A Universe Without Origin and End?

[Nicholas Kang]

So, when we reverse the inflation, and the universe will be much smaller than now and time will be reversed. I think so. That is my hypothesis but without evidences. I welcome anyone to falsify my hypothesis.

 

You see, after Big Bang, the universe inflate and expand and time runs forward into future. So, when we reverse the situation, the opposite happens.

[Strange]

I think some very serious scientists have proposed exactly what you suggest. They suggest we perceive time moving forwards because of increasing entropy, which may be related to the expanding universe.

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

http://preposterousuniverse.com/eternitytohere/faq.html

[Nicholas Kang]

Great, and I love it.

Do you agree with them? Or you have your own speculation?

[Strange]

I've never thought about it.

[Mordred]

myself I personally consider the use of entropy to be a poor way to define time, whether the universe contracts, expands or stays static itself doesn't define time well by itself. For example entropy can be thought of as an increase in the number of degrees of freedom, in thermodynamics. So when the universe contracts the universe would heat up. Particles would reach thermal equilibrium so the total degrees of freedom of distinguishable particles decreases. Now take we discussed time flowing one way when the universe expands, and flowing the other way when it contracts, does it make any sense to say time stops when it is static? I think not.

 

-then there is the question of is time determined just by its thermodynamic properties? if everything stays in thermal equilibrium is there no time? if so how would you define time then, would you say time doesn't exist?

but then time is also a measure of duration duration includes a period of no change as well as change, so how does this work with entropy?

 

I particularly like this short answer

 

"The first mystery of the arrow of time is that it's nowhere to be found in the fundamental laws of physics. Those laws work perfectly well if we run processes backwards in time. (More rigorously, for every allowed process there exists a time-reversed process that is also allowed, obtained by switching parity and exchanging particles for antiparticles -- the CPT Theorem.) Nevertheless, the macroscopic world we observe is full of irreversible processes. The puzzle is to reconcile microscopic reversibility with macroscopic irreversibility"

 

I wonder if one could use this argument to argue against the universe starting from a BH lol, I'll have to put some thought into that question

 

"In the early universe, when it was just a homogenous plasma, the entropy was essentially the number of particles -- within our current cosmological horizon, that's about 10⁸⁸. Once black holes form, they tend to dominate; a single supermassive black hole, such as the one at the center of our galaxy, has an entropy of order 10⁹⁰, according to Stephen Hawking's famous formula. If you took all of the matter in our observable universe and made one big black hole, the entropy would be about 10¹²⁰. The entropy of the universe might seem big, but it's nowhere near as big as it could be."

 

The article has some good arguments, and he clearly states there is still lots of work to be done to fully understand entropy in terms of arrow of time. I only mentioned some of the aspects. The tendency of a system to evolve is something I agree with, however using the expansion, contraction of the universe itself without other considerations isn't a good way to define the arrow of time

Edited June 26, 2014 by Mordred

[Ten oz]

I view time as a messurement of movement just as electrical voltage is a messurement of electron movement and the potential for it. If there were no movement in the universe at the atomic level then there would be no time. The scale of time messurement is absolute zero to the speed of light. Anything above or below can't be messured by time.

[Nicholas Kang]

Do you think the effort of defining time is a waste of time? I learnt a lesson from the earlier topic regarding the classification of Pluto as a dwarf planet or a planet. Mr. imatfaal taught me that Science is objective but not subjective. So, there should be too many definition for Time, shouldn`t it? And we hardly know which is correct.

[ZVBXRPL]

Is it possible that our universe has no start and end? Maybe the Cosmic Microwave Background Radiation is just some radiation emitted from an unknown source? It might not be the evidence of Big Bang but the only clue for a new theory to emerge? Maybe the universe is just always exist or somehow we can use Darwin`s Evolution and Natural Selection Theory in this context. So, we may assume that the universe is just an evolution form an older universe, so the universe can only be old but not young, so, the universe will eventually die and fade and it is the end, no new Big Bang?

I believe the Universe is infinite. The Big Bang theory is a theory and it is the currently accepted theory by the mainstream. That does not make it truth. 200 years ago there was no Big Bang theory. Will the Big Bang theory still be the accepted theory by the mainstream 200 years from now, 2,000 years from now, 2,000,000 years from now? There is no evidence for the Big Bang theory. There is only evidence to support the "its the best model we got at the moment" approach.

[StringJunky]

There is only evidence to support the "its the best model we got at the moment" approach.

...and this is as good as it can be. 'Truth' is for philosophy, metaphysics and religion. If a scientist said "this is true" then he has closed his mind to possible future falsification in the light of new evidence. Maintaining persistent doubt as a matter of professional habit is what stops scientists becoming complacent.

 

 

Do you think the effort of defining time is a waste of time? I learnt a lesson from the earlier topic regarding the classification of Pluto as a dwarf planet or a planet. Mr. imatfaal taught me that Science is objective but not subjective. So, there should be too many definition for Time, shouldn`t it? And we hardly know which is correct.

Time is defined as what clocks measure ...it's just a parameter. You don't see people cogitating about 'length' do you?

[Strange]

I believe the Universe is infinite.

 

Which is irrelevant to the big bang theory.

 

 

There is no evidence for the Big Bang theory. There is only evidence to support the "its the best model we got at the moment" approach.

Of course there is evidence for the big bang theory; that is why it is the best theory we have at the moment.

Edited June 28, 2014 by Strange

[Ten oz]

Do you think the effort of defining time is a waste of time? I learnt a lesson from the earlier topic regarding the classification of Pluto as a dwarf planet or a planet. Mr. imatfaal taught me that Science is objective but not subjective. So, there should be too many definition for Time, shouldn`t it? And we hardly know which is correct.

Time has to be calculated for. Pluto by any name or classification is an actual thing. It exists. Regardless of the words used to define time, time still must be accounted for. So it isn't a waste of time to have an understanding or definition.

 

If I am sailing a boat in the ocean and and lower an analog device into the water to messure the speed at which the boat is moving through the water that messurement alone would not accurately tell me my speed of travel sailing to a destination. The ocean itself moves. So if my hull over water speed is 10kts but I am sailing against 4 kts of current I am actually only traveling at 6kts. Another factor is drift. My boat may drift a nautical mile parallel to my direct of travel for every X amount of nautical miles I gain. Sailors have formulas to account for these factors. It took us thousands of years to get to a place where we could accurately calculate it.

 

Time is a messurement just like a nautical mile is a messurement and lots of things effect it just like set and drift for boats. Gravity and relative speed (object to object) effect time calculations just like current, drift, and speed over water effect nautical travel. Of course we don't have all the math worked out for time to speed to gravity yet so there isn't a single formula we can apply. Doesn't mean it is a waste of tme though.

[Nicholas Kang]

So, time has to be calculated for but not to be defined? JUst calculate time but no argument over what is time?

[Ten oz]

So, time has to be calculated for but not to be defined? JUst calculate time but no argument over what is time?

While driving I can observe an obstacle in the road and calculate for it by changing lanes without ever knowing what it was.

[imatfaal]

So, time has to be calculated for but not to be defined? JUst calculate time but no argument over what is time?

 

To an extent - yes, that is exactly it. We only look to a deeper investigation if that might lead to some form of experiment (whether currently feasible or not) which will yield different results for different notions of time.

 

That doesn't mean we don't think about it - but we are also happy just to "shut up and calculate" (this is a famous quote about the interpretations of quantum mechanics). You might also like to look at the differences between the different ideas of mass; passive/active gravitational mass, mass/energy, and inertial mass. We constantly look for ways to differentiate or confirm that no difference exists - but in most experiments and theories it is just mass.

[Nicholas Kang]

To avoid obstacles, you must first know that there is obstacles. You observe obstacles, that`s why you avoid it. And when you observe obstacles. You will definitely know what it is.

 

If it is a huge stone, maybe several meters across, you have to flip your tires more to avoid it.

If it is just a small stone, maybe 30-70 cm across, you just have to flip your tires less to avoid it.

If it is very tiny, simply ignore it and still no harm to your car.