changing the laws of physics
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so when i was doing the dishes last night, i came up with a thought. I found it quite interesting, but the problem is it is a physics question and the only thing i know about physics is everything falls at the same rate. anyways, lets say we live in an alternate universe that is exactly the same as this one, except for one change in the laws of physics. the heavier something is, the faster it falls. my question is what would happen if i put a piece of paper underneath a book and dropped it. what would happen? however, when i asked on irc they brought up some more interesting questions, primarily what would the world be in general?
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Not a physicist, but I would say the piece of paper would be pushed down by the book. Just like how a piece of paper would be pushed down by my hand in "normal" physics universe. Gravity is just a force, like my hand. Unless this piece of paper is able to provide a counter force, then it's going to be pushed down by the book.
As for how the universe in general would be different, that's a hell of a question. I'm curious what people think.
As for how the universe in general would be different, that's a hell of a question. I'm curious what people think.
Our understanding of what would happen depends entirely on our understanding of the laws of physics.
If we are changing the laws of physics, then we are literally changing everything we know. Which means everything we know is wrong, and needs to be re-observed.
So there is no answer to this question. We would have to observe the behavior for ourselves to see what would happen.
If we are changing the laws of physics, then we are literally changing everything we know. Which means everything we know is wrong, and needs to be re-observed.
So there is no answer to this question. We would have to observe the behavior for ourselves to see what would happen.
closed account (EwCjE3v7)
Okay if I throw a peace of paper in the air and than push it down from the top, well I would be pushing it and it would be the same for the book but the force would be gravity
Any logic that parallels with what we see in our universe is irrelevant, because what we see depends on the current laws of physics.
This thread is assuming the laws of physics have changed. This means we cannot begin to predict what will happen in this case.
Maybe the rock will push the paper down. Maybe the paper will hold the rock up. Maybe it'll create some kind of chemical reaction and explode when the two materials come in contact with each other.
Everything we know is wrong.
This thread is assuming the laws of physics have changed. This means we cannot begin to predict what will happen in this case.
Maybe the rock will push the paper down. Maybe the paper will hold the rock up. Maybe it'll create some kind of chemical reaction and explode when the two materials come in contact with each other.
Everything we know is wrong.
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Damnit Disch. You came into an interesting topic, applied logic, and made it no fun anymore :(
closed account (EwCjE3v7)
Sorry was this supposed to be a funny topic?
That was actually a good question.
That was actually a good question.
| Sorry was this supposed to be a funny topic? |
no actually. i was curious about the science behind it and know nothing about physics
| lets say we live in an alternate universe that is exactly the same as this one, except for one change in the laws of physics. |
Well to be fair, some scientists do theorize that the possibility of infinite parallel universes beside ours where everything is the same cept for a minor change. I don't see why one of the changes couldn't very well be physics being different in one of them. Until there is actual proof of this, it is nothing more than a theory and flight of fantasy.
closed account (z05DSL3A)
| Until there is actual proof of this, it is nothing more than a theory... |
There is no answer because the hypothetical situation is ill-defined. That objects are accelerated towards each other with equal force isn't a property of the universe. It's a consequence of the nature of gravity that same amounts of matter generate same amount of gravity. The respective masses of a book and a piece of paper are negligible when compared to the mass of the Earth, so the respective acceleration forces that each apply on the Earth are also negligible, but non-equal. If the objects were much, much heavier, you'd see them fall to the Earth (and towards each other) at different rates, since they'd also move the Earth towards them. The heavier object would pull harder.
So, back to the original question: to properly define the hypothetical, you need to define a form of gravity that would cause objects much, much lighter than another to accelerate that other object towards them at noticeably different rates. It's not at all clear to me at the moment how one could define such a thing.
So, back to the original question: to properly define the hypothetical, you need to define a form of gravity that would cause objects much, much lighter than another to accelerate that other object towards them at noticeably different rates. It's not at all clear to me at the moment how one could define such a thing.
| however, when i asked on irc they brought up some more interesting questions, primarily what would the world be in general? |
I'm going to try to explain this... (it causes huge problems):
If heavier objects fell faster, the energy the object was gaining from the gravitational field it was in would be in some way proportional to its mass. Given that gravity is actually a distortion of a space and time, that means that the amount time and space is distorted in a gravity field depends not only on the value of the field at that point (as is the case now) in space, but also the mass present in that space, a whole new variable, which only adds to the value of gravity at that point.
The problem comes in when you realize the object which is falling also has a gravitational field. This means that as the object falls, it falls a little bit faster. As it falls faster, it gains more energy. As it gains more energy, it is increasing its mass and it creates a stronger gravity field. This makes the gravitational field in that area even stronger, which makes the object fall even faster, which makes the object even heavier...
Since this feedback loops is one way (i.e. keeps increasing), any object in a gravitational field would eventually collapse all objects within that gravitational field to its centre. Since gravity has an unlimited range, this means that first stars, dust, gas, planets etc would collapse into black holes and that in relatively short time, the entire universe would eventually collapse into one black hole.
It might be interesting to the OP to know that the current set up of the laws of physics is known (as of last year, thanks to the LHC!) to be unstable, as the now proven Higg's field sits at a very high value. This value will one day become lower. This will change the laws of physics as we know them, dramatically and unpredictably. No-one can say for now what changes this will bring, but, with no high value Higg's field holding our molecules together, we won't be around anymore to see them.*
*Before you lose too much sleep over that thought, the predicted time scale for such a change is many many times the current accepted age of the universe.
closed account (EwCjE3v7)
| no actually. i was curious about the science behind it and know nothing about physics |
No I forgot to write who I was replying to. I was replying to Resident as he wrote
| Damnit Disch. You came into an interesting topic, applied logic, and made it no fun anymore :( |
| So, back to the original question: to properly define the hypothetical, you need to define a form of gravity that would cause objects much, much lighter than another to accelerate that other object towards them at noticeably different rates. It's not at all clear to me at the moment how one could define such a thing. |
I was thinking it was ill defined because "something" is not defined. Without defining "something" it is entirely meaningless.
How do you distinguish the book and paper as separate objects, also, how do you distinguish the book as a single object rather than a collection of objects.
If you defined what you consider something, then the consequences would give rise to a new definition of gravity that would be well defined enough to give a meaningful answer.
| Since this feedback loops is one way (i.e. keeps increasing), any object in a gravitational field would eventually collapse all objects within that gravitational field to its centre. |
That two objects accelerate each other more strongly as they are closer doesn't by itself imply that their accelerations will become infinite.
| A function can have an always-positive slope and its range still be bound. For example, -1/x < 0 for all real values of x. That two objects accelerate each other more strongly as they are closer doesn't by itself imply that their accelerations will become infinite. |
If you take it that all laws of the universe are the same, but general relativity is modified such that the mass of the falling object increases the gravitational field strength at that point, it means all mass will pull together much more strongly. Since the universe is only just at the point at which it is not collapsing in on itself already, it would easily be pushed over the edge.
| How do you distinguish the book and paper as separate objects, also, how do you distinguish the book as a single object rather than a collection of objects. |
We only changed one parameter in gravity. You can do that in the maths equations and just see what result you get. Sure, it's not like super scientific or anything, but it's a fun thread.
My bad, then. I thought you were talking about the actual universe, not the hypothetical.
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