In mathematics, a minimal surface is a surface that locally minimizes its area. This is equivalent to having a mean curvature of zero. The term “minimal surface” is used because these surfaces originally arose as surfaces that minimized total surface area subject to some constraint. Physical models of area-minimizing minimal surfaces can be made by dipping a wire frame into a soap solution, forming a soap film, which is a minimal surface whose boundary is the wire frame. However the term is used for more general surfaces that may self-intersect or do not have constraints.
Art by Paul Nylander.
Once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return.
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| — | Leonardo da Vinci (via shuttleisland) |
Image credit: NASA, ESA, N. Smith (University of California, Berkeley), and The Hubble Heritage Team (STScI/AURA).
Some interesting info: This is very reminiscent of the Baby X experiments, in which it was discovered that people reacted differently to a baby’s behavior depending on whether or not they believed the baby to be male or female. People were asked to watch a video of a baby reacting to a startling image (a Jack-in-the-box popping up), and describe the baby’s emotional state. When people believed the baby to be female, they described the baby as being scared and upset; when they thought the baby was male, they perceived the baby to be angry. This was very telling, as it showed that literally identical behavior could be construed differently based on the perceived gender of the subject.
The last telegram ever is about to be sent
On July 14, someone somewhere in India will tap out what is being called the world’s last telegram. India’s state-owned telecom company, Bharat Sanchar Nigam Limited, has been holding out as other countries around the world retire their antiquated telegraph services. Now, after delaying the move for two years, the business operating what is considered to be the world’s last telegraph service is finally ready to pull the plug, saying telegrams are no longer commercially viable in the age of digital communications.
It’s Plane To See …
Yes! All the planets are, more or less, on the same plane. This means that their orbits all follow the same flat, circular path. This is illustrated by the following animation:
The planets are not perfectly lined up on the same orbit, though. If we define Earth’s orbit to be “the perfectly perfect ecliptic”, then the other planets orbit within a few degrees of that. Why?
When the solar system formed, there was a massive rotating cloud of debris and dust spinning around the young star we now orbit. We call it the Protoplanetary Disk, which would make a great name for a spaceship. When something spins while being tethered in place by gravity, its mass wants to fly outward into a pizza-like shape, like frosting flying from errantly-aimed eggbeaters. The Earth even bulges a bit around the equator because of this “force”. This means that before the planets ever became planets, their planetary “stuff” was already on the same plane. Naturally, they thought this was just fine, and as they matured into the orbs we know and love, they stayed there.
This can be easily observed in the night sky. When multiple planets are visible, you can draw the line of the ecliptic through them! It’s also why we seem to have so many nights when planets are “near” each other in the sky, but never quite on top of each other (called “conjunction”, check it out in this video)
By now, many of you are fidgeting uncomfortably, barely able to contain the following comment: “Bah! You are wrong, science man! Pluto doesn’t orbit on the ecliptic! It’s wonky as hell!”
Well, the question was “Are all the planets in the solar system on the same plane?” And the answer to that is most definitely yes. You’re just going to have to get over the fact that Pluto is not a planet anymore. Its tilted orbit is one of the main reasons why.
The first step to healing is acceptance. The second step is realizing that this wacky ball of ice is so off-kilter that it’s lucky it didn’t fly right off into interstellar space:
(images via Wikipedia)
The Root Cause of Diabetes Has Been Identified
A quote from the article
Fiorina and his team studied hundreds of pathways in animals with diabetes. They eventually isolated one, known as ATP/P2X7R, which triggers the T-cell attacks on the pancreas, rendering it unable to produce insulin.
“By identifying the ATP/P2X7R pathway as the early mechanism in the body that fires up an alloimmune response, we found the root cause of diabetes,” says Fiorina. “With the cause identified, we can now focus on treatment options. Everything from drug therapies to transplants that require less immunosuppression is being explored.”
Silicon wafers are the foundation for computer chips and solar cells, and they require a polymer coating before they can be used. This process, called “passivation,” protects the wafers from corrosion and ties up any loose atomic bonds. Seen here is a silicon wafer with a polymer coating at 500x magnification.
Image by Sarah Walters, University of Rochester.
The excretory system of Schmidtea mediterranea, a small freshwater flatworm. S. mediterranea have a remarkable ability to regenerate. Cutting one in half will generate two fully functional flatworms; cutting it into quarters will generate four; and so on. In fact, scientists have shown that even a single cell from one flatworm is capable of regenerating an entire organism.
Image by Hanh Vu, Stowers Institute for Medical Research, Kansas City, Missouri.
Huh, chewing gum is a weird one, and probably not as effective as other methods. But most tips are actually helpful because they either minimise the amount of sulfur gas getting to your eyes, or minimise the amount released in the first place. MOST USEFUL TIPS:
- Refrigerate the onions, because it slows down the chemical processes. Don’t freeze them because honestly how’re you going to cut them if they’re rock hard
- Use a sharp knife so you do minimal damage to cell walls—a dull knife crushes more of the cells
- Move onions away from you as soon as they’re cut
- Cut the onions underwater, because water will dissolve sulfur compounds
- Light a candle near your cutting board—the heat will draw the gas away
- Leave the root end on until the very end instead of cutting it off first, because the sulfur compounds are concentrated there
- Wear safety goggles. Cooking is serious business.
