TED Talks often get 100 or more comments — a mixed bag of kudos, critiques and questions. Looking back on the year, here are a few comments that wowed us.

Do you know more about a topic than the speaker had time to share in their talk? Here’s a great example of how a knowledgeable commenter filled in some of the blanks. We know that for every TED Talk we post, many of our viewers are experts in the field. If a talk is up your professional alley, we’d love to hear you elaborate on an interesting detail.

Here, commenter Robert Graham shares more on the implications of the talk “Boaz Almog levitates a superconductor”:

“Great demonstration of a great technology. For those of you interested, since the speaker didn’t get in to the details of the potential for this technology:

Superconductivity is a phenomenon that has applications so far and wide that, if we were able to apply it wherever we wanted, it would change the world on a scale comparable to the advent of electricity itself. The problem is that we only know how to make superconductivity work at very cold temperatures with very specific materials. Over time, researchers have discovered materials that transition to superconductivity at higher and higher temperatures until, today, it can be achieved well above the boiling point of nitrogen. Obviously, the holy grail here is finding a material that goes “super” at room temperature. That’s a discovery that would change the world.

What makes this so suspenseful is that scientists don’t actually understand HOW superconductivity occurs at such high temperatures. In the past, scientists thought they had figured it out and so concluded that superconductivity could not occur above about 30 kelvin, much less room temperature (about 300k). The suspense was over…. until the discovery of superconductors that operated at temperatures much higher. Scientists were baffled, and still are, as superconductors continue to be discovered at temperatures higher than anyone had ever imagined was possible.

Potential applications? Too many to list. You could let your imagination go wild.

• Energy? Cheaper, much cleaner, much more efficient
• Computers? Cheaper, much faster
• Transportation? Cheaper, faster
• Magnets? Much stronger (magnets are used to produce electrical current, among other things)
• Batteries? Yep
• Data storage … and so on.”

Not an expert, but have a great resource to share? These links connected us to even more to see and do.

Commenter Eric Olofson gives more info on Daphne Bavelier’s talk “Your brain on video games”:

“Given the number of commenters critiquing the methodology of the mental rotation study without having read the research (which was conducted by a different lab, as she notes), you can read the study here:

http://ixdcth.se.hemsida.eu/courses/2012/ciu185/sites/default/files/files/2007_GenderDifferenceSpatialAbility.pdf

The study she describes is Experiment 2. While there may be critiques, the lack of a control group is not one of them.”

Commenter Michael LeVine on Nina Tandon’s “Could tissue engineering mean personalized medicine?“:

“Great talk Nina! Anyone in NYC should consider checking out the DIY science discussion panel put on by SpotOn NYC on Thursday, where Nina will be on the panel!

http://www.nature.com/spoton/event/diy-science/”

Boaz Almog demonstrates “quantum locking” — which causes a small, supercooled superconductor to levitate above a magnetic track — in this amazing raw footage from TEDGlobal, shot by photographer James Duncan Davidson.

Want to know when Boaz Almog’s full TEDTalk goes online? Sign up for an email notification >>

After rescuing his equipment from UK customs, where it had been stuck for several days, Boaz Almog take the stage to demonstrate his remarkable research.

It uses a well-known phenomenon of superconductivity — a state of matter where the electrical resistance drops to zero. Normally, electrons moving through a conductor collide occasionally, losing energy to heat — that is resistance. But in a superconductor, there are no collisions, none at all (this is one of the strange effects of quantum mechanics), and hence no resistance. Additionally, the superconductor expels all magnetic fields, another defining characteristic.

But sometimes strands of magnetic field can get stuck inside a superconductor. In that case, they are quantized: they come in discrete units that behave like particles. He calls them fluxons, because they’re particles of magnetic flux.

Now, if you put the superconductor inside a magnetic field, the material doesn’t like the fluxons to move, because that would create resistance, so the object will “lock” the magnetic fields in place. So Almog can use that to create what he calls “quantum locking.”

He does just that, spectacularly, by taking a supercooled superconductor out of a container of liquid notrogen and holding it above a magnet, seemingly magically locking it into position.

How many strands in a disk, you might ask? 100 billion in a 3-inch disk, it turns out. But that’s not the end of the story. The actual part of the disk that’s a superconductor is only a half a micron thick, but it can levitate the entire disk — 70,000 times its own weight.

Almog then takes the disk and puts it on a circular track. Amazingly, the disk appears locked in place while it races around the track, even if the track is turned upside down.

In writing, this sounds a bit like an ordinary magnet. It’s not. When you see the disk in action, it’s obvious that something more is going on. Normal magnets wiggle, and this one sits there, completely locked in place. To get a sense of that,  watch a demonstration of the quantum locking disk >>

What can quantum locking be used for? Hm. Currently we use superconductors for magnets in MRI machines or for storing energy. We’re just beginning to see what quantum locking could be used for, Almog says, but he can easily imagine a tiny wafer that could hold the weight of an entire car.

What does this look like? Have a look:

Photos: James Duncan Davidson