In September, Torres was leading visitors into a floodplain surrounding Peru’s Tambopata Research Center, located near the western edge of the Amazon. From a distance, they saw what resembled a smallish, dead spider in a web. It looked kind of flaky, like the fungus-covered corpse of an arthropod.
But then the flaky spider started moving.
A closer looked revealed the illusion. Above the 1-inch-long decoy sat a much smaller spider. Striped, and less than a quarter-inch long, the spider was shaking the web.
A devout Hindu, Ramanujan said that his findings were divine, revealed to him in dreams by the goddess Namagiri.
While on his death-bed in 1920, Ramanujan wrote a letter to his mentor, English mathematician G. H. Hardy. The letter described several new functions that behaved differently from known theta functions, or modular forms, and yet closely mimicked them. Ramanujan conjectured that his mock modular forms corresponded to the ordinary modular forms earlier identified by Carl Jacobi, and that both would wind up with similar outputs for roots of 1.
“We proved that Ramanujan was right,” Ono says. “We found the formula explaining one of the visions that he believed came from his goddess.”
As a biologist, Lindenmayer worked with yeast and filamentous fungi and studied the growth patterns of various types of algae, such as the blue/green bacteria Anabaena catenula. Originally the L-systems were devised to provide a formal description of the development of such simple multicellular organisms, and to illustrate the neighbourhood relationships between plant cells. Later on, this system was extended to describe higher plants and complex branching structures.
The recursive nature of the L-system rules leads to self-similarity and thereby fractal-like forms are easy to describe with an L-system. Plant models and natural-looking organic forms are easy to define, as by increasing the recursion level the form slowly ‘grows’ and becomes more complex. Lindenmayer systems are also popular in the generation of artificial life.
Here is an L-System Explorer that you can play around with, created by Miles Egan. I made:
Update: Here is another good L-system explorer.
Autoscopic doubles are not good company. They can also be evidence that things aren’t exactly right in your brain. They come with migraines, epilepsy, post-traumatic disorders, encephalosis of schizophrenia — so you don’t want them around, and you are probably happy when they go.
But while they’re there, hanging around, it must be strange, even slightly fascinating, to have a second you always nearby, making your moves, not because it wants to, but because you made it. You’re the boss. It’s your slave. And nobody chose this. Not you. Not it. It’s like you’re both in a prison of someone else’s making. So, like prisoners everywhere, you both surrender.
Geographically accurate map of the 2008 presidential election:
Map of the 2008 presidential election, adjusted for population density:
Map of the world, adjusted for population density (click for full size):
In essence, the innovation — called coded TCP — makes packet loss completely disappear. In wired networks, packet loss is incredibly rare, but in wireless networks it’s one of the biggest issues affecting throughput. According to Technology Review, MIT’s WiFi networks generally lose 2% of packets — while on a fast train, packet loss is nearer 5%.
With coded TCP, blocks of packets are clumped together and then transformed into algebraic equations that describe the packets. If part of the message is lost, the receiver can solve the equation to derive the missing data. The process of solving the equations is “simple and linear,” meaning it doesn’t require much processing on behalf of the router/smartphone/laptop.
By comparing the specimens’ ages and degrees of DNA degradation, the researchers calculated that DNA has a half-life of 521 years. That means that after 521 years, half of the bonds between nucleotides in the backbone of a sample would have broken; after another 521 years half of the remaining bonds would have gone; and so on.
The team predicts that even in a bone at an ideal preservation temperature of -5 ºC, effectively every bond would be destroyed after a maximum of 6.8 million years. The DNA would cease to be readable much earlier — perhaps after roughly 1.5 million years, when the remaining strands would be too short to give meaningful information.
Learned helplessness is a technical term that refers to the condition of a human or animal that has learned to behave helplessly, failing to respond even though there are opportunities for it to help itself by avoiding unpleasant circumstances or by gaining positive rewards. Learned helplessness theory is the view that clinical depression and related mental illnesses may result from a perceived absence of control over the outcome of a situation. Organisms which have been ineffective and less sensitive in determining the consequences of their behavior are defined as having acquired learned helplessness.
“It taught me that the tough thing is figuring out what questions to ask, but that once you do that, the rest is really easy,” Musk says, referring to the novel’s revelation that the answer to the ultimate question of “life, the universe, and everything” is 42. “I came to the conclusion that we should aspire to increase the scope and scale of human consciousness in order to better understand what questions to ask. Really, the only thing that makes sense is to strive for greater collective enlightenment.”
I now know what I want to do for the rest of my life.