Silver Slipstreams

The Capetonians who venture to this part of the blogosphere may remember the viral video of a longboarder setting off the Kloof Nek speed camera early this year.  Although I gave this a very brief mention at the time, the video deserves a repost…

… if only because of what comes next.

Meet Decio Lourenco: graphic design student by day, downhill longboarder by night.  After gaining fame (and notoriety from the Western Cape traffic officials) for the Kloof Nek stunt, Decio was contacted by Mercedes-Benz to hurtle down a section of Franschhoek Pass alongside an A 45 AMG driven by former professional racing driver Robbi Smith.

With the blessing of aforesaid traffic officials, who closed off the pass specifically for this to happen, a film crew from Bring Back Choirboy spent three days filming the pair of four-wheeled adrenaline junkies.  The result — a simply breathtakingly choreographed high-speed ballet.

Further words simply do not do what you’re about to see justice.

This doesn’t do what you think it does

Earlier this week, I noticed some folks over on Facebook sharing a video of a red hot ball of nickel being dumped in a bucket of water, so out of sheer curiosity, I decided to take a look.

It doesn’t do what you might think it does.

Of course, this made me even more curious, so I did some Googling, and found this explanation:

For those of you who don’t know, this is an example of the leidenfrost effect. The ball is so hot that the water touching it immediately evaporates and the vapor around it insulates it from the rest of the water (the vapor is a much worse thermal conductor than liquid water). This is why you can stick your hand in liquid nitrogen for a short period of time. However, eventually the nickel ball cools to a point where it’s not hot enough to instantly vaporize the water and it stops.

The Wikipedia article on the Leidenfrost effect has a more detailed description of what’s going on:

The Leidenfrost effect is a phenomenon in which a liquid, in near contact with a mass significantly hotter than the liquid’s boiling point, produces an insulating vapor layer which keeps that liquid from boiling rapidly. This is most commonly seen when cooking; one sprinkles drops of water in a pan to gauge its temperature—if the pan’s temperature is at or above the Leidenfrost point, the water skitters across the metal and takes longer to evaporate than it would in a pan that is above boiling temperature, but below the temperature of the Leidenfrost point. The effect is also responsible for the ability of liquid nitrogen to skitter across floors. It has also been used in some potentially dangerous demonstrations, such as dipping a wet finger in molten lead[1] or blowing out a mouthful of liquid nitrogen, both enacted without injury to the demonstrator.[2] The latter is potentially lethal, particularly should one accidentally swallow the liquid nitrogen.

The article then goes into detailed scientific formulae on calculating the Leidenfrost point, heat transfer correlations and that kind of thing, but for us laymen, the synopsis above is perfectly good enough.

What really interested me afterwards is that, while attempting to hone my rather non-existent cooking skills, I have seen this before; I just didn’t know what it was, or indeed give it any second thought, until now.  In fact, this can easily (and relatively safely) be reproduced in your kitchen: heat up a stove plate to full, then put a drop of water on it.  (Just don’t try any of the potentially lethal demonstrations with molten lead or liquid nitrogen, unless you’re presenting an episode of Mythbusters.)  This free image from the Wikimedia Commons shows what happens when you try this:

Leidenfrost droplet

You learn something new every day.

No, really — what does the fox say?

In the aftermath of a certain viral video, the Huffington Post got hold of some experts to answer the question of what does the fox really say.

First up was Bob Huddelson, the owner of Lost River Game Farm, and apparently a breeder of such animals.  His response was rather bemused:

This almost sounds like a joke. A red fox makes about three different noises, but I’m not about to make them on the phone right now. You know how a cat purrs? Ok, when a fox — when a female fox — is looking for a male fox she does a loud purr that is very loud. And she’ll make that, and it probably lasts 3 seconds or 4 seconds. That’s one noise that a fox makes. Then, if you stumble on a fox’s den where she’s got puppies and she feels like you’re a threat, she’s got a wild scream that she makes that 99 percent of people would run for their lives [from], and that’s the idea. When that happens, she’ll move the puppies to a new den. A young fox, they make two or three noises as well. Most of them are soft, kind. [Sounding slightly exasperated] You have to play with a young fox to really hear what they’re like.

For comparitive purposes, HuffPost then obtained a response from Brian L. Cypher, a research ecologist at California State University studying San Joaquin kit foxes:

I’m actually away on vacation and just saw this. Probably too late to do much good. And anyway, most of my work has been with kit foxes and island foxes. They are relatively quiet compared to other foxes. I’m assuming the fox in the video is likely a red fox, although I haven’t see the video yet. Red’s tend to be a bit more vocal, from what I understand.

And then, I found this video of a screaming red fox:

So, that’s settled then.  Foxes make several noises.  And judging by Bob Huddelson’s decription and the red fox screaming video, Ylvis wasn’t that far off after all…

Have a break, have… an Android?

Fresh from this morning’s Slashdot news feed is this:

Today Google revealed that the next major version of the Android mobile operating system will be called ‘KitKat.’ The naming convention has always used sugary snacks in alphabetical order — Jelly Bean (4.1 – 4.3) followed Ice Cream Sandwich (4.0), which followed Honeycomb (3.1 – 3.2), which followed Gingerbread (2.3), and so on. Unlike the previous releases, KitKat is named after an actual product, rather than a generic treat. Thus, Google contacted Nestle, who was happy to jump on board and take advantage of the cross-marketing opportunities. According to an article at the BBC, the Android team was originally going to use ‘Key Lime Pie,’ but they decided it wasn’t familiar enough to most people. After finding some KitKat bars in the company fridge, they made the choice to switch. Nestle was on board ‘within an hour’ of hearing the idea.

Naturally, I couldn’t resist finding and posting this:

I'm not sure who to credit for this image, since it's propagated through the intarwebs at a rapid rate of knots.  If you do know, or if it's you, please get in touch.