Group items tagged

biology would have to be popping up all over the place.

Andrew Ellington, of the Center for Systems and Synthetic Biology at the University of Texas, Austin, “I can’t tell you what the probability is. It’s a chapter of the story that’s pretty much blank.”

Given that rather bleak-sounding assessment, it may be surprising to learn that Ellington is actually pretty upbeat. But that’s how he and two colleagues come across in a paper in the latest Science. The crucial step from nonliving stuff to a live cell is still a mystery, they acknowledge, but the number of pathways a mix of inanimate chemicals could have taken to reach the threshold of the living turns out to be many and varied. “It’s difficult to say exactly how things did occur,” says Ellington. “But there are many ways it could have occurred.

The first stab at answering the question came all the way back in the 1950s, when chemists Stanley Miller and Harold Urey passed an electrical spark through a beaker containing methane, ammonia, water vapor and hydrogen, thought at the time to represent Earth’s primordial atmosphere.

Scientists have learned so much, in fact, that the number of places life might have begun has grown to include such disparate locations as the hydrothermal vents at the bottom of the ocean; beds of clay; the billowing clouds of gas emerging from volcanoes; and the spaces in between ice crystals.

The number of ideas about how the key step from organic chemicals to living organisms might have been taken has multiplied as well: there’s the “RNA world hypothesis” and the “lipid world hypothesis” and the “iron-sulfur world hypothesis” and more, all of them dependent on a particular set of chemical circumstances and a particular set of dynamics and all highly speculative.

“Maybe when they do,” says Ellington, “we’ll all do a face-plant because it turns out to be so obvious in retrospect.” But even if they succeed, it will only prove that a manufactured cell could represent the earliest life forms, not that it actually does. “It will be a story about what we think might have happened, but it will still be a story.”

The story Ellington and his colleagues have been able to tell already, however, is a reason for optimism. We still don’t know the odds that life will arise under the right conditions. But the underlying biochemistry is abundantly, ubiquitously available—and it would take an awfully perverse universe to take things so far only to shut them down at the last moment.

The system is small: about 1-2% the mass of the Milky Way and is rich in heavier elements.

astronomers are likely to discover even more distant galaxies when Nasa's James Webb Space Telescope (JWST) is launched and other ground-based telescopes come online.

One very interesting way to learn about the Universe is to study these outliers and that tells us something about what sort of physical processes are dominating galaxy formation and galaxy evolution. "What was great about this galaxy is not only is it so distant, it is also pretty exceptional."

But it has a surprising feature: it is turning gas and dust into new stars at a remarkable rate, churning them out hundreds of times faster than our own galaxy can.

This is an important step forward, but we need to continue looking for more.

In January 2013, astronomers used Kepler's data to estimate that there could be at least 17 billion Earth-sized exoplanets in the Milky Way galaxy.

The number of confirmed planets frequently increases because as scientists analyse the data they are able publish their results online immediately. But as the finds are not yet peer reviewed, the total figure remains subject to change.

"That's why the other catalogues just lag behind. The review is reliable as it's exactly the same as what the journals do."

"no consensus for the definition of a planet" a

"Some objects, like some Kepler planets, are declared 'confirmed planets' but have not been published in [referenced] articles. It does not mean that they will not be published later on, but it introduces another fuzziness in the tally," he added.

"I don't just want to know where the exoplanets are, I want to understand the stars, because they are the hosts for the planets. I want to understand the whole galaxy and the distribution of the stars because everything is connected," he explained.

For him, the most exciting discoveries are Earth-like planets which could be habitable.

This planet likely has the same mass as Earth but is outside the "habitable zone" as it circles its star far closer than Mercury orbits our Sun.

it’s good to know about your environment even if it doesn’t promise a reward right now; knowledge may be useless today, but vital next week. Therefore, evolution has left us with a brain that can reward itself; satisfying curiosity feels pleasurable, so you explore the environment even when you don’t expect any concrete payoff

What’s more, curiosity doesn’t just ensure new opportunities for learning, it enhances learning itself

subjects better remembered those appearing after trivia questions that made them curious. Curiosity causes a brain state that amplifies learning.

This function of curiosity — to heighten memory — is the key to understanding why we’re curious about some things and not others. We feel most curious when exploration will yield the most learning.

Suppose I ask you, “What’s the most common type of star in the Milky Way?” You’ll obviously feel no curiosity if you already know the answer. But you’ll also feel little interest if you know nothing about stars; if you learned the answer, you couldn’t connect it to other knowledge, so it would seem nearly meaningless, an isolated factoid

We’re maximally curious when we sense that the environment offers new information in the right proportion to complement what we already know.

Note that your brain calculates what you might learn in the short term — your long-term interests aren’t a factor

Many websites that snare your time feature scores of stories on the front page, banking that one will strike each reader’s sweet spot of knowledge. So visit websites that use the same strategy but offer richer content, for example, JSTOR Daily, Arts & Letters Daily or ScienceDaily.

Curiosity arises from the right balance of the familiar and the novel. Naturally, writers vary in what they assume their audience already knows and wants to know; when you find an author who tends to have your number, stick with her.