# Thread: Final attempt and theory to understand physics

1. Im pretty much obsessed with the idea that the universe is cyclic, cursed as i am - i suck at math and have no deep knowledge of physics etc. This is my LAST ATTEMPT to try and make sense of it all. So when you have facepalmed and told me why the following isnt possible, ill stop spamming the physics forum forever. (Dr.Rocket, open the champagne!)

Ive taken the following laws into account as i understand them:

The law of conservation of energy (Energy cannot be created or destroyed)
For every action there is an equal but opposite reaction" (Newtons law)
The law of universal gravitation.

Here goes (bear in mind english is not my native tongue):

1) Big bang moment (X), we now have 100% of all energy in the universe contained in one spot.

2) An action makes this energy expand (X+). The force is strong enough to resist its own gravity from pulling it back, continuing the expansion (Current Universe)

3) When the energy has expanded so much that it is "Thinned out" sufficently, the force weakens. Instead of 100% of all energy in one spot you eventually will have 0.000(+lots of more zeroes)1% of all energy spread out in space in a larger area. This weakens the force enough to be taken by gravity, which reacts.

4) As the force weakens completely, gravity will cause the action made by the big bang (X+) to reverse in its appropriate reaction (X-), by yet again massing all energy back to one spot (because energy will become to "Weak" to resist the gravitational pull, and the strength will increase the more energy it pulls back). First slowly then at an accellerating state gravity will crush all energy back into 1 point in the universe (X) so hard that (Here it comes) when the weight of the impact reaches the center, the energy and mass clashes so hard that all the energy goes "Through" itself, much like if 2 balls of water would hit eachother in high speed, creating (X+)

5) Because the energy of the universe is finite and constant (100%X) this means no energy will be LOST from this process and it can continue indefinatly.

In short:

The energy of the universe expands at high speed, but retain its sum of energy. As the energy is divided, the force of the spread weakens.

At a point, energy will become so weak that gravity will contract the energy back to the starting point, restarting the process infinitly with the following collision.

A FINITE amount of energy allows space, which further allows INFINITE cycles. As these Opposites allows Action/Reaction to occur.

2.

3. Originally Posted by Raziell
Im pretty much obsessed with the idea that the universe is cyclic, cursed as i am - i suck at math and have no deep knowledge of physics etc. This is my LAST ATTEMPT to try and make sense of it all. So when you have facepalmed and told me why the following isnt possible, ill stop spamming the physics forum forever. (Dr.Rocket, open the champagne!)

Ive taken the following laws into account as i understand them:

The law of conservation of energy (Energy cannot be created or destroyed)
For every action there is an equal but opposite reaction" (Newtons law)
The law of universal gravitation.

Here goes (bear in mind english is not my native tongue):

1) Big bang moment (X), we now have 100% of all energy in the universe contained in one spot.

2) An action makes this energy expand (X+). The force is strong enough to resist its own gravity from pulling it back, continuing the expansion (Current Universe)

3) When the energy has expanded so much that it is "Thinned out" sufficently, the force weakens. Instead of 100% of all energy in one spot you eventually will have 0.000(+lots of more zeroes)1% of all energy spread out in space in a larger area. This weakens the force enough to be taken by gravity, which reacts.

4) As the force weakens completely, gravity will cause the action made by the big bang (X+) to reverse in its appropriate reaction (X-), by yet again massing all energy back to one spot (because energy will become to "Weak" to resist the gravitational pull, and the strength will increase the more energy it pulls back). First slowly then at an accellerating state gravity will crush all energy back into 1 point in the universe (X) so hard that (Here it comes) when the weight of the impact reaches the center, the energy and mass clashes so hard that all the energy goes "Through" itself, much like if 2 balls of water would hit eachother in high speed, creating (X+)

5) Because the energy of the universe is finite and constant (100%X) this means no energy will be LOST from this process and it can continue indefinatly.

In short:

The energy of the universe expands at high speed, but retain its sum of energy. As the energy is divided, the force of the spread weakens.

At a point, energy will become so weak that gravity will contract the energy back to the starting point, restarting the process infinitly with the following collision.

A FINITE amount of energy allows space, which further allows INFINITE cycles. As these Opposites allows Action/Reaction to occur.

The current cosmological model. based on general relativity with a positive cosmological constant (aka dark energy) precludes a cyclic universe. Dark energy is not well understood. (That may be the understatement of the week.)

Nevertheless there are some very speculative cyclic theories. See, for instance the books Cycles of Time: An Extraordinary New View of the Universe by Roger Penrose or Endless Universe, Beyond the Big Bang by Paul Steinhardt and Neil Turok. None of these theories bear any significant resemblance to yours. They all require significant modifications of and extensions of the theories that constitute the currently accepted foundations of physics. Penrose bases his speculation on conformal models and a statistical view of the second law of thermodynamics. Steinhardt and Turok base their model on their interpretation of M-theory, which has thus far defied any clear definition, by anyone, including the guy who invented it. ("What is M Theory ?" remains the biggest open question in M Theory.). I would not bet much on the likelihood that these ideas will pan out any time soon, or even in the long run, but I would not bet a lot on the current dark energy, continually accelerating expansion model either.

Here's my own opinion.

The current combination of general relativity and the Standard Model of particle physics is completely inadequate for an understanding of either the first seconds or the next trillion + years. What is needed is a theory that is testable and that treats gravitation and the fundamental forces in a unified way. Unless and until we have that, speculation regarding the very young or very old universe is pretty much useless, but people will undoubtedly write books about it anyway. In the meantime the current theories are good guides to everything from a second after the big bang to several billion years from now.

Instead of telling the naive how string theory can explain mysteries of the cosmos, string theorists might more profitably formulate a theory that can be defined in rigorous terms to experts and that can be used to make real predictions about real experiments that are not adequately handled by the Standard Model and general relativity. Relativists might take a harder look at singularities and ask whether they might be better understood or eliminated altogether by alternate theories, perhaps Einstein-Cartan theory or quantum gravity (whatever that might turn out to be).

Speculating on the answers that may eventually result from theories that do not exist at the moment may be great fun and sell books, but it is just fiction. The authors have the very great luxury that such speculation cannot be disproved. Penrose, at least, is careful to note when he is speculating and to explain why he thinks the speculation might be made precise and subject to testing.

In the meantime we can concentrate on understanding the time interval , which ought to be adequate for quite a while.

Can I put the bottle on ice now ?

4. One aspect of the current Lambda-CDM model that puzzles me is the Lambda part of the model. As I understand it, the energy fueling the continued (and accelerating) expansion of the universe is scalar. It doesn't weaken as space expands but remains uniformly constant. Thus it's called the cosmological constant.

If this model is correct, then it seems to me that the total amount of energy in the universe would increase over time. Is this correct, or am I missing something?

Chris

5. Originally Posted by CSMYTH3025
One aspect of the current Lambda-CDM model that puzzles me is the Lambda part of the model. As I understand it, the energy fueling the continued (and accelerating) expansion of the universe is scalar. It doesn't weaken as space expands but remains uniformly constant. Thus it's called the cosmological constant.

If this model is correct, then it seems to me that the total amount of energy in the universe would increase over time. Is this correct, or am I missing something?

Chris
I'm not sure.

The cosmological constant does not appear in the stress-energy tensor. Neither does "gravitational energy".

There are problems with global energy conservation in GR. It works fine at a point, but not over finite regions.

6. DrRocket, ive read your answer several times but im having difficulties understanding it. Could you explain in simpler words why what im thinking of couldnt be true?

Also, a main problem is that ... yes... scientists say the universe is accellerating and NOT slowing down. This is also part of the my idea, that the big bang is so powerfull that expansion will go faster and faster untill it reaches a peak point (Our current universe could simply be in a early accellerating phase?), then slow down until a stop. Where gravity takes over and sucks the universe back in.

Ofcourse it would seem this "doesent change" when you consider the unimaginable amount of time such a cycle would take, compared to human perception. For us, it must feel like someone simply paused the universe to a complete stop, leaving only ourselves left with motion?

7. Originally Posted by Raziell
...Also, a main problem is that ... yes... scientists say the universe is accellerating and NOT slowing down. This is also part of the my idea, that the big bang is so powerfull that expansion will go faster and faster untill it reaches a peak point (Our current universe could simply be in a early accellerating phase?), then slow down until a stop. Where gravity takes over and sucks the universe back in.
I believe that observations indicate that the expansion of the universe was, indeed, slowing down up to about 5-6 billion years ago - although it was slowing down at a rate somewhat less than was expected purely from the effect of gravity.

There then came a point when dark energy (whatever that is) overtook the effect of gravity and the rate of expansion has been increasing ever since. There's no known mechanism by which gravity can reassert itself as the dominant force in its fight with dark energy.

This is the reason why mainstream comologists feel that a contracting universe is not in our future.

Chris

8. Yes, it seems as if gravity lost the fight with whatever causes the acceleration of the expansion of the universe, something around six billion years or so ago.

9. Originally Posted by Raziell
DrRocket, ive read your answer several times but im having difficulties understanding it. Could you explain in simpler words why what im thinking of couldnt be true?
CSMYTH3025 gave you one reason which is quite valid.

The basic problem is that you propose an imagined sequence of events with no supporting rationale based on either physical theory or observational data. Worse, the theory and data would tell you that what you say is wrong. Your use of "energy" simply makes no sense. You need to learn some physics.

While I am very very skeptical towards the cyclic theory of Steinhardt and Turok, because their idea is based on M theory (and NOBODY knows what that is), they do a very nice job of explaining the current model and the physics that supports it in their book. While that model itself may well eventually prove to need modification it would behoove you to understand it and the reasoning behind it. Read the Steinhardt and Turok book. Their explanation of the conventional model is clear and correct. Their criticism of it is also valid. They understand it, and in fact played a role in its development.

This is complicated and sophisticated stuff. An amateur has essentially no chance of developing a theory that would supercede that developed by the professionals. There is just too much data and too much subtle and complex theory to consider. But you can read and understand the popularizations and get some appreciation for the issues involved. But remember to read with skepticism and recognize that a great deal simply is not known -- the popularizations tend to greatly underplay how much is not known.

10. Originally Posted by DrRocket
Originally Posted by Raziell
DrRocket, ive read your answer several times but im having difficulties understanding it. Could you explain in simpler words why what im thinking of couldnt be true?
CSMYTH3025 gave you one reason which is quite valid.

The basic problem is that you propose an imagined sequence of events with no supporting rationale based on either physical theory or observational data. Worse, the theory and data would tell you that what you say is wrong. Your use of "energy" simply makes no sense. You need to learn some physics.

While I am very very skeptical towards the cyclic theory of Steinhardt and Turok, because their idea is based on M theory (and NOBODY knows what that is), they do a very nice job of explaining the current model and the physics that supports it in their book. While that model itself may well eventually prove to need modification it would behoove you to understand it and the reasoning behind it. Read the Steinhardt and Turok book. Their explanation of the conventional model is clear and correct. Their criticism of it is also valid. They understand it, and in fact played a role in its development.

This is complicated and sophisticated stuff. An amateur has essentially no chance of developing a theory that would supercede that developed by the professionals. There is just too much data and too much subtle and complex theory to consider. But you can read and understand the popularizations and get some appreciation for the issues involved. But remember to read with skepticism and recognize that a great deal simply is not known -- the popularizations tend to greatly underplay how much is not known.
Yeah i get that now. I wish i could go back in time and tell myself to start taking an interest in math and physics at a younger age. Anyway, thanks for your time and enjoy your champagne

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