We never sit here under the weight of all this air, the 5 x 10^18 kg of atmosphere that sits above everyone on Earth, and say “Gosh, that sure is heavy!”
You don’t realize just how powerful that 1 bar (~100 kPa) of pressure is until a train car is filled with steam, allowed to cool, and then implodes ohmygod did that just happen?
For more implosion goodness, check out this awesome video from Veritasium.
This triple gear is a real thing, and thanks to some intricate math and the advent of 3-D printing, it exists. Before this, at least as far as I can tell, a triple-meshed gear required one of the gears to turn in the opposite direction as the other two. That is no longer the case.
I can’t for the life of me imagine what this would be used in, but hey … at least we have it now. Get to designing!
(via henryseg on Shapeways)
How Brain Grows, Differentiates and Matures
The embryonic and fetal brains of all mammals develop in similar ways. The embryonic spinal cord develops along common sequences and patterns. The nervous system emerges from a simple elongated tube of cells, called the neural tube. The head (cranial) end of the embryonic tube expands and differentiates more robustly (than does the spinal end) into several clusters of cells which emerge as the forebrain (telencephalon and diencephalon), midbrain (mesencephalon) and hindbrain (metencephalon and myelencephalon) portions.
Image: Christine Daniloff/MIT
There seems to be no stopping the technological breakthroughs in improving efficiency in solar energy generation. This time, it appears to be able to break the fundamental limit to efficiency: the Shockley–Queisser limit.
…researchers at MIT have shown that there is a way to blow past that limit as easily as today’s jet fighters zoom through the sound barrier — which was also once seen as an ultimate limit.
Their work appears this week in a report in the journal Science, co-authored by graduate students including Daniel Congreve, Nicholas Thompson, Eric Hontz and Shane Yost, alumna Jiye Lee ‘12, and professors Marc Baldo and Troy Van Voorhis.
The principle behind the barrier-busting technique has been known theoretically since the 1960s, says Baldo, a professor of electrical engineering at MIT. But it was a somewhat obscure idea that nobody had succeeded in putting into practice. The MIT team was able, for the first time, to perform a successful “proof of principle” of the idea, which is known as singlet exciton fission. (An exciton is the excited state of a molecule after absorbing energy from a photon.)
In a standard photovoltaic (PV) cell, each photon knocks loose exactly one electron inside the PV material. That loose electron then can be harnessed through wires to provide an electrical current.
But in the new technique, each photon can instead knock two electrons loose. This makes the process much more efficient: In a standard cell, any excess energy carried by a photon is wasted as heat, whereas in the new system the extra energy goes into producing two electrons instead of one…
The breakthrough will, apparently, enable solar cells to achieve efficiencies of more than 30% - a huge leap compared to an industry which, according to professor Baldo, strives “for an increase of a tenth of a percent.”
For previous breakthroughs in solar efficiency:
Malformed – A Collection of Human Brains from the Texas State Mental Hospital
Hiroshi Sugimoto - Theaters (1978-93)
“I’m a habitual self-interlocutor. Around the time I started photographing at the Natural History Museum, one evening I had a near-hallucinatory vision. The question-and-answer session that led to this vision went something like this:
Suppose you shoot a whole movie in a single frame?
And the answer:
You get a shining screen.
Immediately I sprang to action, experimenting toward realizing this vision. Dressed up as a tourist, I walked into a cheap cinema in the East Village with a large-format camera. As soon as the movie started, I fixed the shutter at a wide-open aperture, and two hours later when the movie finished, I clicked the shutter closed.
That evening, I developed the film, and the vision exploded behind my eyes.”
Jim Parsons and Rihanna
These two gorgeous photos are of the Moon and Venus, as shot by astrophotographer Iván Éder of Hungary.
They were shot in two completely different years, 2007 (top) and 2004 (bottom). (Check out his crazy equipment!)