cargo cult quantum physics

From time to time I encounter people online who are enamoured of quantum physics in a dilettante sense, obsessed with the implications upon macroscopic reality, and the broader philosophical questions about what is real anyway. I’ve come to think of their arguments as “cargo cult physics” because in a way, they simply snowball the debate with terminology, quote papers, etc and basically obfuscate beyond the capability of anyone to really follow what they are saying.

Here’s an example from a particularly painful (for this, and other reasons) thread at Talk Islam.

aziz 3:03 pm on January 26, 2011 Permalink | Edit
Keid, you take the extremist position that there is no reality – and then you insist that reality is only empirical. There’s a fundamental tension that not even Godel can save you from here.

I welcome your intellectual pity, and i reciprocate.

THE 6:56 pm on January 26, 2011 Permalink | Edit
OK deconstruct. I am not saying there is no reality. (How could I possibly know that?). I am saying reality is for us a theory.

Now it’s very possible that it is a true theory. It certainly agrees with all the empirical evidence, in the information flows we have access to, that there is an external causal reality. That external stuff also seems to form our physical substrate.

But we try to make theories now about the nature of that external & substrate-level reality. We start to understand that although it obeys rules that seemed to be mechanical when we first started to study it, the deeper we go into the structure, the more it becomes abstract and information-like.

Particles become quanta become qubit states in a information-bearing field?

Also very important this: The whole notion of a continuous space with continuous fields, breaks down as you get to the Planckian level, 10^-35 meters. So we need a new paradigm.

So now we postulate: Is there a supportive subPlanckian substrate to the entire world? Presumably it could be even more information-like, more abstract. Could it be pure information?

How could this work?

Well there are clues. Number one IMHO is the holographic conjecture. We can reinterpret the quantum fields that make up the universe as a isomorphic to fields in an outgoing 2 dimensional surface at the edge of the universe. The area of that surface has to be quantized into planck-sized areas. Could it be a cellular lattice of some kind? In some, as yet unknown, geometry?

Then the information could be qubits being exchanged between cells in that geometry.

Understand that lattices can arise naturally, e.g Crystals. Geometry just has to have the right symmetry, thats all, to form repeating cells capable of computation.

I know this is vague and impressionistic, but I’m not a real physicist and I’m out of my depth here.

As you can imagine, I’m paying a lot of attention to current attempts to confirm Hogan’s noise.

THE 8:12 pm on January 26, 2011 Permalink | Edit
I found Paola Zizzi’s paper thought provoking.

How to respond to this? Well of course, reality is a theory. But it’s a damn good one. The entire point of theory is to approximate reality in a useful way. Invoking crystals and quantum cubits and whatnot is just adding noise. Unlike Hogan’s noise, this noise is well confirmed.

Anyway I am not trying to pick on my interlocutor here, just frustrated with the way these sorts of debates turn out. Basically it’s all a condescending attempt to wave big words around at me to intimidate me because I have spiritual faith. Pointing out I have a PhD in physics is kind of pointless here. I believe in God, so I must be an idiot on some fundamental way, and here’s the proof: [insert gibberish].

You see the same sort of thing with people who believe in Singularity – but I’m a Singularity skeptic.

quantitative analysis of gold farming

This is a fascinating academic study of gold farming networks in EverQuest2. I am sure someone is doing something similar for WoW. I love this kind of stuff. These virtual worlds are not just fantasy worlds, the fact that humans are the primary characters makes them into fascinating real-world models for various behaviors.

Recall that MMORPGs have also been used to model disease epidemiology – for example, the “Corrupted Blood” in World of Warcraft which got published in Lancet!

“ancient” is a human concept, not a universal one

I was totally mesmerized by the APOD a few weeks ago:

Milky Way Over Ancient Ghost Panel
The Ghost Panel and the Milky Way

There are two kinds of antiquity here – one cosmic, the other human. Of course the age of the foreground is insignificant compared to the age of the background, but I confess to being more viscerally awed by the former.

I think it’s impossible to really relate to things beyond human timescales. The idea of something being “ancient” has no meaning if it predates our human comprehension. The Neanderthals disappeared 30,000 years ago, which is probably really the farthest back we can reflect on. When we start talking about human forebears of 100,000 years ago and more, it becomes more abstract – that’s why it’s no coincidence that the Battlestar Galactica series finale set the events 150,000 years ago, well beyond even the reach of mythological narrative.

Scotty’s send-off

The remains of James Doohan have been sent into space (briefly):

UPHAM, N.M.–The cremated remains of actor James Doohan and U.S. Mercury astronaut Gordon Cooper soared to suborbital space yesterday aboard a rocket.

It was the first successful launch from Spaceport America, a commercial spaceport being developed in the southern New Mexico desert.

The Canadian-born Doohan was most famous for portraying engineer Scotty on Star Trek. Cooper, one of the original Mercury astronauts, had been in space twice during his lifetime.

Doohan died in July 2005 at age 85. Cooper, who first went into space in 1963, died in 2004 at age 77. Doohan inspired the legendary catchphrase “Beam me up, Scotty” – even though it was never actually uttered on the popular television show.

Suzan Cooper and Wende Doohan fired the rocket carrying small amounts of their husbands’ ashes and those of about 200 others at 8:56 a.m. local time from the launching grounds near Truth or Consequences, N.M.

During the 15-minute flight, the rocket separated into two parts and returned to Earth on parachutes – coming down at the White Sands Missile Range – with the capsules holding the remains. The maximum height reached was about 116 kilometres. Capsules containing the ashes are retrieved, mounted on plaques and given to relatives.

While nicely symbolic, I think a far more powerful memorial to Doohan was his final turn as Scotty in the TNG episode Relics. In a way, that episode really closed the book on the old Star Trek for me. And whose heart didn’t leap when Scotty walked onto the holodeck and recreated the Enterprise bridge, “no bloody A, B, C, or D!” ? It’s hard not to think that Scotty’s words to Picard on that recreated bridge of legend weren’t as much coming from Doohan himself.

star-trekkin’ across the universe

Sometimes there’s a visible gulf between geekdom and academia, despite the stereotype of these two realms being congruent. I am reminded of this gulf by this odd story about a paper by William Edelstein, a senior and distinguished physicist (in my own field of MRI research), who has calculated the lethality of interstellar travel:

Interstellar space is an empty place. For every cubic centimetre, there are fewer than two hydrogen atoms, on average, compared with 30 billion billion atoms of air here on Earth. But according to William Edelstein of the Johns Hopkins University School of Medicine in Baltimore, Maryland, that sparse interstellar gas should worry the crew of a spaceship travelling close to the speed of light even more than the Borg decloaking off the starboard bow.

Special relativity describes how space and time are distorted for observers travelling at different speeds. For the crew of a spacecraft ramping up to light speed, interstellar space would appear highly compressed, thereby increasing the number of hydrogen atoms hitting the craft.

Worse is that the atoms’ kinetic energy also increases. For a crew to make the 50,000-light-year journey to the centre of the Milky Way within 10 years, they would have to travel at 99.999998 per cent the speed of light. At these speeds, hydrogen atoms would seem to reach a staggering 7 teraelectron volts – the same energy that protons will eventually reach in the Large Hadron Collider when it runs at full throttle. “For the crew, it would be like standing in front of the LHC beam,” says Edelstein.

The spacecraft’s hull would provide little protection. Edelstein calculates that a 10-centimetre-thick layer of aluminium would absorb less than 1 per cent of the energy. Because hydrogen atoms have a proton for a nucleus, this leaves the crew exposed to dangerous ionising radiation that breaks chemical bonds and damages DNA. “Hydrogen atoms are unavoidable space mines,” says Edelstein.

The fatal dose of radiation for a human is 6 sieverts. Edelstein’s calculations show that the crew would receive a radiation dose of more than 10,000 sieverts within a second. Intense radiation would also weaken the structure of the spacecraft and damage its electronic instruments.

All well and good and I have no reason to doubt Dr. Edelstein’s calculations (we medical physics types do have a professional interest in radiation dose and shielding, after all). But clearly Dr. Edelstein is not a fan of Star Trek, because even the most newbie of Trekkies knows about the Navigational Deflector Array. In addition, Starfleet vessels also have Bussard Collectors on the warp nacelles, which are the sci-fi-ified version of the Bussard ramjet.

My point is, physics geeks and sci fi geeks clearly aren’t as overlapping sets as I had assumed. But where a medical physicist might see errant hydrogen atoms as dose, a different kind of physicist might see them as fuel. In a way we scientists do bring our own biases to the table…

Take me out, to the black

This is just really, really cool – the crew of Endeavour STS-130 awoke this morning to the Ballad of Serenity.

And NASA announced it on Twitter – and is even hosting the mp3 for download. Though you can also get it from the Firefly Wiki.

funny comment from the thread at Whedon’s site: “and then the Space Shuttle program was cancelled. Coincidence?”

here’s the lyrics:

Take my love, take my land
Take me where I cannot stand
I don’t care, I’m still free
You can’t take the sky from me
Take me out to the black
Tell them I ain’t comin’ back
Burn the land and boil the sea
You can’t take the sky from me
There’s no place I can be
Since I found Serenity
But you can’t take the sky from me…

NASA Serenity

The Geminid Meteor Shower peaks tonight

The Geminids are coming tonight!

“It’s the Geminid meteor shower,” says Bill Cooke of NASA’s Meteoroid Environment Office. “and it will peak on Dec. 13th and 14th under ideal viewing conditions.”

A new Moon will keep skies dark for a display that Cooke and others say could top 140 meteors per hour. According to the International Meteor Organization, maximum activity should occur around 12:10 a.m. EST (0510 UT) on Dec. 14th. The peak is broad, however, and the night sky will be rich with Geminids for many hours and perhaps even days around the maximum.

Cooke offers this advice: “Watch the sky during the hours around local midnight. For North Americans, this means Sunday night to Monday morning.”

Geminids are pieces of debris from a strange object called 3200 Phaethon. Long thought to be an asteroid, Phaethon is now classified as an extinct comet. It is, basically, the rocky skeleton of a comet that lost its ice after too many close encounters with the sun. Earth runs into a stream of debris from 3200 Phaethon every year in mid-December, causing meteors to fly from the constellation Gemini: sky map.

As the NASA page explains, the Geminids are relatively recent in origin, first appearing in the early 19th century, and have been gradually intensifying since then, because Jupiter’s gravity has been pulling the debris stream towards Earth’s orbit.

The reason meteor showers interest me is not the light show (truthfully, I’ve seen very few, due to viewing conditions or simply missing them) but rather the cometary aspect of them. Meteors are comets’ bones. I’ve been obsessed with comets since grade school. I remember making every effort I could to see Halley’s comet when I was 12 years old, but the geometry of that sighting was suboptimal – all I remember is a light smudge. I’m hoping that when I turn 87, I’ll have a better show.

For more information on the 2009 Geminids, see the International Meteor Organization’s live tally page, which is already recording an increase in sightings.

and I thought the Shoe Event Horizon was satire

apparently, Douglas Adams was on to something:

For months now, consumers have been hunkering down in an economic storm, buying only what they need to survive, like groceries, diapers, medicine — and shoes.

Shoes?

The American public, it would seem, cannot carry on without new shoes. Boots, booties, sneakers, pumps — for the last few months they have all been selling well as the broader economy struggles toward recovery.

… Among the more curious explanations proffered for the relative strength of shoe sales is that women — who make up the lion’s share of the American shoe market — get an emotional lift from shoe shopping in a way they do not when trying on jeans and cocktail dresses.

As a reminder, I actually am enough of a H2G2-geek that i transcribed the entirety of the Shoe Event Horizon bit from the Radio Series a while back. Read it again, and note just how eerily prescient DNA was about this whole thing in light of the excerpted article above.