Triple backflip on a bike, including the helmetcam fotage.
New Zealand BMXer Jed Mildon has created action-sports history today by landing the world’s first Triple Backflip at the Unit T3 Mindtricks BMX Jam in Taupo, New Zealand.
Category Archives: Physics
Planes, Trains and Automobiles … and Airships?
Helium Hokum: Why Airships Will Never Be Part of Our Transportation Infrastructure
[A]irships got left behind. Why? They have an Achilles’ heel. No, it’s not the weather, hydrogen, or the materials of the day—and it’s not some conspiracy or a crewman with a bomb on the Hindenburg ruining it for everybody. Like a lot of things, the facts are simple and scientific, and thus boring—unless you’re intrigued by simple scientific facts. Either way it’s this: airships are inefficient.
The purpose of transportation is to get a thing from one place to another. The measure of any vehicle’s efficiency—be it by land or by sea or even by air—is how much it carries vs. how hard you have to push it and how fast it goes. At the end of the day, we all want to get it there fast, and we all want to get it there cheap.
Always Demand an Inertial Frame of Reference
The time-lapse starfield has been edited to show the rotation of the Earth from the point of view of the stars.
The Odd Couple
Skulls in the Stars: Water has properties that are positively electrifying!
Why is water so strongly attracted to static electricity? It turns out that the answer is somewhat complicated, and the complete explanation was a bit of a minor mystery for nearly eighty years!
If You Build it, Fingerprints Will Come
Slightly smaller than a square tissue box, AIRprint houses two 1.3 megapixel cameras and a source of polarized light. One camera receives horizontally polarized light, while the other receives vertically polarized light. When light hits a finger, the ridges of the fingerprint reflect one polarization of light, while the valleys reflect another. “That’s where the real kicker is, because if you look at an image without any polarization, you can kind of see fingerprints, but not really well,” says Burcham. By separating the vertical and the horizontal polarization, the device can overlap those images to produce an accurate fingerprint, which is fed to a computer for verification.
I’m guessing that what they mean is that the light source is polarized and the cameras have polarizing filters in front of them to see the two components. Reflectivity generally depends on the polarization and angle of the incident light; the whole reason that polarized sunglasses are effective is that light scattered off of a surface tends to be polarized parallel to that surface, and at Brewster’s angle absolutely none of the perpendicular component will be reflected. So it seems reasonable that detection of the two polarizations improves the contrast of the image you get. Light at normal incidence will reflect the polarized light with no change, but light scattered off of the valleys will mix in some of the orthogonal polarization, which gets picked up by the other camera.
It's a Series of Cubes!
Backreaction: The cube of physical theories
To our best present knowledge these constants are indeed constant, but you can imagine varying them and ask what happens to the theory then. In many cases this corresponds to some physical limit. For example, if your theory contains terms in v/c, where v is velocity, then the limit of velocities small compared to c (i.e. non-relativistic) formally corresponds to taking c to infinity, ie 1/c to zero.
Becoming a Fan o' Flow
Water Helps Them Relax
cm-scale origamis unfolding when placed on the surface of water, as the paper absorbs the water from capillary action.
Science is Not a Wrestling Match
Refuting Einstein: a media controversy in Ireland
At first, professional physicists paid very little attention to the story. In the few instances where their opinion was sought, the ‘debate’ was portrayed as one voice against another, not as the overwhelming consensus of 100 years of scientific evidence against one engineer. Most of all, the debate was portrayed as Kelly vs Einstein – I do not recall a single journalist draw attention to the fact that physicists’ belief in relativity stems not from a belief in Einstein, but from the mountain of experimental evidence that supports the theory (a confusion of the context of discovery with the context of justification).
The author makes a lot of good observations about what’s bad in science journalism, most of which I agree with and have pointed out a number of times in the past, such as manufacturing controversy by making it appear that both sides have equal merit. Sacrificing scientific accuracy for the sake of the appearance of neutrality is something that ultimately undermines your credibility. When the average reader gets the message that relativity is a religion, you’re doing it wrong.