According to one of the most popular theories of the origin of universe, the Big Bang theory, the universe began as a result of a colossal explosion of matter, antimatter and energy. After the big bang, everything was chaotic in the newborn universe...protons, neutrons, electrons and other exotic particles moved about freely...matter and antimatter annihilated each other releasing energy...and there were no such thing as stars...Everything was random.
But gradually, as the universe expanded, particles came together and formed atoms...Eventually, these atoms came together and formed clouds of dust and gases, which in turn condensed and formed stars. Nuclear reactions started, creating heavier elements from hydrogen atoms. Then, planets came into being, again due to forces between atoms and molecules.
But doesn't this seem as if things have always been tending towards orderedness? Isn't this a direct contradiction to the Second Law of Thermodynamics, which states that the entropy of the universe always increases (i.e., universe tends towards randomness)?
Another example is here on earth itself. Young earth was a hostile place...there were only a few simple molecules such as CO2, N2, O2, etc, and the temperature was too high to support life.
However, as the earth cooled down, newer, bigger, and more complex molecules began forming (like proteins and carbohydrates). Slowly, simple life forms started emerging, and as a result of evolution, kept on getting more complicated and adept at surviving.
Here too, we see that things have tended towards orderedness, rather than rondomness. So how does the Second Law of thermodynamics hold in these instances?
Please think about it and answer...
33Are another xpanation i can think of that is...
In initial stage when universe was small probaility of finding any particle in a given region was high as compared to pressent when prob of finding one thing in space is 0 (almossssssssssssssst) so entropy has increased
1yup but u r relating a non living hole to liv human being
i dun thnk this is correct
1yes, kinda...
see...suppose the area of hole is 1 square unit (considering the grid on the balloon to be the surface).
initial prob = 1/10
after the balloon has been inflated, final prob = 1/10 because the hole still measures 1 square unit on the balloon surface.
1Vishal,
the area of the hole increases with respect to us. But it doesn't wid respect to sum1 who lives on the surface of the balloon (hypothetical, obviously!)
Celestine,
sorry, but i cudn't get ur point. heat released in what process??
and Abhishek,
nice point again! if what i said were true, then we cudn't hav observed inflation of the universe ourselves! i'll think about it and answer...
33in b/w
for those who want to see relationship b/w probability and entropy
can see:
http://en.wikipedia.org/wiki/Maximum_entropy_probability_distribution
33@ Celestine..
Gud point
Temperature (avg temperature of universe is toooooo small)
so entropy will not make that much difference i suppose until it is too large
33@ Shreyan
gr8 thoughts...
This paves way to a big big discussion but 1 pt...
So u say universe expands and so does everything including the scale to measure it so the probabilty is same as empty space expands as much as the object(whose Prob is to found)
But if U think this way..then...
Then we should not have been able to feel that universe expands as if a stick of length 10 cm expands to 11cm(to previous scale) and ruler also expands by the same so you will feel stick has not expanded..
this isn't that simple i believe
9ur forgetting heat released in process
ΔG = ΔH - TΔS ΔH highly negative so its spontaneous
1nice work but i want to make 2 pnts
1. by assuming space as balloon u r contradicting ur own ist view
2. how come area nt inc
1hey hey hey...found a contradiction to that too!
Abhishek, u were trying to explain entropy on the basis of probability. But this can be done just as long as you do not do it on cosmological scales. Let me give u an example to explain my point...
Suppose there are three molecules inside a room of initial volume Vi. Let the vol of the three molecules together be Vm
=> prob of finding a molecule initially P(i) = Vm/Vi
Now suppose the room expands to a volume of Vf.
now, the prob of finding a molecule P(f) is Vm/Vf
Since P(f) < P(i), entropy has increased.
But the important point here is that the volume of the room has increased because more space has been occupied.
However, this is not the same with universe. In the expansion of the universe, space itself is expanding!! So there is no question of more space coming inside its boundaries! That means the probability will always remain the same!
Another analogy to explain this point...
Consider a balloon to be the universe. When deflated, u mark a grid on it such that there are, say, 10 squares on its surface. Now suppose there was a hole in the balloon of area A square units.
Initially, the prob of finding the hole will be A/10.
If the balloon were inflated, the probability would still be A/10 because there are still 10 squares on the balloon surface and the area of the hole still is A square units (with respect to the balloon).
Get the point? Finally, it boils down to that the probability of finding matter in the universe will be unchanged no matter how much it expands!
(Dunno how much true this is....this is only based on my thinking...)
33Ref:
Another example is here on earth itself. Young earth was a hostile place...there were only a few simple molecules such as CO2, N2, O2, etc, and the temperature was too high to support life.
However, as the earth cooled down, newer, bigger, and more complex molecules began forming (like proteins and carbohydrates). Slowly, simple life forms started emerging, and as a result of evolution, kept on getting more complicated and adept at surviving.
Here too, we see that things have tended towards orderedness, rather than rondomness. So how does the Second Law of thermodynamics hold in these instances?
...................................
Here to if u in initial earth picked a molecule you probability of it being a specific molecule was comparatively high but now as there are many molecules so probability of it being a particular molecule is very less...
so entropy has increased...
1thanx everyone...never thought my question will create such a buzz!!!
anyway, Abhishek, u had a gud point...
i think that must b the answer...
still, i wud like the discussion to continue.
1well forgive me if my answer seems irrelevant.
the molecules , as they get bigger definitely have more entropy than before. It's due to the many different conformations possible in a large molecule. So entropy has increased and not decreased. This I'm sure. even though I might not have given a very sound explanation . this is true . ( I dunno any furhter regarding this.)
also nice explanation Abhi.
1Excellent..............Now that i call a revolutionary and a pathbreaking theory and awonderful contradictory concept......
1i meant something like that ... at the beginning , in universe, everything was small and they tried to come together to become big.. now everything is big and they try to move away ( thus entropy must increase ) but maybe after some point, things will again try to come together ...
1wel wat bout d pulsating theory?????? d universe expands and then compresses??????????
1I think it is one of these kind of things that when it is small it tends to become big and when it is big, it tends to become small ... now everything is big and we only see things trying to become small but there can be a time later and/or before when things will try to become big ..... if you understand what i mean :P
1big bang also tells that the universe is expanding this is nothing but disorderedness
1no use talking about higg's boson now..
its still a hypothesis ...
but u do have a pont...
1you cant say all laws were not applicable .energy got converted to light and mass. fussion reactions, attractions of unlike charges,mass anhillation ,are physics laws i persume
11The laws are not applicable at that instant only. We're talking about a few 1000 yrs after the Big Bang.
1after a few seconds of big bang there was no such thing as matter existed.its the higgs boson responsible for proton and electron .they collided with each other and no extra particle was left over.but in this prorcess a strange process called baryongenesis happened which created one antiparticle more than the particle.as you said electrons were in random motion but because of mass anhillation the protons formed the hydrogen nuclii but lacked with electrons when light emerged (energy output)the energy of electrons reduced forcing it to combine with proton to form elements.randomness is possible when it could acquire sufficient energy.but here there is loss of energy.i think hence forth it did not tend towards randomness
11Wonderful topic. Opens up a huge topic for debate and as akand says, it will be a revolutionary one. :)
11Observe that the violations come at the start of a new organisation or whatever u want 2 call it. That's also the case with people, isn't it? Assume, humans see each other for the first time after they see the rest of the organisms. Won't they get closer and form a community? Isn't going from disorderliness to order? After a while we see enemity, which is again disorder, isn't it? Think about it! :)