Melt a stack of pennies, burst a glass bottle, damage various food items, and incinerate wood using the power of the Sun! This four-foot magnifying Fresnel lens reclaimed from an old TV melts concrete and nearly anything else that gets in its way.
Tag Archive: science
Eruptive events on the Sun can be wildly different. Some come just with a solar flare, some with an additional ejection of solar material called a coronal mass ejection (CME), and some with complex moving structures in association with changes in magnetic field lines that loop up into the Sun’s atmosphere, the corona.
On July 19, 2012, an eruption occurred on the sun that produced all three. A moderately powerful solar flare exploded on the Sun’s lower right hand limb, sending out light and radiation. Next came a CME, which shot off to the right out into space. And then, the Sun treated viewers to one of its dazzling magnetic displays — a phenomenon known as coronal rain.
Over the course of the next day, hot plasma in the corona cooled and condensed along strong magnetic fields in the region. Magnetic fields, themselves, are invisible, but the charged plasma is forced to move along the lines, showing up brightly in the extreme ultraviolet wavelength of 304 Angstroms, which highlights material at a temperature of about 50,000 Kelvin. This plasma acts as a tracer, helping scientists watch the dance of magnetic fields on the Sun, outlining the fields as it slowly falls back to the solar surface.
The footage in this video was collected by the Solar Dynamics Observatory’s AIA instrument. SDO collected one frame every 12 seconds, and the movie plays at 30 frames per second, so each second in this video corresponds to 6 minutes of real time. The video covers 12:30 a.m. EDT to 10:00 p.m. EDT on July 19, 2012.
Credit: NASA SDO
This is something I’ve been wondering about for some time now. I’ve noticed that some people have dark rings around the outside of their eyes’ irises, between the iris and the white. It’s like a dark, bottomless pool of pure color. Other people don’t have it. Their irises slam right up into the white.
Last month, Notional Geographic magazine celebrated their 125th anniversary with a special photo issue. On the cover is their iconic and haunting photo of a young Afghan girl. I’m sure you’ve seen it:
Her sea-green eyes are the most striking I think I’ve ever seen. And she has those dark rings, too. I kept seeing the photo and wondering about those rings.
So I Googled it. They’re called “limbal rings,” and psychologists say they are an unconscious measure of attractiveness. They make the eyes “pop” and make the whites look whiter. Thick, dark limbal rings are also a measure of general physical health, as they fade with age and disease. Contact lens makers have long been making colored lenses that enhance the limbal ring:
My eyes are hazel, green on the outside and brown on the inside. The dark limbal ring is a deep green color.
Destin at Smarter Every Day examines the aerodynamics of butterfly flight.
4,000 ping pong balls go boom on the Ellen Show:
The Slo-Mo Guys place fireworks inside tubs of paint and film the spectacular results at 1,600 frames per second.
I’ve been thinking for some time about dreams. I really don’t remember my dreams; in fact, I remember them so rarely that I have a dream diary in which years can pass between entries. But I am aware that I dream. Sometimes I just have the sense upon waking, that it’s been a “busy” night. Other times, during waking hours, I may just get a flash of a dream, a fragment of a memory, and I know it came from a dream, often a recurring one. And in those moments, I wonder: what just made that memory pop up? And why right now? Was I thinking of something related to the dream? No…
Then one day recently, I heard a very interesting hypothesis: that we may always be dreaming, all the time. It’s only during REM cycle, and the last hour or two before waking, when all other external stimuli are damped down enough for our dreaming to filter up to the surface. And, perhaps, even when the mind is still and quiet enough during waking hours.
From DreamResearch.net, a service of the University of California at Santa Cruz:
“Sometimes we can have dreamlike moments during waking if we are in a relaxed state of mind and not noticing anything in our surroundings, as demonstrated in two different studies of people awake in slightly darkened rooms who were signaled at random intervals to say what was going through their minds. And the investigators knew these people were awake because their brain wave activity was being monitored via EEG. So, it may be that we dream any time that the following conditions are met: (1) an adequate level of brain activation; (2) a shutting out of external stimuli; and (3) a shutting down of the self-awareness system that helps focus our minds when we are awake.”
This was quite a revelation for me. Suddenly, these “flashes” of dream fragments took on another possible nature: they aren’t memories of a dream I had earlier, but a “bubbling up” of a dream I’m having right now!
There’s something else that has spoken to me for years. The Mayans took their lucid dreaming very seriously. In fact, I once found the Mayan hieroglyphs that read “Dreaming I wake; Waking I dream.” I still have it. If I ever decided to get a tattoo, it would be these hieroglyphs twined around my arm.
This concept of dreaming while waking and waking during dreaming, also strongly reminded me of mastering lucid dreaming: becoming self-aware during the dream, and taking control of it, and doing important and useful things in dreamtime. Then later, one also harnesses the power and magic of the dream state during one’s waking hours.
There is also the Australian aborigine’s concept of “Dreamtime,” a realm more real than the physical, in which life and death struggles may play out.
Dreaming I wake; Waking I dream.
The Slo-Mo Guys, Gavin and Daniel, kick over some trays full of flaming fuel, and film the results at 2,500 frames per second.