ريتشارد دوكنز's Blog, page 570
February 3, 2016
The Migrant Crisis: No End in Sight
Photo credit: Sergey Ponomarev
By Russell Goldman
The refugees keep coming.
Forced from their homes by war and economic deprivation, tens of thousands of migrants made the perilous journey to Europe last month.
These asylum seekers, the latest surge in a great tide of human movement, have braved winter weather, stormy seas and closed borders in their escape from the Middle East, Afghanistan and Africa.
On Thursday in London, the European Union and international donors are expected to pledge to increase their aid to Syrians displaced by war.
The toll, whether measured in lives or in dollars, is staggering.
More than 67, 000 migrants have arrived in Europe by sea since the start of the year. By comparison, 5,000 migrants made the journey across the Mediterranean in January 2015, according to the International Organization for Migration.
These newcomers join more than one million people who sought refuge in Europe last year. But more telling than the total number of migrants is the number who have been formally resettled: 190 in 2015, despite pledges to relocate almost 200,000.
“We have to go,” said Mohamed Salem Abrahim, a 17-year-old Afghan trying to make his way to Germany. Mohamed arrived in Greece two months ago after traveling through Iran and catching a leaky boat from Turkey. “What is the choice — to stay in our country and be killed, or come to Europe where we can be free?”
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Evaluating Our Importance In The Universe
Photo credit: ESA/NASA
By Marcelo Gleiser
For the past two weeks we’ve been exploring some of the questions related to life’s origin on Earth and possibly elsewhere.
We know life was present on Earth at least 3.5 billion years ago. It may have been present even earlier, but results remain controversial. The window of opportunity for life to emerge and take root here opened after the Late Heavy Bombardment calmed down some 3.9 billion years ago. Before then, conditions were too harsh for living creatures to survive; if anything lived, it was most probably destroyed, leaving no clues. Life’s early history is written in rocks. As primal rocks melted and got mixed and remixed in a churning inferno, life’s early experiments were erased into oblivion.
We can’t know what really happened to life that early on. We can study possible metabolic and genetic pathways to life, collect fossilized evidence from old rocks, and conduct experiments in the laboratory, expanding our understanding of this most vexing of questions, the transition from nonlife to life. But even if we are able to make life in vitro, we can’t be sure that this is what happened around 3.6 billion years ago here.
What we do know is that the history of life in a planet depends on the planet’s life history: change the sequence or intensity of events — asteroid collisions, massive volcanic eruptions, radical changes in atmospheric composition — and life’s history is rewritten.
This casts the question of life here, and elsewhere, into new focus. We can state, with high confidence, that even if there are other intelligent creatures in the universe, even humanoid ones, they won’t be like us. We are the only humans in the cosmos, the product of a very particular set of cosmic, geochemical and evolutionary circumstances. Life is an experiment in natural selection, and an amazingly creative one at that. There may be certain biological patterns that offer an evolutionary advantage and would be fairly common, such as two eyes or left-right body symmetry. But details will vary as they do with snowflakes, all coming from the same chemistry but amazingly diverse due to environmental details.
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Seed-Scattering Birds May Help Trees Cope With Climate Change
The tree people in the Lord of the Rings—the Ents—can get around by walking. But for real trees, well, it's harder to uproot. "Because it's a sessile organism, literally, rooted into the ground, it is unable to leave and go elsewhere." Mario Pesendorfer, a behavioral ecologist at the Cornell Lab of Ornithology. "When a tree first starts growing in a certain area, it's likely that the climactic envelope, so the temperature, humidity, soil composition and so on suits it, because it would otherwise be unable to grow from a seedling. But as it ages, these conditions may change and the area around it may no longer be suitable for its offspring."
And if that happens? Walnuts, hazelnuts, chestnuts, oaks, pines—many rely exclusively on so-called "scatter-hoarders," like birds, to move their hefty seeds to new locales. "Many members of the family Corvidae—the crows, jays and magpies—are scatter-hoarders. Meaning they like to store food for the winter, which they then subsequently retrieve."
Or not. And when they do forget something, a seedling has a chance to grow, sometimes a good distance away. "The Clark's nutcracker, which is found in alpine regions of western North America, is definitely the rock star among the scatter-hoarding corvids. They hide up to 100,000 seeds per year, up to 30 kilometers away from the seed source, and have a very close symbiotic relationship with several pine species, most notably the whitebark pine.”
Pesendorfer and his colleagues catalogue the seed-scattering activities of the Clark's nutcracker and its cousins in a new review paper, in the journal The Condor: Ornithological Applications. [Mario B. Pesendorfer et al, Scatter-hoarding corvids as seed dispersers for oaks and pines: A review of a widely distributed mutualism and its utility to habitat restoration]
They also write that, as trees outgrow their ideal habitats in the face of climate change, or battle new insects and disease, these flying ecosystem engineers could be a big help replanting trees. It's a solution, Pesendorfer says, that's good for us—getting birds to do the work is cheap and effective— and it could give vulnerable oaks and pines the option to truly "make like a tree and leave."
—Christopher Intagliata
[The above text is a transcript of this podcast.]
Nuclear fusion device’s 1st test with hydrogen declared a success
Scientists in Germany flipped the switch Wednesday on an experiment they hope will advance the quest for nuclear fusion, considered a clean and safe form of nuclear power.
Following nine years of construction and testing, researchers at the Max Planck Institute for Plasma Physics in Greifswald injected a tiny amount of hydrogen into a doughnut-shaped device — then zapped it with the equivalent of 6,000 microwave ovens.
The resulting super-hot gas, known as plasma, lasted just a fraction of a second before cooling down again, long enough for scientists to confidently declare the start of their experiment a success.
“Everything went well today,” said Robert Wolf, a senior scientist involved with the project. “With a system as complex as this you have to make sure everything works perfectly and there’s always a risk.”
Among the difficulties is how to cool the complex arrangement of magnets required to keep the plasma floating inside the device, Wolf said. Scientists looked closely at the hiccups experienced during the start-up of the Large Hadron Collider in Switzerland more than five years ago to avoid similar mistakes, he said.
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The Noise From Ships Interferes With Orca Communication
Photo credit:
The hum of ships was not known to be of a high enough frequency to affect orcas. Tony Kallman/Shutterstock
We know that plastics littering the oceans are a major problem to the marine environment, but if you were to dip your head under the waves near a busy port, you’d be able to hear another considerable problem.
Tim Peake Fires Up Astro Pi Computers On The International Space Station
Photo credit:
One of the Astro Pi computers on the ISS. ESA/NASA
Some British school children just got a pretty awesome bit of news from space: British astronaut Major Tim Peake has used some miniature computers designed by them on the International Space Station (ISS).
Peake activated two modified Raspberry Pi computers, nicknamed Astro Pi, this week. Their applications were designed by students in schools across the U.K.
Ice Age’s End Triggered Volcanic Eruptions
Photo credit:
The end of the Ice Age saw a huge increase in eruptions from volcanoes like Eyjafjallajokull as the ice sheets retreated. Erosion may have been a contributing factor to the pressure release that triggered this. Johann Helgason/Shutterstock
At the end of the last Ice Age there was a major increase in volcanic activity. However, a paper in Geophysical Research Letters explains this story doesn't go the way you might be expecting. Not only did the greenhouse gases from the volcanoes warm the planet, the melting ice triggered the volcanic eruptions, and in more ways than we previously realized.
Planet-Forming Disc Found To Be Colder Than Expected
Photo credit:
The star is in the Rho Ophiuchi star formation region. Digitized Sky Survey 2/NASA/ESA
Astronomers observing a distant planet-forming disk of dust and gas have found that it is much colder than expected. The findings, published in Astronomy & Astrophysics Letters, could have implications for how planetary systems form.
Scientists to inject fuel in experimental fusion device
Scientists in northeast Germany were poised to flip the switch Wednesday on an experiment they hope will advance the quest for nuclear fusion, considered a clean and safe form of nuclear power.”
Researchers at the Max Planck Institute in Greifswald planned to inject a tiny amount of hydrogen and heat it until it becomes a super-hot gas known as plasma, mimicking conditions inside the sun. It’s part of a world-wide effort to harness nuclear fusion, a process in which atoms join at extremely high temperatures and release large amounts of energy.
Advocates acknowledge that the technology is probably many decades away, but argue that — once achieved — it could replace fossil fuels and conventional nuclear fission reactors.
Construction has already begun in southern France on ITER, a huge international research reactor that uses a strong electric current to trap plasma inside a doughnut-shaped device long enough for fusion to take place. The device, known as a tokamak, was conceived by Soviet physicists in the 1950s and is considered fairly easy to build, but extremely difficult to operate.
The team in Greifswald, a port city on Germany’s Baltic coast, is focused on a rival technology invented by the American physicist Lyman Spitzer in 1950. Called a stellarator, the device has the same doughnut shape as a tokamak but uses a complicated system of magnetic coils to achieve the same result.
The Greifswald device should be able to keep plasma in place for much longer than a tokamak, said Thomas Klinger, who heads the project.
“The stellarator is much calmer,” he said in a telephone interview. “It’s far harder to build, but easier to operate.”
Known as the Wendelstein 7-X stellarator, or W7-X, the 400-million-euro ($435-million) device was first fired up in December using helium, which is easier to heat. Helium also has the advantage of “cleaning” any minute dirt particles left behind during the construction of the device.
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February 2, 2016
Plastic Pollution Perturbs Oyster Offspring
As many as 12 million tons of plastic waste end up in the world's oceans every year, according to a 2015 estimate in the journal Science. Over time, wind and waves grind and chew that plastic trash into tiny bits of what’s called 'microplastic'—which happen to be about the same size and shape as the micro algae that filter feeders like oysters snack on. Meaning oysters can ingest it.
To find out the effects of consuming the debris, researchers at the French Institute for Ocean Studies raised oysters in water polluted with plastic microbeads, in concentrations similar to those observed in field studies. The shellfish sucked up the six-micrometer-wide plastic particles extremely efficiently—as they evolved to do with the tiny algae.
Two months later, the oysters exposed to microplastics produced half as many eggs and slower swimming sperm than did oysters that fed on algae alone. Perhaps, the researchers say, because plastic interferes with the oysters' energy uptake. And the offspring of the plastic-eaters were also smaller and slower-growing than the progeny of control oysters. The study is in the Proceedings of the National Academy of Sciences. [Rossana Sussarellu et al, Oyster reproduction is affected by exposure to polystyrene microplastics]
The scientists say oysters will probably survive in spite of plastic pollution—they're still prolific reproducers. But until we clean up our act, there's no question we're giving them a raw deal.
—Christopher Intagliata
[The above text is a transcript of this podcast.]
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