Big bang / Big crunch

[DevilSolution]

Hi guys im just curious as to why the big crunch is dismissed so much by top end scientists and physicist's. To me the logical outcome of the big bang is the big crunch, it works perfectly with the laws of physics i know of (namely gravity in so much as what goes up must come down). I believe scientists think the rate of inflation for our universe is increasing, which i would not deny for a second however it doesnt matter if it increasing now because at some point in time (billions even trillions of years time) there MUST be a cut off point, now im not being funny but our universe is not the monetary system so i dont want to hear about perceptual inflation, its just not true of our universe. So if we dismiss perceptual inflation then by what other means would scientists be so dismissive of the big crunch?

 

thank you please very much so........ http://www.youtube.c...h?v=wcmuPc8_SWQ

Edited May 11, 2011 by DevilSolution

[Schrödinger's hat]

Hi guys im just curious as to why the big crunch is dismissed so much by top end scientists and physicist's. To me the logical outcome of the big bang is the big crunch, it works perfectly with the laws of physics i know of (namely gravity in so much as what goes up must come down). I believe scientists think the rate of inflation for our universe is increasing, which i would not deny for a second however it doesnt matter if it increasing now because at some point in time (billions even trillions of years time) there MUST be a cut off point, now im not being funny but our universe is not the monetary system so i dont want to hear about perceptual inflation, its just not true of our universe. So if we dismiss perceptual inflation then by what other means would scientists be so dismissive of the big crunch?

 

thank you please very much so........ http://www.youtube.c...h?v=wcmuPc8_SWQ

 

Well the issue is that we look at the universe, see that it's expanding and that the rate of expansion is increasing.

If we think only about gravitational attraction between matter the rate would be slowing and you have one of two situations:

Matter is not moving fast enough to escape, so eventually it stops and leads to a big crunch.

Matter is moving at or above escape velocity and so will slow down, but approach a constant speed -- Not sure about the details of this one, if there is infinite matter in the universe then escape velocity is also infinite. At any rate a quick bit of modelling would show whether it could be the case.

 

Armed with our prediction we looked at the universe and saw that the rate of expansion was increasing rather than decreasing.

Exactly why this is the case is unknown, but it completely blew a lot of our understanding of the universe away. We have dubbed the cause of this repulsion dark energy.

[Realitycheck]

Because 5 billion years or so ago, the rate of universal expansion started increasing. This happened because matter kept becoming more and more diluted to the point where gravity had less of an effect and could not rein the matter in, so normal galactic expansion, ie. the cosmological constant, sped up and there is no known mechanism to cause a reversal and resulting crunch.

[DevilSolution]

im not denying the universe is expanding even at an increased rate but unfortunately if the big crunch doesnt exist lots of laws of physics are broken

 

just so were clear, you guys think what goes up keeps going up faster and faster? americaaaa

 

escape velocity to where? another universe? gravity still exists and a constant doesnt, gravity is always at work even from one side of the universe so there MUST be a cut of point.....tick tock tick tock tick tock

Edited May 11, 2011 by DevilSolution

[keelanz]

im not denying the universe is expanding even at an increased rate but unfortunately if the big crunch doesnt exist lots of laws of physics are broken

 

just so were clear, you guys think what goes up keeps going up faster and faster? americaaaa

 

escape velocity to where? another universe? gravity still exists and a constant doesnt, gravity is always at work even from one side of the universe so there MUST be a cut of point.....tick tock tick tock tick tock

 

Gravity is a constant

[Realitycheck]

Its called the Big Freeze. As the universe spreads out thinner and thinner, it gets cooler and cooler, and gravity has less and less of an effect (except locally). Why should it spring back if it is stretched out to its max, lifeless, and frozen? What god said that the universe must cycle forever?

 

Dark energy IS the cosmological constant. Now, you're saying that dark energy doesn't exist?

Edited May 11, 2011 by Realitycheck

[DevilSolution]

Im saying i am the dark energy atleast to what you have in-formation. It doesnt require god it requires laws of physics, the universe isnt quite like an elastic band but i appreciate the analogy, im also glad you told us you think things like gravity are living and can freeze but your right in your thinking of there being a MAX limit to the universe. If the original force of the big bang, which i guess your naming "dark energy" has only just started in relative terms to the overall lifespan of the universe then it makes sense that expansion is inflating, infact it will do for a long time period, there would be no point comprehending that time period as it could be millions of years, billions, trillions or millions of billions of trillions of googols.....there is no force stronger than gravity in relative terms of time other than the original break of a singularity which balances the forces. I think the big crunch has to exist for anything to exist in a multi-verse that isnt lived for less than a millisecond of its own reality for example if you believe in string theory all the string's you comprehend existing would themselves be expanding or still (frozen?), but never rhythmatic as imagined because unless there is a cycle on the level below that string doesnt even exist (which it probably doesnt anyway, i prefer being in the white mans beard theory). Seriously though what goes up must come down no matter how hard you throw it or under any physical conditions aslong as gravity exists.

hear (is) the real string theory

Edited May 11, 2011 by DevilSolution

[Spyman]

just so were clear, you guys think what goes up keeps going up faster and faster?

Yes, that is what we currently observe when we look at very distant objects.

 

 

Seriously though what goes up must come down no matter how hard you throw it or under any physical conditions aslong as gravity exists.

In physics, escape velocity is the speed at which the kinetic energy plus the gravitational potential energy of an object is zero. It is the speed needed to "break free" from a gravitational field without further propulsion.

 

For a given gravitational potential energy at a given position, the escape velocity is the minimum speed an object without propulsion needs, to be able to "escape" from the gravity (i.e. so that gravity will never manage to pull it back).

 

http://en.wikipedia.org/wiki/Escape_velocity

Edited May 11, 2011 by Spyman

[Airbrush]

DS: ".....there is no force stronger than gravity in relative terms of time other than the original break of a singularity which balances the forces. I think the big crunch has to exist ...."

 

There is one factor you are ignoring....space. Space is SO vast that gravity cannot bound it all beyond a limit. There is just more space than you (or anyone else) can imagine. The Big Bang was always in motion, from the very beginning. Nothing can stop it as far as we know.

Edited May 11, 2011 by Airbrush

[DevilSolution]

Space as far as we know is endless but the end exist when the original propulsion of the big bang slows by gravity to the point where it starts deflating the same as it inflated, thats too say at some point in the future the speed of inflation will slow but the deflation will be just as slow as the inflation was at the relative point. Also are you saying that the space between 2 objects would be too large for gravity to work? because as far as i was aware if the distance is large the force would just be smaller thats to say in decimal terms the distance may make the force look almost non-existent, for example 10(100) 0's before we get a digit for the force like 0.00000000 googol 0000002543, the force still exists and relative terms of time it would be pointless to calculate how long it would take that force to spring into action, we just need to know it will.

Edited May 11, 2011 by DevilSolution

[Realitycheck]

Just speculation in defiance to studies performed by COBE AND WMAP satellites. And while the new Gravity Probe B seals the deal on gravity (no surprise there), it offers nothing to contradict cosmological expansion.

Edited May 11, 2011 by Realitycheck

[zapatos]

Seriously though what goes up must come down no matter how hard you throw it or under any physical conditions aslong as gravity exists

You are mistaken. Read what Spyman posted.

[DevilSolution]

Just speculation in defiance to studies performed by COBE AND WMAP satellites. And while the new Gravity Probe B seals the deal on gravity (no surprise there), it offers nothing to contradict cosmological expansion.

 

im not denying the expansion of the universe just the inevitable outcome of it.

 

so to clarify the general belief of most physicists is that dark energy will cause the big freeze and when the big freeze happens gravity no longer exists? or just heat transfer?

 

You are mistaken. Read what Spyman posted.

 

Ill rephrase, no matter how hard you throw it EVEN IF IT FUELS ITSELF WITH DARK ENERGY, the fuel will run out and it will fall back.....

 

to be honest i obviously have my own bias, i was just curious as to why scientists believe what they do, its almost ammo.

i also believe in science as a means to an end, but were far from that end so its interesting to see what people believe without the full picture.

Edited May 11, 2011 by DevilSolution

[Airbrush]

im not denying the expansion of the universe just the inevitable outcome of it.

 

so to clarify the general belief of most physicists is that dark energy will cause the big freeze and when the big freeze happens gravity no longer exists? or just heat transfer?

 

Ill rephrase, no matter how hard you throw it EVEN IF IT FUELS ITSELF WITH DARK ENERGY, the fuel will run out and it will fall back.....

 

to be honest i obviously have my own bias, i was just curious as to why scientists believe what they do, its almost ammo.

i also believe in science as a means to an end, but were far from that end so its interesting to see what people believe without the full picture.

 

You are denying what the experts in the field tell us? What do you know that they don't?

 

Gravity will always exist, it will just be too weak to have any effect on the expansion of the universe.

 

Dark energy is the "fuel" of empty space. So the more space there is between pockets of matter, the more fuel for accelerated expansion.

 

Scientists believe what they do because they are on the front lines doing experiments and reading the data. I tend to trust them to know better than I do. What data have you been reading that they haven't?

 

Sorry that they don't have the whole picture, they are just telling us the best they can with what limited information they have. And they tend to agree with each other on this issue.

[zapatos]

Ill rephrase, no matter how hard you throw it EVEN IF IT FUELS ITSELF WITH DARK ENERGY, the fuel will run out and it will fall back.....

You are mistaken. Read what Spyman posted.

[DevilSolution]

Yes, that is what we currently observe when we look at very distant objects.

 

 

 

In physics, escape velocity is the speed at which the kinetic energy plus the gravitational potential energy of an object is zero. It is the speed needed to "break free" from a gravitational field without further propulsion.

 

For a given gravitational potential energy at a given position, the escape velocity is the minimum speed an object without propulsion needs, to be able to "escape" from the gravity (i.e. so that gravity will never manage to pull it back).

 

http://en.wikipedia....Escape_velocity

 

why do you make me do this? OKAY so escape velocity is a variable and it depends on the current gravity and kinetic , i KNOW the universe is expanding i trust the scientists but if the escape velocity is a variable then relative to TIME the PROPULSION may be increasing now but given TIME the outcome is still inevitable, just becasue on our own scale of things we see it speeding up doesnt necessarily mean it wont ever slow down, it simply means that right now certain matter is going outward faster than gravity can pull it back but you seem to forget gravity will ALWAYS be in motion and therefore the original propulsion will come to its natural conclusion especially given the big freeze, i think i understand how your looking at it, like the current escape velocity states the gravity has no force on an object moving at an increased rate but as i will fail to persuade you it doesnt matter because its a variable and increased inflation will have its limit, dont trust me but think for yourselves.

 

You are denying what the experts in the field tell us? What do you know that they don't?

 

Gravity will always exist, it will just be too weak to have any effect on the expansion of the universe.

 

Dark energy is the "fuel" of empty space. So the more space there is between pockets of matter, the more fuel for accelerated expansion.

 

Scientists believe what they do because they are on the front lines doing experiments and reading the data. I tend to trust them to know better than I do. What data have you been reading that they haven't?

 

Sorry that they don't have the whole picture, they are just telling us the best they can with what limited information they have. And they tend to agree with each other on this issue.

 

im not denying the facts im denying the theory, as i stated the picture isnt full so their conclusions arent right, mine might not be either im simply trying to increase my understanding of the subject from which i probably wont be moved from

[csmyth3025]

...im simply trying to increase my understanding of the subject from which i probably wont be moved from

This isn't the statement of a person who is trying to learn. It's the statement of a person who has already made up his mind that he's right. End of discussion.

 

Chris

[DevilSolution]

This isn't the statement of a person who is trying to learn. It's the statement of a person who has already made up his mind that he's right. End of discussion.

 

Chris

 

let the artist's paint the picture not the robots trying to put pixels in-formation

 

if someone wants some of the bits of in-formation to help paint the picture then; yes end the conversation, half a picture always looks best?

Edited May 13, 2011 by DevilSolution

[Airbrush]

...im not denying the facts im denying the theory, as i stated the picture isnt full so their conclusions arent right, mine might not be either im simply trying to increase my understanding of the subject from which i probably wont be moved from

 

Then explain how gravity could somehow bring everything back together in a big crunch when we see the universe is accelerating its' expansion. The universe has gone beyond its' own escape velocity. As space between superclusters increases the expansion accelerates even more. What can bring that back together?

 

Correct that the picture isnt full yet. They are giving us their best guess. Do you think they suffer massive collective delusion? They admit they don't know yet and are simply trying to increase their understanding, just like you.

[DevilSolution]

Then explain how gravity could somehow bring everything back together in a big crunch when we see the universe is accelerating its' expansion. The universe has gone beyond its' own escape velocity. As space between superclusters increases the expansion accelerates even more. What can bring that back together?

 

 

Answer = Time.

 

ill have a go, if the universe is still expanding at an increased rate due to dark energy (or the fact its burning up all its energy in gasses with heat transfer etc) then im fairly sure what goes up will come back down no matter how fast you throw it or what fuels it (unless perceptual inflation exist's) then gravity will keep slowly slowing the universe down, its all just relative to time.

 

this is my thinking, escape velocity is relative to the time you calculate the equation so right now the escape velocity exists but is only accountable to that moment in time and isnt really an escape velocity at all, although it accounts for the force of gravity being 0 it doesnt account for the time that gravity will effect the forces of the original propulsion (and increased expansion) so gravity is always at play even if its shadowed by the illusion of escape velocity and accelerated expansion (the reason its speeding up can be explained in physics but it really cant just keep speeding up (unless you think planets will travel faster than light))

 

its also contradictory to things including multi-verses like string theory, if on the multi-verse level things dont cycle on the level below then they will just be frozen or they will inflate to nothingness like e=mc^2 without a counterbalancing equation

 

to sum up it is my belief that theoretical physics is very contradictory(false) but very fun to comprehend & really the answer is simple and always has been. gravity is a very weak force relatively in the universe at the moment (well not on our scale of things) but for the whole picture its a rather feeble force compared with the speed of expansion however when you account for the universe as a whole it is the only counter balance force to the energy which increases propulsion and the original burst from the singularity, gravity and time will work together to cause the big crunch and the only possible way i see for it not too is via perceptual inflation or if gravity and dark energy work as poles on magnets

 

also i have a few questions to verify my own understanding

in the big freeze is all energy turned into mass and frozen?

is all this mass just free falling in space so to speak?

then is it physicists understanding that gravity is frozen too?

in a vacuum if we have an object with the net value of 1 and an object with the value of 100, given the right propulsion the value of 1 hits the escape velocity, whats your opinion of the outcome? given only them 2 objects exist within the vacuum

is dark energy just a weird name for acceleration?

do we use dark energy to calculate the mass of the universe as a force?

is there any other reasons that the big crunch doesnt exist, like my example of perceptual inflation or gravity and dark energy being poles of a magnet?

Edited May 14, 2011 by DevilSolution

[pwagen]

Answer = Time.

 

ill have a go, if the universe is still expanding at an increased rate due to dark energy (or the fact its burning up all its energy in gasses with heat transfer etc) then im fairly sure what goes up will come back down no matter how fast you throw it or what fuels it (unless perceptual inflation exist's) then gravity will keep slowly slowing the universe down, its all just relative to time.

My guess is that it's not like the universe is "using up" its dark energy, especially since energy can't be destroyed, only reformed. And also, when the universe is very very expanded due to the expansion, all the mass and energy will be so spread out, it's negligible. Funny thing is, so is gravity, so it won't really have an effect on anything left behind.

 

This might be a bit of ignorant speculation though, because I don't know a whole lot, even compared to the educated people who still don't really know.

 

in the big freeze is all energy turned into mass and frozen?

No, it's when mass and energy are so spread out, it's too cold to sustain life.

http://en.wikipedia....anding_universe

 

is all this mass just free falling in space so to speak?

No more than now, I guess. Just more spread out.

 

then is it physicists understanding that gravity is frozen too?

Gravity doesn't have a temperature, so I would say no.

 

 

in a vacuum if we have an object with the net value of 1 and an object with the value of 100, given the right propulsion the value of 1 hits the escape velocity, whats your opinion of the outcome? given only them 2 objects exist within the vacuum

What do the values signify?

 

is dark energy just a weird name for acceleration?

It's the weird name for whatever force is causing the accelerated expansion of the universe, but not the name of any acceleration. Like a car's.

[DevilSolution]

in a vacuum if we have an object with the net value of 1 and an object with the value of 100, given the right propulsion the value of 1 hits the escape velocity, whats your opinion of the outcome? given only them 2 objects exist within the vacuum

What do the values signify?

 

is dark energy just a weird name for acceleration?

It's the weird name for whatever force is causing the accelerated expansion of the universe, but not the name of any acceleration. Like a car's.

 

weight

 

is it because we know what causes the acceleration of the car? in comparison to not knowing what accelerates the universe? hence the name

[Spyman]

this is my thinking, escape velocity is relative to the time you calculate the equation so right now the escape velocity exists but is only accountable to that moment in time and isnt really an escape velocity at all, although it accounts for the force of gravity being 0 it doesnt account for the time that gravity will effect the forces of the original propulsion (and increased expansion) so gravity is always at play even if its shadowed by the illusion of escape velocity and accelerated expansion (the reason its speeding up can be explained in physics but it really cant just keep speeding up (unless you think planets will travel faster than light))

Escape velocity is a true concept that really limits if gravity is able to bring back an object or not, even if it gets infinite time to act on it. Unless there are unknown laws of gravity or the way nature behaves changes over time or space, then it is in fact impossible for gravity to retract an object with escape velocity.

 

Your thinking can be splitted in three parts: your belief of a Big Crunch, your speculations of Dark Energy and your misunderstanding of escape velocity.

 

The Big Crunch is still considered one possible scenario the Universe could "end" in, but is deemed unlikely due to current observations that the rate of expansion is speeding up. There are some still very hypothetical research indicates that our Big Bang might have been the result of a previous Universe collapsing in a Big Crunch called the Big Bounce. But the important thing to notice here is that according to current knowledge even if the expansion stops and reverses it is not going to be done by gravity alone, the collapse is going to need help from an external force or something else not yet known.

 

Dark Energy is still something unknown and can still surprise us when we learn more, so it might "run out of fuel" and stop accelerating the expansion. But Dark Energy might also continue to accelerate expansion for ever or it could even be phantom like and get its fuel from the emptyness it creates, as such it would cause the expansion to accelerate at an exponential rate until it literally rips everything apart, even the nucleus of atoms would get destroyed. Our current knowledge limits the speed objects can move through space to lightspeed but there is no limit on how fast space can expand, translation of redshift of light from distant objects tells us that they actually do recede from us faster than light. The objects that emitted the Cosmic Microwave Background Radiation that we observe today was receding from us with ~ 57 times lightspeed when they emitted the light that reaches us now and according to our best models of the expansion they are now receding with ~3.3 times lightspeed.

(Cosmos Calculator Omega=0.27 Lambda=0.73 Hubble=71 Redshift=1100)

 

Escape velocity is the speed an projectile needs to have to reach infinite far from the object expelling gravity before its speed drops to zero. If the projectile is distancing itself faster than escape velocity it will still have excess speed when it reaches infinite far from the gravitating object. Unless our knowledge of gravity is wrong this is matematically proven true and you should try to learn and understand it.

 

When the projectile are moving away from gravity it will never be able to leave its grasp but as it gets farther the force from gravity weakens with the square of the distance. As such both the speed of the projectile is slowed down by gravity and gravity is weakened with newfound distance. The important thing about escape velocity is the rate of how fast both the speed and gravity decreases. If the speed is low then gravity will be able to slow down the speed faster than what the newfound distance will weaken gravity but if the speed is high enough then it will always continue to move with a speed that weakens gravity at a rate faster than what gravity can slow down the projectile. Therefore the projectile will always continue to be slowed down by gravity but gravity will never be able to completely stop it and start to revers its movement.

 

Escape velocity can also be explained with potential and kinetic energy. When the projectile is resting on Earth's surface it has a calculatable potential energy and zero kinetic energy relative Earth's center. When it gets launched from Earth we give it some extra kinetic energy and as the projectile moves up, this kinetic energy is transformed to potential energy. According to conservation laws, it gains exactly equal potential energy as it loses kinetic energy. If gravity enables to stop the projectile then all of the given kinetic energy has been transformed to potential energy at the turning point. If it starts to fall back, it converts back the potential energy to kinetic energy and precisely when it hits the surface the kinetic energy is equal to what was given to it at the launch and the initial potential energy is also exactly as it was.

 

Normally we consider the difference in potential energy to be equal for each meter the projectile travels upward, but when very high altitudes are considered we need to recalculate the gravitational acceleration at the new altitude to get an accurate value of potential energy. As it turns out when gravity weakens with the square of distance the difference of one meter high up is less worth than one meter close to the surface. Therefore the gain in potential energy a projectile gets when climbing towards an infinite distance is lesser and lesser, making the maximum potential energy finite instead of infinite.

 

If you have managed to follow me so far then logic tells us that if we manage to bring a projectile infinite far away, it will have a finite potential energy and since that finite potential energy must equal the kinetic and potential energy at the surface of Earth, we can conclude that the kinetic energy must also be finite, which then also means that the needed speed to reach that value of kinetic energy must also be finite.

 

So when we give a projectile more speed than the needed escape velocity it will still have kinetic excess energy when it reaches infinite far away.

[DevilSolution]

If you have managed to follow me so far then logic tells us that if we manage to bring a projectile infinite far away, it will have a finite potential energy and since that finite potential energy must equal the kinetic and potential energy at the surface of Earth, we can conclude that the kinetic energy must also be finite, which then also means that the needed speed to reach that value of kinetic energy must also be finite.

 

Logic tells me that when we start with one we end with one, im not sure i have the intellectual capacity to understand everything you just told me so im not going to pretend i did however i did grasp some of the concepts you showed and would be greatly interested in taking it one step at a time to get a better understanding as what you just said seems to require some pre-requisites.

 

Oh about the particles and planets moving faster than light

, you sure about that?>

 

"Your thinking can be splitted in three parts: your belief of a Big Crunch, your speculations of Dark Energy and your misunderstanding of escape velocity." - Agreed

Edited May 14, 2011 by DevilSolution

[Spyman]

Oh about the particles and planets moving faster than light

, you sure about that?>

Yes.

 

While special relativity constrains objects in the universe from moving faster than the speed of light with respect to each other, there is no such theoretical constraint when space itself is expanding. It is thus possible for two very distant objects to be moving away from each other at a speed greater than the speed of light (meaning that one cannot be observed from the other).

http://en.wikipedia.org/wiki/Metric_expansion_of_space

 

There is a distinction between a redshift in cosmological context as compared to that witnessed when nearby objects exhibit a local Doppler-effect redshift. Rather than cosmological redshifts being a consequence of relative velocities, the photons instead increase in wavelength and redshift because of a feature of the spacetime through which they are traveling that causes space to expand. Due to the expansion increasing as distances increase, the distance between two remote galaxies can increase at more than 3×10⁸ m/s, but this does not imply that the galaxies move faster than the speed of light at their present location which is forbidden by Lorentz covariance.

http://en.wikipedia.org/wiki/Redshift