"Cactus" bucks are bucks that are in velvet and have points sticking out all over their head. When a buck has very small testes, or has no testes at all, known as cryptorchidism — meaning they haven’t descended from the body cavity and thus do not function — you get cactus bucks. Since they never shed, each spring new antlers develop on top of the old ones. Further north these extra antler tines may freeze in winter and break off, but if the weather isn’t too bad, antlers tines grow over old antlers tines and you get these weird looking bucks. The older they get, the odder the growths become.
A holepunch or fallstreak cloud is an atmospheric phenomenon believed to be caused by a combination of both mother nature and man. For the fallstreak hole to begin, cirrocumulus or altocumulus must contain super-cooled water which cannot freeze without a tiny particle to first cling to. Scientific opinion as to what finally causes the ice to form and begin to crystallize in the atmosphere has only solidified in recent years as meteorologists have become more certain that airplanes flying through the clouds start the process. Air passing along propeller blades or wings expands and cools rapidly. The ice crystals begin to form and after the plane is long gone - the crystals can still be seen where they’ve dropped down below the cloud. What’s left above the drifting ice particles is a round hole in the cloud that can sometimes be very large.
Photo credit: Marc Eilbeck on Twitter.
Therefore Bill Gates should buy North Korea and solve a lot of problems
New Super Black Material Absorbs 99.965% Of Light
Goths of the world, rejoice. Scientists have produced Vantablack, a product so dark it becomes impossible to make out shapes formed from it.
Surrey Nanosystems, a British nanoelectronics company have used carbon nanotubes 10,000 times thinner than a human hair to absorb 99.965% of visible light, a world record. The tubes are so small photons cannot get inside, but can fit into the small spaces between the tubes, where they are captured.
For comparison, fresh asphalt reflects 4% of the light that falls on it, and after a while this rises to 12%, while coal seldom gets below 0.5%.
"You expect to see the hills and all you can see … it’s like black, like a hole, like there’s nothing there. It just looks so strange," Surrey Nanosystems’ technical director Ben Jensen told The Independent.
The manufacturers grow Vantablack (Vertically Aligned carbon NanoTube Array) on aluminum foil, making it easy to create complex topography that is entirely invisible to the eye. They point out their low-temperature nanotube growth processes give it a significant advantage past super-black materials that require high temperatures to produce, and are therefore incompatible with sensitive electronics.
While there is probably a market for practical jokes, Surrey Nanosystems are talking up the capacity of Vantablack to calibrate astronomical cameras and infrared scanners, which need to be shown the darkest object possible for comparison with tiny points of light. They also hint darkly at military uses, which may benefit from the enormous tensile strength and heat conductivity.
“We are now scaling up production to meet the requirements of our first customers in the defense and space sectors, and have already delivered our first orders,” said Jensen. So far at least Vantablack is far too expensive to be used for clothes or toys but Jensen said, “You would lose all features of a dress. It would just be something black passing through.”
The properties of Vantablack have been described in Optics Express.
A Rainbow in the Clouds
If you see a rainbow among the clouds low in the sky on a sunny summer day, it’s a natural phenomenon called a circumhorizon arc. It is seen nearly exclusively in summer, because it requires that the sun be very high, to create the right angle of light beams.
It also requires thin, wispy cirrus clouds. Cirrus clouds are thin layers extremely high in the atmosphere and the water they contain is usually frozen. The ice crystals act like small prisms, fracturing the sunlight passing through them. If the clouds are across the sky you might see a full rainbow arc, but if there are only shreds of them here and there you’re more likely to just see a fragment of a rainbow.
The sun can produce a number of types of cloud rainbows, but circumhorizon arc rainbows are always parallel to and often not too far above the horizon.
photo by Gavin Anderson, shared on Wikimedia Commons
(via: Peterson Field Guides)