Does Violating the Second Law imply Time Reversal, And Sheehan's Perpetual Computer
Even if one could reverse entropy and violate the second law, this
wouldn't necessarily create a time machine or a way to go back in time, or
reverse the exact events that happened. Consider if you were able to
violate the second law with a brownian ratchet or with Daniel Sheehan's
perpetual computing device, or the devices at
olsonb.com. This would
decrease the entropy in the universe (if hypothetically it worked)
but wouldn't cause the whole universe to run in reverse, nor would
it even reverse an isolated part of the system locally since the
information would end up in a different place (different configuration
of particles) in the new low entropy state after the violation. Time
would still exist. Sheehan's computer or the brownian motion electric
generator would just cool down the universe in that particular local
section that it was working in, it wouldn't set the information
(particles) back exactly to what it was 10 seconds before, or 4
I therefore highly doubt the idea that the second law defines time, since
even if the second law were broken, time would still exist, and have
direction (with only some decreases in entropy occurring). If one could build
a perpetual energy generating machine, our lives would continue as they
are now; just it would be a lot easier to generate electricity. The
universe would not go into reverse and start doing things backwards, as
the new low entropy state would be different configuration of information
(particles) than 20 seconds ago when it was lower entropy.
Even if you decrease the entropy of a system without expending energy
(2nd law violation) this does not guarantee that the information will be
in the *exact* earlier state it was before - the information could end up
in new positions, but still low entropy.
Consider for example a brownian motion device that generates
due to random vibrations... you violate the second law and time goes
in reverse? No, you just end up organizing electrons in a low entropy
state in a capacitor. But the electrons were not gathered up in the
capacitor 10 seconds ago or 10 minutes ago in that configuration,
the electrons were on wool.
Now on the other hand if you could somehow make a 2nd law violating
machine that took the information from an earlier point and rearranged
that information exactly as it was before, then this would create a local
small time machine. By local I mean it doesn't reverse the entire history
of the universe, it only reverses what is in the petri dish that you are
reversing ( or under your microscope with nano technology ). Sort of like
total entropy of the universe versus local entropy.
A very important point to consider is that it would be much easier to
create a second law violating device that did not reverse time, it would
be much easier to create a device that simply reorganizes the particles or
information into a low entropy state that was different than the previous
low entropy state. This is because you then do not need to replicate
exactly the old low entropy state with exact configuration of information.
It is much harder to configure information exactly the same as old
information, than it is to just arrive at a low entropy state of any
kind. An example is a corrupted hard drive where a poem has a few
words in it that just so happen to rearrange into equally as poetic
words: "The dog went to the store." becomes "The god went to the store"
The word dog becomes corrupted, and becomes god, making the poem
more meaningful, even though corruption is supposed to be high entropy
and disordering information (religious joke about mutations).
Are local time machines possible where one reverses the information back
to its original state locally and not the entire universe? An example is
a computer simulation that you could rewind so the characters could
relive their exact same lives, only slightly differently, or even exactly
the same way with no differences at all - is a computer system a local
time reversal machine since one can reverse the lives of computer
simulation characters, like Second Life or Grand Theft Auto virtual worlds?
A computer works by adding energy to the system and does not violate the
second law, but Sheehan's perpetual computing system would violate the
law - could you recycle the heat back into the computer and would
Shannon's information theory be revised?
Sheehan's perpetual computer wouldn't reverse time as far as I know, as
it would reconfigure information to a new low entropy state than the
previous low entropy state. Similarly if you used the
olsonb.com devices to power a computer
you wouldn't reverse time locally or universally, you would simply
reconfigure information (particles) to a new low entropy state. Low
entropy doesn't have to be the same exact low entropy as a previous
state. For example if you hooked up an
to the CPU to turn all heat into electricity again, the electrons
would be in a new low entropy state that was not the same configuration of
information 2 seconds ago when it came out of the CPU as heat, or
more seconds ago when it was electricity before it reached the
CPU chip (in some capacitor in the circuit).
As for Shannon Information Theory and how a second law violation would
affect it, this is an open area of research and I am still thinking
about it. I will update this article or point to a new article when
I have come up with any words that could possibly describe the
implications. What would happen to the equations, redundancy, error
correction: second law violation to a new low entropy state would
probably mean will still need redundant error correction (like in http
browsers that send sockets), just that your computer would run much
more cooler. However I have not thought about it nearly enough to
make proper comment yet.