Saturday, March 2, 2013

Το συν απειρο

Της 17χρονης Δεσποινας Μπαξεβανη,

Δε μ' αρέσουν τα μαθηματικά. Κάποτε μ' άρεσαν. Όχι πια. Τώρα τα βλέπω σα σύμβολα, δίχως λογική° σα διαδικασία.
Δε μ' ενοχλεί το "δίχως λογική", πότε μου δε μ' ενόχλησε. Ψοφάω να μιλάω για κάτι αόριστο, κάτι αόριστο που είναι τόσο συγκεκριμένο όσο κάτι που δείχνεις με το δείκτη του δεξιού σου χεριού, του αριστερού, αν είσαι αριστερόχειρας. Ωστόσο είμαστε όλοι αρκετά εγωιστές, για να καταλαβαίνουμε ο,τι μπορούμε να καταλάβουμε, με βάση τα δικά μας μέτρα και σταθμά. Μ' αυτή την έννοια, πάντα μα πάντα μιλάω για κάτι γενικό.
Ίσως αυτή τη φορά ν' αποτελεί κομμάτι της δικής μου αμφιθυμίας, μα όλοι λίγο πολύ πάσχουμε από αυτήν. Κι ενώ από την πρώτη στιγμή το δήλωσα ξεκάθαρα πως δε μ' αρέσουν τα μαθηματικά, πες το αριθμητική ή άλγεβρα αν θες, υπάρχει κάτι που με συγκλονίζει στο συν άπειρο.

Μ' αρέσει το συν άπειρο, γιατί έχει κάτι το μυστηριώδες, κάτι το άγνωστο. Όλοι το ξέρουν μα κανείς πραγματικά. Κι ίσως αυτό που θες πραγματικά είναι αυτό που σου είναι αδύνατο να αποσυμβολοποιήσεις, σαν το συν άπειρο.

Ο,τι γνωρίζεις λίγο λίγο το βαριέσαι. Μα το συν άπειρο είν' αδύνατο να το γνωρίσεις κι ίσως επειδή πότε σου δεν το γνώρισες, γι' αυτό είν' ακόμη το συν άπειρο, γι' αυτό δεν ξεπεράστηκε ποτέ. Σαν ένα πρόβλημα που δεν κατάφερες να λύσεις κι ακόμα κι αν μπορείς να φέρεις εις πέρας δεκάδες άλλα, αυτα δεν αποτελούν πρόκληση ούτε για 'σένα, ούτε για 'μένα, ούτε για κανέναν που αναζητά ένα συν άπειρο.

Είναι χαοτικό να θες ένα συν άπειρο. Νόμιζα πως όλοι θελαν ένα μα προς μεγάλη μου απογοήτευση έκανα λάθος. Κι έτσι μένουν λίγοι αλλοπαρμένοι, σαν κι εμένα, να ψάχνουν να βρουν ένα δικό τους. Ωστόσο τους λυπάμαι αυτούς που διάλεξαν έναν κοινό αριθμό, σχεδόν όσο θαυμάζω εκείνους τους ευτυχισμένους που το βρήκαν. Κι αρνούμαι κατηγορηματικά να σταματήσω να το ψάχνω, όχι από εγωισμό, ούτε γιατί απαξιώνω όλους τους άλλους αριθμούς, αλλά από δέος σ' ο,τι με κάνει και το ψάχνω.

Ένα συν άπειρο θα σε κάνει πάντα δυστυχή. Κι ίσως ζηλέψεις, στην πορεία, όλους αυτούς που βλέπουν μονάχα ένα ξαπλωτό οκτώ. Σκέψου απλά. Σου φτάνουν μόλις δυο δεύτερα για να μετρήσεις ως το οκτώ μα ακόμα κι αν μπορούσες να μετράς απ' το πρώτο σου δευτερόλεπτο στον κόσμο, αυτή η ζωή δε φτάνει για ν' αγγίξεις το συν άπειρο.

Ωστόσο υπήρξαν κάποιοι που το θέλησαν πολύ. Κι ήρθαν και κούμπωσαν ο ένας πάνω στον άλλον και το κατάφεραν μαζί, σαν δυο μηδέν το ένα δίπλα στ' άλλο. Κι αν πράγματι μπορούσες να το δεις με λίγη παιδική φαντασία, θα βλεπες πως το συν άπειρο δεν είναι τίποτε άλλο απ' τη δική σου θέληση να κυνηγήσεις αυτό που πάντα ονειρευόσουν.

Στην τελική, δεν έχει σημασία "τί" είναι κατ' ουσίαν το συν άπειρο. Είναι άλλο για 'μένα κι άλλο για 'σένα, σαν φυσική υπόσταση, σαν επιδίωξη, σα στόχος. Αν υπάρχει κάτι που μετράει, για να μιλήσουμε κάπως πιο "μαθηματικά", αυτό είναι η άρνησή σου να συμβιβαστείς μ' ο,τι μεσολαβεί απ' το μηδέν ως το άπειρο και η επιδίωξη να κατορθώσεις το ακατόρθωτο.

Saturday, February 23, 2013

Plastic Bag Ban Legislation Introduced in California


Sonoma County Assemblyman Marc Levine has introduced legislation that would ban the use of single-use plastic bags in the state of California by the year 2015. The bill, known as AB 158, would target grocery stores with more than $2 million in annual sales, or retailers with more than 10,000 square feet of floor space. In place of plastic, the stores would have to make reusable bags available for purchase. A similar bill is moving through the senate for the County of Sonoma, California.


47 Japanese Nuclear Reactors Placed in “Long-Term Shutdown”

The International Atomic Energy Agency (IAEA) has officially changed the status of 47 Japanese Nuclear Reactors to “Long-Term Shutdown,” or LTS, on its online database known as the Power Reactor Information System (PRIS). Japan’s loss brings the world total of operational nuclear reactors from 437 down to 390, making for the lowest levels since 1986. Still, many question the validity of the IAEA’s evaluations, as there seems to be no consistently clear set of rules used to determine activity status judging by the wide ranging characteristics of previously listed LTS sites. Nonetheless, the fact that only two nuclear reactors are currently functionally operating in Japan is testament to the country’s environmental progress in spite of a purportedly pro-nuclear Japanese administration.


Rail power generated by passing trains could save more than $10 million

A way to harvest energy from vibrations generated by passing trains could save more than $10 million in trackside power costs and reduce carbon dioxide emissions by 3,000 tons in New York alone, says its inventor, Stony Brook University professor Lei Zuo.

The device converts the irregular up-and-down vibration of a train track to a unidirectional rotation of a generator. The concept is similar to other energy-harvesting devices such as the speed bump.


Monday, February 11, 2013

We could refreeze the Arctic, should we?

By Bob Weber

A record loss of Arctic sea ice and faster-than-expected melting of Greenland’s ice cap made worldwide headlines in 2012, but research published in major science journals in the fall suggest warming in the North doesn’t have to continue.

We could refreeze the Arctic, proposed a paper in Nature Climate Change. It wouldn’t even cost that much, said an affiliated study in Environmental Research Letters.

The question is should we?

“In terms of pure technical capacity, any significant nation in the world could do it,” said David Keith, a Calgarian and professor of applied physics at Harvard University, one of the lead authors in both studies.

“The really hard questions here aren’t mostly technical. They’re questions about what kind of planet we want and who we are.”

In a world that seems unable to come to grips with carbon dioxide emissions driving climate change, manipulating the Earth’s climate to cool it down has some calling geoengineering a bad idea whose time has finally come.

Scientists have long theorized that injecting reflective particles of some kind into the high atmosphere could reduce the amount of sunlight reaching the Earth’s surface and compensate for the greenhouse effect. High CO2 levels would continue to trap heat, but with less energy coming in to begin with, temperatures on the surface would go down.

Keith’s paper used climate models to cautiously suggest that the method could be adapted to engineer regional effects. The right amount of aerosols in the right place at the right time could restore the Arctic’s frozen glory.

“With an average solar reduction of only 0.5 per cent, it is possible to recover pre-industrial sea ice extent,” the paper says. “Decisions involving (solar radiation management) do not need to be reduced to a single ‘global thermostat.’”

A separate paper concluded that it could all be done with a few modified Gulfstream jets widely available on the used market. Annually, it could cost somewhat less than $8 billion — about the price of a major oil pipeline.

While Keith believes emissions should be cut, he doesn’t advocate such a plan, at least not yet.

He suggested geoengineering may be a viable response to a “climate emergency” — a sudden collapse of ice sheets or a killing drought.

“If your primary view is pragmatic, and you want to reduce the risk to Asian farmers who might get hit by high temperatures that make their crops not germinate, then the answer is you should do whatever is actually safe and controllable and produces the outcomes.”

Some environmentalists are starting to think there may be something to that.

“We all agree: mitigation, that’s the thing you should do,” said Steve Hamburg, chief scientist of the U.S.-based Environmental Defense Fund. “But everyone also recognizes that even if we did that, we may have climate surprises. We’d be irresponsible not to try and understand what our options are.

“It’s easy to dismiss this as too radical a solution, but that does a disservice to what we don’t know. We need to be prepared with information to understand what our options are or aren’t depending on how things play out.”

If we don’t at least understand the risks, a desperate situation may lead to a disastrous decision, Hamburg said.

Keith Allott, head of climate change for the World Wildlife Fund UK, agrees that research is needed.

“We do see the need for a grown-up conversation about the type of research that may be acceptable at this stage,” he said.

The United Nations, through its Convention on Biological Diversity, has ruled out open-air or large-scale geoengineering experiments. Current research, including some that Environment Canada is involved in, is restricted to using models to better understand how the Earth’s climate might respond to manipulation.

Hamburg said discussions on everything from how research is conducted to who gets to set the global thermostat are just beginning.

He’s part of the Solar Radiation Management Governance Initiative, a partnership between his group and several scientific academies from around the world.

“Everybody has to feel like their interests are represented,” he said.

“It can’t be about North American and European voices. It has to be about global voices and global communities being aware of it so that there is some kind of consensus that ignorance is our enemy.”

Peter Mooney of the Ottawa-based Etc Group, an environmental technology watchdog, is skeptical of anyone’s ability to manage geoengineering.

“There’s a marvellous naivete to it all,” he said. “We need to prepare for this horrible thing of Plan B because governments have proved themselves incapable of addressing the real problem. Therefore, we need to have governments go ahead and do Plan B.”

But that thinking is flawed, he suggested.

“The governments who screwed up in the first place can’t be expected to take something like planetary systems management and do a better job of it.”

Others hold that geoengineering is just more of the same kind of thinking that caused the problem — a reliance on technical fixes instead of looking at causes.

“They kind of like the fact the problem is hard to solve because it gives you a lever to say we have to make these deep reforms in consumer culture, which I personally would like to see,” said Keith.

But really, he asks, what is society but one technical fix after another? Sanitation, for example, is a technical fix for cities producing sewage.

Mooney feels it’s asking too much of governments to expect they’ll make science-based unbiased decisions.

“It’s naive to think that once Plan B becomes a political option that governments won’t just take it on and interpret it as they wish. They will always find scientists who will give them the spin that they want.

“(We shouldn’t be) opening up the back door for politicians to creep out of, claiming that, ‘Don’t worry folks. We don’t need to do anything because we have technological fixes that we can deploy on short notice.’”

Allott, too, is concerned that geoengineering could become a way to excuse the continued consumption of CO2-causing fossil fuels.

“There are some unfortunate overlaps between parts of the geoengineering community and parts of the fossil fuel lobby,” he said. “That’s not OK.”

He also points out that no plan to manage solar radiation does anything to address ocean acidification, another byproduct of CO2 emissions. The best way forward, he said, is to reduce the emissions in the first place.

“People talk about this as if (geoengineering) is an easy option. That ain’t true.”

Geoengineering isn’t likely to become a reality any time soon. There are no aerosol-laden planes on a tarmac waiting for clearance to take off.

But the debate is coming, predicted Hamburg.

“We’re not going to put the genie back in the bottle … (We need) a robust and broad conversation about how to govern research in this area with widely agreed-upon rules of the road.”

Even then, said Keith, we need to cut CO2 emissions.

“If we do this and we do not cut emissions, we just walk further and further off the cliff, like Wile E. Coyote.”


Sunday, February 10, 2013

the Ants Are Talking

By Carrie Arnold


If you want to survive as an ant, you'd better get ready to make some noise. A new study shows that even ant pupae—a stage between larvae and adult—can communicate via sound, and that this communication can be crucial to their survival.

"What's very cool about this paper is that researchers have shown for the first time that pupae do, in fact, make some sort of a sound," says Phil DeVries, an entomologist at the University of New Orleans in Louisiana who was not involved in the study. "This was a very clever piece of natural history and science."

Scientists have known for decades that ants use a variety of small chemicals known as pheromones to communicate. Perhaps the most classic example is the trail of pheromones the insects place as they walk. Those behind them follow this trail, leading to long lines of ants marching one by one. However, the insects also use pheromones to identify which nest an ant is from and its social status in that nest. Because this chemical communication is so prevalent and complex, researchers long believed that this was the primary way ants shared information.

However, several years ago, researchers began to notice that adults in some ant genuses, such as Myrmica, which contains more than 200 diverse species found across Europe and Asia, made noise. These types of ants have a specialized spike along their abdomen that they stroke with one of their hind legs, similar to dragging the teeth of a comb along the edge of a table. Preliminary studies seemed to indicate that this noise served primarily as an emergency beacon, allowing the ants to shout for help when being threatened by a predator.

Larvae and young pupae have soft outer skeletons, which means their specialized spikes haven't yet formed and they can't make noise. However, as the pupae mature, their covering hardens into a tough exoskeleton like that found in adult ants. These older pupae do have fully functional spikes but were generally thought to be silent.

Karsten Schönrogge, an entomologist at the Centre for Ecology & Hydrology, Wallingford, in the United Kingdom, thought it odd that mature pupae would have the capability to produce sound but remain silent. So he and his colleagues listened in to a group of Myrmica scabrinodis ants. These 4- to 5-millimeter-long, reddish-brown ants are commonly found in northern Europe, in low-lying areas like peat bogs.

Using an extra-sensitive microphone that would pick up on the faint acoustic signals, the researchers measured the sounds produced by 10 differentM. scabrinodis larvae, six immature pupae, and six mature pupae. Whereas the larvae and immature pupae were completely silent, the mature pupae produced brief pulses of sound, the team reports online today in Current Biology.

Further analysis of this noise showed that it was a simplified version of the more complex adult sound. It was as if the mature pupae were saying, "Help!" while the adults were saying "Hey, I'm over here! Please come help! It's your friend!"

To test the function of these noises in the mature pupae, the researchers first played back the sounds made by either the mature pupae or adult M. scabrinodis. Adult worker ants responded the same way to both recordings, such as walking over to the speaker, rubbing their antennae against it, and guarding it. They didn't show these responses when Schönrogge and colleagues played white noise. These behaviors, which represent a worker ant's attempts to protect its nestmates, indicate that acoustic communication served to bring assistance in both mature pupae and adult ants.

To see how the ants used this acoustic communication, the team removed the abdominal spike from some of the mature pupae in a nest. The researchers then disturbed the nest, spilling out larvae, pupae, and adult workers into an experimental arena. Normally, the adult ants rescue their nestmates in a specific order: mature pupae, immature pupae, and, finally, the larvae. In the experiments by Schönrogge and colleagues, the adult workers indeed rescued the unmuted mature pupae first. However, the adult ants completely ignored the muted ants. It was as if the mute mature pupae simply didn't exist.

"The sounds they make rescue them by signaling their social status," Schönrogge says. "There is complex information in these signals," that combine with chemical signals to provide an array of information about the individual. Researchers have yet to decode everything the ants are communicating by sound and how the ants interpret these signals. Acoustic communication may be especially important in mature pupae because they don't yet produce the full array of adult pheromones, but they also don't smell and behave like larvae, either.

DeVries cautions that the discovery doesn't mean that chemical communication in ants is less important. "Ants live in these enormously sophisticated societies," he says. "Acoustic signaling adds another gorgeous piece to what we know about how insect societies communicate."



Αλλα σημεια αναφορας



Αμειλικτες πεθερες



Friday, February 8, 2013

How the world’s oceans could be running out of fish

By Gaia Vince
a science writer and broadcaster who is particularly interested in how humans are transforming planet Earth and the impacts our changes are having on societies and on other species. She has visited people and places around the world in a quest to understand how we are adapting to environmental change.

It has been some time since most humans lived as hunter-gatherers – with one important exception. Fish are the last wild animal that we hunt in large numbers. And yet, we may be the last generation to do so.

Entire species of marine life will never be seen in the Anthropocene (the Age of Man), let alone tasted, if we do not curb our insatiable voracity for fish. Last year, global fish consumption hit a record high of 17 kg (37 pounds) per person per year, even though global fish stocks have continued to decline. On average, people eat four times as much fish now than they did in 1950.

Around 85% of global fish stocks are over-exploited, depleted, fully exploited or in recovery from exploitation. Only this week, a report suggested there may be fewer than 100 cod over the age of 13 years in the North Sea between the United Kingdom and Scandinavia. The figure is still under dispute, but it’s a worrying sign that we could be losing fish old enough to create offspring that replenish populations.

Large areas of seabed in the Mediterranean and North Sea now resemble a desert – the seas have been expunged of fish using increasingly efficient methods such as bottom trawling. And now, these heavily subsidised industrial fleets are cleaning up tropical oceans too. One-quarter of the EU catch is now made outside European waters, much of it in previously rich West African seas, where each trawler can scoop up hundreds of thousands of kilos of fish in a day. All West African fisheries are now over-exploited, coastal fisheries have declined 50% in the past 30 years, according to the UN Food and Agriculture Organisation.

Catches in the tropics are expected to decline a further 40% by 2050, and yet some 400 million people in Africa and Southeast Asia rely on fish caught (mainly through artisanal fishing) to provide their protein and minerals. With climate change expected to impact agricultural production, people are going to rely more than ever on fish for their nutritional needs.

The policy of subsidising vast fishing fleets to catch ever-diminishing stocks is unsustainable. In Spain, for example, one in three fish landed is paid for by subsidy. Governments, concerned with keeping jobs alive in the fishing industry in the short-term, are essentially paying people to extinguish their own long-term job prospects – not to mention the effect on the next generation of fishermen. Artisanal fishing catches half the world’s fish, yet it provides 90% of the sector’s jobs.

Protect depletion

Clearly, industrialised countries are not about to return to traditional methods. However, the disastrous management of the industry needs to be reformed if we are to restore fisheries to a sustainable level. In the EU alone, restoring stocks would result in greater catches of an estimated 3.5 million tonnes, worth £2.7 billion a year.

Rather than having a system in which the EU members each hustle for the biggest quotas – which are already set far beyond what is sustainable – fisheries experts suggest individual governments should set quotas based on stock levels in their surrounding waters. Fishermen should be given responsibility over the fish they hunt – they have a vested interest in seeing stocks improve, after all – and this could be in the form of individual tradable catch shares of the quotas. Such policies end the tragedy of the commons situation whereby everyone grabs as much as they can from the oceans before their rival nets the last fish, and it’s been used successfully in countries from Iceland to New Zealand to the US. Research shows that managing fisheries in this way means they are twice as likely to avoid collapse as open-access fisheries.

In severely depleted zones, the only way to restore stocks is by introducing protected reserves where all fishing is banned. In other areas, quota compliance needs to be properly monitored – fishing vessels could be licensed and fitted with tracking devices to ensure they don’t stray into illegal areas, spot-checks on fish could be carried out to ensure size and species, and fish could even be tagged, so that the authorities and consumers can ensure its sustainable source.

The other option is to take humanity's usual method of dealing with food shortages, and move from hunter-gathering to farming.

Already, more than half of the fish we eat comes from farms – in China, it’s as high as 80% – but doing this on an industrial scale has its problems. Farms are stocked with wild fish, which must then be fed – larger fish like salmon and tuna eat as much as 20 times their weight in smaller fish like anchovies and herring. This has led to overfishing of these smaller fish, but if farmed fish are fed a vegetarian diet, they lack the prized omega-3 oils that make them nutritious, and they do not look or taste like the wild varieties. Scientists are working to create an artificial version of omega-3 – current synthetic omega-3 versions are derived from fish oils.

Fish farms are also highly polluting. They produce a slurry of toxic run-off – manure – which fertilises algae in the oceans, reducing the oxygen available to other species and creates dead zones. Scotland's salmon-farming industry, for example, produces the same amount of nitrogen waste as the untreated sewage of 3.2 million people – over half the country's population. As a result, there are campaigns to ban aquaculture from coastal areas.

Farmed fish are also breeding grounds for infection and parasites that kill off large proportions of fish – escapees then frequently infect wild populations. Farmers try to control infestations with antibiotics, but usually only succeed in creating a bigger problem of antibiotic resistance.

Dangerous predator

Humanity is not limiting its impacts to fish most commonly found on menus. Exotic sea creatures from turtles to manta ray to marine mammals are being hunted to extinction. Shark numbers, for example, have declined by 80% worldwide, with one-third of shark species now at risk of extinction. The top marine predator is no longer the shark, it’s us.

A decline in shark numbers has a significant impact on the marine ecosystem: it can lead to an increase in fish numbers further down the food chain, which in turn can cause a crash in the population of very small marine life, such as plankton. Without the smallest creatures, the entire system is threatened.

One of the repercussions, which I have discussed before, is an increase in jellyfish numbers, but overfishing, pollution, climate change and acidification also affect the marine ecosystem. Warmer waters are pushing species into different habitats, causing some to die off and others to adapt by creating entirely new hybrid species. Meanwhile, trawlers are netting bycatch that include marine mammals and even seabirds – as many as 320,000 seabirds are being killed annually when they get caught in fishing lines, pushing populations of albatrosses, petrels and shearwaters to the edge of extinction.

Some solutions are easier than you might think. Seabirds can be protected by using weighted lines and scaring off birds with lines that have flapping streamers attached – these methods alone have reduced seabird deaths by more than 85-99% where they are used.

Conservation plea

Strengthening and expanding protected marine reserves would also go a long way to conserving species. Currently, less than 1% of the ocean is protected, although by 2020, the international community has agreed to raise this to 10%. Reserves, when properly patrolled and monitored, do protect marine life, and nation after nation is stepping up to the plate. The tiny Pacific islands have banded together to create a giant protected area of 1.1 million square kilometres, for example. Not to be outdone, Australia has created the world’s biggest protected area, and countries around the world from Britain to New Zealand are joining the effort.

But useful as they are, marine reserves – often around points like coral reefs or rock islands – are only effective if governments have the resources to patrol and protect them. Also, many marine creatures, from whale sharks to whales, are migratory – they don’t stay in the protected areas, making them easy prey for fishermen. What’s needed, many argue, are mobile reserves that follow migratory animals, and those that shift habitat due to currents or climate phenomena like El Nino.

The zones need to be well-targeted and needn’t impact on fishermen’s livelihoods. For example, one study found that designating just 20 sites – 4% of the world’s oceans – as conservation zones could protect 108 species (84%) of the world’s marine mammals.

The rivers in many European cities were so overfished, polluted and dammed up by the mid 20th century that they emptied of fish, and many species went locally extinct. But thanks to clean-ups, riverbank restoration and fishing restrictions, fish are returning to waterways, even in inner cities. A decade ago, few people would have imagined that salmon would return to my local river, the Thames. If it is possible to bring back fish to 'dead' rivers, there is surely hope for the world's oceans.