We got to talking about space warfare last night, and I realized something pretty weird: FTL drives effect massive shifts in velocity.

Almost every FTL spacecraft, in fiction, is capable of moving between planets in different star systems. The ship starts out roughly stationary relative to planet A, and winds up roughly stationary relative to planet B. How fast are A and B moving compared to one another? How fast do stars move?

Proxima Centauri has a radial velocity (relative to the solar system's center-of-mass) of -21.7 +/- 1.8 km/s. Its proper motion vector is -3.77530 arcsec/year in right ascension, and 0.76933 arcsec/year in declination. At 4.243 light-years away, its proper motion relative to sol is 23.777 km/s. Its total relative velocity to sol is somewhere around 32.19 km/s, which is just a little faster than the velocity of the earth, rotating around the sun.

Jumping from Proxima Centauri to Sol means a ship's faster-than-light drives can effect a delta-v in real space of at least 32 km/s per jump. These are tame velocities for stellar neighbors. If Earth is headed straight for Proxima Centauri at jump time, and the ship departs from a similar planet headed towards Sol, we can assume routine jumps impart up to 91 km/s velocity differentials.

If the Millennium Falcon has a mass of roughly 1.5 x 10⁶ kg, its FTL drives are capable of imparting 6.211 x 10¹⁵ J of kinetic energy to the ship per jump, which is roughly 2/3rds of the energy released in the impact forming Meteor Crater in Arizona. This means the Falcon could, with a single jump, put a hole in the earth roughly 1.2 kilometers across. We're talking about an independent freighter captain operating a device which routinely yields the destructive power of a fusion warhead.

If a Mon Calamari cruiser has a mass of 15 million metric tons, a similar jump imparts 6.2 * 10¹⁹ joules of kinetic energy to the hull, or roughly 14 gigatons of TNT. That's more than 100 times more powerful than the Tsar Bomba.

The Battlestar Galactica is roughly ~1400 x 500 x 180 meters, or roughly 10⁸ cubic meters. If we assume it's ~90% air and the remainder has the density of iron, its mass is 1.4 * 10⁸ kg air + 9.9 * 10¹⁰ kg iron, or 9.8 * 10¹⁰ kg. In the very first episode it makes 237 jumps, one every 33 minutes. If each jump can impart 32 km/s, its final velocity relative to origin could be 75,000 km/s, or 2.5% of c.

In this universe, a forty-year old spacecraft due for decommissioning is capable of acquiring 2.7 * 10²⁶ J of kinetic energy (assuming uniform Newtonian mechanics cuz I'm lazy). That's 6.5 * 10¹⁶ tons of TNT. Almost the energy output of the entire sun in one second. We're talking 3.067 * 10⁹ kilograms of mass converted to kinetic energy by e = mc² (a good chunk of the Battlestar itself, if you're wondering).

Chicxulub crater is 180 kilometers across. The impact caused a megatsunami and boiled the atmosphere. We think it caused a mass extinction event. That took 4.2 * 10²³ J.

If you rammed a planet with the Galactica, we're talking about an impact a thousand times more powerful.

Why bother with nukes? You can wipe out entire planets with a single ship apiece, without any concomitant radioactivity, and do it a billion times faster. There's no need to infiltrate computer systems or engage in elaborate orbital battles. Just jump in-system at 2.5% the speed of light. If you miss the planet, it's no big deal. Just jump back and give it a second go.

You don't even have to waste the whole ship. Just jump in-system, let go of a suitable chunk of rock or metal, and jump into open space before hitting the atmosphere. The only practical limit is the ablative shielding required to survive relativistic velocities in the interstellar medium, but… I dunno, magnetic fields or something.

Quit playing around. Sci-fi superweapons are easy.

So Technology Review published a summary of an arxiv article arguing for mass quantization in black holes. Looks like an ultraviolet catastrophe argument, which is fascinating in itself. But first, I have to address this journalistic clusterfuck:

Of course, the question of this kind of black hole production at the LHC once again raises the thorny question of whether the safety assurances we've been given about these experiments are valid.

No, it means the exact opposite. The article is prompted by the absence of black holes in experimental products. The implications of the model are that black holes are harder for the LHC to create.

We've looked at the arguments before. One important question is whether state-of-the-art theoretical physics is up to the task of making a trustworthy prediction that the LHC is safe.

Today's paper makes clear that our understanding of micro black hole physics is rapidly changing. So it would be entirely reasonable to ask on what basis physicists are able to make safety assurances.

...

This is a debate that particle physicists are strangely reluctant to engage in, having ignored most of the questions marks over safety.

Physicists are not reluctant to engage. We've given you the answer over and over again, apparently without effect. LHC collisions are 7 tera-electron volts. Cosmic rays, which hit the earth constantly, are 100 exa-electron volts. That's EIGHT ORDERS OF MAGNITUDE bigger.

To give you some scale here, if a cosmic ray hitting our atmosphere is equivalent to a Ford Excursion slamming into a solid concrete slab at 60MPH, the LHC is roughly a paperclip tossed at the wall. If car crashes like that happened every minute with no ill effects, would you really expect the paperclip to end the world? Absolutely not; to suggest otherwise is senseless fearmongering. To ignore the wealth of experimental and theoretical arguments published by CERN and independent reviewers on collider safety is just plain lazy.

And the rich frosting on this intellectual spongecake?

(Let's put aside for a moment the question of whether particle physicists are in any position to make safety assessments in the first place, given that they have the most to gain from running these experiments.)

Who else would you suggest we ask about particle safety? Would you refuse to trust a vehicle's airbag system with your life because it was evaluated by automotive engineers? Avoid bridges and buildings because they were designed by structural engineers? Shall we demand that spacecraft safety be signed off on by a panel of MBAs or English professors? In every project involving the quantitative projection of risk to human lives, we place our trust, quite sensibly, in people who dedicate themselves to understanding the matter at hand. It's great to have people double-checking, but to make a claim about a complex system without understanding how it works is, quite simply, bullshit.

Personally, I'm holding out for the day when editors fact-check the articles in MIT publications.

Killing animals and eating them may be immoral, but can we please stop claiming humans are "naturally" vegetarian? We're opportunistic omnivores, which probably has something to do with why vegans need to watch their diets carefully in order to have working blood cells.

Look at your teeth. Now back to me. NOW BACK TO YOUR TEETH. That's generalized dentition, and appears in classic omnivores. Look left. It's a chimpanzee, our nearest evolutionary relative. He's killing and eating a Colubus monkey, their most frequent prey. Look down. What's that in your gut? Oh that's right; it's a lack of a fermenting vat, efficient digestive enzymes for grasses, and inability to synthesize key vitamins and amino acids. Look again. THOSE DEFICIENCIES ARE NOW A COLONY OF SYMBIOTIC BACTERIA WHICH METABOLIZE ANIMAL TISSUES. I'm eating a horse.

I enjoy fruits and vegetables. I eat a lot of them. Probably more than most vegans. And don't get me started on how amazingly delicious (and good for you!) vegan food can be. But we really are omnivores—PETA's bad science to the contrary.

Please adapt your moral schema if necessary.

Jump to 1:50 for the fireworks.

Dear Mr. O'Reilly

I am amused that you brought up tides in an attempt to argue for the necessity of faith in explanations of the natural world. Perhaps you were unaware that the church, under the inquisition, found Galileo’s heliocentric model of the tides so threatening that it suppressed the original title of his Dialogue: “Dialogue on the Ebb and Flow of the Sea” in 1632. The uncensored version remained on the Index of Prohibited Books until 1835.

Galileo’s model was not very correct. However, a mere fifty years later Newton postulated a revolutionary model of universal gravitation, which accurately accounted for the dynamics of the ocean under an inverse square force. Luckily his Principia met with a more favorable intellectual climate, although perhaps it failed to garner controversy because few people could actually understand it.

The debate over the causes of the tides was, for all intents and purposes, resolved over three hundred years ago. The prevailing supernatural explanation has been abandoned in favor of a hugely successful model rooted in physics.

Perhaps, then, you understand how laughably anachronistic it sounds to challenge a non-supernatural interpretation of the world on the basis of tides. I urge you to consider what other explanations you may have rejected in favor of faith.

–Kyle Kingsbury

P.S. It should be noted, of course, that Newton’s model was not strictly speaking correct; it was a mathematical approximation. Since then we have refined our models of spacetime and gravity significantly, mapped much of the ocean floor, and our predictions have become much more accurate. At no time have we thrown up our hands and claimed “Ah, God did it.”

P.P.S. The supervening question of whether God is, in some sense, physics… is of course open to debate. This is why I use the words “supernatural” and “natural” quite carefully.

I think the most terrifying part of A mathematical model for the determination of total area under glucose tolerance and other metabolic curves is the abstract's implication that medical researchers were, before this groundbreaking application of Riemann sums, unable to find the area under an experimentally obtained curve.

75 citations? Really?

Some recent reports have suggested incidents of scientific misconduct in the climate science community. While that is not evidence of incorrect conclusions, it does cast some doubt on the findings of the organizations involved--and right so, I believe. The APS newsletters for December and January have been chock-full of climate discussion--arguing for the retraction of the APS's climate change statement or alteration to reflect uncertainty, counterarguments, and so forth.

My personal take on it is this: climate is really effing complicated. I know a little about the scientific method, publishing, data analysis, and review, but basically have no awareness of the intricacies of modeling the world's atmosphere and hydrology. I'm also aware that plenty of people have significant personal and economic interests in the matter, and an underabundance of understanding. The only reasonable conclusion I can come to is this: trust the people who spend their lives trying to understand climate, and maintain some awareness of their methods. It is my belief, from the limited reading I've been able to do, that the vast majority of climate researchers are doing good science, and working hard to understand and explain to others a very complex problem.

Anyway, that's why I think RealCimate's analysis of the recent challenges over the IPCC's AR4 is a good read.

These are pictures of various transverse electromagnetic modes for the laser we're working with.

Laser beams aren't constrained to being nice little smooth dots, though that's one of the possible modes (TEM₀₀). Since TEM₀₀ has the most tightly focused beam, and the fewest irregularities, it's the one many laser manufacturers force their device to operate at. There are other possible solutions, with varying patterns. The subscripts here indicate the number of divisions in the beam—I'm guessing on some of the higher ones. There's also a strange pattern which looks like it has radial, not rectilinear, divisions; I'm not sure what that is, exactly.

TEM00	TEM01	TEM02
TEM11	TEM22	TEM23
TEM33?	TEM35?	Radial mode?

These pictures are taken by projecting the beam through an enlarging lens onto a whiteboard. Kind of a hack, but it works surprisingly well. Images are enhanced to show contrast; in reality, they're just red.

You know what's going to be awesome? When I have to get a normal job.

"So, why do you think you'd be great at Jimmy John's Sub Shop?"
"Ummmm... I can compute first-order perturbations to degenerate Hamiltonians. Please hire me?"
"What else?"
"I can design your web site and ordering system..."
"Nope, already got one."
"I can be thrown around safely!"
"Next please."

I have the weirdest skill set on the planet.