Tuesday, December 27, 2011

Eggnog ruminations

So... all our oil and coal originates from plant and animal matter, right?  Living stuff was buried over millennia, compressed and reduced and cooked until all that remains is a sludge of hydrocarbons: long branches of carbon bursting with hydrogen atoms like ripe fruit ready for the fiery picking.

And our industrialized, world-changing society was built on finding these puddles of free energy, just lying there*.

So what if we, or a race like us, rose up in the Cretaceous?  The first abundant complex life on earth rose up at the end of the Proterozoic Eon, around 600 million years ago; but the Cretaceous period, where there's massive complex animal life in the form of dinosaurs and other beasties was around 100 million years ago already.  Would there be oil to find, to fuel their own industrial explosion?

I had this sudden image of velociraptors learning to herd smaller, dumber dinosaurs; setting up colonies and competing nations; languages, philosophies, dances about the hunt.  Their brains grow, they make fences and weapons, they discover surface metals and learn to shape them.  A rich and flowering culture emerges, celebrating their prime and central place at the top of the foodchain.

And it all just sticks around until it goes kablooie with the asteroid impact, because there's no oil to fuel a truly industrial velociraptor society.  Their theropoda alphabet fades, unfossilized, the writings of Velocishakespeare and his violent (but hilarious!) comedies vanish.  The universe murders their society in cold blood, and you can't do anything about it unless you have a space program**.

Of course, this probably didn't happen.  We would see fossilized pipes and predator bling at least; and the oil was probably there already anyway, with 500 million years to develop.

But that just begs another question: why are we the first species on Earth to tap into all this stored energy and have a chance of spreading away from our home planet?  That's hard to say.  Maybe pure predators just have an intelligence cap, or a population cap, and intelligent species are much more likely to develop from animals with general ability (i.e. fingered omnivores).  Maybe the exact evolutionary pressures that lead to intelligence are rare, so it's a one in a billion chance.  Maybe other lingual species have existed, but didn't develop tools (or leave tools in the fossil record) and were wiped out before they spread.   Maybe intelligence is SO rare that its impossible except for uplift***.

Maybe we are inevitable.  And maybe, we are special.

Have a Merry Christmas!

"Man becomes man only by his intelligence, but he is man only by his heart."
-Henri Frederic Amiel

* not necessarily true: most of the structure for our world-changing civilization was already in place well before industrialization and the primacy of oil.  Metal-based civilizations arose with just wood for smelting, and there was plenty of wood in the Cretaceous.  But stick with me for a moment.
** Take a look at some groups that are actually working on this problem, as well as many other potentially earth-shattering or catastrophic possibilities for life as we know it, at The Lifeboat Foundation.
*** also comes in futuristic space opera flavor!

Thursday, December 22, 2011

update re: Tidal energy

Part of why physics is fun is that it lets you put numbers to off-the-wall concepts.

For instance, I mentioned a couple of posts ago that if you use the tides to make electricity, you are actually taking energy out of the Earth's rotation, making the day longer.  But by how much?

You can start by calculating the energy stored in the rotation of the Earth.  As a freshman in college (if you take physics) you learn that there's a quantity called Rotational Inertia (I) for solid bodies that behaves like normal inertia (mass).  So, where energy for linear motion is E = (1/2)*(mass)*(velocity)^2,  energy for rotational motion is E = (1/2)*(I)*(rotational speed)^2.  And you can calculate I for any geometry of solid.

For a rigid, uniform sphere, I = (2/5)*(mass)*(radius)^2.  Earth is neither rigid nor uniform, but we'll assume this is close for now.

Then with the magic of Google Calculator, you can just plug all these in for the earth and get it's rotational energy.  Seriously, copy-paste this into Google:

" (1/2)*(2/5)*mass of earth * radius of earth^2 * (2*pi / day)^2 in gigawatt*hours".

It will tell you that the Earth stores about 7*10^16 gigawatt-hours of energy.  Google calculator is so magic.

Well, the US uses 30,000 gigawatt-hours of energy a year.  So the annual energy usage of the US is about 0.4 billionths of the energy stored in the rotation of the Earth.  If you take that amount out of the Earth's rotational energy, you can use the energy formula in reverse to figure out how much the Earth slowed down.  The answer: 18 microseconds (that's 18 millionths of a second).

So there you go.  If you run the entire US on tidal energy, you slow the Earth's rotation down by 18 microseconds each year.  Amazingly, this is almost exactly the amount of slowing that is measured to occur naturally due to torque from the Moon (17 +/- 0.5 microseconds/year).

Obviously the aliens living inside the hollow sphere of the Earth are powering their invasion bases with tidal power.  It's the only explanation.  Don your tinfoil hats!

"Someday, after mastering the winds, the waves, the tides and gravity, we shall harness for God the energies of love, and then, for a second time in the history of the world, man will have discovered fire."
- Pierre Teilhard de Chardin

Bearded dwarves

Needless to say I, like most of the rest of the Tolkien fandom, cultivated a healthy skepticism about "The Hobbit" movie part 1, which I then heretofore and summarily ejected in its totality upon my first glimpse of the trailer for The Hobbit: an Unexpected Journey.

Sure, we might claim the movie's being made in two parts on account of 'teh dollarz,' but Look! it's Gandalf! Tales and adventure spouted up all over the place wherever he went*!  And hobbits, and Rivendell, and... is that Galadriel? Huh.  Also, there's Sting; dwarves sing, and a shiny ring.  Jubilate, ye neurons!

Anyone who's read both the Hobbit and The Lord of the Rings knows that where LotR is an epic war history of myth, heroism and linguistics, the Hobbit is a jaunty adventure story with close calls, jokes and little poems.  And where for Tolkien, the Hobbit formed a seed for the gestation of his most famous (and much longer) work, for Peter Jackson and Guillermo del Toro** they're doing it in reverse, having already created huge parts of Middle Earth (and very thoroughly) for the previous films.

I wonder how this will work out.  The trailer is already hitting us over the head with 'it's a LOTR prequel'.  From the beginning, we get: Old Bilbo talking to Young Frodo, the Bag End set, camera angles of Gandalf talking and smoking that are taken directly from Fellowship, the Map; then there's the Rivendell set, Galadriel (not in the book!  Maybe Elrond's on vacation so she's watching the place while he's away), the Shards of Narsil, Sting,... and the closer, Gollum and the Ring.  All of this makes good sense.  We're being told, 'we're taking you back to Middle Earth, but you're going to see a part we didn't show you before'.  I assume that with Jackson and del Toro at the helm, they'll use these features to add additional emotional valence to what is otherwise a stand-alone story.

Of course, we've also been told that Tolkien's canon-but-less-well-read writings regarding Gandalf and the White Council's parallel encounter with the Necromancer in Mirkwood are also being mined for these movies, presumably so the audience doesn't have to wonder why the Grey Pilgrim keeps leaving the party whenever it's dramatically convenient to raise the stakes.  I suspect that means the tone of this movie will lie somewhere in-between the bedtime-story quality of parts of the Hobbit and the serious-business feel of much of LotR.

Well, I'm not complaining.  What I really came here to talk about is beards.

Remember Gimli in LotR?  Well, he's the son of Gloin, one of Thorin's 13 companions.  He looks like this:

You may notice something about him:  he is prodigiously hairy.

Indeed, in the entirety of  LotR we only saw about four dwarves (at the council of Elrond), of which Gimli is one.  Here they are:
The one to the left of Gimli is probably Gloin.  You will notice they are all sporting Extreme Beards.  In fact, beards are generally pointed to as being the primary dwarf characteristic, after their height. (Dwarf women have beards too!)

Take another look at the dwarves in the trailer.  They have facial hair, yes.  But for the most part they're pretty well groomed, comparatively: not these giant waterfalls of red locks obscuring most of their faces.  Thorin in particular has a very visible mouth and cheeks (shown here looking wicked with his elf-sword Orcrist):

Why?  two reasons.  The audience suddenly has thirteen of these guys thrown at them in virtually the opening scene.  We have to be able to distinguish these guys pretty quickly, or we'll just be confused.  Thus we get Fili and Kili's light-and-dark stubble, Oin and Gloin's more classic dwarf look,  Bombur's trucker beard, and Bifur's goth stylings***.  Second: they're the main characters, and we have to see Thorin's longing and resolve when he sings of The Lonely Mountain, etc.  You can't see that stuff through all that beard.

You may remember that Gimli - the short, bearded redhead - ended up as the comic relief in LotR.  You can do that with crazy hair.  You can't do dramatic lead.

So well-groomed dwarves make a better Hobbit movie.  Awright, let's do this!  When's it come out?


*he was, you see, a Wizard.
** If you haven't seen Pan's Labyrinth, do: it's an ambiguous and uneasily beautiful child's view fairy-story set in the Spanish civil war.  Apart from the thematic elements, his fantasy realism aesthetic should work well with the Jackson vision of Middle Earth.  Also, see Hellboy: its a story about a demon who fights Nazis!
*** I think that's an axe in his head...

Monday, December 19, 2011

Tangent: all energy is fusion energy

...at some point in its life-cycle.  Check it out:
  • Solar:  Deep in the sun's core, all that gravitational pressure compresses hydrogen until it's just so energetic and dense that the protons fuse together to make a deuteron (a nucleus with proton + neutron).  Then the deuterons fuse with each other to make tritons (1 proton, 2 neutrons) or Helium-3 (2 protons, 1 neutron) and so on up the long ladder.  As it turns out, the particles like company: so at each step, as you're building bigger and bigger nuclei, you get a little bit of free energy out.  It's like the protons are getting all excited at coming together with their friends so they start throwing a hell of a party.  All those little parties heat up the sun yellow-hot and it radiates light to space - to us.  That's sunlight.  This has been going on for four and a half billion years.  
  • Wood, tomatoes, hamburger buns:  Plants are nature's solar cells: they eat light.  Unlike our solar cells that make conducting electrons, plants turn it into sugars and starches, and use it to build vitamins and proteins and cellulose.  (If plants were crystalline or metallic, they might use electricity directly: anyone good at genetic engineering?)  Eating plants, you get to metabolize all that energy; burning them, you get beautiful toasty fire.  And fire and sugar are stored sunlight - and sunlight is fusion power.  QED.
  • Coal, oil, natural gas: biomass, concentrated, heated and pressurized until made delicious to jet planes and locomotives.  Nothing new here.
  • Meat: just processed plants, buddy.  Super delicious, super inefficient.  next:
  • Wind: That's right: wind is solar power, and therefore fusion.  Weather systems are generated by temperature differentials on the globe north-south and across the terminator (excuse me, the terminator).  And what causes temperature differentials?  You guessed it!  (in the background, there).
So that's all pretty straightforward and obvious.  Here comes the tricky part.  Lets do this.
  • Nuclear Fission: Fission power is fusion power.  
Wait (says you), that's oxymoronic, you... oxymoron.  Fission is the exact OPPOSITE of fusion.  Instead of getting energy out by building up heavier atoms from light ones, you get power by breaking down super-heavy atoms, like Uranium.  

(aside: why do these both work?  Well, protons & neutrons have a limit to the size of party that they enjoy.  When the crowd in a nucleus gets too big, they don't like going into it anymore; and you have to give them energy to make them go in.  That limit is actually at Iron, element no. 26.  I guess nuclei in heavier elements are increasingly awkward.)  

But where do those super-heavy atoms come from?  They can't be made by fusion in stars, the stars fizzle when they get to iron.  No:  they're made in supernova.  When a large star runs out of fusion fuel and its core collapses, the resulting burst of energy tears apart some of those nuclei it spent so much time building and bombards the rest with their fragments.  There's so much energy that the protons and neutrons are crammed into these huge atoms like uranium, where they all stare at each other and have long pauses in the conversation.  

So it's fusion that puts all the energy in these radioactive heavy atoms, and that you release in a fission reactor.  Bam.

I think there's a few more:
  • Geothermal: The earth is heated by radioactive decay of heavy atoms.  See above.
  • Monkeys on bicycles: powered by bananas, powered by sunlight, powered by fusion.
  • Magic (literature): powered by the minds of authors, powered by food, etc.
  • Magic (real-world): powered by cold fusion. 

  • Tidal:  ...
Okay, you got me.  The tides aren't fusion-powered.  Tidal energy is powered by the rotation of the Earth, and the orbit of the moon, and those come from the interstellar dust spinning more in one direction than the other when the solar system was formed, which is pretty much just random chance.  Fun fact, though: if you use tidal energy to generate electricity, you are slowly making the day longer.

So what lesson can we take from all this?  Just one: nucleons are hipsters.

They want to maximize Irony.

And I'm done.

Sunday, December 18, 2011

Solar is fusion power too!

In my day job I research fusion energy, so I'll probably say a lot about the energy we use and where it comes from.  And I believe energy is probably the most important issue facing our world this century, because every societal problem reduces to an energy problem*.  Well, a lot of them do, anyway, the ones that wars get fought over.  I'll talk more about that later.

For now I just want to point out a really fascinating bit of work coming from the University of Texas at Austin.  A researcher named Xiaoyang Zhu has discovered a way to double the efficiency of solar cells made of a plastic semiconductor called pentacene.  Their test batch has an efficiency of 40% in normal sunlight.

(If you head over to that link, you can read a bunch of mumbo jumbo quantum jargon about how they did it which will leave you pleasantly confused, if you're into that sort of thing.  Science reporters:  please don't tell people about dark quantum "shadow states" and leave it at that.  You are just confusing people.)

Basically: when an electron absorbs a particle of light, it is too energetic to be captured.  It's a 90 MPH fastball coming at you; and you're not a major-league catcher, you're just you.  So they found a way to take all that energy and split it into two, slower electrons that can be captured more easily, kind of like if the baseball hit another baseball in midair so they both came at you with a more reasonable speed - and if you look closely, you can see just where the metaphor breaks down.

So goody! yay solar cells.  Why's it important?

Well, the discovery is exciting in its own right because of two things.  Firstly, 2x improvement is a lot in a field that used to fight for percentage points.  Secondly, the fact that these cells are plastic instead of typical crystal semiconductors like Silicon (or more expensive stuff like Gallium Arsenide) means they should be much easier and cheaper to manufacture.  I.e. this could be that greatest of things, the heart's desire of any creative person: A Breakthrough.

But this is just the latest in an ongoing trend of breakthroughs where solar cells get cheaper and cheaper in terms of energy/dollar.  And we (as usual) have the benefit of living in interesting times: a recent study has showed that solar photovoltaics are now at grid parity with conventional electricity sources in some sunny places.

This is kind of a surprise: most sources prior to this study were telling us solar was years away from grid parity**.  But the field's been growing exponentially, and exponentials are powerful stuff - very confusing to analysts (I guess Excel only does polynomial fits***).

I could (and probably will) write a whole nother bit on the numbers and problems of solar electricity, but for now just keep the following numbers in mind:  To power the entire US with solar continuously, you would need ~ 27000 square kilometers of solar panels operating at 30% efficiency.  (By the way, that's ALL US power use, not just electricity: that includes natural gas, oil, bio-fuels, wood, peat, horsepower, candlepower, and candypower.)  That's about the area of Massachusetts.  That's the area of one half of the Mojave desert in southern California.

A sense of scale is probably the biggest gift that a physicist can give you.  Happy Chanukah!

All the forces in the world are not so powerful as an idea whose time has come.
-Victor Hugo

*level up +1 Hyperbole!
** "grid parity" just means that the average cost of electricity from solar is equal to the cost from other sources (coal/nuclear/hydro/...) when you include the full lifetime cost (installation, maintenance, legal fees for relocating the protected bird species that decides to nest there, ...)
*** This line is really funny, by the way, in case you didn't notice.

We are the music makers, and we are the dreamers of dreams

So:  The future is weird.  Think about it.  We live in the future of the year 1995, and you had no conception in 1995 that AIM would evolve into Twitter, that the space shuttle would die out, that the American military would routinely use robot aircraft for military strikes.  That all those housing developments would trigger a global financial meltdown.  That so much of our lives would be lived on the internet.  That Tunisia would spark revolutions across the Arab world.  That we would have an African-American president.  That macs would become cool.

But the origins of all those events (and more!) must have been there already in the world of 1995.  Although some of them were unthinkable at the time, simple evolution of that world brought us to now.  Some steps were drastic; some chaotic; some even random; but on the whole all the ideas and all the actions that bridge the years of human history are encoded in the lives and worlds of we who live it.

History is based on inferences upon an incomplete knowledge.  So is future-history.  Our conception of the next five or five-hundred years is a story we tell ourselves, extrapolating from what we know about the past and what is happening now.  And, given the level of complexity in the world at large, that story is always wrong.

Of course, it's still fun to think about it.  At some level, every surprising event will make some sense when you dig into it: and all the keys to the mystery of the future are around us already.

That's why, no matter how weird the future is, the present is even weirder.

I'll use this space to talk about curious and interesting events in technology, science, society, ethics, and the arts.  I hope you'll all enjoy my musings, and join in a conversation about where our world is going and what we think about that.

thanks for reading!

"It is by no means an irrational fancy that, in a future existence, we shall look upon what we think our present existence, as a dream." Edgar Allan Poe

(disclaimer:  I will be using the word 'physics' occasionally in this blog.  My legal team* has informed me that I need to tell you this to prevent myself from liability in the case of nausea, heart attacks, or mild brainwork among my readership.  Don't worry about the p-word.  Even if you, like, hated it in high school and the teacher was such a dweeb: physics is an attempt to robustly predict the future, which is cool.)

*Law firm of Juniper Steele & associates