- #1
TheScienceOrca
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I have been thinking for the past couple months on how the expansion of the universe effects the matter and energy within it. Please read every line, skipping any part of this thread will lead to confusion. Hopefully someone can shed some light on this amazing new question of universal expansion
Before I jump into the discussion let's review a few aspects of universal expansion that are crucial for the following aspect;
The universe expands to our currently knowledge due to "Dark Energy".
Dark energy is referred to use a force, but it is important to keep in mind Dark Energy can not be measured and does not induce any forces on matter or energy.
It simply expands the universe, which will lead into my next point.
Two Objects at rest in imaginary universe with no forces separated by 1 million light years will expand from each other.
So the distance is increasing but the velocity (kinetic energy) is still 0.
This is one of the most important factors of expansion.So no energy is being used, yet the distance is increasing (remember this).
Now for the second aspect of the concept.
We know that if you take two masses and separate them, gravitational potential energy is gained in proportion to the distance of the objects.
So as distance increases energy is gained, as those masses will accelerate towards each other due to a force we know as "Gravity".This force is a relatively weak force, although when large masses are involved it can hold you in your seat literally.
So knowing those two aspects, let's take at this easy to visualize analogy I have made.Imagine a universe with 2 planets separated by 1 light year.
These planets will accelerate towards each other until impact gaining velocity (kinetic energy) the whole time. This is something everyone knows, drop an apple on your head and you will feel the impulse caused by the kinetic energy.
Lets go back to the imaginary universe, this time there is one large planet and one baseball.
To move this baseball 1 meter off the ground it takes 1N of energy.
If we separate these two masses by transferring energy from a machine or for simplicity let's say you are on the planet and threw this ball extremely far 1 light year away.
The energy you transferred into the ball is not lost simply transferred to KE and then from there transferred slower and slower to gravitational potential between the two masses.
Keep in mind gravitational potential is energy that both masses share.
If you ignore expansion this ball in a vacuum will return with exactly the same energy that you originally induced on it, following the laws of conservation of energy.
This is where the expansion of the universe gets tricky.
As the ball is traveling away the space between the planet and the ball when the ball reaches its climax is now greater due to the expansion. This means on the way back, there is more distance and thus energy that the ball will have. The universe also expands on the way back.
The measure is 68Km/s per million light years per second. So it is a VERY noticeable distance.This also makes sense of why objects further away have increased red shift.
As distance increases expansion rate relative to acceleration induced by gravity is just too great so the masses increase in distance even though they are increasing in velocity, but decreasing in acceleration.This does not break the laws, as conservation of energy does not apply to GR.Let me know what you think and please leave any questions below, I coded a software to simulate this and am currently processing the simulation. Hopefully this will be a key to our understanding of how the universe works.
Before I jump into the discussion let's review a few aspects of universal expansion that are crucial for the following aspect;
The universe expands to our currently knowledge due to "Dark Energy".
Dark energy is referred to use a force, but it is important to keep in mind Dark Energy can not be measured and does not induce any forces on matter or energy.
It simply expands the universe, which will lead into my next point.
Two Objects at rest in imaginary universe with no forces separated by 1 million light years will expand from each other.
So the distance is increasing but the velocity (kinetic energy) is still 0.
This is one of the most important factors of expansion.So no energy is being used, yet the distance is increasing (remember this).
Now for the second aspect of the concept.
We know that if you take two masses and separate them, gravitational potential energy is gained in proportion to the distance of the objects.
So as distance increases energy is gained, as those masses will accelerate towards each other due to a force we know as "Gravity".This force is a relatively weak force, although when large masses are involved it can hold you in your seat literally.
So knowing those two aspects, let's take at this easy to visualize analogy I have made.Imagine a universe with 2 planets separated by 1 light year.
These planets will accelerate towards each other until impact gaining velocity (kinetic energy) the whole time. This is something everyone knows, drop an apple on your head and you will feel the impulse caused by the kinetic energy.
Lets go back to the imaginary universe, this time there is one large planet and one baseball.
To move this baseball 1 meter off the ground it takes 1N of energy.
If we separate these two masses by transferring energy from a machine or for simplicity let's say you are on the planet and threw this ball extremely far 1 light year away.
The energy you transferred into the ball is not lost simply transferred to KE and then from there transferred slower and slower to gravitational potential between the two masses.
Keep in mind gravitational potential is energy that both masses share.
If you ignore expansion this ball in a vacuum will return with exactly the same energy that you originally induced on it, following the laws of conservation of energy.
This is where the expansion of the universe gets tricky.
As the ball is traveling away the space between the planet and the ball when the ball reaches its climax is now greater due to the expansion. This means on the way back, there is more distance and thus energy that the ball will have. The universe also expands on the way back.
The measure is 68Km/s per million light years per second. So it is a VERY noticeable distance.This also makes sense of why objects further away have increased red shift.
As distance increases expansion rate relative to acceleration induced by gravity is just too great so the masses increase in distance even though they are increasing in velocity, but decreasing in acceleration.This does not break the laws, as conservation of energy does not apply to GR.Let me know what you think and please leave any questions below, I coded a software to simulate this and am currently processing the simulation. Hopefully this will be a key to our understanding of how the universe works.
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