Nano ho-ho

In the spirit of Christmas, I'd like to share with you all the world's smallest snowman.

(Click on image for link to site)

Credit: NPL site

The snowman was developed by the UK's National Physical Laboratory, and is a marvel of festivity-inspired nano-jollity.

According to the website, it's 10 µm across, which equates to roughly 1/5th the width of a human hair.

It wasn't made out of snowballs, of course, as these on average measure about half an inch, and we have yet to develop the ability to do the whole 'Honey, I shrunk the snowflake' thing.

Instead, it was made out of two tiny little tin balls. hilariously, they're normally used to correct microscope astigmatism, which brings to mind wonderful images of a microscope with glasses, peering at the objects/tissues it needs to focus on.

I'm looking forward to tiny Christmas trees with even tinier tinsel. Of course, a treetop angel on this scale might also bring whole new answers to the classic question involving angels and the heads of a pin...

The LHC's first collisions

Woohoo! I couldn't, personally, be more thrilled.

No doubt, people who actually understand properly the physics and true awesomeness behind the LHC couldn't be more thrilled either. Even more so than I.

Because, * fanfare *, the first collisions in the new, better-than-broken, up-and-running, ghost-in-the-machine lacking LHC have been observed!

A brief history lesson - the LHC, or Large Hadron Collider, is a truly gobsmacking feat of engineering which has taken a decade to build, billions of euros, and, no doubt, the sanity (or at least youth) of a number of engineers who've had to fight various problems, including errant baguette-bearing birds, to finally get it up and running. Properly.

And why has this wonderfully photogenic machine been built? Why, to find new particles! Amongst other things, of course. Of particular interest is the possibility that our scientists may be able to spot the elusive Higgs boson. (I have a fantastic image in my head of scientists in khaki, with binoculars, and a David Attenborough voice-over). The Higgs boson, or 'god particle', has thus far only been theorised, but it's thought that it could be what gives everything in the universe mass.

Basically, it works like this (there's a better explanation here):

The Higgs boson (or particle) carries the Higgs field, which imparts mass to objects as they move through the field, kinda like this...

People evenly distributed in a room, akin to the Higgs field (CERN)

Then Thatcher (yes, yes, I know!) enters the room, people gather, mass increases (CERN)

Of course, the LHC has also lead to howls and terrors from various quarters about its potentially causing the end of the world, or a huge black hole, or something. Amusingly, some physicists even suggested that it (well, the universe) could be sabotaging itself from the future.

But I digress. The news here is that the first collisions have been observed, and they look like this!

The green lines denote changed particles (following the collision), which are, apparently, generally pions (not peons, although those can also be unstable during changing circumstances).

[Pions] are unstable particles consisting of an up quark and an anti-down (or an anti-up and a down). Though they are unstable, they live long enough to nearly always leave tracks in the detector.

Then, the yellow bits denote the silicon strip detectors responsible for recording our particles

After that, it all gets quite technical. A far more knowledgeable account of it, and the source of the quote above, can be found here (which, by the way, is a great blog).

Mostly, I'm just happy she's started up, and I'd like to raise a toast to her: we're happy to have you back with us, dear gal, and we look forward to the show!

There's also a lovely Nat Geog article on it. I love the subheading 'happy physicists' - it's a warm and fluffy thought.

The teapot effect, end of

So apparently, there's something called the teapot effect. Or, rather, there was.



No, it's not what you might first imagine it is. At least, it's not what I first imaged it was. Instead, it's apparently the name used for the phenomenon whereby the spouts of teapots dribble, and even English women who've been pouring tea for posh friends for decades are unable to pour that perfect, immaculate cup of tea.

"Previous studies have shown that dribbling is the result of flow separation where the layer of fluid closest to the boundary becomes detached from it. When that happens, the fluid flows smoothly over the lip. But as the flow rate decreases, the boundary layer re-attaches to the surface causing dribbling."

And here's where fluid dynamicists have stepped up, donned their superhero cloaks, and sorted the problem. Huzzah!

The factors involved?

"Previous studies have shown that a number of factors effect this process such as the radius of curvature of the teapot lip, the speed of the flow and the "wettability" of the teapot material. But a full understanding of what's going on has so far eluded scientists.

"Now Cyril Duez at the University of Lyon in France and a few amis, have identified the single factor at the heart of the problem and shown how to tackle it. They say that the culprit is a "hydro-capillary" effect that keeps the liquid in contact with the material as it leaves the lip. The previously identified factors all determine the strength of this hydro-cappillary effect."

The solution is two-fold: make the lip of the teapot as thin as possible, and and coat it with superhydrophobic materials (materials, in other words, that really, really, really, really don't like water).

Even more fun, apparently there are materials in which the superhydrophobicity can be turned on and off electronically. Meaning that to dribble or not to dribble would no longer be hypothetical...

And, because there's no better way to end things than with wry, physics-based sarcasm, there was this comment, as well:

"(Of course, there are one or two other potential applications in shaping the fluid flow in microfluidic machines but these pale into insignificance compared with the teapot revolution in hand.)"

On another teapot-related note, I had not idea, but apparently teapot-blowing (again, not what you think) is something of an artform!

p.s. Yes, I know the original arXiv post isn't that new - sadly, life has perforce distracted me somewhat of recent.

Universal snacks

Well, the title might be a misleading. This is mostly an excuse to post this, which I thought was funny. After all, what better way to enjoy your next handful of peanuts (particularly when sitting on a plane, of course) - than by expanding for your fellow passenger the central tenets of physics and how they apply to universe shape.



Or not.

And then, just as we had narrowed the possibilities down (they also include, theories that it might be dodecahedral, although I have yet to find a snack shaped like that - possible new product angle, anyone?), someone went back and relooked at our assumptions.

Which is wonderful. Super. Very scientific. And, often, a stunningly good way to upset not only the apple cart, but the entire market with repercussions all the way back to the farm.

You see, it's been realised that dark energy (the black sheep of physics, hngh hngh) might have far more of an effect on the shape of the universe than we thought. Which makes sense. But it really does confuse the matter even more.

And, in a wonderful chicken and egg scenario, this lack of knowledge about the size and shape of the universe, in turn, makes it very difficult to further explore (i.e. find/work out anything, at all, about) dark energy.

Fun, non?

Sixty Symbols

Wow, so, I've been promising to start this up for ages.

Ah well, here goes. Our first link will be to Sixty Symbols (click on the logo below), kindly brought to us by the University of Nottingham (nice one, chaps)



60 symbols is brilliant: it's perfect for those of us with an interest in physics, but not, perhaps, the ability to read and comprehend the often dense physics textbooks (or the accompanying lectures, for that matter).

The fact that the concepts are presented by people clearly expert in them's even better, and I've found I've learnt some brilliant new things, including concepts with which I already thought myself familiar.