Welcome to this week’s installment of the From Eternity to Here book club. Now for something of a palate-cleanser, in the form of Chapter Nine, “Information and Life.”
Excerpt:
Schrödinger’s idea captures something important about what distinguishes life from non-life. In the back of his mind, he was certainly thinking of Clausius’s version of the Second Law: objects in thermal contact evolve toward a common temperature (thermal equilibrium). If we put an ice cube in a glass of warm water, the ice cube melts fairly quickly. Even if the two objects are made of very different substances—say, if we put a plastic “ice cube” in a glass of water—they will still come to the same temperature. More generally, nonliving physical objects tend to wind down and come to rest. A rock may roll down a hill during an avalanche, but before too long it will reach the bottom, dissipate energy through the creation of noise and heat, and come to a complete halt before very long.
Schrödinger’s point is simply that, for living organisms, this process of coming to rest can take much longer, or even be put off indefinitely. Imagine that, instead of an ice cube, we put a goldfish into our glass of water. Unlike the ice cube (whether water or plastic), the goldfish will not simply equilibrate with the water—at least, not within a few minutes or even hours. It will stay alive, doing something, swimming, exchanging material with its environment. If it’s put into a lake or a fish tank where food is available, it will keep going for much longer.
This chapter starts with something very important: the relationship between entropy and memory. Namely, the reason why we can “remember” the past and not the future is that the past features a low-entropy boundary condition, while the future does not. I don’t go into great detail about this, and we certainly don’t talk very specifically about how real memories are formed in the brain, or even in a computer. But when we get to the next chapter, about recurrences and Boltzmann brains, it will be crucial to understand how the assumption of a low-entropy boundary condition enables us to reconstruct the past. It’s hard for people to wrap their brains around the fact that, without such an assumption, our “memories” or records of the past will generally be unreliable — knowledge of the current macrostate wouldn’t allow us to reconstruct the past any better than it allows us to predict the future. (Which is only logical, since it’s only this hypothesis that breaks time-reversal symmetry.)
The rest of the chapter, meanwhile, is more about having fun and mentioning some ideas that are not directly related to our story, but certainly play a part in understanding the arrow of time. Information theory, life, complexity. I’m not an expert in any of these fields, but it was a lot of fun reading about them to pick out some things that fit into the broader narrative. The Maxwell’s Demon story, in particular, is one that every physicist should know (up through it’s relatively modern resolution), but relatively few do. And I think Jason Torchinsky did a great job with the illustrations of the Demon.
A lot of big ideas here, of course, and much of this stuff is still very much in the working-out stage, not the settled-understanding stage. We’re still arguing about basic things like the definition of “complexity” and “life.” It’s relatively easy to state the Second Law and explain how the arrow of time is related to the growth of entropy, but there’s a tremendous amount of work still to be done before we completely understand the way in which the universe actually evolves from low entropy to high.
- I Spy With My Little Eye… [Last Updated On: November 7th, 2009] [Originally Added On: November 7th, 2009]
- A Crack Opens in the Ethiopian Landscape, Preparing the Way for a New Sea | 80beats [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- The Politics of Addiction | The Intersection [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Finally! An iPhone App That Lets You Track Your Bathroom Habits | Discoblog [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Don’t Pack Your Bags Yet—New Planet-Finder Hobbled by Electronic Glitch | 80beats [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- In Controversial Scent Lineups, a Dog’s Nose Picks Out the Perp | 80beats [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Are You a Cognitive Miser? | Cosmic Variance [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- The Secret Lives and Loves of Great White Sharks | 80beats [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Britain’s New Protected Minority: Tree-Huggers | Discoblog [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Inspired by Maple Seeds, a Robotic Whirligig Takes To The Skies | Discoblog [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- New Statesman on Accommodationism | The Intersection [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Laser-Powered Robot Climbs to Victory in the Space-Elevator Contest | 80beats [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Checking Back In With SEAPLEX | The Intersection [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Podcast: An Embarrassment of Genomes | The Loom [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- A Baby Neutron Star, Swaddled in a Carbon Atmosphere | 80beats [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Butterfliiiies… iiinnnn… SPPPAAAAACCCCEEEEE! | Bad Astronomy [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- My Slate Dialogue with Michael Specter Begins | The Intersection [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Musical, Fahrvergnügen-Inspired Staircase Makes Commuters Less Lazy | Discoblog [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Laser-Etched Fruit Is an Answer in Search of a Problem | Discoblog [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Ares and the carnivals | Bad Astronomy [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Toddler Gets a Telescoping, Prosthetic Arm Bone That Grows With Him | 80beats [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Neutered HIV Virus Delivers Treatment to Fatally Ill Boys | 80beats [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Specter’s First Reply: Denialism Kills People | The Intersection [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- LRO sees a Moonslide | Bad Astronomy [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Al Gore’s New Book: A Focus on Solutions | The Intersection [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- The Universe Has Us in Its Crosshairs | Bad Astronomy [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Makers of Universes | Cosmic Variance [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Can Your Pet Catch & Spread Swine Flu? Yes, If Your Pet’s a Ferret | 80beats [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Droid 2.0 Vs iPhone | The Intersection [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Tangled Bank News: An Excerpt and More | The Loom [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- LHC Shut Down By Wayward Baguette, Dropped by Bird Saboteur | Discoblog [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Careidolia | Bad Astronomy [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Slate Reply to Specter Up–We Need a National Dialogue on Synthetic Biology | The Intersection [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Pray this doesn’t get passed | Bad Astronomy [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- You Can’t Make This Stuff Up | Cosmic Variance [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Mother Tongue, Indeed: Newborn’s Cries Mimic Mama’s Accent | 80beats [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Ripped From the Journals: The Biggest Discoveries of the Week | 80beats [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Alternative Landscapes | The Loom [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Can an iPhone App Decipher Your Baby’s Cries? | Discoblog [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Reminder: Carl Sagan Day | Bad Astronomy [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Are There Pesticides in Your Soup? Dunk a Pollution Dipstick to Find Out. | 80beats [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Log in and Join the Conference [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Conference Ends [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Conference Archive Opens [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Galaxy Zoo [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- .Astronomy 2009 Dates [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- .Astronomy 2009: Programme and venue details [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- .Astronomy Gets Some IYA Love [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- 2009 Posters and Imagery [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- 2009 Sponsors [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- When in Holland… [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- The WHAT Cloud? [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- The Jewel Box [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Happy Halloween! [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Ares 1-X Launch [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Confessions of an Alien Hunter [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- LRO Spies Apollo 17 Site [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Mercury in Color [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Hubble and M83 [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Cassini Flyby of Enceladus [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Preserving A Moth [Science Tattoo] | The Loom [Last Updated On: December 12th, 2009] [Originally Added On: December 12th, 2009]
- Another Russian rocket spiral lights up the sky | Bad Astronomy [Last Updated On: December 12th, 2009] [Originally Added On: December 12th, 2009]
- A (Very Gentle) Riddle to Complete Your Saturday [Last Updated On: December 12th, 2009] [Originally Added On: December 12th, 2009]
- Darwin Gets Swine Flu: The YouTube Edition | The Loom [Last Updated On: December 12th, 2009] [Originally Added On: December 12th, 2009]
- Happy Slothy Holidays | The Loom [Last Updated On: December 12th, 2009] [Originally Added On: December 12th, 2009]
- Jetting to Copenhagen | The Intersection [Last Updated On: December 12th, 2009] [Originally Added On: December 12th, 2009]
- Michael Gerson Attempts Thoughtfulness on “ClimateGate,” Then Gives it Up | The Intersection [Last Updated On: December 13th, 2009] [Originally Added On: December 13th, 2009]
- Incredible VISTA of the cosmos | Bad Astronomy [Last Updated On: December 13th, 2009] [Originally Added On: December 13th, 2009]
- Bundle up Sunday Night to Watch the Geminid Meteor Shower | 80beats [Last Updated On: December 13th, 2009] [Originally Added On: December 13th, 2009]
- “ClimateGate” a PR Disaster That Will Be “Taught in University Communications Courses” | The Intersection [Last Updated On: December 13th, 2009] [Originally Added On: December 13th, 2009]
- Is Google the Guardian Angel of Rainforests? | 80beats [Last Updated On: December 13th, 2009] [Originally Added On: December 13th, 2009]
- La ciencia es importante. Una vez mas. | Bad Astronomy [Last Updated On: December 13th, 2009] [Originally Added On: December 13th, 2009]
- Sensenbrenner Pulls an Inhofe, Asserts Global Warming is an “International Conspiracy” | The Intersection [Last Updated On: December 13th, 2009] [Originally Added On: December 13th, 2009]
- Let Kids Eat Dirt: Over-Cleanliness Linked to Heart Disease | 80beats [Last Updated On: December 13th, 2009] [Originally Added On: December 13th, 2009]
- What Are The Best Science Papers Of The Past Decade? | The Intersection [Last Updated On: December 13th, 2009] [Originally Added On: December 13th, 2009]
- Finally! Math Shows How to Cut Evenly Sized Pizza Slices | Discoblog [Last Updated On: December 13th, 2009] [Originally Added On: December 13th, 2009]
- Half-baked math | Bad Astronomy [Last Updated On: December 13th, 2009] [Originally Added On: December 13th, 2009]
- Can “Biological Passports” Save Sports From Doping? | 80beats [Last Updated On: December 13th, 2009] [Originally Added On: December 13th, 2009]
- Aiiiieeee! Slow down! | Bad Astronomy [Last Updated On: December 13th, 2009] [Originally Added On: December 13th, 2009]
- Weekly News Roundup: Bad Headlines, Martian moons, and Rotating Houses | Discoblog [Last Updated On: December 13th, 2009] [Originally Added On: December 13th, 2009]