6 Billion Year Old Particles Maintain Weight

In the case of subatomic particles, the phrase "still the same after all these years" should be taken literally. As German astrophysicists recently discovered, the mass ratio of the proton and the electron is the same as it was 6 billion years ago.

Specifically, protons weighed 1,836 times more than electrons back then, and they still do!The researchers who performed the study had originally detected ammonia in a very far off galaxy, by observing its absorption of radio waves from a powerful bundle of energy called a quasar, located behind the galaxy.

Because light from such a distant object takes time to travel to us here on earth, the farther away scientists probe the universe, the farther back into the past they see. Therefore, they actually viewed ammonia as it was millions and millions of years ago.

Because of its pyramid-like structure, ammonia behaves differently than other molecules when absorbing the energy from radio waves. In a feat of subatomic gymnastics, an ammonia molecule actually flips inside out, its three hydrogens moving from the bottom of the pyramid to the top, while its nitrogen resumes the base position.

As researchers knew, the key to the flip lies in the ratio between the mass of the proton and the electron. They compared the ammonia absorption data to other molecules within the same galaxy and found that absorption was basically the same, indicating that the proton/electron mass ratio had not changed.

We all know subatomic particles are really, really tiny, so who cares what they weigh? Turns out that question is a loaded one. Many scientists believe that changes in particle masses provide evidence that universal constants like the speed of light, are well, not so constant after all. This idea might provide explanations for dark energy, and hidden extra dimensions proposed by string theory.
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When Regular Atoms Become Superatoms

Atoms act really weird if only a few of them are grouped together. Gold and other (typically metal) atoms begin to form highly symmetrical structures depending on the number of atoms clustering together. These clusters take on the characteristics of the single atoms of a completely different element, transforming into what scientists have dubbed "superatoms".

What makes regular atoms become superatoms is their ability to transform physical properties and imitate those of other elements at extremely small scales. What we can observe with the naked eye, the size, shape and color of a certain material, changes as the number of atoms is reduced, starting at around a few million. For example, silicon is normally rigid and breakable, but group a small number of silicon atoms together and they become malleable, almost supple. Quantum dots, a type of semi-conducting particle, displays light across a spectrum of colors, depending on their size.

Superatom behavior is even more perplexing at smaller scales. Take 20 gold atoms and they will aggregate into a solid pyramid. Remove a couple, and 16 atoms will display a cage-like structure. Groups of tin atoms behave like conductors or semiconductors, depending on the addition or removal of just a few atoms.

Scientists have recently created several new supersatoms and determined their structures. The goal is to use the superatoms of elements such as gold and carbon to develop completely new materials. These custom-made materials would have all sorts of useful properties that we can't obtain from natural materials. Scientists are currently working on a superatom material capable of storing solid hydrogen at room temperature, in hopes of solving the difficult and expensive problem of transporting and storing hydrogen, needed for the development of hydrogen fuel cells.
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I like my soccer NANO-SIZED!!

Some people prefer American soccer over Australian, but I prefer NANO-SIZED!

Buckyballs (nano-sized soccer-ball-like carbon cages) have been making headlines this week as researchers from Rice University and Sandia National Laboratory successfully videotaped the creation of a buckyball. Watch it here:

Nature produces nano-sized soccer balls which scientists have dubbed buckyballs. Buckyballs (more generally called fullerenes) are made up of 60 carbon atoms all put together just like American soccer balls: twelve pentagons (the black patches) and twenty hexagons (the white patches) linked together into a cage formation. I won’t go into it all, but go to Nova’s webpage for a very entertaining and precise history and description of the buckyball, with no science jargon: http://www.science.org.au/nova/024/024key.htm

But hold your horses, sports fans. The video doesn’t make any sense until you read the paper published about it. Luck for you, I’ve done the dirty work. Here’s my play-by-play (use this as a guide to the video):

The two boulder-shaped things are giant fullerenes, or large versions of buckyballs. While buckyballs consist of 60 carbon atoms, these GF’s can be made up of over a thousand.

The lower boulder starts with 1300 atoms of carbon, and the higher one starts with 1100.

The higher one doesn’t disappear, it just moves off screen. It seems that the giant buckyballs don’t actually roll, they slide.

You are watching the GF’s lose carbon atoms and shrink in size.

The actual buckyball, size C₆₀, doesn’t appear until near the end of the video.

Watch it twice and note the last frame where you can really see a circle with room inside it: right after that, you’re looking at a buckyball. It is about one billionth of a meter across!

The process you’re watching is being called “shrink-wrapping,” because those GF’s, which are easier to create, are being shrunk down to the size of a buckyball. They’re heated up and begin to shrink via evaporation of carbon atoms. The actual buckyball appears at about 2000^o C. The paper discusses in detail how they think the balls manage to shrink, but more importantly they think they’ll soon be able to stop the shrinkage whenever they want, creating fullerenes of specific sizes.

The people who discovered the buckyballs won the Nobel Prize in 1996. It’s amazing what these Buckyballs might be able to do. They could swim safely through your veins or clean up toxic waste! Nanotubes of similar structure might be able to both conduct and insulate current, based on small changes in size.

View the papers abstract from APS: http://link.aps.org/abstract/PRL/v99/e175503

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Matter/AntiMatter Molecule Created

Scientists at CERN, a giant particle accelerator straddling the border between France and Switzerland, have created the first molecule made of both matter and antimattter.

The researchers made the molecules by slowing antiprotons and letting them interact with hydrogen molecules, leading to molecules consisting of a single proton bound to a single antiproton, as well as leftover hydrogen atoms.

(Bear in mind that scientists have long ago managed to join electrons and positrons together into positronium, which is a lot like a molecule, but molecules really should have atoms in them, rather than just electrons and their antimatter positron partners.)

The researchers reported their work in this week's edition of Physical Review Letters.

Now the big question -- what do we call the stuff?

The CERN folks are going with "antiprotonic hydrogen." A bit hard on the tongue, I think.

My friends at Physics News Update (PNU), who reported the story first, like "protonium." That's probably the best bet, but if we are following convention established with positronium (which is named after the antimatter particle), it should be called "antiprotonium."

Wikipedia already has an entry for protonium, so I think my PNU friends have made the right call.

Regarding the graphic above, you can't really take pictures of atoms and small molecules, but these shapes (spherical harmonics) are closer to the way hydrogen atoms would actually look if you could see them. If CERN releases images of protonium/antiprotonium/anitprotonic hydrogen, I'll post those instead.

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