## Tuesday, January 14, 2014

### Sailing Away to Narnia

I stumbled upon an article a few months ago that I've been meaning to blog for a while and never got around to.

The original article is by Chris van den Broeck, and deals with the subject of warp drives.

Yes, warp drives.  The Alcubierre warp drive engine is a device that stretches the spacetime around a spaceship, forming what is known in scientific literature as the "warp bubble" (really, that's what we call it).  Within the warp bubble, the ship is moving at "normal speeds", but outside of the bubble, the ship is moving faster than the speed of light.  The geometry for this is known and well understood, and the means of producing it are also fully understood.

You're probably wondering, if we know how to make a warp drive, why we haven't actually... you know... made a warp drive.  And that's a wonderful question.  We haven't made a warp drive because it requires a lot of stuff that probably doesn't exist, namely negative energy mass.  It requires a whole lot of it.  Like, ten times the positive mass of the entire universe in negative mass.

Van den Broeck proposed an idea to get around this, one elegant in both its simplicity and apparent absurdity.

Here's what you do: Take a bag.  Distort space, so that the inside of the bag is bigger than the outside of the bag.  The inside is big enough to hold a spaceship, and the outside if around the Planck length.  Now stick your spaceship inside of the bag, and then put a warp bubble around the bag.   It requires a lot less negative energy.  Voila!  Crisis averted.
 Schematic from original article. Region II is the bag. Region I is where the ship is. Region IV is the warp bubble
Now, warp drives are cool of themselves, but what I really want to talk about is the device that distorts space so the inside of the bag is bigger than the outside of the bag.  This is sometimes called a "van den Brocek bubble", or, somewhat more appropriately, a Bag of Holding.

We've gone from warp drives to the bag of holding, and we're not even done yet.  We're going all the way to Narnia.

## Saturday, December 28, 2013

### Please Stop Ruining the Hobbit

I just saw the second movie in the Hobbit "trilogy".

The movie itself is a series of pointless sword fighting and action scenes with a cast of a dozen or so flat characters whose stories go nowhere.  I guess if you like Michael Bay movies, go see the Hobbit; you'll love it.

There is precisely one interesting character in the movie, and that is Tauriel.  This is a Peter Jackson original character.  And I'm saying a lot here when I say that Bilbo, Gandalf, and Smaug, the three characters who near single-handedly enchanted my childhood, do not come across as as interesting as some random elf lady practically from legolas by laura, thrown in to appease focus groups.

I've determined that the only way to make sense of the movies is to perceive them as fan fiction.  Extremely expensive, high budget fan fiction.  Peter Jackson is telling his own made-up story using the characters and elements of Middle Earth, and it just happens to vaguely correspond somewhat to the series of events in the Hobbit.  And it's great if Peter Jackson wants to write fan fiction and spend billions turning it in to a movie, but I'm sorry to say that Peter Jackson isn't as good of an author or story teller as J.R.R. Tolkien.

So why is the cinema making the movie about Peter Jackson's fan fiction, and not about Tolkien's story, the one that sold all the millions of copies and inspired all the millions of authors?

## Saturday, December 21, 2013

### The Cross-Section of Angels

Solidity is an illusion.

You may or may not already know this.  Matter is mostly empty space: when you smack your hand against a table, what prohibits the further movement of your hand is the interaction of electrons, protons, and neutrons.  At base, everything is likely a point particle, and all appearance of volume is caused by energetic excitations.

When you fire one point particle at another point particle, from a strictly geometric standpoint, the probability of collision is 0%.  Nothing should ever hit anything else.  And yet, two electrons launched at one another will "bounce"; the reason there being the electromagnetic repulsion.  To account for this discrepancy between the expected geometric probability of scattering and the empirical measured scattering caused by the interaction, physicists who study such collisions use a quantity called a scattering cross-section.  A scattering cross section is, more formally, a fictitious area describing the strength of interaction between two particles.  This is given as a ratio: number of scattered particles divided by total incoming particles.

This ratio can be measured empirically in the lab by mere bean counting, but it can also be derived theoretically from considerations of the interaction potential.  This is how we know the majority of what we know about anything on scales smaller than molecular.  The existence of the nucleus within the atom, for instance (as opposed to Thompson' plum-pudding model) was discovered through a scattering experiment.  We only know about quarks and the strong interaction through scattering.  The recently discovered Higgs particle is also a result of scattering experiments.  In all of these cases, just bouncing particles off of something and measuring the exact way that the particles bounce is enough to tell us what a thing is made of, how it is shaped, and -- more importantly -- the kinds of interactions that it undergoes.

Visible light is not normally useful to this purpose at subatomic lengths, but actually normal vision is an example of a kind of scattering experiment.  Light from a bulb bounces off of an object and to your eye: you in a sense "measure" the angular deflection and intensity of this incoming light, and can thus determine the size, shape, and color of the object in question.

All of the things that you can see scatter light because all of the things that you can see are made of charged particles.  Charged particles participate in the electromagnetic interaction, as does light, which means that normal matter is able to scatter light (as opposed to, say, dark matter).  Were it not for the interaction (or coupling) between light and matter, then the electromagnetic cross-section of matter would be zero; light would see every surface as having zero area and therefore not bounce off of it.

To make this point more clearly, consider the neutrino.  Neutrinos are not known to participate in any interaction besides the weak interaction.  Therefore, neutrinos can fly right through the planet without slowing down.  They're not flying through it like bullets, boring tiny holes; they're just flying through it.  The solid matter of the earth is, to them, intangible and ethereal.  They don not undergo the electromagnetic interaction, and so do not "see" the earth there.

I say all of this as introduction.  What I really want to discuss are angels.  In particular, how do we see them?

## Friday, December 13, 2013

### Christmas: the Meta-Holiday

I would like to introduce a word to the language: meta-holiday.  A meta-holiday is a holiday that celebrates the fact of its celebration.

Initially, holidays are celebrated because of actual reasons.  Purim celebrates the deliverance of the Jews from the plotted genocide of Haman.  Passover celebrates the deliverance of the Jews from slavery in Egypt.  Yom Kippur celebrates redemption and atonement.  To stop picking on the Jews, Easter celebrates the Resurrection of Jesus.  The Feast of the Immaculate Conception celebrates the Catholic belief in beginning of the life of Mary without Original Sin.

Actual things.

But after a while, people stop caring about the reasons for the celebration.  But not only do they keep celebrating, but the particulars of the celebration become the reasons for the celebration.  Thanksgiving is celebrated because turkey and pie.  Halloween is celebrated because candy and costumes.  St. Patricks Day is celebrated because green beer and clovers.  Talk Like a Pirate Day is celebrated because talk like a pirate.

The worst of these is Christmas.

Christmas is the celebration of the celebration of Christmas.

## Sunday, November 24, 2013

### Please, Ask Me How the Football Team is Doing

My Alma Mater didn't have a football team, and I love this fact intensely.  While I was there, the most important sport was intramural Ultimate Frisbee.  It was serious business.  I don't really like Ultimate Frisbee, but I was okay with this.  It's a quirky kind of thing, and a fact that I'm proud of repeating.

Sadly, my Alma Mater doesn't give out PhDs, especially not in physics, and so I had to go elsewhere to finish my education.  Specifically, I had to go to a Research I university, because those are the sorts of schools that give out physics PhDs.

What is a Research I university, you might ask?  Well, in the simplest possible terms, it is a school that receives and spends more money on college athletic programs than it does on academics.  Or at least that's the definition I've arrived at from observation.

 Let's not forget that fresh scent of Porta-Jons
The school I attend now has a proud tradition of inviting alumni back every Saturday in the Fall to get drunk on the school lawn and listen to terrible music at obnoxious volume levels while throwing hackey sacks in to holes cut out of plywood boards while some young adults in college at a 5th-grade reading level throw a ball around and concuss each other in a nearby stadium.  They then leave their mountains of ill-smelling trash behind to soak in the streets until a garbage crew comes by to pick it up.  My university endures this because those same people are so attached to this tradition that they are willing to pay large amounts of money for the privilege of doing it, and really, it's money.

The physics building is right next to the stadium at my school.  This means that once a week I am incapable of entering my office, because it is surrounded by the hordes of barbecuing barbarians offering their drunken libations and burnt sacrifices to their pagan football deities, and if I try to go in then they will sneak in behind me and start a conga-line to the bathroom -- a situation that happened once before and resulted in me having to call campus security to get them evacuated from the building.

Maybe you can tell by my tone, but I don't really like football.  The actual game itself is kind of dumb, but you know what, whatever.  Have fun playing it, and have fun watching it.  A lot of people think fantasy novels are dumb, or math is dumb (or rather, too smart for them to be able to perform properly), or Christianity is dumb, or whatever.  People can like whatever stupid things they want to.  I certainly do.

What annoys me about football, though, is the ridiculous status granted to it by society.  If I'm at a restaurant trying to enjoy some food and conversation, woe to me if there's some game on somewhere, as now I must endure everyone in the bar feeling entirely justified in standing out of their seats and screaming at the top of their lungs every five minutes.  Normally, that's considered rude and discourteous.  But if you do it because of football?  Then it's perfectly fine, the team's doing good -- and who's that antisocial jerkwad over there in the corner scowling and not cheering them on?  (Fun fact: football players can hear the cheers of their fans all over the world when directed at their images on TV screens.  Kind of like how God hears prayer.)
 Um, excuse me?  My friend and are trying to enjoy a beer and discuss our lives.  Thanks.
Watching people feel entitled to act like overbearing jackasses because of something that is pretty boring and mediocre (He threw the ball.  He caught the ball.  He is running after having caught the ball.  His running was impeded before its completion. Yay.) is really annoying.  Having my daily routine impeded because of the moronic devotion of football fans (like when they all decide to leave the stadium at the exact same time and now I can't leave my house or go anywhere or even get something to eat for the next two hours) is too much.

So all of that ranting is sort of just background.  Point is, my school has a really big football team, and about all my school has is a big football team, and about all my school cares about is its big football team, and I hate it all with a passion.  Football itself isn't interesting or compelling enough to hate -- the extent to which people care about it, however, definitely is.

Recently, I was helping my dad with a fundraiser he was putting on, the proceeds of which go to helping endangered wildlife.  I was moving tables and selling raffle tickets.  Some people would ask me what I do.  I'd tell them, I'm working on my PhD in physics.

"Oh, that's nice," they'd say, "Where do you go?"

So I'd tell them the name of my school.

Do you know what they'd say to me next?

They'd start talking about how "my" team is getting its butt whooped by some other team.  Or did really well against some other team.  Or is going to the championships or whatever it is football has.

Which... is really depressing.

Those people are fine.  They donated a lot of money to help save endangered species and their habitats.  And they don't know any better than to ask me about football.  They were trying to be friendly and start small talk with one of the event volunteers.   What better thing to talk about than the All-American game that everyone loves all the time forever?  And I go to one of the biggest football name schools in the world, so of course I'm going to love hearing all about it.

But it's sad that that's all people know about my school.  And it's sad that for the rest of my life, this will be the flow of conversation.  I tell them where I got my PhD.  They ask if I saw the game last week.  I silently curse cruel fate under my breath, and ask what game they're talking about, because for all I care they mean the water polo tournament.

It's sad that my school is firstly a football name brand and marketing device, and secondly an academic institution.  And it's sad that I'll be reminded of this fact for as long as I live.

My question to the general, vague, swirling ether of the internet (to whomsoever might read this): is there some school I could go to instead where I won't be constantly reminded of the sophomoric displays of group-think and tribalism that prevented me from entering my office on Saturdays?

Am I just at the wrong institution, or is this going to happen no matter where I go?

Is it just a fact of life, established by the Providence of God to humble physicists at dinner parties by constantly reminding us that no one cares about our big-brain fancy learnin', it's all about how the team does?

Or is there a PhD-granting school which either does not have a football team, or has a team that no one cares about, at all (not even undergrads)?

Please say there is, or that's just too depressing to be real.

## Thursday, September 19, 2013

### Upon Discovering Alien Life Forms

Some scientists in England recently claimed to have discovered alien life.  They even published an article about it in a peer-review journal.  So this is probably pretty legit.

The article is pretty easy to read.  Except the word "diatom frustule" (whatever the heck that is) it doesn't use a lot of jargon, or have any difficult math or anything.  But let me briefly summarize, anyway.

## Friday, September 6, 2013

### Jack the Giant Slayer: Good Speculative Fiction, Terrible Movie

I recently watched the movie "Jack the Giant Slayer".  It was at Red Box, and nothing else looked good, and "Jack" at least looked terrible.  Sometimes watching corny movies is fun.  But also, I wanted to see something fantastical, something out of a fairy tale.  So I gave "Jack" a try.

My review can be summed up, Great Speculative Fiction, Terrible Movie.

Everything after the first forty minutes of the movie is pretty much terrible.  The characters are kind of bland, the dialogue is kind of stiff and is like someone's dad trying way too hard to make corny jokes, and honestly the special effects are kind of hokey.  I don't normally care about special effects, but when half of the characters are CGI giants, it seems your special effects budget should be larger.  Personally, I'd have preferred it if they used puppets rather than CGI, because puppets always look real while CGI always looks like computer generated images... but no one in Hollywood asks my opinion.  Really, the plot of the movie and the characters and all of that aren't really noteworthy.  The movie isn't even bad enough to make fun of, contrary to what I suspected.

As a movie, and as a story, the whole thing stunk so much that it isn't even worth pointing out how much it stunk.

So why am I writing this?

Because whoever wrote the first thirty minutes knew what he was doing.

The story takes place in the Kingdom of Cloister.  There, long ago, a group of monks of an ancient order sought to climb to Heaven to reach God.  After searching for a ladder, they finally turned to magic and enchanting a set of seeds to grow in to a giant plant that reaches all the way to Heaven.

However, midway between Heaven and Earth, they got stuck.  Floating there in the sky was the realm of giants, who are cruel and stupid beasts.  The giants found the monks, captured them, and ate them; and once they had the taste of human flesh, they started to crave it.  The giants climbed down the beanstalk and started attacking the countryside slaying people where they found them.  The kingdom nearly fell.  At long last, the king of the giants was slain, and his black, stone heart was melted down in magic fires, and the monks formed dark spells to forge the giant's heart in to a crown.  Whoever wore the crown could command the giants to do his will.  Soon the giants were forced to bow in allegiance to the new king of cloister, and sent back up the beanstalk.  The stalk was cut down an the beans hidden in secret.  The King of Cloister continued to hold on to the crown that rules the giants, passing it along through the generations.

Jack is a young orphan living in the country with his uncle.  Due to hard times, he is sent to the castle to sell their last horse, which hopefully will bring back enough money to buy food.  Jack is not successful.  Towards the end of the day, as he's leaving, suddenly an alarm is sounded an guards block off the exits and begin searching everyone leaving.  They are looking for a monk trying to leave the castle.  At that moment, the monk in question sees a young man with a horse, and tells him that he needs it to escape the castle.  It is urgent.  Something dangerous has been stolen from the abbey, and the monk is trying to sneak it out of the castle lest it fall in to evil hands.  But Jack refuses to let go of the horse without money.   The monk has none.  Reluctantly, seeing an opportunity, the monk turns the dangerous artifact to Jack: it is a small leather bag of beans.  He tells Jack, within the week, to bring these beans to the abbey and he will be richly rewarded.  And so saying, the monk hops on to the horse and escapes, leaving Jack with nothing more than a small bag of beans.

So that's how Jack comes to own a set of magic beans that grow in to a giant beanstalk reaching to the sky, to a land between Heaven and Earth filled with giants.

Maybe i'm weird, but I think that's a fascinating beginning.  It is mythopoeia at its finest.  It makes a world and a history, and then the characters interact with that world.  Why are there magic beans?  Because an ancient sect of monks used magic to try to reach heaven.  Why is an old man trying to get rid of the magically enchanted beans?  Because he's trying to sneak the out of the castle past guards, fearing some sort of plot to use the beans to summon the giants.  And why does Jack fall for a stupid promise of magic beans?  Because the man who offered them is a monk needing help, and promises Jack a reward if he helps brings the beans out of the castle and helps the monk escape.  It all connects, to make something as ridiculous as a giant magic bean stalk reaching a kingdom of giants in the clouds seem actually plausible, and sensible.

After that, the movie very quickly goes downhill, and almost nothing interesting happens at all for the rest of the movie.  Really, not worth watching, I don't recommend it to anyone, but dang, whoever wrote the backstory should start doing novels.  That's my take on things, anyway.