Category Archives: Physics

Promises, Promises

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Nick asks “What’s the holdup?” in bringing graphene into our everyday lives.

 

Here are some promises: Graphene Will Change the Way We Live

 

There are two sides to this coin — I can recall the promises made after high-temperature superconductors were discovered. Levitating trains were right around the corner, and we’re still waiting; though continual improvements were made, the thin-film materials never scaled up to bulk material, nor did the temperature get high enough to become practical for everyday use. The danger of overblown claims of the potential of a discovery is always present.

On the other side is that six years of basic R&D is a very short window. Others have mentioned the relatively short time it took to award the Nobel to this discovery, so I think perhaps it’s premature to expect finished products at so early a date. There may be other developments required to fully enable graphene in order to full exploit it.

Smile! You're on Wifi Camera

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Wifi Camera

The Wifi Camera is a camera that takes “pictures” of spaces illuminated by wifi in much the same way that a traditional camera takes pictures of spaces illuminated by visible light.

The camera reveals the electromagnetic space of our devices and the shadows that we create within such spaces, in particular our wifi networks which are increasingly found in our daily lives, in coffee shops, offices and homes throughout cities of the developed world.

The Magnetism of Light

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Measuring the Magnetism of Light

When light interacts with matter, the dominant action is often a “shaking” up and down of electrons in response to the electric field. This interaction is typically 10,000 times larger than the “swirling” action from a light wave’s magnetic field. The case is different in metamaterials, which contain small components like metal rings that are often tailored to have an enhanced response to magnetic fields. Thanks to this sensitivity, light traveling through a metamaterial can bend in unusual ways, making feasible such devices as super-lenses and invisibility cloaks.

I See What You Did There

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Sound can leap across a vacuum after all

I saw this retweeted by Jennifer, but sorry — No, it can’t.

When a sound wave reaches the edge of one crystal, the electric field associated with it can stretch across the gap and deform the crystal on the other side, creating sound waves in that second crystal (Physical Review Letters, vol 105, p 125501). “It is as if the sound waves don’t even recognise the vacuum – they just go through,” says Prunnila.

This is the kind of writing that really, really annoys me. Redefining terms in order to sensationalize the material. Sound doesn’t jump across the vacuum barrier — an electric field does, and that’s perfectly cromulent. The electric field causes the piezoelectric transducer on the other side to vibrate and recreate the sound. Neat. But if this counts as sound going through a vacuum, then transmissions using a satellite has to count, too. We’ve been doing this for more than 50 years.

Not Related to the "No-Hair" Theorem

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The Virtuosi: Beards and Pulsars

The Hulse-Taylor binary is almost exactly what it sounds like: it’s a pulsar binary where one of the pulsars is pointed towards earth. It was the first binary of it’s kind discovered and offers a unique look into a very high gravity environment. It also provided a very nice test for General Relativity. General Relativity predicts that two orbiting massive bodies should emit gravitational waves. This emission of gravitational waves will then cause the orbit to decay and the two bodies to move closer together.
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So doing a quick division, we find that the rate at which the Hulse-Taylor binary’s orbit is shrinking is roughly 14 times beard [growth] speed

Evil Genius Physics

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French Thieves Use Vacuums to Suck Thousands from Safes

The key to the thieves’ nearly uninterrupted streak of success, per French reports, is the way that Monoprix delivers money from the checkouts to its safes: Envelopes of cash are funneled in via pneumatic suction tubes. Whereas breaching the safe itself might be considerably difficult, requiring explosives or safecracking, the thieves realized that if they just drilled into the delivery tubes near the safebox and hooked up a powerful vacuum, they could suck the money out and get at it much more easily.

I don’t know the specifics, so there may be a good reason that they haven’t fixed this problem during the four years the thieving has been going on, but it would seem a check valve would be useful here.

Revenge of the Ant Overlords

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Vdara visitor: ‘Death ray’ scorched hair

The “hot spot” was visible during one of the visits, but no guests were in its reach. An employee pointed out the zone and said it was “like a magnifying glass that shines down” over a space about 10 feet by 15 feet, which moves as the Earth rotates. At this time of year, the bright reflection is present for about an hour and a half, both before noon and after, according to the young man.

Also: Sunbather Singed by Shiny Hotel’s Reflected “Death Rays”