(This is for Groupon employees, but I’m posting it publicly since it will leak anyway)
People of Groupon,
After four and a half intense and wonderful years as CEO of Groupon, I’ve decided that I’d like to spend more time with my family. Just kidding – I was fired today.
If you’re wondering why… you haven’t been paying attention. From controversial metrics in our S1 to our material weakness to two quarters of missing our own expectations and a stock price that’s hovering around one quarter of our listing price, the events of the last year and a half speak for themselves. As CEO, I am accountable.
The best CEO goodbye letter ever. Maybe they should keep him just cause he’s so funny.
Will we ever… simulate the human brain?
A billion dollar project claims it will recreate the most complex organ in the human body in just 10 years. But detractors say it is impossible. Who is right?
For years, Henry Markram has claimed that he can simulate the human brain in a computer within a decade. On 23 January 2013, the European Commission told him to prove it. His ambitious Human Brain Project (HBP) won one of two ceiling-shattering grants from the EC to the tune of a billion euros, ending a two-year contest against several other grandiose projects. Can he now deliver? Is it even possible to build a computer simulation of the most powerful computer in the world – the 1.4-kg (3 lb) cluster of 86 billion neurons that sits inside our skulls?
The very idea has many neuroscientists in an uproar, and the HBP’s substantial budget, awarded at a tumultuous time for research funding, is not helping. The common refrain is that the brain is just too complicated to simulate, and our understanding of it is at too primordial a stage.
Then, there’s Markram’s strategy. Neuroscientists have built computer simulations of neurons since the 1950s, but the vast majority treat these cells as single abstract points. Markram says he wants to build the cells as they are – gloriously detailed branching networks, full of active genes and electrical activity. He wants to simulate them down to their ion channels – the molecular gates that allow neurons to build up a voltage by shuttling charged particles in and out of their membrane borders. He wants to represent the genes that switch on and off inside them. He wants to simulate the 3,000 or so synapses that allow neurons to communicate with their neighbours.
Erin McKiernan, who builds computer models of single neurons, is a fan of this bottom-up approach. “Really understanding what’s happening at a fundamental level and building up – I generally agree with that,” she says. “But I tend to disagree with the time frame. [Markram] said that in 10 years, we could have a fully simulated brain, but I don’t think that’ll happen.”
Even building McKiernan’s single-neuron models is a fiendishly complicated task. “For many neurons, we don’t understand well the complement of ion channels within them, how they work together to produce electrical activity, how they change over development or injury,” she says. “At the next level, we have even less knowledge about how these cells connect, or how they’re constantly reaching out, retracting or changing their strength.” It’s ignorance all the way down.
“For sure, what we have is a tiny, tiny fraction of what we need,” says Markram. Worse still, experimentally mapping out every molecule, cell and connection is completely unfeasible in terms of cost, technical requirements and motivation. But he argues that building a unified model is the only way to unite our knowledge, and to start filling in the gaps in a focused way. By putting it all together, we can use what we know to predict what we don’t, and to refine everything on the fly as new insights come in.
I hope some major breakthrough comes from funding his work in brainsimulations…time will tell
New astonishing pictures by the European Space Agency have revealed a 1500 km long and 7 kilometre wide river that once ran across Mars.
The agency’s Mars Express imaged the striking upper part of the remnants of Reull Vallis River on Mars with its high-resolution stereo camera, ESA said in a statement.
New analogies are giving planetary geologists tantalising glimpses of a past on the Red Planet not too dissimilar to events on our own world today.
Reull Vallis, is believed to have formed when running water flowed in the distant Martian past, cutting a steep-sided channel through the Promethei Terra Highlands before running on towards the floor of the vast Hellas basin.
This sinuous structure, which stretches for almost 1500 km across the Martian landscape, is flanked by numerous tributaries, one of which can be clearly seen cutting in to the main valley towards the upper (north) side.
The new Mars Express images show a region of Reull Vallis at a point where the channel is almost 7 km wide and 300 m deep. The sides of Reull Vallis are particularly sharp and steep, with parallel longitudinal features covering the floor of the channel itself.
These structures are believed to be caused by the passage of loose debris and ice during the “Amazonian” period - which continues to this day - due to glacial flow along the channel.
The structures were formed long after it was originally carved by liquid water during the Hesperian period, which is believed to have ended between 3.5 billion and 1.8 billion years ago.
Similar lineated structures, believed to be rich in ice, can also be found in many of the surrounding craters. In the wider context image, the tributary intersecting the main channel appears to be part of a forking of the main valley into two distinct branches further upstream before merging back into a single main valley.
The northern part of the main image is dominated by the Promethei Terra Highlands with their high and soft-rounded mountains shown in these images, rising around 2500 m above the surrounding flat plains, the statement said.
The perspective view below shows one of these mountains with nearby sediment-filled impact craters. The region shows a striking resemblance to the morphology found in regions on Earth affected by glaciation.
The images show circular step-like structures on the inner walls of the sediment-filled crater in the foreground of the second perspective view. Planetary scientists think that these may represent former high water or glacial levels, before ice and water sublimated or evaporated away in stages at various times.
The morphology of Reull Vallis suggests it has experienced a diverse and complex history, with analogies seen in glacial activity on Earth.
Read Article here
Image Credit: ESA/DLR/FU
SUBMISSION: Anatomy of Valo Light (courtesy of @themgoods, @alejohcandelo)
Some things have such an intrinsic style. I love those skates