Does Entropy Increase With Time or Does It Make Time

5/20/2018 Does Entropy Increase With Time or Does It Make Time

IO9 (/)

(/)

Does entropy increase with time or does it maketime? (http://io9.com/5667872/doesentropy-increase-with-time-or-does-it-make-time)

(/)

Search

31,838 2Dr. Dave Goldberg (http://dave_goldberg.kinja.com)

Filed to: ASK A PHYSICIST (/TAG/ASK-A-PHYSICIST) 10/21/10 9:00am (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-m(http://dave_goldberg.kinja.com)

In this week's Ask a Physicist, we're going to go old school and do some thermodynamics. I'll explore why disorder is such a big deal and

whether it might explain the mysteries of how time works.

Photo by Jef Safi (http://www.flickr.com/photos/jef_safi/).

In our bi-weekly "Ask a Physicist" chats, I know we normally do cosmology (http://io9.com/5526583/if-the-universe-is-expanding-what

expanding-into), relativity (http://io9.com/5596491/ask-a-physicist-how-long-does-it-take-for-you-to-fall-into-a-black-hole), quantum

mechanics (http://io9.com/5526583/if-the-universe-is-expanding-whats-it-expanding-into), particle physics (http://io9.com/5630725/

physicist-can-i-build-a-doomsday-device-using-neutrinos) and whatnot, but I thought it'd be a nice change of pace to hit the 19th centur

some good old-fashioned thermodynamics. Don't give me that face! Thermodynamics made the industrial revolution possible, and will

ultimately be responsible for the death of the universe. I think it's earned your respect.

(http://io9.com/5526583/if-the-universe-is-expanding-whats-it-expanding-into)

If The Universe Is Expanding, What's It Expanding Into? (http://io9.com/5526583/if-the-universe-is-expanding-whats-it-expanding-into)If The

Universe Is Expanding, What's It Expanding Into? (http://io9.com/5526583/if-the-universe-is-expanding-whats-it-expanding-into)I f The Universe

Is Expanding, What's It Expand (ht tp://io9.com/5526583/if-the-universe-is-expanding-whats-it-expanding-into)

Last week the readers of io9 asked their most nagging questions about physics to a real-live
http://io9.com/5526583/if-the-universe-is-expanding-whats-it-expanding-intohttp://io9.com/5526583/if-the-universe-is-expanding-whats-it-expanding-intohttp://googleads.g.doubleclick.net/aclk?sa=L&ai=CZrf2gBn8U6_CNcL09QX7g4HwBOLQ5v4FAAAQASDywYsoUMGY2KP______wFg5YKAgOApyAEC4AIAqAMByAOdBKoEnAFP0Ks-v6a1zF7LwAwu8KqG-Bfb_ujcvHFCyKc_t83n9S0b1K1jDaZeWBJBNVCO_94eO5i3k7ICBH55nyvgTSfqdqA022j2v5NP8Yb3GnV1MTeSo2aPmGUfnvSErze7HTYxC3F33erhQuMGr9tRJUb3zuTXlQVLUMRLzGMpEiXmsTQSdRx1toxK4wTYVmXnua1gvyXugBDYRHjDCHbgBAGgBhQ&num=0&sig=AOD64_3QxbK9ltBnpHKLqMrt-6i63Gf9eg&client=ca-pub-0711137789465427&adurl=http://io9.com/about-io9-452391760&nm=1http://io9.com/5526583/if-the-universe-is-expanding-whats-it-expanding-intohttp://io9.com/5526583/if-the-universe-is-expanding-whats-it-expanding-intohttp://io9.com/5526583/if-the-universe-is-expanding-whats-it-expanding-intohttp://io9.com/5526583/if-the-universe-is-expanding-whats-it-expanding-intohttp://io9.com/5630725/ask-a-physicist-can-i-build-a-doomsday-device-using-neutrinoshttp://io9.com/5526583/if-the-universe-is-expanding-whats-it-expanding-intohttp://io9.com/5596491/ask-a-physicist-how-long-does-it-take-for-you-to-fall-into-a-black-holehttp://io9.com/5526583/if-the-universe-is-expanding-whats-it-expanding-intohttp://www.flickr.com/photos/jef_safi/http://dave_goldberg.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-timehttp://io9.com/tag/ask-a-physicisthttp://dave_goldberg.kinja.com/http://io9.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-timehttp://io9.com/http://io9.com/


Our question this week comes from Andrew Cameron, who had the good sense to email me at [email protected]

(mailto:[email protected]). He asks:

Alright, I get that entropy is a measure of disorder in objects, but really, why is it that important that it should be a law?

If you look at almost all of the laws of physics, the flow of time seems to be an afterthought. Make a movie of two electrons colliding into

another and then run that movie in reverse, and the time-reversal version will look as normal and physically valid as the forward versionthe microscopic level, time seems to be completely symmetric (http://io9.com/5655307/why-are-past-present-and-future-our-only-opti

(Attention nitpickers: The exception is the weak force, but that doesn't matter for this discussion.)

On the macroscopic level, it's a whole different deal. You don't remember the future, for example, and you can't unscramble an egg or un

cocktail. And while I'll be happy (should someone have the foresight to send me a question (mailto:[email protected])) to talk abou

possibility of time travel, in general, there is a single arrow of time.

There is one common denominator distinguishing the future from the past: everything seems to get messier. You may know this as "The

Second Law of Thermodynamics (http://en.wikipedia.org/wiki/2nd_law_of_thermodynamics)." Or you may not. I won't judge.

The Second Law says, colloquially, that things fall apart, or that things get more and more disordered with time, but this isn't quite right.

it really says is that the total entropyof a closed system increases with time. Entropy is a measure of the number of ways that you could sthings around and still have all of the macroscopic quantities remain the same.

Read more (http://io9.com/5526583/if-the-universe-is-expanding-whats-it-expanding-into)

(http://io9.com/5655307/why-are-past-present-and-future-our-only-options)

Why are past, present, and future our only options? (http://io9.com/5655307/why-are-past-present-and-future-our-only-options)Why are past,

present, and future our only options? (http://io9.com/5655307/why-are-past-present-and-future-our-only-options)Why are past, present, and

future our only opt ions (http://io9.com/5655307/why-are-past-present-and-future-our-only-options)

In this week's "Ask a Physicist," we're going to figure out why the universe we Read more (http://io9.com/5655307/why-are-past-present-and-future-our-only-options)

This Is What Gentrification Really Is (ht tp://io9.com/stop-complaining-about-

gentrification-unless-you-know-w-1620913091)

The 13 Greatest Science Fiction Comedies Of All Time (http://io9.com/the-13-greatest-

science-fiction-comedies-of-all-time-1613425431)

I Re-Watched Forrest GumpSo No One E lse Ever Has To (http://jezebel.com/i-re-

watched-forrest-gump-so-no-one-else-ever-has-to-1601861903)

Scale of the Universe (http://observationdeck.io9.com/scale-of-the-universe-1595991215)

The Most Important Mathematician You've Never Heard Of (http://io9.com/the-most-

important-mathematician-youve-never-heard-of-1594835772)

Scient ist Offers $10,000 To Anyone Who Can Disprove Climate Change

(http://io9.com/scientist-offers-10-000-to-anyone-who-can-disprove-cli-1595320736)

Are High Energy Neutrinos from Outer Space Really a Big Deal? (http://io9.com/are-

high-energy-neutrinos-from-outer-space-really-a-big-1594267938)

10 Scient ific Ideas That Sc ientists Wish You Would Stop Misusing (http://io9.com/10-

scientific-ideas-that-scientists-wish-you-would-stop-1591309822)

What would a teaspoonful of neutron star do to you? (ht tp://io9.com/5805244/what-would-a-teaspoonful-of-neutron-star-do-to-you)

RECOMMENDED BY DR. DAVE GOLDBERG (HT TP://DAVE_GOLDBERG.KINJA.COM/)

TRENDING ON RELATED BLOGS

7 things you maybe didn't know about Guardians of the Galaxy

(http://sploid.gizmodo.com/7-things-you-maybe-didnt-know-about-guardians-of-the-

ga-1626743956)
http://sploid.gizmodo.com/7-things-you-maybe-didnt-know-about-guardians-of-the-ga-1626743956http://dave_goldberg.kinja.com/http://io9.com/5805244/what-would-a-teaspoonful-of-neutron-star-do-to-youhttp://io9.com/10-scientific-ideas-that-scientists-wish-you-would-stop-1591309822http://io9.com/are-high-energy-neutrinos-from-outer-space-really-a-big-1594267938http://io9.com/scientist-offers-10-000-to-anyone-who-can-disprove-cli-1595320736http://io9.com/the-most-important-mathematician-youve-never-heard-of-1594835772http://observationdeck.io9.com/scale-of-the-universe-1595991215http://jezebel.com/i-re-watched-forrest-gump-so-no-one-else-ever-has-to-1601861903http://io9.com/the-13-greatest-science-fiction-comedies-of-all-time-1613425431http://io9.com/stop-complaining-about-gentrification-unless-you-know-w-1620913091http://io9.com/5655307/why-are-past-present-and-future-our-only-optionshttp://io9.com/5655307/why-are-past-present-and-future-our-only-optionshttp://io9.com/5655307/why-are-past-present-and-future-our-only-optionshttp://io9.com/5655307/why-are-past-present-and-future-our-only-optionshttp://io9.com/5655307/why-are-past-present-and-future-our-only-optionshttp://io9.com/5526583/if-the-universe-is-expanding-whats-it-expanding-intohttp://en.wikipedia.org/wiki/2nd_law_of_thermodynamicsmailto:[email protected]://io9.com/5655307/why-are-past-present-and-future-our-only-optionsmailto:[email protected]


A very nerdly example

Let me give you an example, since it will help to make things concrete. Suppose you had three air molecules and you put them into the le

of a box. This is a very tidy, very low-entropy way to arrange things. Allow nature to do its business, and the molecules will fly around, ea

spending about half its time on the left and half the time on the right.

At any moment, you'll see a randomized snapshot of the three molecules. There are 8 different ways to arrange the m olecules, but only 2

them (LLL, RRR) have all three of the molecules on one side of the container. That's only a 25% probability. The rest of the time, the atom

(more or less) distributed uniformly. And a uniform distribution is a higher state of entropy than a concentrated one.

You could play this same game by taking a hand full of coins and tossing them into the air. For every head, it's like a molecule is in the le

hand side of the room, and vice-versa. Do this a bunch of times, and you'll see that the molecules are almost always nearly equally distrib

Big numbers turn probabilities into a law

As you increase the num ber of air molecules to, say, 1026 or more (the number that would fit in a washing machine box), probability dic

that random motions will ultimately make the molecules spread out "evenly." To put numbers on it, the typical deviation from even is ab

divided by the square root of the number of particles, so in this case, we're saying that the two halves of the box will typically be equally fi

about one part in 101 3 (1 in 10 trillion).

Because of quantum mechanics, there really is a fundamentally random (http://usersguidetotheuniverse.com/?page_id=1120) compone

all of this. For what it's worth, while it's technically possible that all of the air molecules randomly fly out of your bedroom (or wherever y

reading this from) in the next few minutes, it's not something you should stay awake at night worrying about.

Increase in entropy is really only a law because there are so many particles in the universe that it becomes staggeringly unlikely that thing

spontaneously arrange themselves into a state of low entropy. We talk about this type of randomness with regards to gambling and weath

prediction in chapter 3 of the "User's Guide to the Universe." (http://alturl.com/82bmw)

As an even geekier example: you wouldn't be surprised to flip 2 heads in a row, but you'd be verysuspicious if someone flipped 100 heads

row. To put things in perspective, if you did 10 flips every second, it would take roughly a trillion times the current age of the universe bef

you'd expect to get a run that long. To put this another way, at some point, systems become so large that it becomes not merely "unlikely

"nearly brain-bendingly impossible" that entropy will decrease. That's why we call it "The Second Law." But in fact, it's really just a very,

good suggestion.

Those creationists among you may use this as evidence that complicated things (like peoples or dinosaurs) couldn't ever form in the first

After all, you are a very highly ordered person, I'm assuming. I f you are somehow a disordered homogeneous cloud of gas, then please a

my apologies. But supposing you area human, it's not that strange that you exist as a little patch of high order.

The real rule is that entropy will increase over the whole universe. So, for example, if you make a nice refrigerator full of cold air, you'll do

the expense of making a lot of high-entropy hot air. This is why your air-conditioner needs an exhaust, but your space heater doesn't. It's

the reason you can't build a perpetual motion machine. Some of the energy will always be converted into heat, so quit asking, already.

Entropy continuously increases with time. You sit in a hot bath in a cool room, and at first, you feel all warm and cozy, but then things ta

unfortunate turn: The water in the room starts to equilibrate with the air and you get cold and shriveled.

The same holds for the future of the universe. As time goes on, heat gets more and more evenly distributed in the universe. Stars burn ou

black holes ultimately evaporate, and everything goes dark and cold. Boo!

Calling Dr. Dave Goldberg (http://observationdeck.io9.com/calling-dr-dave-goldberg-

1500629355)

How the Cavefish Lost Its Eyes (http://io9.com/how-the-cavefish-lost-its-eyes-

1481689405)

When will the universe end? (http://io9.com/when-will-the-universe-end-1451601485)

Oprah pisses off atheists by saying they've no sense of awe or wonder

(http://io9.com/oprah-pisses-off-atheists-by-saying-theyve-no-sense-of-1445600667)

Stop calling it "The God Particle!" (http://io9.com/5923170/stop-calling-it-the-god-

particle)

To write this heartfelt emotional story, I had to do trigonometry (http://io9.com/to-

write-this-heartfelt-emotional-story-i-had-to-do-tr-1342338403)

What do you really need to know about the universe? (http://io9.com/what-do-you-

really-need-to-know-about-the-universe-1292293332)

Rush Limbaugh Has Written a Terrible Magic School BusRip-Off for Kids

(http://jezebel.com/rush-limbaugh-has-written-a-terrible-magic-school-bus-r-

1260415137)

Why can't Einstein and Quantum Mechanics get along? (http://io9.com/why-cant-

einstein-and-quantum-mechanics-get-along-799561829)

Ask a Physicist ... And Win a Book! (http://io9.com/ask-a-physicist-and-win-a-book-

511463568)

Waitress Pays for a Breastfeeding Mom's Dinner (ht tp://jezebel.com/waitress-pays-for-a-

breastfeeding-moms-dinner-832666253)
http://jezebel.com/waitress-pays-for-a-breastfeeding-moms-dinner-832666253http://io9.com/ask-a-physicist-and-win-a-book-511463568http://io9.com/why-cant-einstein-and-quantum-mechanics-get-along-799561829http://jezebel.com/rush-limbaugh-has-written-a-terrible-magic-school-bus-r-1260415137http://io9.com/what-do-you-really-need-to-know-about-the-universe-1292293332http://io9.com/to-write-this-heartfelt-emotional-story-i-had-to-do-tr-1342338403http://io9.com/5923170/stop-calling-it-the-god-particlehttp://io9.com/oprah-pisses-off-atheists-by-saying-theyve-no-sense-of-1445600667http://io9.com/when-will-the-universe-end-1451601485http://io9.com/how-the-cavefish-lost-its-eyes-1481689405http://observationdeck.io9.com/calling-dr-dave-goldberg-1500629355http://alturl.com/82bmwhttp://usersguidetotheuniverse.com/?page_id=1120


Time and the Second Law

One of the big debates going on in physics is whether the Second Law of Thermodynamics works the other way around. In other words, i

flow time determined by the increase in entropy in the universe? Sean Carroll has written a very interesting book

(http://www.amazon.com/Eternity-Here-Quest-Ultimate-Theory/dp/0525951334/?ref=pd_sim_b_6&&tag=io9amzn-20&ascsubtag=

[referrer|www .google.co.in[type|link[postId|5667872[asin|0525951334[authorI d|5726132905349161225) on this very subject.

Stephen Hawking famously related "psychological time," the way we remember things, to "entropic time." In other words, were the flow

entropy to reverse itself then literally (as far as our brains are concerned) time would be flowing in the opposite direction.

One of the big reasons that these ideas have gained traction is because of an observational puzzle. The early universe seems to be in a stat

very high order, but there's no fundamental reason w hy that should have been the case. The universe set up right after the big bang coul

been full of disorder, but instead, it was about as orderly as you could possibly get. High entropy gravity systems tend to be clumpy (prod

stars, galaxies, and black holes), but the universe was about as smooth as you can get. Why?

Others have gone even further. Erik Verlinde, for example, claims that phenomena like gravity (http://arxiv.org/abs/1001.0785) come o

the second law of thermodynamics (and string theory).

I should point out that these are interesting ideas, but notthe consensus view of physics. Most would say that time makes entropy increas

that entropy creates time. That's the view I take. For my part, I think entropy is just something that happens. Or, at very least, somethin

is very, very likely to happen.

(http://www.amazon.com/gp/product/0525951 334?tag=io9amzn-20&ascsubtag=

[postId|5667872[asin|0525951334[authorId|5726132905349161225[referrer|www.google.co.in[type|mod-image)

From Eternity to Here: The Quest for the Ultimate Theory of Time (http://www.amazon.com/gp/product/0525951334?tag=io9amzn-

20&ascsubtag=[postId|5667872[asin|0525951334[authorId|5726132905349161225[referrer|www.google.co.in[type|mod-title)From

Eternity to Here: The Quest for the Ultimate Theory of Time (http://www.amazon.com/gp/product/0525951334?tag=io9amzn-

20&ascsubtag=[postId|5667872[asin|0525951334[authorId|5726132905349161225[referrer|www.google.co.in[type|mod-title)FromEternity to Here: The Quest for the Ultima... (http://www.amazon.com/gp/product/0525951334?tag=io9amzn-20&ascsubtag=

[postId|5667872[asin|0525951334[authorId|5726132905349161225[referrer|www.google.co.in[type|mod-title)

Amazon.com: $22.39 (http://www.amazon.com/gp/product/0525951334?tag=io9amzn-20&ascsubtag=[postId|5667872[asin|0525951334[authorId|5726132905349161225[referrer|www.google.co.in[type|mod-price)

Buy now (http://www.amazon.com/gp/product/0525951334?tag=io9amzn-20&ascsubtag=[postId|5667872[asin|0525951334[authorId|5726132905349161225[referrer|www.google.co.in[type|mod-button)
http://www.amazon.com/gp/product/0525951334?tag=io9amzn-20&ascsubtag=[postId|5667872[asin|0525951334[authorId|5726132905349161225[referrer|www.google.co.in[type|mod-buttonhttp://www.amazon.com/gp/product/0525951334?tag=io9amzn-20&ascsubtag=[postId|5667872[asin|0525951334[authorId|5726132905349161225[referrer|www.google.co.in[type|mod-pricehttp://www.amazon.com/gp/product/0525951334?tag=io9amzn-20&ascsubtag=[postId|5667872[asin|0525951334[authorId|5726132905349161225[referrer|www.google.co.in[type|mod-titlehttp://www.amazon.com/gp/product/0525951334?tag=io9amzn-20&ascsubtag=[postId|5667872[asin|0525951334[authorId|5726132905349161225[referrer|www.google.co.in[type|mod-titlehttp://www.amazon.com/gp/product/0525951334?tag=io9amzn-20&ascsubtag=[postId|5667872[asin|0525951334[authorId|5726132905349161225[referrer|www.google.co.in[type|mod-titlehttp://www.amazon.com/gp/product/0525951334?tag=io9amzn-20&ascsubtag=[postId|5667872[asin|0525951334[authorId|5726132905349161225[referrer|www.google.co.in[type|mod-imagehttp://arxiv.org/abs/1001.0785http://www.amazon.com/Eternity-Here-Quest-Ultimate-Theory/dp/0525951334/?ref=pd_sim_b_6&&tag=io9amzn-20&ascsubtag=[referrer|www.google.co.in[type|link[postId|5667872[asin|0525951334[authorId|5726132905349161225


2 93

Dave Goldberg (http://www.twitter.com/askaphysicist) is the author, with Jeff Blomquist, of "A User's Guide to the Universe: Survivin

Perils of Black Holes, Time Paradoxes, and Quantum Uncertainty." (http://www.amazon.com/Users-Guide-Universe-Surviving-

Uncertainty/dp/0470496517/?ref=sr_1_1?ie=UTF8&s=books&qid=1254702514&sr=8-1&&tag=io9amzn-20&ascsubtag=

[referrer|www.google.co.in[type|link[postId|5667872[asin|0470496517[authorId|5726132905349161225) (follow us on twitter

(http://www.twitter.com/askaphysicist) , facebook (http://www.facebook.com/pages/A-Users-Guide-to-the-Universe/130714312680?r

or our blog (http://www.usersguidetotheuniverse.com).) He is an Associate Professor of Physics at Drexel University. Feel free to send e

to [email protected] (mailto:[email protected]) with any questions about the universe.

(http://www.amazon.com/gp/product/0470496517?tag=io9amzn-20&ascsubtag=

[postId|5667872[asin|0470496517[authorId|5726132905349161225[referrer|www.google.co.in[type|mod-image)

A User's Guide to the Universe: Surviving the Perils of Black Holes, Time (http://www.amazon.com/gp/product /0470496517?

tag=io9amzn-20&ascsubtag=[postId|5667872[asin|0470496517[authorId|5726132905349161225[referrer|www.google.co. in[type|mod-

title)A User's Guide to the Universe: Surviving the Perils of Black Holes, Time (http://www.amazon.com/gp/product/0470496517?

tag=io9amzn-20&ascsubtag=[postId|5667872[asin|0470496517[authorId|5726132905349161225[referrer|www.google.co. in[type|mod-

title)A User's Guide to the Universe: Surviving t. .. (http://www.amazon.com/gp/product/0470496517?tag=io9amzn-20&ascsubtag=

[postId|5667872[asin|0470496517[authorId|5726132905349161225[referrer|www.google.co.in[type|mod-title)

Amazon.com: $18.91 (http://www.amazon.com/gp/product/0470496517?tag=io9amzn-20&ascsubtag=[postId|5667872[asin|0470496517[authorId|5726132905349161225[referrer|www.google.co.in[type|mod-price)

163 readers bought this (http://www.amazon.com/gp/product/0470496517?tag=io9amzn-20&ascsubtag=

[postId|5667872[asin|0470496517[authorId|5726132905349161225[referrer|www.google.co.in[type|mod-conversions)

Buy now (http://www.amazon.com/gp/product/0470496517?tag=io9amzn-20&ascsubtag=[postId|5667872[asin|0470496517[authorId|5726132905349161225[referrer|www.google.co.in[type|mod-button)

The following replies are approved. To see additional replies that are pending approval, click Show Pending. Warning: These may contain graphic material.

SHOW PENDING

10/21/10 9:28am RenRenstarted this

RenRen (http://rfnajera.kinja.com) Dr. Dave Goldberg

10/21/10 9:28am (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31118828#comments)(http://rfnajera.kinja.com)

"But supposing you are a human, it's not that strange that you exist as a little patch of high order."

Getting away from the theological argument before the other IO9'ers tear me a new one, as they often do...

Is the universe old enough to have more "patches of higher order" around? I mean, is 15 billion years enough to make more than one adv

civilization (ours)?

Dr. Dave Goldbergs Discussions (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time)

All replies (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time/all)

Chip Overclock (http://coverclock.kinja.com) RenRen

10/21/10 9:33am (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31119199#comments)(http://coverclock.kinja.com)

@RenRen: This question is at the heart of the Fermi Paradox, which IMNSHO should be the principal philosophical and theological quesour age.

372Like
http://coverclock.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31119199#commentshttp://coverclock.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time/allhttp://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-timehttp://rfnajera.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31118828#commentshttp://rfnajera.kinja.com/http://www.amazon.com/gp/product/0470496517?tag=io9amzn-20&ascsubtag=[postId|5667872[asin|0470496517[authorId|5726132905349161225[referrer|www.google.co.in[type|mod-buttonhttp://www.amazon.com/gp/product/0470496517?tag=io9amzn-20&ascsubtag=[postId|5667872[asin|0470496517[authorId|5726132905349161225[referrer|www.google.co.in[type|mod-pricehttp://www.amazon.com/gp/product/0470496517?tag=io9amzn-20&ascsubtag=[postId|5667872[asin|0470496517[authorId|5726132905349161225[referrer|www.google.co.in[type|mod-titlehttp://www.amazon.com/gp/product/0470496517?tag=io9amzn-20&ascsubtag=[postId|5667872[asin|0470496517[authorId|5726132905349161225[referrer|www.google.co.in[type|mod-titlehttp://www.amazon.com/gp/product/0470496517?tag=io9amzn-20&ascsubtag=[postId|5667872[asin|0470496517[authorId|5726132905349161225[referrer|www.google.co.in[type|mod-titlehttp://www.amazon.com/gp/product/0470496517?tag=io9amzn-20&ascsubtag=[postId|5667872[asin|0470496517[authorId|5726132905349161225[referrer|www.google.co.in[type|mod-conversionshttp://www.amazon.com/gp/product/0470496517?tag=io9amzn-20&ascsubtag=[postId|5667872[asin|0470496517[authorId|5726132905349161225[referrer|www.google.co.in[type|mod-imagemailto:[email protected]://www.usersguidetotheuniverse.com/http://www.facebook.com/pages/A-Users-Guide-to-the-Universe/130714312680?ref=tshttp://www.twitter.com/askaphysicisthttp://www.amazon.com/Users-Guide-Universe-Surviving-Uncertainty/dp/0470496517/?ref=sr_1_1?ie=UTF8&s=books&qid=1254702514&sr=8-1&&tag=io9amzn-20&ascsubtag=[referrer|www.google.co.in[type|link[postId|5667872[asin|0470496517[authorId|5726132905349161225http://www.twitter.com/askaphysicist


10/21/10 9:04am Mister_Robotostarted this

Mister_Roboto (http://mister_roboto.kinja.com) Dr. Dave Goldberg

10/21/10 9:04am (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31116845#comments)(http://mister_roboto.kinja.com)

There's no back ground layer in that sky, and who doesn't love lens flare?

1

Show more replies in this thread (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31118828#comments)

I mean, srsly, 15 billion years, and we haven't heard hide nor hair of _anyone_ else? Rly? WTF?

revdrkevind (http://revdrkevind-old.kinja.com) RenRen

10/21/10 9:39am (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31119678#comments)(http://revdrkevind-old.kinja.com)

@RenRen: Given that our neighborhood doesn't seem to be very special compared to other neighborhoods around us, and we took a gala

eyeblink to come out, and assuming a similar process is going on everywhere...

It is mind-bendingly unthinkable that intelligent life isn't everywhere*.

*Everywhere in the sense that, technically, you are (and everything else is) made up of empty space and the atoms that compose you are

virtually anomalies compared to the space between them.

gerrylum ( http://gerrylum.kinja.com) Chip Overclock

10/21/10 9:43am (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31119988#comments)(http://gerrylum.kinja.com)

@Chip Overclock: I don't think it's that odd. You must take into consideration the lifespan of a civilization, which would be drastically red

if faster-than-light travel is difficult enough that most civilizations die out before it is ever achieved.

Even if human civilization doesn't die out for another 200,000 years, it still means that we were only here for a small blip of time in the

cosmological timescale.

If that is true with other civilizations, the probability that two civilizations would exist at the same time and at close enough distances to b

to contact each other would be extremely low.

jetRink (http://jetrink.kinja.com) RenRen

10/21/10 9:52am (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31120655#comments)(http://jetrink.kinja.com)

@RenRen: It's less a question of the age of the universe, and more a question of how likely our civilization is. That's what the Drake equa

(http://en.wikipedia.org/wiki/Drake_equation) tries to estimate.

We're not the product of some exceedingly random fluctuation, we didn't just pop into existence, we're here because something about the

universe makes our existence relatively likely. I'll leave it up to you to decide whether that something needs to involve a god or not.

Rahll (http://rahll.kinja.com) Mister_Roboto

10/21/10 10:17am (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31122617#comments)(http://rahll.kinja.com)

@Mister_Roboto: Lmao, good call.

Mister_Roboto (http://mister_roboto.kinja.com) Rahll

10/21/10 10:28am (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31123451#comments)(http://mister_roboto.kinja.com)
http://mister_roboto.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31123451#commentshttp://mister_roboto.kinja.com/http://rahll.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31122617#commentshttp://rahll.kinja.com/http://en.wikipedia.org/wiki/Drake_equationhttp://jetrink.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31120655#commentshttp://jetrink.kinja.com/http://gerrylum.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31119988#commentshttp://gerrylum.kinja.com/http://revdrkevind-old.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31119678#commentshttp://revdrkevind-old.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31118828#commentshttp://mister_roboto.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31116845#commentshttp://mister_roboto.kinja.com/


10/21/10 10:03am Corpore Metalstarted this

Corpore Metal (http://corpore-metal.kinja.com) Dr. Dave Goldberg

10/21/10 10:03am (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31121467#comments)(http://corpore-metal.kinja.com)

Excuse me, Dave, but this confuses me:

"At the microscopic level, time seems to run in one direction, and not the other. (Attention nitpickers: The exception is the weak force, b

doesn't matter for this discussion.)"

Given your prior example of time not appearing to matter at the quantum level shouldn't this sentence read:

"But at the microscopic level, we see that time seems to run in one direction, and not the other."

I mean, I understand what you're trying to get at here. Aside from Thermodynamics and some aspects of chaotic dynamics, most the equ

of physics don't really care which direction time runs in. I just think the paragraph should have been a little clearer on that point.

10/21/10 10:00am mattycakesstarted this

mattycakes (http://mattycakes-old.kinja.com) Dr. Dave Goldberg

10/21/10 10:00am (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31121220#comments)(http://mattycakes-old.kinja.com)

(https://reader003.{domain}/reader003/html5/0227/5a94ddd769e8e/5a94ddea6b082.jpg)

Wait, flipping heads 100 times in a row is odd?

@Rahll: That pocket of the universe is missing the background! Someone unlocked it!

OrtenseCaiti (http://ortensecaiti-old.kinja.com) mattycakes

10/21/10 10:31am (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31123661#comments)(http://ortensecaiti-old.kinja.com)

@mattycakes: Only if such laws are assumed to still be in effect.

_Mr_X_ (http://mister-x-.kinja.com) mattycakes

10/21/10 11:41am (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31128848#comments)(http://mister-x-.kinja.com)

@mattycakes: +1 for Rosencrantz & Guildenstern reference.

robert.heffern (http://robert-heffern-old.kinja.com) mattycakes

10/21/10 12:59pm (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31134427#comments)(http://robert-heffern-old.kinja.com)
http://robert-heffern-old.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31134427#commentshttp://robert-heffern-old.kinja.com/http://mister-x-.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31128848#commentshttp://mister-x-.kinja.com/http://ortensecaiti-old.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31123661#commentshttp://ortensecaiti-old.kinja.com/http://cache.gawker.com/assets/images/comment/8/2010/10/caf723c1126e9c8dbfcb980a7076f785/original.jpghttp://mattycakes-old.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31121220#commentshttp://mattycakes-old.kinja.com/http://corpore-metal.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31121467#commentshttp://corpore-metal.kinja.com/


10/21/10 4:56pm txtphilestarted this

txtphile (http://txtphile.kinja.com) Dr. Dave Goldberg

10/21/10 4:56pm (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31150564#comments)(http://txtphile.kinja.com)

Wonderful article, thanks. And that non-consensus view of entropy/time would make a great sci-fi story.

10/21/10 9:19am SupaChupacabra started this

SupaChupacabra (http://supachupacabra.kinja.com) Dr. Dave Goldberg

10/21/10 9:19am (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31118035#comments)(http://supachupacabra.kinja.com)

So this boils down to: Time is a Michael Bay movie that cannot be unwatched.

10/21/10 10:55am stereobotstarted this

stereobot (http://stereobot-old.kinja.com) Dr. Dave Goldberg

10/21/10 10:55am (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31125624#comments)(http://stereobot-old.kinja.com)

I would think that time leads to entropy.

Without space, there is no time.

Without space-time, there is no where for matter to move about and become disordered.

First there must be space for entropy to be possible, time is measured by entropy taking place but the entropy isn't "making time".

More space-time allows more possibilities of matter becoming m ore dis-organized.

Therefore, entropy does increase with time, which increases with space.

Now - what caused the "space" to come into existence?

When the Big Bang happened and the matter was evenly distributed through space, how was that any different from the previous state it

in? If the matter "before" the Big Bang expanded into a larger volume but was evenly distributed, how could you say there was any entro

before that initial expansion?


@mattycakes: I was too late to post this, you beat me too it.

1Grand_Marquis (http://1grand_marquis-old.kinja.com) _Mr_X_

10/21/10 1:46pm (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31138083#comments)(http://1grand_marquis-old.kinja.com)

@cc: +1 for noticing a Rosencrantz & Guildenstern reference.

aberudo (http://aberudo-old.kinja.com) stereobot

10/21/10 12:42pm (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31133264#comments)(http://aberudo-old.kinja.com)

@stereobot: Aren't space and time inexorably linked into Space-time? I sn't that kind of w hat Einstein was going on about? Space doesn't

without time, and vice versa.

As a corollary, if that's true, if space-time creates the need for/causes entropy, or entropy causes space-time ...
http://aberudo-old.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31133264#commentshttp://aberudo-old.kinja.com/http://1grand_marquis-old.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31138083#commentshttp://1grand_marquis-old.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31121220#commentshttp://stereobot-old.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31125624#commentshttp://stereobot-old.kinja.com/http://supachupacabra.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31118035#commentshttp://supachupacabra.kinja.com/http://txtphile.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31150564#commentshttp://txtphile.kinja.com/


10/21/10 12:17pm CVDonstarted this

CVDon (http://cvdon-old.kinja.com) Dr. Dave Goldberg

10/21/10 12:17pm (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31131461#comments)(http://cvdon-old.kinja.com)

This is a pretty great article in many ways.

I have a few questions (and most likely the answers are that the analogies I am using are from the wrong domain of physics).

1. What about magnetic particles floating around in space. Will they not combine and collect? Is this against the way entropy is defined b

physicists?

2. Generalize that to any object with mass. Won't mass tend to collect and co-locate as time goes on. Is this against the way entropy is def

by physicists as well?

3. As things cool down as t goes to infinity, where does the heat go? Does it turn into more matter?

4. It should take energy to break clusters of matter apart. Where does this energy come from if the limit to which energy goes as t goes to

infinity is zero?

I kind of think that the concept of disorder in entropy is sort of arbitrarily defined, at least in non-mathematical understandings of it.

Somebody please set me straight.

-D


That would mean that if the Big Bang was an explosion out of a completely ordered state, that perhaps space-time didn't exist until the in

the universe entered a disorderly state of being.

wdef2001 (http://wdef2001-old.kinja.com) stereobot

10/21/10 12:49pm (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31133689#comments)(http://wdef2001-old.kinja.com)

@stereobot: There is no "before" the Big Bang so that is not a meaningful statement.

stereobot (http://stereobot-old.kinja.com) aberudo

10/21/10 1:31pm (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31136993#comments)(http://stereobot-old.kinja.com)

@aberudo: Yes, Space and Time = "space-time", they are one.

As far as I understand, entropy cannot exist if there is no space or time, so spacetime had to exist before entropy could happen.

If the Big Bang was an explosion out of a completely ordered state, why did it happen? How could a change have happened if there was n

space time and/or entropy?

Maybe Dr. Goldberg can step in at this point, but with my understanding of the Big Bang it was really more of an expansion rather than

explosion.

1Grand_Marquis (http://1grand_marquis-old.kinja.com) stereobot

10/21/10 1:42pm (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31137791#comments)(http://1grand_marquis-old.kinja.com)

@stereobot: re: what wdef said. the Big Bang was an explosion of spacetime itself, not the stuff inside spacetime that makes up the observ

universe.
http://1grand_marquis-old.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31137791#commentshttp://1grand_marquis-old.kinja.com/http://stereobot-old.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31136993#commentshttp://stereobot-old.kinja.com/http://wdef2001-old.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31133689#commentshttp://wdef2001-old.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31125624#commentshttp://cvdon-old.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31131461#commentshttp://cvdon-old.kinja.com/


bug (http://jonas_danielsson.kinja.com) CVDon

10/21/10 1:04pm (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31134796#comments)(http://jonas_danielsson.kinja.com)

@CVDon:

1 and 2: The thing is, unless they collide, their total energy will remain the same, and if that total energy allows them to be far apart, then

are many many more ways for them to be far apart, and so they will not collect.

3. When they say things cool down, they actually mean the temperature gets even over all particles in the universe, but it doesn't go to zer

4. No energy is gone, it is just more evenly distributed. That energy that kept clusters of matter together is released into kinetic energy wh

dissipated over the huge, cold, surroundings.

I don't like the image of disorder that much myself, but just thinks about it as number of ways the system can be realized. However, that

already too abstract for pop science, not to mention 'number of accessible microstates' or 'hypervolume of the accessible phase space' whi

even more exact and descriptive definitions.

CVDon (http://cvdon-old.kinja.com) bug


@bug: Interesting thoughts.

I guess what I am wondering is what would induce the state of a system to leave a local minimum state of entropy in favor of a better lo

minimum, or an absolute minimum.

Also, by what process according to these definitions could a minimum be selected in the event of multiple possible states of equal minimu

ness.

Either I'm missing some nuance of this theory or applying it out of context, or otherwise something smells fishy.

-D

bug (http://jonas_danielsson.kinja.com) CVDon

10/21/10 3:21pm (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31144752#comments)(http://jonas_danielsson.kinja.com)

@CVDon: Well, the prediction is only valid to if the assumption of all states with the same energy is equally probable, which in principle m

there has to be a way to get from one state to the all other. How that path looks is not really a problem of thermodynamics, more a probl

the dynamics. In the classical picture, this means that there has to be a enough energy in the universe to overcome all those barriers.

Also, it doesn't really make sense to take about a 'state' of maximum entropy, since entropy is in itself a measure of how many states are

available. It is not like potential energy that changes depending on the relative position of the particles, it is a property of all possible positi

the particles ...

CVDon (http://cvdon-old.kinja.com) bug


@bug: AHHHH yes, the number of available states. That is a distinction I had ignored.

Doesn't that mean that entropy is sort of a false or at least artificial measure then? For example, to count the available states wouldn't you

to know them all to begin with? Would that mean you would have to have a complete parametrization or representation of the system?

When in the pop sci context someone says entropy with respect to something like "the universe" do they mean a specific agreed upon defi

which for lack of a better term means a homogeneous distribution of particles in space?
http://cvdon-old.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31150372#commentshttp://cvdon-old.kinja.com/http://jonas_danielsson.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31144752#commentshttp://jonas_danielsson.kinja.com/http://cvdon-old.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31136780#commentshttp://cvdon-old.kinja.com/http://jonas_danielsson.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31134796#commentshttp://jonas_danielsson.kinja.com/


10/21/10 9:12am hwilamstarted this

hwilam (http://hwilam.kinja.com) Dr. Dave Goldberg

10/21/10 9:12am (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31117505#comments)(http://hwilam.kinja.com)

I'm confused: when I decrease the entropy in my system (i e clean up my apartment), I'm going backwards in time?

10/22/10 12:12am Pavement clawing maniacstarted this

Pavement clawing maniac (http://taylocn.kinja.com) Dr. Dave Goldberg

10/22/10 12:12am (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31170801#comments)(http://taylocn.kinja.com)

It's been 10 years since my thermo class, but I don't remember any sort of statistical model being taught. I actually think that describing

statistically is doing a disservice. It has more to do with the generation of waste heat. Basically, the entropy of the universe is always incre

because of waste heat. This sounds like an odd term. Why not use that heat for something instead of just wasting it, you ask? Well, surely

you burn a stick of wood, you can use the heat released to increase the temperature of a body of w ater, and use that water to heat up

something else, and if it's a closed system, the heat will not be lost. However, the hot water is obviously a lower temperature than the

temperature of the burning wood, which means it can only transfer this heat into a system which has a temperature lower than that of th

water. Therefore, the heat is now less useful than it was before, and the entropy of the system has increased.

Also interesting, there is a certain explosive I've read about which does not explode due to a rapid oxidation of fuel, but using entropy as a

driving force instead. Weird.


revdrkevind (http://revdrkevind-old.kinja.com) hwilam

10/21/10 9:41am (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31119787#comments)(http://revdrkevind-old.kinja.com)

@hwilam: Feat not- all that sweat you've put into your clothes, all that awful mouth-breath you've expelled mucking about for everyone

inhale.. you've done more than your share to increase entropy globally, even if locally things seem much better.

liesandslander (http://liesandslander.kinja.com) hwilam

10/21/10 9:41am (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31119790#comments)

(http://liesandslander.kinja.com)

@hwilam: besides the stains on the carpet and destroyed door, yes.

gallahad (http://gallahad.kinja.com) hwilam

10/21/10 9:43am (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31119967#comments)(http://gallahad.kinja.com)

@hwilam: No, because you expend energy in cleaning up your apartment.

disrael (http://disrael-old.kinja.com) hwilam

10/21/10 11:31am (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31128140#comments)(http://disrael-old.kinja.com)

@hwilam: Shhhhh!!!

I'm trying to convince my wife that physics definitively proves that it is impossible to clean up the house, so why should I bother?
http://disrael-old.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31128140#commentshttp://disrael-old.kinja.com/http://gallahad.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31119967#commentshttp://gallahad.kinja.com/http://liesandslander.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31119790#commentshttp://liesandslander.kinja.com/http://revdrkevind-old.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31119787#commentshttp://revdrkevind-old.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31131461#commentshttp://taylocn.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31170801#commentshttp://taylocn.kinja.com/http://hwilam.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31117505#commentshttp://hwilam.kinja.com/


Help (http://help.gawker.com/) Terms of Use (http://legal.kinja.com/kinja-terms-of-use-90161644) Privacy (http://legal.kinja.com/privacy-policy-90190742)

Advertising (http://advertising.gawker.com/) Permissions (http://advertising.gawker.com/about/index.php#contact)

Content Guidelines (http://legal.kinja.com/content-guidelines-90185358) RSS (http://feeds.gawker.com/io9/full) Jobs (http://grnh.se/2ctqpi)

View Popular Discussion (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time)

mark.veyette (http://mark-veyette-old.kinja.com) Pavement clawing maniac

10/22/10 8:33am (http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31185428#comments)(http://mark-veyette-old.kinja.com)

@Pavement clawing maniac: The Second Law is entirely statistical. The only reason entropy tends to increase is because it is so immeasu

probable to do so. Also, heat depends on much more than just temperature.
http://mark-veyette-old.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-time?comment=31185428#commentshttp://mark-veyette-old.kinja.com/http://io9.com/5667872/does-entropy-increase-with-time-or-does-it-make-timehttp://grnh.se/2ctqpihttp://feeds.gawker.com/io9/fullhttp://legal.kinja.com/content-guidelines-90185358http://advertising.gawker.com/about/index.php#contacthttp://advertising.gawker.com/http://legal.kinja.com/privacy-policy-90190742http://legal.kinja.com/kinja-terms-of-use-90161644http://help.gawker.com/

Does Entropy Increase With Time or Does It Make Time

Documents

Transcript of Does Entropy Increase With Time or Does It Make Time