Point of Contact

(A brain cell grown directly onto a microchip, the process through which all Brain-Computer Interface technology works.)

From the NY Times:

Two monkeys with tiny sensors in their brains have learned to control a mechanical arm with just their thoughts, using it to reach for and grab food and even to adjust for the size and stickiness of morsels when necessary, scientists reported on Wednesday.

The report, released online by the journal Nature, is the most striking demonstration to date of brain-machine interface technology. Scientists expect that technology will eventually allow people with spinal cord injuries and other paralyzing conditions to gain more control over their lives.

You really have to just see it:

Just beneath the monkeys’ skulls, the scientists implanted a grid about the size of a large freckle. It sat on the motor cortex, over a patch of cells known to signal arm and hand movements. The grid held 100 tiny electrodes, each connecting to a single neuron, its wires running out of the brain and to a computer. The computer was programmed to analyze the collective firing of these 100 motor neurons, translate that sum into an electronic command and send it instantaneously to the arm, which was mounted flush with the left shoulder.

Like that cell-phone implant a few months ago, this is another example of a technology that's been steadily progressing behind the scenes for years. In both cases, announcements were only made once there was something really interesting to show the press. On one hand, this is good. It keeps the hype to a minimum until there are real results (think "Segway incident"). The flipside is that it freaks people out that we can suddenly do these things.

The thought that we'll soon be able to drive cars and operate computers without touching them, through a microchip in our brain is terrifyingly revolutionary enough that we should maybe let people warm up to it a bit before showing them cyborg-monkeys.

Warren Ellis' response (unquotable in this blog) has been my favorite.

"How Stuff Works" (of all places) has a great overview of this technology.

Dude, jetpack.

Finally, life imitates G.I. Joe.

Video of first flight:

The Daily Mail ran a story about the inventor / pilot.

Endothelial junction, what's your function?

(Section of artery wall. Note the gap, or "fenestration" in the endothelium at the center of the image which would allow material carried along by the red blood cells on the right to escape into the surrounding tissues.)

"Blood-Brain Barrier" is one of those medical phrases that gets thrown around a lot without being defined. The general idea can be gleaned from the phrase itself: there exists a wall somewhere in or around the brain that prevents most things (chemicals, viruses and bacteria, etc) in the blood from entering the brain itself. Neat, the brain has an extra layer of security. But what, where, and how works the "Blood-Brain Barrier"?

Like most of the body's coolest features, it's amazingly simple. The innermost layer of all blood vessels are composed of endothelial cells. In the vessels supplying blood to most of the body, there are gaps between the cells (see image). The endothelial cells in the capillaries of the brain are arranged differently, in "tight junctions" where more endothelial cells are packed into a smaller surface area.

If you imagine endothelial cells as quarters, they would be arranged in the blood vessels of the body face up, overlapping, like scales. Within the capillaries of the brain, they would be arranged as in a roll of quarters, standing up, face to face.

Damage to the endothelial cells of the cerebral capillaries is now theorized to play a role in the development of Multiple Sclerosis, Alzheimer's, and other degenerative neurological diseases. Specifically, damage caused by free-oxygen that escapes from red blood cells as they're blasting through the capillaries.

Kylie Minogue, physicist.

Long before Ron Mallett began playing with "closed timelike curves" in order to warp time, Kylie Minogue was exploring this concept in music video form. From those beautiful astronomical "blueprints" in the "love at first sight" video, to this fascinating exploration of both asymmetric gravity and causality interactions in "come into my world", it's become clear to me that Kylie Minogue LOVES physics:

Wikipedia's default entry for "Love at First Sight"

Love at First Sight

From Wikipedia, the free encyclopedia

(Redirected from Love At First Sight)

This article is about the Kylie Minogue song. For the phenomenon about love, see Love at first sight.

Luckily, I was trying to look up the Kylie song, so it all worked out. Anyway, I defy you to stay in a crappy mood after watching this:

Note Kylie's revealing of spatial geometry, the invisible structure of the universe. Represented here by a "grid" superimposed over the world that Kylie inhabits, it's also shown to extend out into the universe. So is Kylie's point that love reveals the secret structure of the universe? Or, more interestingly, is she comparing not being in love to the pre-Einsteinian geometry of Euclid?

Euclid was the man until Einstein came along and showed that massive objects warp space and time to such an extent that Euclidean geometry becomes useless. The distance between points expands and contracts according to the mass of the objects between those points. So is Kylie saying that in the presence of love, all of our old points of reference are useless? Well played, Dr. Minogue.

Kylie continues her exploration of non-Euclidean spacetime in the video for "come into my world".

Feral Children

FeralChildren.com

What? How do you waste time on the internet?

Every story is some kind of tragedy, because of both the circumstances that led to the child going feral in the first place, and also because what the hell do you do with them afterwards?

Sometimes they have to clarify: "No, that child was not actually raised by squirrels, he's just autistic". A huge number of hoaxes, but many very true, very fascinating cases of children found, raised, protected, or reared by wild animals.

More

That time travel guy at UCONN

("Frame-dragging": The Earth, like anything with mass, warps spacetime around it. The math shows that it may also "drag" spacetime as it spins.)

Jumping forward in time is easy. We do it constantly. Every time you board a plane, drive on the highway, or move at any significant speed, time moves more slowly for you than for the rest of the world. At the speeds we can currently achieve, you gain only billionths of a second, and this has no practical effect whatsoever, but this is technically time travel as predicted by relativity. As the speed at which humans routinely travel increases over the next centuries, this effect will have to be taken into account. Eventually, as we begin to travel close to the speed of light, travellers will find that while hours have passed for them, years will have passed on earth. Take a light-speed ship out to the nearest star and back, and you'll return to a future earth. The real trick is travelling backwards in time:

I like Ron Mallett, I think he's a neat guy with a fascinating story, and his previous work on standard physics problems is solid. That said, his "laser time travel" device is cuckoo-bananas. The paper that lays out the physics behind his device is here.

Basically, Mallett has shown that by creating a circular high-energy laser, he can mimic the mass of a very large object. Awesome! We're all with him so far, but this is the point at which he leaves experimental physics and enters theoretical and speculative physics. From this spinning mass, he predicts, we might observe some amount of "frame-dragging". Now, frame-dragging is probably an observable effect, but we've not actually observed it yet.

(The math predicting frame-dragging has been around since 1918, but developing experiments to prove the theory took a bit longer to work out. Until last year, actually, when we began gathering data with "Gravity Probe-B". It's a pretty amazing satellite, launched in 2004 to detect the frame-dragging effects of the closest giant spinning object around, the Earth. The data is....complicated. The scientists doing the work think it will be at least 2010 before they've worked out exactly if / how the theory fits the reality.)

So okay, Mallett is on theoretically solid ground here. Whether he can replicate an effect with a desktop-sized device that we're barely sure is created by the whole earth is a different story.

Mallett then adds a theoretical property to a theoretical effect. With enough frame-dragging, he proposes, a "closed time-like curve" (CTC) could emerge, where space and time are so warped that "distance" (across space and time) becomes meaningless. Leaving aside for a moment the fact that space twisted around itself to that extent is not really a place you want to hang out (Mallett says just particles for now), and assuming he can work out all of the engineering problems that arise from channeling that much energy through some lenses and mirrors (no answers on this yet), the absolute best case scenario is that the particle would exit the loop just before it entered. That would be cool, but we won't be hunting T-Rexes anytime soon.

I gave him the benefit of the doubt several times there, and now I'm going to take it back. Mallett claims that the metric tensor he's worked out creates BOTH CTCs and an exit vector. Either I'm missing something big (totally possible), or Mallett's imagination has far outrun his math. Every solution I can think of just makes a death-trap, an inescapable loop that neither light nor particle can emerge from once entered. Essentially, a black hole. In order to bend a lightcone enough to make it fold back on itself (and therefore allow something to return to the place in time and space that it entered), you need A LOT of mass (or in this case, a VERY powerful laser mimicking a LOT of mass). This mass bends one edge of an object's lightcone around it, but it bends the other side too. So nothing could emerge without turning off the laser. But the device would have to be on to send a particle back in time. Theoretically, a particle should emerge the first time Mallett moves toward the "ON" switch. But then he'd have to be sure to turn the machine on anyway. Clearly, there are also some causality issues to be worked out.

In reading his paper, I couldn't help but notice that he solved the Einstein field equations with a metric based on an INFINITELY long cylinder of light. On one hand, this is genius (more on why at the end), on the other hand, it's a total cop-out. We've long known (since Frank Tipler in 1974) that an infinitely long cylinder of matter can produce relativistic effects that might make limited forms of time travel possible. This hasn't been particularly useful due to the...shall we say, difficulties, of building something infinite. This is the genius and the stupidity of Mallett's work. He's shown that light will behave the same way (genius), but ignored the irrelevence of the proof if it only works with infinite light (stupid). He has not addressed this issue, but has instead gone ahead with building a finite laser based on the theoretically sound properties of an infinite one.

Again, Mallett HAS done something genius here by applying the mass-energy equivalence rule of relativity to lasers. I can think of 10 amazing potential uses for this technology. Time travel, I'm afraid, will never be one of them.

Camus on Science and Poetry

From "The Myth of Sisyphus":

And here are trees and I know their gnarled surface, water and I feel its taste. These scents of grass and stars at night, certain evenings when the heart relaxes - how shall I negate this world whose power and strength I feel? Yet all the knowledge on earth will give me nothing to assure me that this world is mine. You describe it to me and you teach me to classify it. You enumerate its laws and in my thirst for knowledge I admit that they are true. You take apart its mechanism and my hope increases. At the final stage you teach me that this wondrous and multicolored universe can be reduced to the atom and that the atom itself can be reduced to the electron. All this is good and I wait for you to continue. But you tell me of an invisible planetary system in which electrons gravitate around a nucleus. You explain this world to me with an image. I realize that you have been reduced to poetry: I shall never know. Have I the time to become indignant? You have already changed theories. So that science that was to teach me everything ends up in a hypothesis, that lucidity founders in metaphor, that uncertainty is resolved in a work of art. What need I of so many efforts? The soft lines of these hills and the hand of evening on this troubled heart teach me much more. I have returned to my beginning. I realize that if through science I can seize phenomena and enumerate them, I cannot, for all that, apprehend the world.

I'm stunned by the beauty of the language in this translation by Justin O'Brien, but I'm not sure if I agree with his point. Do you?

Vampire Phone of Tomorrow, Today

Why, yes. That is a prototype cell phone implant. What powers it? Your blood. From PhysOrg:

The basis of the 2x4-inch "Digital Tattoo Interface" is a Bluetooth device made of thin, flexible silicon and silicone. It´s inserted through a small incision as a tightly rolled tube, and then it unfurls beneath the skin to align between skin and muscle. Through the same incision, two small tubes on the device are attached to an artery and a vein to allow the blood to flow to a coin-sized blood fuel cell that converts glucose and oxygen to electricity. After blood flows in from the artery to the fuel cell, it flows out again through the vein.

This makes sense. Oxygen and glucose carry enough energy to power the most complex system we know of, the brain, so there should be plenty left over to power your cell phone too. I wonder if this would increase your appetite? I knew blood-powered implants were being developed, but I had no idea we were anywhere near a prototype. Awesome.

You know I'm going to say it...

We live in the future.

In other news, puppies cause cancer.

From CNN, Study: Snowflakes may contain bacteria

Seriously, this is why people hate science.