figured out.
Flip the question around backwards: why do we need relativity (or quantum mechanics) if Newtonian physics work just fine?
Answer: Newtonian physics work just fine when observing specific things. If you want to calculate the orbit of a planet around a star or the speed at which an apple falls from a tree, you can figure ~everything out without relativity or quantum. Now what if you ask ‘what holds the galaxy together?’ or ‘what’s happening inside of a proton?’. Newtonian physics can’t get you to a complete answer that matches the things we can see and measure at those massive or miniscule example scales.
It’s the same problem when you go the way you asked. If you take quantum mechanics and try to create a big many-equations computer model that shows how basic everyday stuff happens (like an apple falling towards earth), you’re either missing pieces you have to handwave or you get a result that isn’t what we can see and measure.
The reconciliation is the idea (which is debated and not proven) that if a set of equations and concepts cannot explain everything at every scale than it must be incomplete and/or incorrect in some way. Current models of quantum mechanics can’t explain all of those things without handwaving at least some parts (e.g., the carriers of gravity and how gravity works at extremely small scales).
Flip the question around backwards: why do we need relativity (or quantum mechanics) if Newtonian physics work just fine?
Answer: Newtonian physics work just fine when observing specific things. If you want to calculate the orbit of a planet around a star or the speed at which an apple falls from a tree, you can figure ~everything out without relativity or quantum. Now what if you ask ‘what holds the galaxy together?’ or ‘what’s happening inside of a proton?’. Newtonian physics can’t get you to a complete answer that matches the things we can see and measure at those massive or miniscule example scales.
It’s the same problem when you go the way you asked. If you take quantum mechanics and try to create a big many-equations computer model that shows how basic everyday stuff happens (like an apple falling towards earth), you’re either missing pieces you have to handwave or you get a result that isn’t what we can see and measure.
The reconciliation is the idea (which is debated and not proven) that if a set of equations and concepts cannot explain everything at every scale than it must be incomplete and/or incorrect in some way. Current models of quantum mechanics can’t explain all of those things without handwaving at least some parts (e.g., the carriers of gravity and how gravity works at extremely small scales).
Flip the question around backwards: why do we need relativity (or quantum mechanics) if Newtonian physics work just fine?
Answer: Newtonian physics work just fine when observing specific things. If you want to calculate the orbit of a planet around a star or the speed at which an apple falls from a tree, you can figure ~everything out without relativity or quantum. Now what if you ask ‘what holds the galaxy together?’ or ‘what’s happening inside of a proton?’. Newtonian physics can’t get you to a complete answer that matches the things we can see and measure at those massive or miniscule example scales.
It’s the same problem when you go the way you asked. If you take quantum mechanics and try to create a big many-equations computer model that shows how basic everyday stuff happens (like an apple falling towards earth), you’re either missing pieces you have to handwave or you get a result that isn’t what we can see and measure.
The reconciliation is the idea (which is debated and not proven) that if a set of equations and concepts cannot explain everything at every scale than it must be incomplete and/or incorrect in some way. Current models of quantum mechanics can’t explain all of those things without handwaving at least some parts (e.g., the carriers of gravity and how gravity works at extremely small scales).
Our best description of gravity says:
>mass and energy distort the spacetime, making straight lines bend and accelerate/decelerate.
It doesn’t dive very deep on **how** mass/energy is able to apply this distortion.
To make it very very simplistic currently we are able to predict gravity’s effect on matter, but we are not able to describe its nature.
I mean, if you want to go very phylosofical-junkie you could even say that spacetime is just a mathematical construct, and not something that materially exists. It is a 4d grid that we use to measure the whole universe, but you won’t be able to touch it, or “measure” it.
So there is still much to explore to improve our description of gravity
Our best description of gravity says:
>mass and energy distort the spacetime, making straight lines bend and accelerate/decelerate.
It doesn’t dive very deep on **how** mass/energy is able to apply this distortion.
To make it very very simplistic currently we are able to predict gravity’s effect on matter, but we are not able to describe its nature.
I mean, if you want to go very phylosofical-junkie you could even say that spacetime is just a mathematical construct, and not something that materially exists. It is a 4d grid that we use to measure the whole universe, but you won’t be able to touch it, or “measure” it.
So there is still much to explore to improve our description of gravity
Our best description of gravity says:
>mass and energy distort the spacetime, making straight lines bend and accelerate/decelerate.
It doesn’t dive very deep on **how** mass/energy is able to apply this distortion.
To make it very very simplistic currently we are able to predict gravity’s effect on matter, but we are not able to describe its nature.
I mean, if you want to go very phylosofical-junkie you could even say that spacetime is just a mathematical construct, and not something that materially exists. It is a 4d grid that we use to measure the whole universe, but you won’t be able to touch it, or “measure” it.
So there is still much to explore to improve our description of gravity
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