What do leopard spots, striped marine angelfish, and sand dune ripples have in common? Their patterns are self-organizing Turing systems! Discovered by Alan Turing in the 1950s, these repeating natural patterns can be created by the interaction of two things that spread at different speeds, one faster than the other.
Gifs are from Creative Commons videos by Jonathan McCabe.
Science Needs Women:
For Women in Science; the L’Oreal Foundation
I’m sharing this video on any platform I can because when I first found it last week it had something like 1,400 views, but it’s the most beautifully produced and succinctly narrated video addressing some of the most complicated issues facing women in STE(A)M fields I’ve found yet.
I’m sharing this for every time I’m called a “feminazi.”
…for every time I’m told that my concerns aren’t valid, our that our issues are imagined.
…for every time I hear “women just don’t like science,” or worse - “women just aren’t good at science.”
…for every time we’re told that we can have a family or a career, but not both - and for every time we feel like we have to decide between the two.
…and because we need more women mentors in these fields to stand up for issues that are not “women’s issues” - these are people issues that affect our collective society as a whole.
The women in this video are my heroes and they should be your heroes, too.
Handedness - the idea that one hand is better able to perform certain tasks than the other - is, if not exclusively a human trait, then certainly a mostly human one. After all, how could you tell if a dog was left-handed or a lion was right-handed? Their paws aren’t evolved to handle complex tasks like our hands are, and there’s no evidence that non-primates favor one limb over any other.
For reasons that can probably best be described as “stupid”, people have historically held left-handers in contempt. You can find evidence of an anti-left bias throughout the world’s languages. The word “left” itself comes from the Anglo-Saxon word “lyft”, which means “weak.” We get the word “sinister” from the Latin word for “left”, and that double meaning persists in the modern Romance languages.
But exactly why humans favor different hands, or why most people tend to be right-handed, remains mysterious. The most common answer is that handedness is determined by the structure of our brains, which are divided into two hemispheres. Our brains are far more specialized than those of other animals, with different regions of the brain responsible for different specific tasks. Admittedly, these are only general guidelines, and most neural activities are shared between the hemispheres to some extent, but we can definitely say that many functions are primarily handled by one hemisphere as opposed to another. This is known as brain lateralization.
Two of the most energy-intensive human activities are language and the use of our fine motor skills - in other words, the use of our hands. One theory suggests that it’s more efficient for the brain to cluster control of these two major tasks in one hemisphere rather than having it spread throughout the brain. Since the vast majority of people have their language functions centered in the left hemisphere, it follows that most people’s fine motor skills would be controlled by the left hemisphere too. Each hemisphere generally controls the opposite side of the body, so the end result is that most people are right-handed.
However, the opposite does not hold true - being left-handed does not mean the language centers are located in the right hemisphere, which is fairly rare. Certainly, lefties are more likelythan righties to have their right hemisphere responsible for language, but it’s still not a common arrangement. Between 61 and 73% of lefties have their language centers in the left hemisphere, compared to over 90% of right-handed people.
This doesn’t necessarily invalidate the division of labor theory. After all, between 70 and 90% of people are right-handed, and well over 90% of those people do indeed cluster language and fine motor skill control in the left hemisphere. What we’re looking at here is the evolutionary equivalent of a rule of thumb. People’s brains are generally organized to maximize energy efficiency, but a reasonably large minority of people - including most lefties - get along just fine with a less efficient arrangement.
What does it actually mean to be right-handed or left-handed?
The everyday answer to that question is probably this: if you write with your right hand, then you’re right-handed. It’s a straightforward enough popular definition, but translating that into scientific terminology is trickier than you might think. Even simply saying that handedness is determined by which hand you prefer to use doesn’t actually help us that much. Let’s consider some of the problems here. Should a person’s dominant hand be determined by the hand they prefer to use, or the hand that performs better in tests? In other words, is handedness primarily psychological or physiological? Even if you can sort that out, there’s still the question of how to categorize all this. Should left-handed and right-handed be considered precisely equal, or does the fact that such a vast majority of people are right-handed suggest that the people are simply either right or non-right? That’s a bit of a charged way to look at things, but it does have some popularity in scientific literature.
And how about people who use different hands for different tasks? I write and throw with my right hand but bat and play(ed) hockey with my left hand - should I be considered primarily right-handed, a mix of right- and left-handed, or ambidextrous, meaning I feel equally comfortable using both hands? And should we look at handedness as something that can be lumped into only a very few categories - say true right-handed, more right-handed, ambidextrous/mix, more left-handed, and true left-handed - or something that exists on a broad spectrum?
Indeed, the very idea that one hand is “dominant” might be a complete misunderstanding of how our hands divide up tasks. In a Science post, Michael Balter details an argument by University of Liverpool archaeologist Natalie Uomini:
Uomini points out that handedness does not mean that one hand is “dominant” over the other. Rather, she writes, “both hands have different but equally important roles.” In right-handed people, for example, the right hand might be used for tasks requiring greater manual dexterity whereas the left hand might perform the more mundane but nevertheless crucial role of supporting an object. (Imagine eating dinner with just a knife but no fork, for example.)
Do Antidepressants Work?
Antidepressants have been hailed as miracle drug rock stars and vilified as brain-changing happy pills. All promotion aside—good or bad—are they effective? The Savvy Psychologist Dr. Ellen Hendriksen digs though the data.
According to the Mayo Clinic, about 13% of Americans—more than 1 in 10—take an antidepressant. Of women between the ages of 50 and 64, nearly 1 in 4 take an antidepressant. Second only to antibiotics, antidepressants are the most commonly prescribed class of medication.
To clarify, when I say antidepressant, I mean the most common of many classes of antidepressants—the selective serotonin reuptake inhibitors, or SSRIs, like Prozac, Celexa, Lexapro, Paxil, or Zoloft. They’re safer and cause fewer side effects than other, older types of antidepressants.
So, do they work? Or do they not work? The answer to both questions seems to be yes. I know that’s a frustrating answer. So let’s look at each side. We’ll start with the claim that they don’t work.
Are White Holes Real?
Sailors have their krakens and their sea serpents. Physicists have white holes: cosmic creatures that straddle the line between tall tale and reality. Yet to be seen in the wild, white holes may be only mathematical monsters. But new research suggests that, if a speculative theory called loop quantum gravity is right, white holes could be real—and we might have already observed them.
A white whole is, roughly speaking, the opposite of a black hole. “A black hole is a place where you can go in but you can never escape; a white hole is a place where you can leave but you can never go back,” says Caltech physicist Sean Carroll. “Otherwise, [both share] exactly the same mathematics, exactly the same geometry.” That boils down to a few essential features: a singularity, where mass is squeezed into a point of infinite density, and an event horizon, the invisible “point of no return” first described mathematically by the German physicist Karl Schwarzschild in 1916. For a black hole, the event horizon represents a one-way entrance; for a white hole, it’s exit-only.
The Origin of Humans Is Surprisingly Complicated
Human family tree used to be a scraggly thing. With relatively few fossils to work from, scientists’ best guess was that they could all be assigned to just two lineages, one of which went extinct and the other of which ultimately gave rise to us. Discoveries made over the past few decades have revealed a far more luxuriant tree, however—one abounding with branches and twigs that eventually petered out. This newfound diversity paints a much more interesting picture of our origins but makes sorting our ancestors from the evolutionary dead ends all the more challenging.
Source: Scientific American
Reading glasses could be banished for ever after scientists developed a technique to reverse vision problems in ageing eyes.
As some people age, their ability to switch focus between near and distant objects diminishes, a condition known as presbyopia.
It can skew the perception of depth and makes reading in poor light impossible.
Now scientists have developed a tiny implant, no bigger than a pinhead, which sits inside the cornea and slightly increases its curvature, to allow the eye to focus again.
Known as a Raindrop corneal inlay, the technique was invented in America but the first operations have now been carried out at a clinic in Leamington Spa, Warwickshire.
Video: NASA’s ‘flying saucer’ tested in the upper atmosphere.
NASA is testing a “flying saucer” designed to land on Mars and deliver large payloads to the Red Planet, and the agency has released a spectacular video of a high-altitude test conducted over Hawaii this past June. In it, the Low Density Supersonic Decelerator (LDSD) is brought up 180,000 feet high into earth’s atmosphere, a place where conditions are similar to those on Mars. After confirming that the vehicle could fly in these conditions, NASA then tried to slow the craft down with two new technologies — a funky, donut-shaped “Supersonic Inflatable Aerodynamic Decelerator” and a massive supersonic parachute.
Using a centrifuge, it is possible to separate blood into three main fractions.
Although we are used to thinking of blood as a simple fluid, it is in fact a suspension of cells, debris and more within a carrier fluid.
The uppermost and clear yellow layer pictured is that fluid: plasma. This is the majority of what makes up human blood - plasma constitutes about 55% of its volume - of which 95% by volume is pure water.
The central layer of opaque white is known as the buffy coat. This fraction is comprised mainly of white blood cells and platelets.
Finally, the lowermost fraction is made up of the all-important red blood cells; erythrocytes. These cells are responsible for oxygen’s transit around the body, and give blood its striking colour.