The common misconception is that, because helium is a lighter element than the main components of air, your vocal chords will vibrate faster if immersed in it. This makes a certain amount of sense. People move faster through air than they do through heavier stuff like water. Less resistance should enable vocal chords to move faster as well.

As it turns out, though, vocal chords vibrate at pretty much the same frequency no matter what gas rushes over them – though chlorine would eventually pose a problem. That factor isn't what changes the sound of your voice.

When an audio speaker – or anything else – makes a sound, it vibrates at a certain frequency. That vibration compresses the air around the speaker. The compression moves through the air, hits a person's ear, and is interpreted as sound. The frequency of the compressions will determine the quality of the sound. A low frequency means a low note. When a high number of waves of compression hit the ear every second, the note will be high.

There are two major things that determine the sound of a person's voice. The first is the size and shape of the vocal chords themselves. The other is the shape of the throat that the air passes through. Vocal chords are not the precision instruments many people imagine them to be. They create not a single note, but a jumble of sound. Of that sound, certain notes are emphasized.

Specifically emphasized are the resonant notes. These are the notes which ‘fit' inside the throat.

Look at the figure to the left. Most people have idly played with a rope like this, whether that rope is a jump-rope, a shoe-lace, a gold necklace that their mother told them not to touch, or a particularly unfortunate snake. A number of different frequencies fit the rope. In the same way, a number of different frequencies fit a person's throat.
Frequencies that don't fit are choked off in much the same way as the waves in the picture above would be if someone were to hold the rope still just beyond point ‘A'.

How does helium change that? Sound travels faster in lighter gas. Because helium hangs out at the top of the periodic table, while nitrogen, oxygen and carbon dioxide, major components of the air we breathe, are heavier, sound will travel faster in a throat filled with helium than it will in a throat filled with air.

The faster speed of sound will allow more frequencies to resonate within a throat. Look again at the figure above. If the rope were made of ordinary twine, it would be relatively easy for two people with decent coordination to get all of those frequencies going. If the rope were made of inch-thick iron links, it would be a different story. Getting metal to move fast is hard, so a strong group would have a tough time getting even the top wave to work. They would, however, have the advantage later on when the inevitable fight broke out. But that's a different story.

When you breathe in helium, your regular voice is joined by a whole host of new, higher resonant frequencies. You'll still be able to sing or speak the same note as you do with regular air, but because the higher frequencies are included, your voice will sound high, odd, and hilariously funny to drunk people.

Speaking of drunk people inhaling things, this is the part of the article in which the dangers of this practice are explained in an earnest attempt to prevent injury and keep from getting sued. Helium inhalation is, as said before, hilarious to the intoxicated. It is also a painless, effective and relatively natural-feeling way to keep oxygen from getting to a person's brain. And yes, people do die from it. One shallow breath is all it takes to say something funny. Take one puff, and pass the balloon along. Any more than that — and it is very possible to die sounding like a gerbil.

Another common mistake is to try to inhale helium straight from the compressed air tank it often comes in. To understand what's wrong with that idea, it's probably best to picture an overfilled balloon popping. Now picture it filled with blood and connected to nerve-endings. Those are lungs. They are designed to take in air at a certain speed only, and everyone should respect that.

What's more, people, in their intrepid search to find more ignominious ways to kill themselves, have figured out that while helium makes a voice go up, heavier-than-air gases have the opposite effect. Heavier gases will limit the number of frequencies that resonate in a person's throat, and make their voices sound deeper. Great stuff, right?

Here's the problem. Even if a person could find a gas that won't kill them to inhale, lungs are very picky about what kind of physical conditions they can work under. They can push out air. They can't push out heavier things. One site, which under no circumstances will io9 link to, recommends hanging upside-down after inhaling these gases, in order to clear the lungs. That technique is included in this article as a way of letting readers know what to do if they have had a heavy gas forced into their lungs by a supervillain, killer robot, lab accident, or vicious-but-nerdy street gang. Do not, repeat, do not go to the park, inhale a bunch of xenon and try to climb onto the monkey bars. It won't end well. It didn't even begin well.

Besides, with any luck, the physics behind this will impress and amuse people much more than the trick itself.

[Via UNSW Physics and CCMR]

Austin Sendek is studying physics at UC Davis, and felt it was time that extremely large units of measurement got their own designation. What better word than hella? I'm already looking forward to Google explaining how hellabytes of storage space it has.

Sendek told a local news station in Davis:

The diameter of the universe is 1.4 hellameters. You know if someone says that's 'hella meters' you know exactly what they're talking about.

His quest may not be entirely in vain. The International System of Units did add a new unit of measurement back in 1991, when they designated "yotta" to describe 10 to the 24th power. Isn't that the word that Hiro is always yelling on Heroes? Hey, if Hiro gets to have his own unit of measurement, why can't we have the hella?

via CBS Local

Discovered in a particle accelerator at the University of Tokyo, Carbon-22 has six protons and a whopping sixteen neutrons in its nucleus. In most such overstuffed isotopes, the excess neutrons create instability and cause the atom to break apart. However, Carbon-22 makes use of a unique arrangement of its nucleus that gives it stability unusual for its size.

While the next biggest carbon isotope, Carbon-21, has a half-life of under 30 nanoseconds - or billionths of a second - Carbon-22 has the relatively long-lived half-life of roughly 6 milliseconds. That might not sound like a lot of time, but it still means Carbon-22 holds together for about a million times the average half-life of Carbon-21.

The reason for this is that Carbon-22 arranges itself in what is called a halo nucleus. In this arrangement, two of the neutrons detach from the nucleus and orbit around it, forming a halo around the nucleus. This essentially alters the nucleus so that it is now a three body system, with a core of six protons and fourteen neutrons along with the two orbiting neutrons. Although physicists still don't exactly know why, this arrangement provides the needed stability for Carbon-22 to hold together longer.

This phenomenon is mysterious because physicists still can't easily model halo nuclei; the mathematics involved are just too hellishly complicated. In the meantime, scientists have taken to nicknaming these arrangements "Borromean nuclei" after the fifteenth century rings. The Borromean rings were three rings interlocked such that cutting any one ring will cause all three to separate. This is in reference to the fact that, for whatever reason, the halo nucleus configuration is the only arrangement that gives Carbon-22 stability, and even the slightest deviation will make it fall apart instantly.

Physicists hope the discovery of Carbon-22 is just the beginning of a far larger exploration of exotic isotopes, as new and better detectors will allow scientists to discover even larger isotopes in halo nucleus configurations.

[PhysOrg]

To understand the Casimir Effect, we must first establish that the unforgiving nothingness of space - which has claimed the lives of so many minor characters in science fiction films, and the sanity of the Reavers in the Firefly TV series - is not truly nothingness at all. It is filled at all times with irregular electromagnetic waves, or by spontaneously appearing and disappearing particles, depending on what side of the particle-wave duality you come down on at the moment.

I'll let Scientific American explain it in terms of waves, and I'll give a run down on the particle side of things. Imagine you are trying to get to someone through a large crowd of randomly moving people. (Feel free to apply a dramatic purpose to this scene and outfit the crowd in period costume.) At first it will take effort to move through the crowd of people. Then, as you get close to each other, there won't be any more people to fight through. There will be a lot of people around you, though, jostling you towards each other. The force of the crowd around the two of you will push you into each other.

That is what the Casimir Effect does to two metal plates held close enough together. As the plates get closer to each other, there will be more particles pushing in on the two plates than there will be pushing out between them. Eventually, they will be pushed towards each other and stick together.

For a long time the Casimir Effect was less a fascinating aspect of our universe than a pain in the ass for nanotechnologists, since it meant that they had to deal with quantum mechanics sticking their materials together as they tried to build the tiny mind-controlling robots we all know they want to make.

It wasn't until physicists came up with a way to reverse the Casimir Effect that things got interesting. Under the right conditions, the two plates will push away from each other, instead of towards each other. It made frictionless technology possible. It also made the Casimir Effect more versatile.

While both effects occur only under very specific conditions, and while they are very slight, they are examples of the supposed 'vacuum' of space creating energy. This is a source of energy that would never run dry, and would be available anywhere. If there were a way to use the push and pull between the plates to propel a starship forward, that ship could travel forever without fuel, harnessing energy from space itself.

At the moment, NASA is "doubtful this energy can be tapped." The energy is there, however, and its potential remains.

Via:

Scientific American

Science Blog

Nasa.gov

Rhett Alain, a physicist at Southeastern Louisiana University, first turns R2's flight into a free body diagram, pictured here. Then he solves for F-thrust, assuming Earth gravity and some atmospheric resistance (you can see all his equations here). Then he reaches the fun part, which is figuring out R2's mass.

Writes Allain, as he solves his equation for mass:

* rho = 1.2 kg/m3
* Area: Wookieepedia says that R2 is 0.96 meters tall. Using tracker video on an image of R2, I am going to approximate it as a rectangle that is 0.42 meters by 0.62 meters for an area of 0.26 m2
* Wikipedia lists the drag coefficient for a smooth sphere as 0.1. It has a smooth brick with a coefficient of 2.1. A skier has a coefficient of 1.0. Wikipedia does not list the drag coefficient for R2, but a value of around 1.0 seems reasonable.
* For the velocity, I took it a little far. I was just going to ballpark guess at his speed, but I didn't. I used Tracker to look at R2's motion in Clone Wars where he flies to rescue Padme. From this, I get a speed of 2.3 m/s.
* I already said I would assume Earth-like gravity. So, g will be 9.8 N/kg
* Theta is about 35 degrees (although it could be as high as 45 degrees).

Using these values, the mass of R2 is 0.1 kg. Yes, 100 grams. How do I know I am correct? I know because Wookieepedia doesn't list R2's mass or weight. They know it is silly, so they left it off.

If this mass is so low, I think R2 doesn't even need thrusters. He would just float (which would actually change my calculations above - I left off the buoyancy force). By my estimations, R2 is about .42 meters in diameter. This would put its volume at about 0.1 m3 and R2's density would be:

I was originally thinking that maybe R2 was made of styrofoam - but that has a density of about 40 kg/m3. So there.

So basically R2 doesn't need thrusters, and is made of spiderwebs. Makes perfect sense!

You really must read the whole post to get the full awesomeness - via Dot Physics

The LHC is a 27-kilometer underground tunnel designed to accelerate atomic particles and smash them into each other. The goal is to see what happens when such particles interact with tremendous amounts of energy, the way they might under extreme conditions in outer space. The results of LHC experiments will reveal a lot about the origins of our universe, and the composition of matter within it.

CERN, the Swiss facility where the enormous underground experiment is located, has announced that test beams in the LHC have zoomed around most parts of the accelerator without incident:

Particles are smoothly making their way around the 27 km circumference of the LHC. Last weekend (7-8 November), the first bunches of injection energy protons completed their journey (anti-clockwise) through three octants of the LHC's circumference and were dumped in a collimator just before entering the CMS cavern. The particles produced by the impact of the protons on the tertiary collimators (used to stop the beam) left their tracks in the calorimeters and the muon chambers of the experiment.

One of the coolest parts about accelerators is that when the microscopic particles smash into the walls, they are moving so fast that they leave long tracks in their wakes. (Researchers can gain information from examining these tracks.)

If everything keeps moving smoothly, we could see some particle-on-particle smashage as early as two weeks from now. As long as the world doesn't end, we're going to get some long-awaited answers to our questions about our universe.

via CERN Bulletin

This means watching for an isotope of xenon decaying into barium, giving off two electrons (the double beta decay), but without giving out any neutrinos. A beta decay process gives off one neutrino, so how could this even be possible? It only works if the neutrino is its own antiparticle, so that the two beta decays each have a neutrino which essentially cancel each other out, like matter and antimatter annihilating. And the possibility that process exists is the reason for the experiment.

If neutrinoless double beta decay is observed, it means the neutrino must be its own antiparticle, a key unknown in the study of neutrinos. If the neutrino is indeed its own antiparticle, it has all kinds of implications for the structure of the Standard Model and the relationships between the fundamental particles.

OK, now I understand both the plot of A Scanner Darkly and what will happen during the season finale of Fringe. It all totally makes sense now.

via Symmetry Breaking

Developed by a research team in Japan, this method of magnifying the nanoverse is called Synchrotron Radiation Scanning Tunnelling Microscopy. Testing was a joint effort of the University of Hyogo and the KEK Photon Factory (best name evar). How does it work? According to Physics World:

It involves placing a sample of interest in the intense x ray beam of a synchrotron source.

Photons from the beam excite core electrons in the sample's atoms, which then spit out "secondary" electrons as they decay back down to their ground states. These secondary electrons are then detected by the tip of the scanning tunnelling microscope (STM) as they tunnel across the gap. The size of the current depends on the specific type of atom that has produced the secondary electrons, which means that each element has a unique "fingerprint."

I just want to know why the STM is covered in tinfoil. Or whatever that puffy, shiny stuff is. Also, that is seriously the coolest lab picture ever. Tangled wires! X-rays shooting everywhere! Hopefully somebody will get superpowers out of this.

via Physics World

Physicists working on the LHC say that even if the device does produce tiny black holes, they will exist for such a short time that they couldn't possibly do any damage. Instead, they're interested in experiments that could reveal for the first time what dark matter is, and what the universe looked like after the big bang.

Though the LHC won't be in full operation until September 10, when the first real experiments there will get underway, this weekend marks the first time the facility will be used. Researchers will shoot a few particle beams through the magnetized, reinforced tunnels that make up the giant particle accelerator. According to Popular Mechanics:

As part of a scheduled injection test, the LHC will be closed off this Friday, and researchers at CERN will fire protons through one of the eight sectors that make up the sprawling concrete-lined collider tunnel. The purpose of this test? “It’s, ‘Let’s see what happens,’ ” says Judy Jackson, head of the Office of Communications at Fermilab. “It’s a very complex machine. This is a step towards getting ready.”

Let's see what happens? You mean, like whether it produces tiny black holes that last longer than a nanosecond? Awesome.

Start Date for the Large Hadron Collider [Popular Mechanics]

Once the two patterns have been compared, you get a kind of black-and-white silhouette of the object you want to photograph. Scientists call this a "ghost photograph." University of Maryland physicist Yanhua Shih has been working on this "ghost photography" for a while, and has been talking to the military about using it in UAVs for photographing bomb damage through smoke.

According to the Air Force Times:

Albert Einstein explored the basic research behind ghost imaging — quantum entanglement — which he called "spooky action at a distance" in 1935. Shih discovered ghost imaging in 1995, but the theory has yet to leave the laboratory.

Air Force satellites could use ghost imaging by pointing a light sensor toward the Earth's surface and another toward the sun. The technique could allow the service to penetrate clouds or the smoke that follows airstrikes . . . Defense manufacturer Lockheed Martin has shown interest in quantum entanglement, acquiring a U.S. patent in May to develop quantum radar that could defeat stealth aircraft and find camouflaged improvised explosive devices and mines, according to the patent.

Discovery May Make Ghost Imaging a Reality [Air Force Times]

Here is the Spherical Torus from above in the Princeton Plasma lab:

And here's a schematic to give you a better idea of what it looks like.

Apparently plasma toroids are all the rage in physics circles right now, so it's time to get rid of all your old-fashioned plasma spheres and ovoids. Also, dear readers, if any physics geeks out there would care to explain the principles of magnetic fusion to us in layperson's terms we'd love to know.

National Spherical Torus Experiment