Sunday, May 26, 2013

Whether Something Can Come From Nothing, and Quantum Mechanics

It is very popular  in certain circles that place a high value on the classical scholastic arguments for the existence of God to ask "why is there something rather than nothing?"  Ex nihil, nihil fit, is the Latin phrase, that from nothing, nothing comes.  If there is something, then why?  How did it get here?

It is then popular in certain circles that place a high value on scientific understanding --- people who perhaps don't understand math well enough to study it for real, but who nonetheless appreciate human efforts to understand the natural world in terms of rational processes and read as much of it as they can understand --- to make the rebuttal claim that, according to the physical understanding of quantum mechanics, something can come from nothing.


You can see an example of this conversation in the below video:


The idea is that in quantum field theory, study has shown that even in the state representing a vacuum, i.e. a system with zero particles, there is still the constant process of random particle-antiparticle pair creation and annihilation going on all the time.  You start with zero particles, and for brief instances you have two particles.  Or, in higher order interactions, four, or one hundred and twenty four.  Therefore, something -- particle-antiparticle pairs -- can come from nothing -- the quantum vacuum.

This idea is right, and it's wrong.  I think both people are talking past each other, and in this post, I would like to try to clarify.

I'm not a field theorist.  I've had some grad classes in it, but it's not anything in which I'm an expert (in fact, there probably isn't anything in which I'm an expert, but it's a helpful caveat).  Still, what I'm about to say is very basic to field theory (if anything in field theory can be called "basic"), and I'm more or less directly citing the text Field Quantization by Greiner and Reinhardt (available on Amazon for only $\$20$!).  What follows is a very, very brief outline of how quantum field theory leads to the understanding of the quantum vacuum, but also how the results therein do not mean what many people think it means.  I have some wikipedia links throughout, so that hopefully people who do not understand math can at least follow along with what I'm trying to say -- the math isn't important, but the physics is.

The Uncertainty Principle and Energy Non-Conservation, part 2

Quantum mechanics is typically interpreted to mean that the conservation of energy can be violated as long as the time scales involved are short.  An old professor of mine used to summarize it as "there is such a thing as a free lunch, if you can eat it fast enough."

Here's how the argument goes.  From quantum mechanics, we get the uncertainty relation
$$\Delta E \Delta t \geq \hbar,$$
where $\Delta E$ is the uncertainty -- or statistical spread -- of the energy, and $\Delta t$ is the uncertainty of the time.

Following this, physicists reinterpret the uncertainty $\Delta E$.  Rather than representing a quantification of our lack of knowledge about the energy of a system, this is interpreted as being, somehow, the amount of "free" energy that a system can borrow in violation of the First Law of Thermodynamics.  So if we have mean energy $E$ and uncertainty $\Delta E$, it means we "actually have" energy $E$, and then Nature gracefully lends us $\Delta E$ to overcome some energy barrier, which we quickly repay in time $\Delta t$.

However, that puts us at 
$$\Delta E \geq \hbar/\Delta t$$
which puts no limitation how much energy we can borrow.  Or, rather, it puts a lower bound; we must borrow at least $\hbar/\Delta t$ worth of energy.  Or, we could borrow even more!   If this is true, then we have infinite energy forever!

The oil companies will go bankrupt!

Saturday, May 25, 2013

Late Night Musings


The other night I was up late, working on a draft for a paper I hope to have submitted before the end of the summer.  I think it was around 4 or so.  After a while, I decided to take a break, and normally I suppose that a break at 4 AM would mean something like sleeping.  For some reason, I was so excited by the research paper that I just didn't want to sleep, and had been just gunning through it pretty much for the past three days straight.  So I didn't sleep, and started updating my paper journal.

I made a poor stroke with the pen, and wanted to amend it.  Reaching in to my desk drawer, I took out the bottle of whiteout that I only now realize I have owned since I was in 3rd grade.  I have only ever in my entire life owned one bottle of whiteout, and it is this one.  I think that's weird.  Anyway, I took out the bottle of whiteout and was shocked to find that all the correction paste had dried up sometime in the past twenty years and would no longer come out of the bottle.

My apartment is a simple affair, single bedroom, bathroom, a kitchen.  The building is also pretty simple; it's a single property with a single building on a pretty quiet street.  The building is brick, two stories, and has a total of eight apartments.  I live on the top floor, and a (married?) couple live below me.  Unfortunately, pretty much every time I put a foot down on my floor, they know about it, so sometimes they've had to come up at, say, four in the morning, and ask me to please stop moving all of my furniture around, because they're trying to sleep like normal people.

Anyway, as I was saying, the whiteout wouldn't come up, and I needed to fix the pen stroke I'd made, and I don't have any other whiteout because I've only ever owned one bottle in my entire life, so I decide, based on my practically non-existent knowledge of chemistry, that I'll just mix hot water in with the dried-up correction fluid and thereby get liquid correction fluid.

So I'm at my sink, and I have the tap water running.  Just a trickle, because I don't want to waste water.  It's running, and heating up, and I put some in... and the whiteout doesn't mix with it.  So I start shaking the bottle, and I just know that with each down-shake I'm reverberating the entire celing of my downstairs neighbors.  But I keep doing this, water's running, I put water in, shake it up some, pour the water out, put more in, shake it up.  Some little flakes are starting to come, and I think, this is good, soon the flakes will be smaller, and then the small flakes will mix with the water like a colloidal dispersion, and then I can use it to correct my mistake.  So I put some water in, shake it up, pour it out, put some more in, shale it up, pour it out.

I don't even know how long I was doing this.  Seriously, maybe like thirty minutes.  I may seriously have spent thirty minutes at 4 in the morning on a weekday trying to revitalize my 3rd grade bottle of correction fluid.

At some point, I hear movement downstairs, and I hear a door open.  The outside door.  Crap, I thought, I woke them up again.  I hate waking them up.  It's rude, really, and I don't like being rude.  So I tried to quiet it down and I got ready for when he'd knock and I'd go to the door to find him standing outside looking like a zombie raised from death not moments before asking me to please, please stop moving around, it's so early and people are trying to sleep, and it's pretty reasonable to ask you to keep it down, so please stop scurrying around doing whatever it is, and what are you even doing anyway?

And it was then that I realized, if they were to ask me what the heck I was doing up at 4 in the morning making all this noise, it would probably be impossible to convince them that I wasn't on drugs.

Wednesday, May 15, 2013

What is Spin? A More Simpler Explanation

The Copenhagen interpretation of quantum mechanics wasn't supposed to be mystical.  In fact, it was made precisely to avoid mysticism: "Shut up and calculate!" is probably the best summary of it possible.  Who cares what wavefunctions are or how they collapse, gimme the expectation value.  It's supposed to be practical, simple.  It's logical positivism at it's more rarified.

courtesy SMBC
Somehow, the refusal to address the complications of quantum and to just skate on by, has led to all sorts of weird mysticism stuff like quantum healing.  Today most non-physicists have misunderstandings of entanglement and many-worlds and why Schrodinger hated cats so much.  And very sadly, most physicists have no ability to correct them, as all they can do is draw squiggly tridents and funny S's and say "here is the answer".  That's all we're taught!  "It's a mystery, no one knows so shut up and calculate!"

The result is that no one really knows anything.  Physicists have a blackbox of expectation values and non-physicists have neat anecdotes for cocktail parties.

Sunday, May 12, 2013

English Place Pronouns Retain Case

There's often confusion about what "Old English" is.

When people talk about Old English, they typically mean Shakespeare or the King James Bible or any flowery language with "thee"s and "thou"s.  Which isn't Old English at all.  Elizabethan and Jacobean English are both just older forms of Modern English.  The fact that modern speakers of English can read these writings without advanced degrees pretty much says it all.  Sure, the older dialects had more grammatical complexity than we are familiar with (separate personal and familiar second persons, distinct conjugations for first, second, and third person singular, etc.), but overall, Modern English is a pretty simple language, grammatically.

Thursday, May 9, 2013

"Just Replace 'Baby' With 'Jesus'"

South Park is normally pretty vulgar and obscene, so I don't normally watch it.  Yet, for all that, they are really quite clever and can make some pretty good points.  And while they can be pretty nasty, they are generally pretty even-handed in offending as many people as possible.  If they cut out all the sex and poop jokes, I just might watch it more.

One of their points, from the 2003 episode "Christian Rock Hard" is that Christian music is basically just a bunch of love songs, but replacing "Baby" with "Jesus".

On a level, there is some validity to it.  Like it's really comical when Christian songs that don't explicitly say "Jesus" get played on the secular radio as love songs.  Songs such as "All Around Me" by Flyleaf, or "I Can't Deny You" by POD, or "Everything" by Lifehouse.

Heck, this problem is Biblical; even today, there is debate about whether the Song of Solomon, ostensibly an erotic love poem, is merely a love poem or if it represents the relationship between Christ and his Church.

Which is probably why the difference between love song and Christian song is blurry at times; even Jesus often says "I love you baby" sorts of things, such as promising his second coming in the words of an engagement speech.

But while South Park makes a good point, it isn't literally true.  Christian songs definitely have an element of "divine romance" to them (literally the name of a song by Phll Wickham), but they aren't just love songs with "baby" replaced by "Jesus".

To prove this point, I decided to take the top 5 Christian songs from 2003, the year the episode was aired, and actually go through and replace various words with "baby".  There was some fudging in which words to replace, but overall the effect is clear: If you sang a song about Jesus to your girlfriend and replaced his name with "baby", you would come off as incredibly clingy and creepy.

Sunday, May 5, 2013

Computer Simulation of a Rift in the Space-Time Continuum Devouring the Universe

Part of my research involves computer simulation of bizarre materials with exotic optical properties; materials that can bend light in almost any manner desired.

I work on the theoretical side of things; I can say that I have in fact touched a beaker and used a pipet to move water from said beaker to another nearly identical beaker (I did this just to feel science-y and say I've done it) but I have no lab experience and would probably destroy everything in your lab if you let me use it.  All this to say, though I can sort of describe these materials (whilst gesticulating with a pipe, and with a dreamy glaze over my eyes and lulling drawl to my voice) I -- me -- am incapable of producing them.  So if I want to convince someone with a lab and knowledge (and a budget) to actually make them, I have to give more than my impressive pipe-gesticulations.

Hence, I use computer algorithms to make simulational models of the bizarre materials, send some simulated light in to them, and can thus prove to these experimental people with labs that the totally awesome sailing ship I just blew through a smoke ring can in fact be built and sailed through physical rings.