BBC.co.uk
Los peces no son simples animales con memoria corta sino que viven en complejas redes sociales, eligen a sus compañeros y los recuerdan, dice un grupo de científicos británicos.
30 dic 2004
29 dic 2004
Mystery of Mars rover's 'carwash' rolls on
NewScientist.com:
NASA's Mars rover Opportunity seems to have stumbled into something akin to a carwash that has left its solar panels much cleaner than those of its twin rover, Spirit. A Martian carwash would account for a series of unexpected boosts in the electrical power produced by Opportunity's solar panels.
NASA's Mars rover Opportunity seems to have stumbled into something akin to a carwash that has left its solar panels much cleaner than those of its twin rover, Spirit. A Martian carwash would account for a series of unexpected boosts in the electrical power produced by Opportunity's solar panels.
26 dic 2004
Evolution Shares a Desk With 'Intelligent Design'
washingtonpost.com
Lark Myers, a blond, 45-year-old gift shop owner, frames the question and answers it. "I definitely would prefer to believe that God created me than that I'm 50th cousin to a silverback ape," she said. "What's wrong with wanting our children to hear about all the holes in the theory of evolution?"
Charles Darwin, squeeze over. The school board in this small town in central Pennsylvania has voted to make the theory of evolution share a seat with another theory: God probably designed us.
If it survives a legal test, this school district of about 2,800 students could become the first in the nation to require that high school science teachers at least mention the "intelligent design" theory. This theory holds that human biology and evolution are so complex as to require the creative hand of an intelligent force.
"The school board has taken the measured step of making students aware that there are other viewpoints on the evolution of species," said Richard Thompson, of the Thomas More Law Center, which represents the board and describes its overall mission as defending "the religious freedom of Christians."
Board members have been less guarded, and their comments go well beyond intelligent design theory. William Buckingham, the board's curriculum chairman, explained at a meeting last June that Jesus died on the cross and "someone has to take a stand" for him. Other board members say they believe that God created Earth and mankind sometime in the past ten thousand years or so.
"If the Bible is right, God created us," said John Rowand, an Assemblies of God pastor and a newly appointed school board member. "If God did it, it's history and it's also science."
This strikes some parents and teachers, not to mention most evolutionary biologists, as loopy science. Eleven parents have joined the American Civil Liberties Union and filed suit in federal court in Harrisburg seeking to block mention of intelligent design in high school biology, arguing it is religious belief dressed in the cloth of science.
"It's not science; it's a theocratic idea," Bryan Rehm, a former science teacher in Dover and a father of four. "We don't have enough time for science in the classroom as it is -- this is just inappropriate."
This is a battle fought in many corners of the nation. In Charles County, school board members recently suggested discarding biology textbooks "biased towards evolution." In Cobb County, in suburban Atlanta, the local school board ordered that stickers be placed inside the front cover of science textbooks stating: "Evolution is a theory, not a fact." State education boards in Ohio and Kansas have wrestled with this issue, as well.
In 1987, the U.S. Supreme Court seemed to settle this question, ruling that Louisiana could not make creationism a part of the science curriculum. The state, Justice William J. Brennan wrote, cannot "restructure the science curriculum to conform with a particular religious viewpoint." (Justice Antonin Scalia dissented, arguing that creationism could be "valuable scientific data that has been censored from the classrooms by an embarrassed scientific establishment.")
Of late, conservative school boards have launched a counteroffensive, often marching under the banner of intelligent design. This theory has lingered on the margins of mainstream scientific discourse with just enough intellectual heft to force its way into some discussions of evolutionary theory.
Essentially intelligent design posits that the human cell, among other organisms, is too finely tuned to have developed by chance. "The human cell is irreducibly complex -- what we find in the cell is stuff that looks strongly like it was designed by an intelligence," said Michael J. Behe, a biology professor at Lehigh University and leading advocate of intelligent design.
Behe acknowledges this theory might lead one to postulate the existence of a supernatural force, such as God. But he said this is unknown and rejects those who would portray him as a creationist. "Our starting point is from science, not from Scripture," Behe said.
Few biologists buy that. There is, they say, a central evolutionary theory embraced by mainstream scientists worldwide: That life on Earth has evolved over billions of years and in fits and starts from one-celled organisms to modern humans. That this theory is pockmarked with unexplained gaps, and subject to debate, is how science is crafted.
"People have an impatience about science," said Kenneth R. Miller, a Brown University biologist and author of the biology textbook used in Dover. "They think it's this practical process that explains how everything works, but that's the least interesting part.
"We understand a lot of the mechanisms of evolution but it's what we don't understand that makes it exciting."
Even today many residents are not sure how Dover, a former farm hamlet become a bedroom community for York and Harrisburg, came to occupy the ramparts in a century-long war over Darwin's theories.
In the 18th century, an erudite French shopkeeper settled in this valley and gave the name Voltaire to his village. German and English settlers, a local history notes, soon discovered that Voltaire was "a French atheist" and "a disbeliever in revealed theology" and changed the town's name.
Dover's modern politics are resolutely Republican -- President Bush polled 65 percent of the vote here -- and its cultural values are Christian, with an evangelical tinge. To drive its rolling back roads is to count dozens of churches, from Lutheran to United Church of Christ, Baptist, Pentecostal and Assemblies of God.
Many here speak of a personal relationship with Christ and of their antipathy to evolutionary theory (A Gallup poll found that 35 percent of Americans do not believe in evolution). Steve Farrell, a friendly man and owner of a landscaping business, talked of Darwin and God in the Giant shopping center parking lot.
"We are teaching our children a theory that most of us don't believe in." He shook his head. "I don't think God creates everything on a day-to-day basis, like the color of the sky. But I do believe that he created Adam and Eve -- instantly."
Back in the town center, Norma Botterbusch talks in her jewelry store, which has been a fixture here for 40 years. "We are a very lenient town," she said. "But why should a minority get to file a lawsuit and dictate school policy? Most of our kids already know who created them."
The evolution revolution in Dover began as a dispute about property taxes. The previous school board spent too much money, and a conservative group defeated them. Last June, board member Buckingham criticized a new biology textbook as "laced with Darwinism." He added, according to the ACLU's lawsuit, that "our country was founded on Christianity and our students should be taught as such."
Neither Buckingham nor the board president nor the school superintendent responded to requests for interviews.
In October, the Dover school board passed this motion: "Students will be made aware of gaps/problems in Darwin's theory and of other theories of evolution including, but not limited to, intelligent design. Note: Origins of Life is not taught."
Several board members resigned in protest. When the remaining board members chose replacements, they subjected certain candidates to withering questions. "I was asked if I was a liberal or conservative, and if I was a child abuser," recalled Rehm, who was known as an outspoken opponent of intelligent design.
In the end, the York Daily Record reported that the board picked a fundamentalist preacher, a home-schooler who does not send his kids to public school for religious reasons, and two more who in effect pledged to support the board.
Dover's evolution policy has left many teachers deeply uncomfortable. One science teacher noted that he avoids talking about the origins of life. "We don't do the monkeys-to-man controversy," he said. "It's just not worth the trouble."
The Discovery Institute in Seattle, which is regarded as a leader in intelligent design theory, also opposes the Dover school board's policy in part because it seems to take three steps into old-fashioned creationism. "This theory needs to be debated in the scientific sphere," said Paul West, a senior fellow. "It's much too soon to require anyone to teach it in high school."
Miller, the Brown University biologist and textbook author, hopes the day that it is taught in high school never arrives. "It's very clear that intelligent design has become a stalking-horse," Miller said. "If these school boards had their druthers, they would teach Noah's flood and the 6,000-year-old design of Earth.
"My fear is that they are making real headway in the popular imagination."
Lark Myers, a blond, 45-year-old gift shop owner, frames the question and answers it. "I definitely would prefer to believe that God created me than that I'm 50th cousin to a silverback ape," she said. "What's wrong with wanting our children to hear about all the holes in the theory of evolution?"
Charles Darwin, squeeze over. The school board in this small town in central Pennsylvania has voted to make the theory of evolution share a seat with another theory: God probably designed us.
If it survives a legal test, this school district of about 2,800 students could become the first in the nation to require that high school science teachers at least mention the "intelligent design" theory. This theory holds that human biology and evolution are so complex as to require the creative hand of an intelligent force.
"The school board has taken the measured step of making students aware that there are other viewpoints on the evolution of species," said Richard Thompson, of the Thomas More Law Center, which represents the board and describes its overall mission as defending "the religious freedom of Christians."
Board members have been less guarded, and their comments go well beyond intelligent design theory. William Buckingham, the board's curriculum chairman, explained at a meeting last June that Jesus died on the cross and "someone has to take a stand" for him. Other board members say they believe that God created Earth and mankind sometime in the past ten thousand years or so.
"If the Bible is right, God created us," said John Rowand, an Assemblies of God pastor and a newly appointed school board member. "If God did it, it's history and it's also science."
This strikes some parents and teachers, not to mention most evolutionary biologists, as loopy science. Eleven parents have joined the American Civil Liberties Union and filed suit in federal court in Harrisburg seeking to block mention of intelligent design in high school biology, arguing it is religious belief dressed in the cloth of science.
"It's not science; it's a theocratic idea," Bryan Rehm, a former science teacher in Dover and a father of four. "We don't have enough time for science in the classroom as it is -- this is just inappropriate."
This is a battle fought in many corners of the nation. In Charles County, school board members recently suggested discarding biology textbooks "biased towards evolution." In Cobb County, in suburban Atlanta, the local school board ordered that stickers be placed inside the front cover of science textbooks stating: "Evolution is a theory, not a fact." State education boards in Ohio and Kansas have wrestled with this issue, as well.
In 1987, the U.S. Supreme Court seemed to settle this question, ruling that Louisiana could not make creationism a part of the science curriculum. The state, Justice William J. Brennan wrote, cannot "restructure the science curriculum to conform with a particular religious viewpoint." (Justice Antonin Scalia dissented, arguing that creationism could be "valuable scientific data that has been censored from the classrooms by an embarrassed scientific establishment.")
Of late, conservative school boards have launched a counteroffensive, often marching under the banner of intelligent design. This theory has lingered on the margins of mainstream scientific discourse with just enough intellectual heft to force its way into some discussions of evolutionary theory.
Essentially intelligent design posits that the human cell, among other organisms, is too finely tuned to have developed by chance. "The human cell is irreducibly complex -- what we find in the cell is stuff that looks strongly like it was designed by an intelligence," said Michael J. Behe, a biology professor at Lehigh University and leading advocate of intelligent design.
Behe acknowledges this theory might lead one to postulate the existence of a supernatural force, such as God. But he said this is unknown and rejects those who would portray him as a creationist. "Our starting point is from science, not from Scripture," Behe said.
Few biologists buy that. There is, they say, a central evolutionary theory embraced by mainstream scientists worldwide: That life on Earth has evolved over billions of years and in fits and starts from one-celled organisms to modern humans. That this theory is pockmarked with unexplained gaps, and subject to debate, is how science is crafted.
"People have an impatience about science," said Kenneth R. Miller, a Brown University biologist and author of the biology textbook used in Dover. "They think it's this practical process that explains how everything works, but that's the least interesting part.
"We understand a lot of the mechanisms of evolution but it's what we don't understand that makes it exciting."
Even today many residents are not sure how Dover, a former farm hamlet become a bedroom community for York and Harrisburg, came to occupy the ramparts in a century-long war over Darwin's theories.
In the 18th century, an erudite French shopkeeper settled in this valley and gave the name Voltaire to his village. German and English settlers, a local history notes, soon discovered that Voltaire was "a French atheist" and "a disbeliever in revealed theology" and changed the town's name.
Dover's modern politics are resolutely Republican -- President Bush polled 65 percent of the vote here -- and its cultural values are Christian, with an evangelical tinge. To drive its rolling back roads is to count dozens of churches, from Lutheran to United Church of Christ, Baptist, Pentecostal and Assemblies of God.
Many here speak of a personal relationship with Christ and of their antipathy to evolutionary theory (A Gallup poll found that 35 percent of Americans do not believe in evolution). Steve Farrell, a friendly man and owner of a landscaping business, talked of Darwin and God in the Giant shopping center parking lot.
"We are teaching our children a theory that most of us don't believe in." He shook his head. "I don't think God creates everything on a day-to-day basis, like the color of the sky. But I do believe that he created Adam and Eve -- instantly."
Back in the town center, Norma Botterbusch talks in her jewelry store, which has been a fixture here for 40 years. "We are a very lenient town," she said. "But why should a minority get to file a lawsuit and dictate school policy? Most of our kids already know who created them."
The evolution revolution in Dover began as a dispute about property taxes. The previous school board spent too much money, and a conservative group defeated them. Last June, board member Buckingham criticized a new biology textbook as "laced with Darwinism." He added, according to the ACLU's lawsuit, that "our country was founded on Christianity and our students should be taught as such."
Neither Buckingham nor the board president nor the school superintendent responded to requests for interviews.
In October, the Dover school board passed this motion: "Students will be made aware of gaps/problems in Darwin's theory and of other theories of evolution including, but not limited to, intelligent design. Note: Origins of Life is not taught."
Several board members resigned in protest. When the remaining board members chose replacements, they subjected certain candidates to withering questions. "I was asked if I was a liberal or conservative, and if I was a child abuser," recalled Rehm, who was known as an outspoken opponent of intelligent design.
In the end, the York Daily Record reported that the board picked a fundamentalist preacher, a home-schooler who does not send his kids to public school for religious reasons, and two more who in effect pledged to support the board.
Dover's evolution policy has left many teachers deeply uncomfortable. One science teacher noted that he avoids talking about the origins of life. "We don't do the monkeys-to-man controversy," he said. "It's just not worth the trouble."
The Discovery Institute in Seattle, which is regarded as a leader in intelligent design theory, also opposes the Dover school board's policy in part because it seems to take three steps into old-fashioned creationism. "This theory needs to be debated in the scientific sphere," said Paul West, a senior fellow. "It's much too soon to require anyone to teach it in high school."
Miller, the Brown University biologist and textbook author, hopes the day that it is taught in high school never arrives. "It's very clear that intelligent design has become a stalking-horse," Miller said. "If these school boards had their druthers, they would teach Noah's flood and the 6,000-year-old design of Earth.
"My fear is that they are making real headway in the popular imagination."
24 dic 2004
Biblical King Solomon Treasure Turns Out to Be Fake
Reuters.com
A tiny ivory pomegranate once believed to be the only relic of King Solomon's biblical era Jewish Temple turns out not to be an artifact from the holy shrine, the Israel Museum said on Friday.
Israeli experts have determined the thumb-sized object is a lot older than believed, dating to the 13th or 14th Century BC, rather than to the 8th Century BC, which scholars say was around the time of Solomon.
A tiny ivory pomegranate once believed to be the only relic of King Solomon's biblical era Jewish Temple turns out not to be an artifact from the holy shrine, the Israel Museum said on Friday.
Israeli experts have determined the thumb-sized object is a lot older than believed, dating to the 13th or 14th Century BC, rather than to the 8th Century BC, which scholars say was around the time of Solomon.
23 dic 2004
La NASA detecta decenas de galaxias 'recién nacidas'
elmundo.es
Miles de millones de años después del "nacimiento" de un gran número de galaxias, una aeronave de la NASA ha detectado a menos de 4.000 millones de años luz de la Tierra docenas de galaxias 'recién nacidas', tan jóvenes como era la Vía Láctea hace 10.000 millones de años.
Estos inesperados "bebés" cósmicos fueron descubiertos por la nave exploradora Galaxy Evolution, que logró detectarlas debido a las grandes cantidades de rayos ultravioletas que emitían a medida que se formaban estrellas a partir de elementos gaseosos, dijeron el martes los astrónomos encargados de la misión.
Miles de millones de años después del "nacimiento" de un gran número de galaxias, una aeronave de la NASA ha detectado a menos de 4.000 millones de años luz de la Tierra docenas de galaxias 'recién nacidas', tan jóvenes como era la Vía Láctea hace 10.000 millones de años.
Estos inesperados "bebés" cósmicos fueron descubiertos por la nave exploradora Galaxy Evolution, que logró detectarlas debido a las grandes cantidades de rayos ultravioletas que emitían a medida que se formaban estrellas a partir de elementos gaseosos, dijeron el martes los astrónomos encargados de la misión.
20 dic 2004
Science in a spin over spider web
CNN.com
Israeli scientists have come up with a way to genetically engineer spiders' webs without the help of the eight-legged creatures.
The development, carried out during the past two years at the Hebrew University of Jerusalem, potentially paves the way for commercial development of the fiber, said to be stronger than silk.
Israeli scientists have come up with a way to genetically engineer spiders' webs without the help of the eight-legged creatures.
The development, carried out during the past two years at the Hebrew University of Jerusalem, potentially paves the way for commercial development of the fiber, said to be stronger than silk.
La NASA estudia plantar pinos en el planeta Marte
elmundo.es
Científicos mexicanos y estadounidenses estudian las causas de la resistencia de los pinos que crecen en las laderas de la montaña más alta de México, el Pico de Orizaba, para plantarlos en Marte. Los científicos analizan desde hace años la sorprendente adaptación y resistencia de los árboles de esa especie que crecen en esa montaña, de 5.647 metros de altura, en condiciones tan adversas como el frío y la falta de oxígeno.
Científicos mexicanos y estadounidenses estudian las causas de la resistencia de los pinos que crecen en las laderas de la montaña más alta de México, el Pico de Orizaba, para plantarlos en Marte. Los científicos analizan desde hace años la sorprendente adaptación y resistencia de los árboles de esa especie que crecen en esa montaña, de 5.647 metros de altura, en condiciones tan adversas como el frío y la falta de oxígeno.
Otro paso hacia la vida artificial
BBC.co.uk
Investigadores en la Universidad Rockefeller en los Estados Unidos están dando los primeros pasos en la tentativa por crear una forma de vida artificial.
Sus creaciones, pequeñas vesículas sintéticas que pueden procesar (expresar) genes, se asemejan a una forma básica de célula biológica.
Investigadores en la Universidad Rockefeller en los Estados Unidos están dando los primeros pasos en la tentativa por crear una forma de vida artificial.
Sus creaciones, pequeñas vesículas sintéticas que pueden procesar (expresar) genes, se asemejan a una forma básica de célula biológica.
17 dic 2004
La Ciencia de 2004
elmundo.es
Alguna vez Marte fue cálido, húmedo y salado, es decir, reunió las características necesarias para albergar vida tal y como se conoce en nuestro planeta. El descubrimiento realizado el pasado mes de marzo por los robots exploradores de la NASA ha sido calificado por la revista 'Science' como el hito científico de 2004.
Esa es, a juicio de los responsables de la revista editada por la Asociación Americana por el Avance de la Ciencia, la noticia científica más destacada de un año rodeado de polémica.
Alguna vez Marte fue cálido, húmedo y salado, es decir, reunió las características necesarias para albergar vida tal y como se conoce en nuestro planeta. El descubrimiento realizado el pasado mes de marzo por los robots exploradores de la NASA ha sido calificado por la revista 'Science' como el hito científico de 2004.
Esa es, a juicio de los responsables de la revista editada por la Asociación Americana por el Avance de la Ciencia, la noticia científica más destacada de un año rodeado de polémica.
16 dic 2004
Cream of the crop
Guardian.co.uk
Millions of users now find it hard to imagine life without the internet - without email, instant messaging, web search engines and online trading or gaming.
Over the past decade since Online was launched, it's the web that has made the difference. It has made it easier to access all the net's facilities, and encouraged a huge explosion in the number and diversity of websites.
With the web still expanding, we have taken the opportunity to ask Online's readers, contributors, and some of the Guardian's journalists to suggest the 100 most useful sites.
Millions of users now find it hard to imagine life without the internet - without email, instant messaging, web search engines and online trading or gaming.
Over the past decade since Online was launched, it's the web that has made the difference. It has made it easier to access all the net's facilities, and encouraged a huge explosion in the number and diversity of websites.
With the web still expanding, we have taken the opportunity to ask Online's readers, contributors, and some of the Guardian's journalists to suggest the 100 most useful sites.
15 dic 2004
Témpano de hielo bloquea Antártida
BBC.co.uk
Google ha firmado un acuerdo con cinco de las universidades más importantes del mundo para digitalizar los contenidos de sus bibliotecas. Las universidades de Michigan, Stanford, Harvard, Oxford y la Biblioteca Pública de Nueva York han sido las escogidas para este proyecto digital. Así los internautas tendrán la posibilidad de visitar las páginas escaneadas de los libros públicos, ya sea para investigación o una simple consulta.
Google ha firmado un acuerdo con cinco de las universidades más importantes del mundo para digitalizar los contenidos de sus bibliotecas. Las universidades de Michigan, Stanford, Harvard, Oxford y la Biblioteca Pública de Nueva York han sido las escogidas para este proyecto digital. Así los internautas tendrán la posibilidad de visitar las páginas escaneadas de los libros públicos, ya sea para investigación o una simple consulta.
Google digitalizará los libros de cinco de las mejores universidades del mundo
elmundo.es
Google ha firmado un acuerdo con cinco de las universidades más importantes del mundo para digitalizar los contenidos de sus bibliotecas. Las universidades de Michigan, Stanford, Harvard, Oxford y la Biblioteca Pública de Nueva York han sido las escogidas para este proyecto digital. Así los internautas tendrán la posibilidad de visitar las páginas escaneadas de los libros públicos, ya sea para investigación o una simple consulta.
Google ha firmado un acuerdo con cinco de las universidades más importantes del mundo para digitalizar los contenidos de sus bibliotecas. Las universidades de Michigan, Stanford, Harvard, Oxford y la Biblioteca Pública de Nueva York han sido las escogidas para este proyecto digital. Así los internautas tendrán la posibilidad de visitar las páginas escaneadas de los libros públicos, ya sea para investigación o una simple consulta.
14 dic 2004
Retiree Duped by Naked Invitation
Reuters.com
An 81-year-old German dropped his trousers and lost his wallet when two young women asked him to join them in a nude photo shoot but they fled with his belongings as he stripped, police said Monday.
"After the pensioner had removed his trousers in eager anticipation, the women left in a hurry," taking the man's wallet with about 250 euros in cash, police in the western city of Wiesbaden said in a statement.
An 81-year-old German dropped his trousers and lost his wallet when two young women asked him to join them in a nude photo shoot but they fled with his belongings as he stripped, police said Monday.
"After the pensioner had removed his trousers in eager anticipation, the women left in a hurry," taking the man's wallet with about 250 euros in cash, police in the western city of Wiesbaden said in a statement.
A Species in a Second: Promise of DNA 'Bar Codes'
www.nytimes.com
When an astronaut sets foot on an alien planet and sees moving shadows in a nearby wood, he whips out a scanning device that immediately identifies the menacing life-form, flashing up a photo of its species and an assessment of its aggressive intent.
If such devices are standard equipment for visiting distant planets, why can't we have them here at home where we really need them? Less than a fifth of the earth's 10 million species of plants and animals have been cataloged, and taxonomists are backlogged with requests to apply their specialist knowledge to identification problems.
When an astronaut sets foot on an alien planet and sees moving shadows in a nearby wood, he whips out a scanning device that immediately identifies the menacing life-form, flashing up a photo of its species and an assessment of its aggressive intent.
If such devices are standard equipment for visiting distant planets, why can't we have them here at home where we really need them? Less than a fifth of the earth's 10 million species of plants and animals have been cataloged, and taxonomists are backlogged with requests to apply their specialist knowledge to identification problems.
Google Is Adding Major Libraries to Its Database
www.nytimes.com
Google, the operator of the world's most popular Internet search service, plans to announce an agreement today with some of the nation's leading research libraries and Oxford University to begin converting their holdings into digital files that would be freely searchable over the Web.
Google, the operator of the world's most popular Internet search service, plans to announce an agreement today with some of the nation's leading research libraries and Oxford University to begin converting their holdings into digital files that would be freely searchable over the Web.
10 dic 2004
8 dic 2004
How a "safe haven" could help save Hubble
MSNBC.com
An “out-of-the-box” plan to put a new space habitat in orbit could be a leading contender for saving the Hubble Space Telescope, private-sector analysts say in a proposal being prepared for NASA. The habitat could be used as an emergency safe haven during the Hubble servicing mission, and then could serve as a base for wider commercial and exploratory space travel.
An “out-of-the-box” plan to put a new space habitat in orbit could be a leading contender for saving the Hubble Space Telescope, private-sector analysts say in a proposal being prepared for NASA. The habitat could be used as an emergency safe haven during the Hubble servicing mission, and then could serve as a base for wider commercial and exploratory space travel.
7 dic 2004
Solar storms smack a comet
CNN.com
Astronomers have pieced together what appears to be the first direct evidence that solar storms can wreck havoc with comets, destroying the ion tails of icy wanderers in a collision of highly charged particles.
But the effect is not permanent and may serve as a marker for scientists trying to track solar storms known as coronal mass ejections (CMEs) as they blow out into space.
Astronomers have pieced together what appears to be the first direct evidence that solar storms can wreck havoc with comets, destroying the ion tails of icy wanderers in a collision of highly charged particles.
But the effect is not permanent and may serve as a marker for scientists trying to track solar storms known as coronal mass ejections (CMEs) as they blow out into space.
Star's pulse of radiation is strongest ever
newscientist.com
The brightest pulse of radiation ever seen has come from a pulsar nearly 12,000 light years away. Lasting less than 15 billionths of a second (15 nanoseconds), the burst was recorded by a massive radio telescope at Tidbinbilla in Australia.
Although the star was discovered decades ago, it is only now that telescopes have become sensitive enough to record such a fleeting phenomenon.
The brightest pulse of radiation ever seen has come from a pulsar nearly 12,000 light years away. Lasting less than 15 billionths of a second (15 nanoseconds), the burst was recorded by a massive radio telescope at Tidbinbilla in Australia.
Although the star was discovered decades ago, it is only now that telescopes have become sensitive enough to record such a fleeting phenomenon.
String Theory, at 20, Explains It All (or Not)
nytimes.com
By uniting all the forces, string theory had the potential of achieving the goal that Einstein sought without success for half his life and that has embodied the dreams of every physicist since then. If true, it could be used like a searchlight to illuminate some of the deepest mysteries physicists can imagine, like the origin of space and time in the Big Bang and the putative death of space and time at the infinitely dense centers of black holes.
By uniting all the forces, string theory had the potential of achieving the goal that Einstein sought without success for half his life and that has embodied the dreams of every physicist since then. If true, it could be used like a searchlight to illuminate some of the deepest mysteries physicists can imagine, like the origin of space and time in the Big Bang and the putative death of space and time at the infinitely dense centers of black holes.
2 dic 2004
Nueva tecnología para producir 'nanoestructuras'
elmundo.es
Una nueva tecnología para la producción de nanoestructuras, 60.000 veces más delgadas que el grosor de un pelo humano, ha sido presentada en un congreso en Viena. El llamado procedimiento de "nanoimprenta" representa una alternativa "económica y segura" para obtener estructuras de dimensiones microscópicas que se usan, entre otras muchas aplicaciones, en la electrónica.
Con los procedimientos litográficos relativamente caros y lentos que se vienen aplicando hasta ahora se alcanzaba tan sólo una reducción del material de unos 50 nanómetros (la millonésima parte de un milímetro), mientras que mediante la exposición a luz ultravioleta de onda corta, a unos 20 nano metros.
Una nueva tecnología para la producción de nanoestructuras, 60.000 veces más delgadas que el grosor de un pelo humano, ha sido presentada en un congreso en Viena. El llamado procedimiento de "nanoimprenta" representa una alternativa "económica y segura" para obtener estructuras de dimensiones microscópicas que se usan, entre otras muchas aplicaciones, en la electrónica.
Con los procedimientos litográficos relativamente caros y lentos que se vienen aplicando hasta ahora se alcanzaba tan sólo una reducción del material de unos 50 nanómetros (la millonésima parte de un milímetro), mientras que mediante la exposición a luz ultravioleta de onda corta, a unos 20 nano metros.
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