The particles in question are pieces of interstellar dust, a substance containing atoms formed during the birthing of the sun and our neighbouring planets. Don Brownlee, a researcher at the University of Washington, likens the dust to a “library of what was in the early solar system.”

You would assume that the first cosmic dust would be discovered in a laboratory by some crazy-haired scientist, but the distinction may go to a Canadian man named Bruce Hudson. Hudson was a participant in Stardust@home, a program that anyone with an internet connection use a virtual microscope to scour the samples for these particular particles. Scientists are currently analysing Hudson’s find and are “cautiously optimistic” that it is the first cosmic dust ever to be returned to Earth.

If Hudson’s particle is indeed interstellar dust, the discovery could give unprecedented insight into the formation of our solar system and the processes by which our universe recycles its materials. It also goes to show that armchair astronomers can really make significant scientific contributions.

So good work, Bruce Hudson. Now get busy on SETI@home. [BBC via PopSci]

Princeton engineer Emily Carter led the project, which took an equation by Llewellyn Hilleth Thomas and Enrico Fermi-Fermi that calculates how many electrons are distributed in a theoretical gas with evenly distributed electrons and figured out how to apply it to real, imperfect materials:

“The equation scientists were using before was inefficient and consumed huge amounts of computing power, so we were limited to modelling only a few hundred atoms of a perfect material,” said Emily Carter, Princeton engineer who led the project.

“Important properties are actually determined by the flaws, but to understand those you need to look at thousands or tens of thousands of atoms so the defects are included. Using this new equation, we’ve been able to model up to a million atoms, so we get closer to the real properties of a substance.”

The results of that effort mean that principles of quantum mechanics, previously limited to small bits of materials, can now be applied on a large scale. Modelling, then, for anything from fuel-efficient cars to electronic devices will happen exponentially faster than it does today. Innovation just got an upgrade. [Princeton via PopSci]

The folks at Wired think that this physics experiment is ideal for all the leftover Valentine’s Day lollies, but I think it’s great all year round.

This is what you’ll be doing:

• Make sure the candy is in a microwave-proof box. Better yet, take the chocolate out and put in a microwave safe dish.
• Remove the turntable in your oven. (You want the candy to stay still while you heat it.) Put an upside-down plate over the turning-thingy, and place your dish of candy on top.
• Heat on high about 20 seconds.
• Take the chocolate out and look for hot spots. Depending on the candy you use, you may have to feel the candy to see where it has softened. With the cherry cordials we used, we saw several shiny spots and one place where the chocolate shell melted through, releasing the sweet syrup inside.
• Measure the distance between two adjacent spots. This should be the distance between the peak and the valley (crest and trough) of the wave. Since the wavelength is the distance between two crests, multiply by 2. Finally, multiply that result by the frequency expressed in hertz or 2,450,000,000 (2.45 X 109)

Ta da. In this example, the final number was a bit lower than the actual speed of light, but it’s still pretty darn close considering the difficulty of finding the exact “hot spots” to measure from. And the difficulty of sacrificing chocolate to science. [Wired]

It’s actually Princeton physicists calibrating a nuclear fusion reactor with a TOY TRAIN

Ok, it’s not as absurd as it sounds, according to the NY Times. In order to fine tune the neutron sensors inside the reactor, scientists at the Plasma Physics Laboratory ran the train on a circular track for three days inside the reactor, carrying a chunk of californium-252 that released neutrons as it disintegrated.

Previously, neutron calibration had been carried out with a stationary chunk of the same element, but scientists at the lab discovered calibration is 10x more accurate if the element is moving around during the reactor maintenance. The reactor is part of a larger Spherical Torus experiments, which is looking at ways to fuse hydrogen atoms at high temperatures, in a similar manner as the sun.

And for all it’s troubles, the train was able to return to it’s spot around the laboratory X-mas tree afterwards. But don’t worry, californium-252 is hardly radioactive, so everyone was safe. [NY Times]

I had a discussion recently with friends about the various depictions of space combat in science fiction movies, TV shows and books. We have the fighter-plane engagements of Star Wars, the subdued, two-dimensional naval combat in Star Trek, the Newtonian planes of Battlestar Galactica, the staggeringly furious energy exchanges of the combat wasps in Peter Hamilton’s books, and the use of antimatter rocket engines themselves as weapons in other sci-fi. But suppose we get out there, go terraform Mars, and the Martian colonists actually revolt. Or suppose we encounter hostile aliens. How would space combat actually go?

First, let me point out something that Ender’s Game got right and something it got wrong. What it got right is the essentially three-dimensional nature of space combat, and how that would be fundamentally different from land, sea and air combat. In principle, yes, your enemy could come at you from any direction at all. In practice, though, the Buggers are going to do no such thing. At least, not until someone invents an FTL drive, and we can actually pop our battle fleets into existence anywhere near our enemies. The marauding space fleets are going to be governed by orbit dynamics – not just of their own ships in orbit around planets and suns, but those planets’ orbits. For the same reason that we have Space Shuttle launch delays, we’ll be able to tell exactly what trajectories our enemies could take between planets: the launch window. At any given point in time, there are only so many routes from here to Mars that will leave our imperialist forces enough fuel and energy to put down the colonists’ revolt. So, it would actually make sense to build space defence platforms in certain orbits, to point high-power radar-reflection surveillance satellites at certain empty reaches of space, or even to mine parts of the void. It also means that strategy is not as hopeless when we finally get to the Bugger homeworld: the enemy ships will be concentrated into certain orbits, leaving some avenues of attack guarded and some open. (Of course, once our ships manoeuvre towards those unguarded orbits, they will be easily observed – and potentially countered.)

Now, Let’s Talk Technology

First, pending a major development in propulsion technology, combat spacecraft would likely get around the same way the Apollo spacecraft went to the Moon and back: with orbit changes effected by discrete main-engine burns. The only other major option is a propulsion system like ion engines or solar sails, which produce a very low amount of thrust over a very long time. However, the greater speed from burning a chemical, nuclear, or antimatter rocket in a single manoeuvre is likely a better tactical option. One implication of rocket propulsion is that there will be relatively long periods during which Newtonian physics govern the motions of dogfighting spacecraft, punctuated by relatively short periods of manoeuvring. Another is that combat in orbit would be very different from combat in “deep space”, which is what you probably think of as how space combat should be – where a spacecraft thrusts one way, and then keeps going that way forever. No, around a planet, the tactical advantage in a battle would be determined by orbit dynamics: which ship is in a lower (and faster) orbit than which; who has a circular orbit and who has gone for an ellipse; relative rendezvous trajectories that look like winding spirals rather than straight lines.

Second, there are only a few ways to manoeuvre the attitude of a spacecraft around – to point it in a new direction. The fast ways to do that are to fire an off-centre thruster or to tilt a gyroscope around to generate a torque. Attitude manoeuvres would be critical to point the main engine of a space fighter to set up for a burn, or to point the weapons systems at an enemy. Either way, concealing the attitude manoeuvres of the space fighter would be important to gain a tactical advantage. So I think gyroscopes (“CMGs” in the spacecraft lingo) would be a better way to go – they could invisibly live entirely within the space fighter hull, and wouldn’t need to be mounted on any long booms (which would increase the radar, visible, and physical cross-section of the fighter) to get the most torque on the craft. With some big CMGs, a spacecraft could flip end-for-end in a matter of seconds or less. If you come upon a starfighter with some big, spherical bulbs near the midsection, they are probably whopping big CMGs and the thing will be able to point its guns at you wherever you go. To mitigate some of the directionality of things like weapons fire and thruster burns, space fighters would probably have weapons and engines mounted at various points around their hull; but a culture interested in efficiently mass-producing space warships would probably be concerned about manufacturing so many precision parts for a relatively fragile vessel, and the craft would likely only have one main engine rather than, say, four equal tetrahedral engines.

How About Weapons?

We have to consider just how you might damage a spacecraft to put it out of action.

Explosions are basically a waste of energy in space. On the ground, these are devastating because of the shock wave that goes along with them. But in the vacuum of space, an explosion just creates some tenuous, expanding gases that would be easily dissipated by a hull. No, to damage spacecraft systems, you can’t hit them with gas unless it’s really, really concentrated and energetic. So unless you want to just wait till your enemy is close enough that you can point your engines at him, the best bets for ranged weapons are kinetic impactors and radiation.

A kinetic impactor is basically just a slug that goes really fast and hits the enemy fighter, tearing through the hull, damaging delicate systems with vibrations, throwing gyroscopes out of alignment so that they spin into their enclosures and explode into shards, puncturing tanks of fuel and other consumables, or directly killing the pilot and crew. You know…bullets. But it sounds much more technical and science-fictiony to say “mass driver” or “kinetic lance” or something of the sort. Of course, the simplest way to implement this sort of weapon in space is just as some kind of machine gun or cannon. Those will work in space (ask the Soviets, they tested a cannon on their first Salyut space station), and the shells will do plenty of damage if they hit anything. However, space is filled mostly with empty space, and hitting the enemy ships might be a challenge. Furthermore, if the impactors are too large, the enemy could counter them by firing their own point-defence slugs and knocking the shells out of line. Therefore, I contend that the most effective kinetic space weapons would be either flak shells or actively thrusting, guided missiles. The flak shells would explode into a hail of fragmented shards, able to tear through un-armoured systems of many craft at once without the shell directly hitting its target, or able to strike a target even after it tries to evade with a last-minute engine burn. The missiles would be a bit different from the missiles we are used to on Earth, which must continuously thrust to sustain flight. In space, such a weapon would rapidly exhaust its fuel and simply become a dummy shell. No, a space missile would either be fired as an unguided projectile and power up its engine after drifting most of the way to its target, or it would fire its engine in sporadic, short bursts. A definite downside to kinetic weapons on a starfighter is that they would impart momentum to the fighter or change its mass properties. Very large cannons or missiles might therefore be impractical, unless the fighter can quickly compensate for what is essentially a large rocket firing. Even that compensation might give the enemy just the window he needs…

Radiation-based weapons that burn out the electronics of a spacecraft sound exotic, but are still potentially achievable. This would be the attraction of nuclear weapons in space: not the explosion, which would affect just about nothing, but the burst of energetic particles and the ensuing electromagnetic storm. Still, such a burst would have to be either pretty close to the target vessel to scramble its systems, or it would have to be made directional in some way, to focus the gamma-ray and zinging-proton blast. But while we’re talking about focused energy weapons, lets just go with a tool that we already use to cut sheet metal on Earth: lasers. In space, laser light will travel almost forever without dissipating from diffraction. Given a large enough power supply, lasers could be used at range to slice up enemy warships. The key phrase there, though, is “given a large enough power supply.” Power is hard to come by in the space business. So, expect space laser weapons to take one of three forms: small lasers designed not to destroy, but to blind and confuse enemy sensors; medium-sized lasers that would be fired infrequently and aimed to melt specific vulnerable points on enemy space fighters, like antennae, gimbals, and manoeuvring thrusters; and large lasers pumped by the discharge from a large capacitor or similar energy storage device to cut a physical slice into the enemy craft wherever they hit. Such a large weapon would likely only be fired at the very beginning of a battle, because the commander of a ship with such a weapon would not want to keep his capacitor charged when it might unexpectedly blow its energy all at once once he’s in the thick of things.

Deflector shields like those in fiction are not possible at present, but it would still make sense to armour combat spacecraft to a limited extent. The spaceframes of the fighters would likely be designed solely for the space environment; the actual ships would be launched within the payload fairings of a rocket or assembled in space. If launched from the ground, armour must be minimised to reduce the launch weight of the spacecraft. But if built and launched in space, it would make sense to plate over vital systems of the vehicle. Thick armour would prevent flak or small lasers from piercing delicate components, and might mitigate a direct strike from a kinetic impactor or heavy cutting laser. However, the more heavily armoured and massive a space fighter is, the more thrust it will take to manoeuvre in orbit and the more energy it will take to spin in place. (Here’s where computer games get space combat all wrong: the mass of a huge space cruiser would not place an upper limit on the speed of a vehicle, but it would reduce the acceleration a given engine could produce compared to the same engine on a less massive vehicle.)

I’m assuming that we’d have some intrepid members of the United Earth Space Force crewing these combat vessels. Or, at least, crewing some of them – robotic drone fighters would be a tremendous boon to space soldiers, but the communication lag between planets and vessels in orbit would make the split-second judgments of humans necessary at times. (Until we perfect AIs… but if we’re giving them the space fighters from the beginning, we deserve the robot uprising we’ll get.) The crews will hardly be sitting around nice conference-room command bridges with no seat belts; nor will they be standing upright in slate-grey console pits with glowing glass displays all over. It’s not even a good idea for them to have windows, which would be vulnerable to flak and could give the crew an intense sense of disorientation as the spacecraft manoeuvres, and could give them tremendous trouble adapting to rapid changes in light levels as the ship rotates near a planet or star. No, they should be strapped into secure couches and centrally located in the most protected part of the spacecraft. They should also be in full pressure suits, and the interior cabin of the spacecraft should already be evacuated – to prevent fires, or any secondary damage if all the atmosphere rushes out a hull breach. This also reduces the need for escape pods. Camera views from the exterior of the ship and graphical representations of the tactical situation would then be projected directly onto helmet faceplates.

Now, for the final word, let’s say the United Earth Space Force defeats the Martian rebels in orbit. What do we do to hit them on the ground? Well, strategic weapons from space are easy: kinetic impactors again. You chuck big ol’ spears, aerodynamically shaped so they stay on target and don’t burn up in the atmosphere, onto ground targets and watch gravitational potential energy turn into kinetic energy and excavate you a brand-new crater. At some point, though, the imperialist Earthlings probably want to take over the existing infrastructure on Mars. Time to get out the Space Marines!

It’s not terribly expensive or difficult, comparatively speaking, to get people from orbit down to a planet surface. You fall. This is the purpose of a space capsule. What’s really, really, prohibitively difficult is getting them back up again. So, the victorious orbital forces would have to bring in a transport ship chock full of Space Marines and drop them all at once in little capsules (little because they can only be so big for the atmosphere to effectively brake them, and because you don’t want all your Marines perishing in some unfortunate incident). Some orbital forces would remain in place to threaten the ground with bombardment and give the Marines a bit more muscle, but really, the ground-pounders are going to have to be pretty self-sufficient. If they ever want to come back up, they would have to build and/or fuel their own ascent vehicle. (This is the problem facing any NASA Mars efforts, too: getting back up through the Martian atmosphere is much harder than any of the lunar ascents were.)

What Would Combat Spacecraft End Up Looking Like?

There are good arguments to have both large and small spacecraft in the Earth forces. A big spacecraft could have a lot more armour to keep its systems and crew safe, more room for large fuel tanks and electrical power supplies, and larger mass to resist impulses from cannon recoil. However, a smaller craft would be less visible to radar, more manoeuvrable, and could achieve higher accelerations for constant engine thrust. As with just about any military force, the role of the craft would be tailored to the tactical operations required, so the Space Force would probably include several sizes of craft.

Enemies could come at your ship from any direction in space, which means that you would want to react, strike, and counterattack in any direction. So, you would either have to mount weaponry all around your starfighter, put the weapons on gimbals so that they could rapidly point in any direction, or make the fighter manoeuvrable enough that it could rapidly point in any direction. Gimbals would be a bad option, because they would introduce points of increased vulnerability, unless they could be very well-armoured. I conclude that the big ships would have many weapons, pointed in many directions; the small ships would have a few weapons, with the main weapon systems pointed in one direction.

Manoeuvrability (angular acceleration) you could achieve with gyroscopes, or by mounting engines or thrusters away from your fighter’s centre of mass. For the highest levels of manoeuvrability, the spacecraft should be close to spherical and these engines should be as off-centre as possible, which might mean putting thrusters on long booms or struts. The problem with this kind of Firefly-like engine layout is that it becomes very vulnerable. If a fighter can achieve high manoeuvrability with gyros, those are probably the best option.

So, I think the small fighter craft would be nearly spherical, with a single main engine and a few guns or missiles facing generally forward. They would have gyroscopes and fuel tanks in their shielded centres. It would make sense to build their outer hulls in a faceted manner, to reduce their radar cross-section. Basically, picture a bigger, armoured version of the lunar module. The larger warships would also probably be nearly spherical, with a small cluster of main engines facing generally backward and a few smaller engines facing forward or sideways for manoeuvring. Cannons, lasers, and missile ports would face outward in many directions. On a large enough space cruiser, it would even be a good idea to put docking ports for the small fighters, so that the fighters don’t have to carry as many consumables on board.

I think it’s time to sketch some pictures and write some stories!

Space-Wide Peace

I certainly hope we don’t get into any space wars. Human nature being what it is, though, and given how scarce a lot of resources really are on the scale of a solar system or a galaxy, I don’t think it’s out of the question. I would like to think that when we start colonising other worlds, we will be sufficiently enlightened to do so from on board the Ship of the Imagination, and not as futuristic conquistadores. Still, the part of me that loves science fiction has fun with these thought experiments.

Reprinted with permission from Joseph Shoer. Photo by TG Daily.

But what is it, you ask? Why, put simply, it’s a great representation of something we primitive humans will never be able to observe directly:

According to string theory, space-time is not four-dimensional as you might expect, but actually 10-dimensional. The extra six dimensions are believed to be compactified or rolled up into such a small space that they are unobservable at human scales of sight. Their size and six dimensions make Calabi-Yau spaces difficult to draw. But, this model shows a three-dimensional cross-section of this likely space to reveal its structure and shape. – Scientifics Online

And all that mind-bending fun is just $US90! String theory in the palm of your hand! Or, if you don’t subscribe to string theory, it’s a paperweight. [Scientifics Online via MSNBC]

Julian left his quantum physics research path, but he certainly carried knowledge and inspiration from it over into his art career. These sculptures are intended to portray some incredible quantum physics ideas for which there are “no consistent mental images.” That craziness aside, the sculptures are lovely eye-candy based on artistic merit alone. [Julian Voss-Andreae via Boing Boing]

The book’s called Voyage To The Heart Of Matter – The Atlas Experiment At CERN and it’s written by Emma Sanders and crafted by Anton Radevsky. It’ll be out at the end of November and run for about $US33. I just want one because it’ll satisfy both the physics dork and the bookworm inside me all at once. [Atlas via Shiny Shiny via OhGizmo!]

Separate from the LHC itself, CERN’s labs are sprawling and fairly old, so it’s understandable if they’re a little industrio-creepy. Which they are!

But considering the facilities are intended for similar purposes (in theory), and the CERN already employs a real-life Gordon Freeman, the likeness here is just uncanny, as if CERN ripped the models and textures from Valve’s FPS and somehow actualised them. (Or, you know, the other way around, which actually makes sense.) Check out the full gallery at: [CERNLove via Reddit]

It took them a while to get there, but once they crossed paths, Boyle and Smith quickly got to work on our beloved CCD image sensors, changing our digital photographs forever. And one day, as the rest of the world had their eyes on the moon in 1969, they finalised their device, which would let us capture images of it.

Williard Boyle had a brief teaching career after his stint in the Royal British Navy, earning his BSc, MSc and PhD from McGill University. He then moved on to join Bell Labs, working up to being director of the Space Science and Exploratory Studies department where he provided “support for the Apollo space program and help[ed] to select lunar landing sites”. After some time away from that, he “returned to Bell Labs in 1964, working on the development of integrated circuits”. All the while it was remarked that he truly was a modest and “self-effacing” man, almost a stereotype of the quiet genius.

While we don’t know whether he was cocky or modest, George E. Smith followed a vaguely similar path: he served in the US Navy, then earned a BSc from the University of Pennsylvania and a PhD from the University of Chicago, where he did in fact write a three-page-long dissertation. He also joined Bell Labs and began to research lasers and semiconductor devices.

Yes, with their beginnings in space exploration and lasers, it seems almost obvious that these two were bound to come up with something incredible, but I doubt that they even dreamed about inventing something that we would use or see results of on a daily basis.

Dearest Williard, beloved George: Today we thank you for your inventions and congratulate you on your Nobel prize. After all, without you, our porn wouldn’t be the high-quality digital video we so enjoy. [Digital Photography Review and Wikipedia and Wikipedia]