Alien invasions, four-armed ETs and the cosmic lottery – New Scientist talks to the founder of Project Ozma and the inspiration for the modern search for extraterrestrial life.
What gave you the inspiration to set up Project Ozma?
In 1957 I was studying the Pleiades star cluster at Harvard University’s radio observatory. On one occasion we saw an added feature in the data. It turned out to be an amateur radio enthusiast near the observatory, but at the time I thought we had detected clear evidence of another civilisation. You feel a very strong emotion that you never feel otherwise. It’s a combination of elation and excitement and the sense that everything we know is going to change.
How optimistic were you when it all began?
In 1960, when Ozma started, every star in the sky could have been radiating signals, for all we knew. There was a chance we’d succeed almost immediately. But we knew so little of the universe that one could not seriously speculate.
You kept Project Ozma secret: was that because your peers would be sceptical?
Back in 1960 it was taboo to think about extraterrestrial life; it was something done by bad scientists. However, we were fearless. We did not feel we should be embarrassed in any way.
Fifty years on, do you think we should have heard something?
Over the years, I’ve gotten more realistic. The equation I devised [the Drake equation] says that we’re going to have to look at 10 million stars before we find one that might host life. Even then there’s no guarantee they’re transmitting, or on the frequency we’re looking at. We’ve done a lot of searching to date but it doesn’t add up to 10 million stars. In a way what we’ve been doing until now is buying a ticket in the lottery. There’s no reason to think we should have succeeded yet.
Should we start broadcasting in a coordinated way?
Frankly, no. A civilisation not much more advanced than ours could build a telescope that could detect the signals we already transmit, such as television. For us to spend our resources adding one more signal to that cacophony would be frosting on the cake.
There is also an argument that broadcasting could elicit an invasion.
Yes, and if that happens it might be my fault! Back in 1974 I broadcast a signal from the Arecibo Observatory in Puerto Rico, which is still the strongest signal ever sent. That stimulated a major outburst from the Astronomer Royal at the time. He was very concerned.
What do you think an alien would look like?
Our physiology and morphology are certainly not unique. Humans are basically a good design: it’s good to stand upright, because it frees our hands to manipulate tools, for instance. It’s best to have the head on top, so you can see prey. Our two arms are arguably not optimum, however, as anyone who has tried to carry groceries from their car to their house will find! So my hypothetical ET looks a lot like us but has four arms. Then again, who knows what evolution will lead to elsewhere?
Archive for January 15th, 2010
Posted by Xeno on January 15, 2010
Posted by Xeno on January 15, 2010
NASA is feeling the pinch in its plutonium supplies.
Many spacecraft are powered by the radioactive decay of plutonium-238, but the US no longer produces the material. Instead, NASA relies on its shrinking stockpile, topped up with purchases from Russia.
Previous estimates suggested the decline would not affect solar-system exploration until after 2020, but NASA is already tightening its belt. Candidates for NASA’s next “New Frontiers” mission, which aims to launch an exploratory spacecraft by 2018, will not be allowed to rely on plutonium for power, effectively limiting the candidate probes to solar power only.
That puts a number of destinations off-limits, says Jim Green, head of NASA’s planetary science division. These include targets beyond Jupiter or even darkened regions closer to the sun, like the polar regions of Mars. “Without the plutonium, there’s just a huge dimension of science we’re going to be missing,” Green told New Scientist.
NASA is also relying on Russia for some plutonium-238 that it needs for its next major mission to the outer solar system – to explore Jupiter and its moon Europa. The US Department of Energy is currently analysing what will be required to restart plutonium-238 production, but new fuel may not be ready in time for the mission to launch as planned in 2020.
There is a reason not to use Plutonium:
Breathing in less than a microgram will cause cancer and kill you. Not right away, but over a decade or so. And if you have a “bulk quantity” that you touch together and it will create a critical mass, the radiation burst will be fatal. You’ll be history within 30 days or less. It’s hard to imagine an elemental substance more dangerous than this one. – answers
Hundreds of tons of plutonium have been produced since World War II. The Cold War is over, yet production of plutonium, one of the most potent cancer-causing substances known to humankind, continues in several countries. While much of it is allegedly now for civilian power generation, all plutonium can be used for nuclear weapons, and proliferation by sale or theft is an increasing risk. Further, plutonium production (“reprocessing”) generates great volumes of highly radioactive liquid wastes, which under certain conditions can explode, as occurred in the Soviet Union in 1957. There is as yet no suitable method for disposing of these wastes or the plutonium itself. – eggheadbooks
Cassini contains over 72 pounds of a radioactive substance called Plutonium Dioxide. Plutonium is commonly referred to as “the deadliest substance known to man” and for good reason. The isotope of plutonium used in Cassini, Pu-238, is especially dangerous because of it’s rapid rate of radioactive decay. It has a very short half-life (87.75 years) which means it emits radiation (in this case mainly alpha particles) at a very high rate. Although it is true that alpha particles can be stopped by a piece of paper, when even a tiny, microscopic particle of Plutonium 238 is inhaled, the localized radiation (the radiation to nearby cells) can be 1000′s of REM, and it can cause lung cancer and other illnesses. - animatedsoftware
Posted by Xeno on January 15, 2010
SUPERMAN’S sparkling Fortress of Solitude they’re not, but giant outcrops of crystals, found on the moon by India’s Chandrayaan-1 probe, prove that a roiling ocean of magma once engulfed the rocky body of our satellite.
The moon is thought to have coalesced more than 4 billion years ago from the molten debris of an impact between the Earth and a Mars-sized object. Models suggest that heat from that impact, as well as from material compressing to form the moon, created a sea of magma that lasted for a few hundred million years. Heavy, iron-bearing minerals should have sunk through this magma to form the moon’s mantle, while lighter, iron-poor minerals called plagioclases should have crystallised and floated to the surface.
But it has been difficult to find direct evidence of the moon’s primordial crystalline crust, as it was likely jumbled by meteoroid impacts and paved over by lava flows early in the moon’s history. Until recently, the only evidence came from lunar samples collected at a few sites by the Apollo astronauts.
Last year, however, Japan’s Kaguya probe spotted patches of the stuff inside a number of craters (Nature, DOI: 10.1038/nature08317). Now, it seems Chandrayaan-1, which orbited the moon for almost 10 months until it failed in August, found the mother lode – vast outcrops of plagioclase crystal along a mountain range inside the moon’s 930-kilometre-wide Orientale basin (below). Lava has resurfaced less of Orientale than other craters of its size.
In 1994, the US orbiter Clementine found regions inside Orientale that seemed to be virtually iron-free, hinting at plagioclase. But Chandrayaan-1 was able to detect the light absorbed by the crystal itself. It found that the rock containing the crystal spans at least 40 kilometres and is quite pure – less than 5 per cent of it is composed of iron-rich minerals.
That is purer than a number of Apollo samples, which until now have been the primary source of information on the moon’s ancient crust. “This is a game-changer,” says Paul Warren of the University of California, Los Angeles. “We now have to rethink a lot of lunar science; issues such as the way the crust originally floated over the denser melt of the magma ocean [and] the extent to which the crust was jumbled by large impacts.” …
Posted by Xeno on January 15, 2010
Astronomers have made the first direct capture of a spectrum of light from a planet outside the Solar System and are deciphering its composition.
The light was snared from a giant planet that orbits a bright young star called HR 8799 about 130 light-years from Earth, said the European Southern Observatory (ESO).
“The spectrum of a planet is like a fingerprint. It provides key information about the chemical elements in the planet’s atmosphere,” said Markus Janson, lead author of a study on the find. “With this information, we can better understand how the planet formed and, in the future, we might even be able to find tell-tale signs of the presence of life.”
HR 8799 has a mass about one-and-a-half times that of the Sun and hosts a planetary system “that resembles a scaled-up model of our own Solar System,” the ESO said. The target was the middle one of three planets – initially spotted in 2008 – that are between seven and 10 times the mass of Jupiter.
The find is important, because hidden within a light spectrum are clues about the relative amounts of different elements in the planet’s atmosphere.
“The features observed in the spectrum are not compatible with current theoretical models,” said co-author Wolfgang Brandner. “We need to take into account a more detailed description of the atmospheric dust clouds, or accept that the atmosphere has a different chemical composition from that previously assumed.”
The result represents a milestone in the search for life elsewhere in the universe, said the ESO. Until now, astronomers have been able to get only an indirect light sample from an exoplanet, as worlds beyond our Solar System are called. …
Posted by Xeno on January 15, 2010
An enormous television screen showing a pornographic film caused a midnight traffic jam in central Moscow Thursday as stunned motorists slammed on the brakes to gawk at the writhing naked bodies.
The owner of the advertising screen, which sits atop a main road about two km (1.2 miles) south of the Kremlin, told the state-run RIA news agency that hackers had broken into the screen’s computer system and turned on the porn.
“They were either acting out of hooliganism or were from a rival company,” Viktor Laptev, commercial director of advertising firm Panno.ru, told RIA.
A short clip showing cars slowing to a halt to look at the screen sprung up on youtube.com and internet sites Friday across Russia, a country which banned nudity on television before the Soviet Union fell in 1991. Authorities said they are investigating, RIA added.
Drivers in downtown Moscow squinted in disbelief as an electronic highway billboard blazed a two-minute pornographic video instead of its regular advertising clips.
Late-night traffic on one of the Russian capital’s busiest roads slowed Thursday as a couple’s explicit escapades appeared on the 9-by-6-meter (yard) display.
Some people took pictures of the sight with their mobile phones and posted them on the Internet.
Passer-by Alyona Prokulatova told The Associated Press that she was “so shocked that I couldn’t even shoot video or take a picture of it.”
The screen’s owner, 3 Stars, told the AP that a hacker attack was likely to blame. Police were investigating the incident. – centraldaily
Here is a video that shows the billboards and how in 2008 and 2009 they were removed from around the Kremlin.
Posted by Xeno on January 15, 2010
Call it pork in a petri dish — a technique to turn pig stem cells into strips of meat that scientists say could one day offer a green alternative to raising livestock, help alleviate world hunger, and save some pigs their bacon.
Dutch scientists have been growing pork in the laboratory since 2006, and while they admit they haven’t gotten the texture quite right or even tasted the engineered meat, they say the technology promises to have widespread implications for our food supply.
“If we took the stem cells from one pig and multiplied it by a factor of a million, we would need one million fewer pigs to get the same amount of meat,” said Mark Post, a biologist at Maastricht University involved in the In-vitro Meat Consortium, a network of publicly funded Dutch research institutions that is carrying out the experiments.
Post describes the texture of the meat as sort of like scallop, firm but a little squishy and moist. That’s because the lab meat has less protein content than conventional meat.
Several other groups in the U.S., Scandinavia and Japan are also researching ways to make meat in the laboratory, but the Dutch project is the most advanced, said Jason Matheny, who has studied alternatives to conventional meat at the Johns Hopkins Bloomberg School of Public Health in Baltimore and is not involved in the Dutch research.
In the U.S., similar research was funded by NASA, which hoped astronauts would be able to grow their own meat in space. But after growing disappointingly thin sheets of tissue, NASA gave up and decided it would be better for its astronauts to simply eat .
To make pork in the lab, Post and colleagues isolate stem cells from pigs’ muscle cells. They then put those cells into a nutrient-based soup that helps the cells replicate to the desired number.
So far the scientists have only succeeded in creating strips of meat about 1 centimeter (a half inch) long; to make a small pork chop, Post estimates it would take about 30 days of cell replication in the lab.
There are tantalizing health possibilities in the technology.
Fish stem cells could be used to produce healthy omega 3 fatty acids, which could be mixed with the lab-produced pork instead of the usual artery-clogging fats found in livestock meat.
“You could possibly design a hamburger that prevents heart attacks instead of causing them,” Matheny said.
Post said the strips they’ve made so far could be used as processed meat in sausages or hamburgers. Their main problem is reproducing the protein content in regular meat: In livestock meat, protein makes up about 99 percent of the product; the lab meat is only about 80 percent protein. The rest is mostly water and nucleic acids.
None of the researchers have actually eaten the lab-made meat yet, but Post said the lower protein content means it probably wouldn’t taste anything like pork.
The Dutch researchers started working with pork stem cells because they had the most experience with pigs, but said the technology should be transferable to other meats, like chicken, beef and lamb.
Some experts warn lab-made meats might have potential dangers for human health.
“With any new technology, there could be subtle impacts that need to be monitored,” said Emma Hockridge, policy manager at Soil Association, Britain’s leading organic organization.
As with genetically modified foods, Hockridge said it might take some time to prove the new technology doesn’t harm humans. She also saidrelies on crop and livestock rotation, and that taking animals out of the equation could damage the ecosystem.
Some experts doubted lab-produced meat could ever match the taste of real meat.
Posted by Xeno on January 15, 2010
Most skin cancers are highly curable, but require surgery that can be painful and scarring.
A new study by Loyola University Health System researchers could lead to alternative treatments that would shrink skin cancer tumors with drugs. The drugs would work by turning on a gene that prevents skin cells from becoming cancerous, said senior author Mitchell Denning, Ph.D.
The study was published Jan. 15, 2010 in the Journal of Biological Chemistry.
More than 1 million people in the United States are diagnosed with skin cancer each year. In the new study, researchers examined a type of skin cancer, called squamous cell carcinoma, that accounts for between 200,000 and 300,000 new cases per year.
Squamous cell carcinoma begins in the upper part of the epidermis, the top layer of the skin. Most cases develop on areas that receive lots of sun, such as the face, ear, neck, lips and backs of hands. There are various surgical treatments, including simple excision, curettage and electrodessication (scraping with a surgical tool and treating with an electric needle) and cryosurgery (freezing with liquid nitrogen). Removing large skin cancers can require skin grafts and be disfiguring.
Sunlight can damage a skin cell’s DNA. Normally, a protein called protein kinase C (PKC) is activated in response to the damage. If the damage is too great to repair, the PKC protein directs the cell to die.
Healthy cells grow and divide in a cell-division cycle. At several checkpoints in this cycle, the cell stops to repair damaged DNA before progressing to the next step in the cycle. The new study found that the PKC gene is responsible for stopping the cell at the checkpoint just before the point when the cell divides. In squamous cell carcinoma, the PKC gene is turned off. The cell proceeds to divide without first stopping to repair its DNA, thus producing daughter tumor cells.
Denning said a class of drugs called protein kinase inhibitors potentially could shrink tumors by turning the PKC gene back on. Several such drugs have been approved by the Food and Drug Administration for other cancers. Denning is pursuing grant funding to test such drugs on animal models.
via News Release Detail.
Crud, I’ve had a bump about this site on my chest for months. I thought it was just an ingrown hair. Seems to be shrinking, but now I think I should get it checked.
Update: had it checked. It was indeed a three month long ingrown hair that is slowly dissolving.
Posted by Xeno on January 15, 2010
Erhan Elibol, a vet, performed a caesarean on the animal to take the lamb out, but was horrified to see that the features of the lamb’s snout bore a striking resemblance to a human face.
“I’ve seen mutations with cows and sheep before. I’ve seen a one-eyed calf, a two-headed calf, a five-legged calf. But when I saw this youngster I could not believe my eyes. His mother could not deliver him so I had to help the animal,” the 29-year-old veterinary said.
The lamb’s head had human features on – the eyes, the nose and the mouth – only the ears were those of a sheep.
Vets said that the rare mutation most likely occurred as a result of improper mutation since the fodder for the lamb’s mother was abundant with vitamin A, CNNTurk.com reports.
A goat from Zimbabwe gave birth to a similar youngster in September 2009. The mutant baby born with a human-like head stayed alive for several hours until the frightened village residents killed him.
The governor of the province where the ugly goat was born said that the little goat was the fruit of unnatural relationship between the female goat and a man.
“This incident is very shocking. It is my first time to see such an evil thing. It is really embarrassing,” he reportedly said. “The head belongs to a man while the body is that of a goat. This is evident that an adult human being was responsible. Evil powers caused this person to lose self control. We often hear cases of human beings who commit bestiality but this is the first time for such an act to produce a product with human features,” he added. The mutant creature was hairless. Local residents said that even dogs were afraid to approach the bizarre animal.
The locals burnt the body of the little goat, and biologists had no chance to study the rare mutation.
Why only one photo? Why no video? Notice that the face seems to be a mask with a ridge running around it? This story seems to have come from two different “tabloid style” web sites, Pravda Online and The Daily Telegraph (not that one). Is this an early Russian April fool’s day? The .au version of the Daily Telegraph says the image source for it’s smaller version of the photo above is the “Daily Telegraph”.
Notes on the two sources:
The new Pravda newspaper and Pravda Online are not related in any way, although the journalists of both publications are still in touch with each other. The paper Pravda tends to analyze events from a leftist point of view, while the web-based, tabloid-style newspaper often takes a nationalist and sensationalist approach.
The Daily Telegraph is an Australian tabloid newspaper published in Sydney, New South Wales and country NSW, by Nationwide News, part of News Corporation. It is named after the British upmarket daily newspaper The Daily Telegraph. – wikipedia
The Pravda site gives a source of CNNTurk.com the the link just goes to the main site, not to the source article. A search on the CNNTurk.com site for “Erhan Elibol” does not return this story. Next, I used a Turkish to English translator to figure out that the Turkish word for lamb is Kuzu and the word for sheep is Koyunlar and I did not find the story, but found other stories about sheep. Also searched for Izmir…. nothing. Then I got it! I used Google and searched for this:
“Erhan Elibol” site:cnnturk.com
Here is the link to the original article on CNNTurk.com: http://www.cnnturk.com/2010/yasam/diger/01/11/izmirde.insan.basli.oglak.dogdu/558834.0/index.html
Here is a word for word translation of the Turkish article:
(Izmir)\’in cotton thread dead while becoming to the human her vet with her face which resembles and turned which sees confused. Tire\’de five the expert at your 29 age which does duty intimidates a vet a physician Erhan Elibol and noon saatlerinde today two pregnant stubborn for birth red to the surgical operation. Dead at the births which are done with the cesarean from the goat kid which exist one her vet turned the face which resembles the human confused. Birth (sonrasinda) Elibol and the mother completed stubborn cure. The Erhan which can not believe Elibol to your eyes \ a goat child’s head benziyordu to a human head. Burnu which has not completed her development made her be recalling a human face which (agzi) and eye pits make mention to smile yet. (Oglaklar) and usual are contrary single ungual \ she told. My medicine Elibol which does to your remarks \ disgusting birth (vakalarinda) the scientific name which is seen while becoming very rare \ Malformasyon \ which (bozuklugu) becomes a formation and which confronted with. Approximate one a at the literature event while mixing your books from a operation’s back after is lived are not lived the event’s reasons \ told. If like vaka this does not become at previous births and a several formation (bozuklugu) a vet whom the expert clarifies that you saw clear Elibol \ which I met more earlier grind at the bosoms. A formation (bozukluklari) a headed double calf and a hand and the single eyed calf whose feet have not become comprised and five footed calves and confronted with. First I am seeing time. This sananen sexual stubborn normal birth time had come, but can not do disgusting birth I gave the cesarean a decision \ diye she talked to. Elibol \ I confronted clear later. Her human turned her head and her face whose villager citizen who becomes the me and the owner recalls goat kid confused. (Kadariyla) which I learned vaka last Zimbabve\’deki Lower Gweru kentinde has been lived. You not can become to the soot whose reason I investigated your reason, at the extreme shape and (bilincsizce) A which becomes used I reached her knowledge which she became they apply the vitamin \ by saying she completed her remarks.
Wow. Seems real. More research would help. Does the village have a name? Who owned the sheep? What was done with the body? Get a tissue sample!
Here also is a link to the “goat with a human head born in central Zimbabwe“.
No way. Bestiality does happen, but human sperm will not fertilize sheep eggs and there could be no offspring because the number of chromosomes is different. Humans have 46 sheep have 54. Unless the chromosomes in the egg and the sperm match, they won’t link together and form a living thing. Not going to happen.
Possible, but unlikely. Why would a genetics lab’s research end up in a village animal? Regarding mixing human and animal DNA, see this:
Sheep that have partially human livers, hearts, brains and other organs are shown here at the University of Nevada, in Sparks, Nev., on April 27.
On a farm about six miles outside this gambling town, Jason Chamberlain looks over a flock of about 50 smelly sheep, many of them possessing partially human livers, hearts, brains and other organs.
The University of Nevada-Reno researcher talks matter-of-factly about his plans to euthanize one of the pregnant sheep in a nearby lab. He can’t wait to examine the effects of the human cells he had injected into the fetus’ brain about two months ago.
“It’s mice on a large scale,” Chamberlain says with a shrug.
As strange as his work may sound, it falls firmly within the new ethics guidelines the influential National Academies issued this past week for stem cell research.
In fact, the Academies’ report endorses research that co-mingles human and animal tissue as vital to ensuring that experimental drugs and new tissue replacement therapies are safe for people.
Doctors have transplanted pig valves into human hearts for years, and scientists have injected human cells into lab animals for even longer.
Biological mixing of species
But the biological co-mingling of animal and human is now evolving into even more exotic and unsettling mixes of species, evoking the Greek myth of the monstrous chimera, which was part lion, part goat and part serpent.
In the past two years, scientists have created pigs with human blood, fused rabbit eggs with human DNA and injected human stem cells to make paralyzed mice walk.
Particularly worrisome to some scientists are the nightmare scenarios that could arise from the mixing of brain cells: What if a human mind somehow got trapped inside a sheep’s head?
The “idea that human neuronal cells might participate in ‘higher order’ brain functions in a nonhuman animal, however unlikely that may be, raises concerns that need to be considered,” the academies report warned.
Mice with human brains
In January, an informal ethics committee at Stanford University endorsed a proposal to create mice with brains nearly completely made of human brain cells. Stem cell scientist Irving Weissman said his experiment could provide unparalleled insight into how the human brain develops and how degenerative brain diseases like Parkinson’s progress.
Stanford law professor Hank Greely, who chaired the ethics committee, said the board was satisfied that the size and shape of the mouse brain would prevent the human cells from creating any traits of humanity. Just in case, Greely said, the committee recommended closely monitoring the mice’s behavior and immediately killing any that display human-like behavior. – msnbc
What the!? Are you kidding me? They kill them if they seem human?!? Mice with almost completely human brain cell is disturbing. How would any researcher know if a little human consciousness gets formed when you do that? Size doesn’t always matter when it comes to brain power.
Getting back to the first story… here is the possibility mentioned in the article.
4. Rare genetic mutation?
I do not think there could possibly be only one or two mutations difference between a human face and a sheep face … more like hundreds, which would pretty much rule this option out, but …
More data is needed, someone please get a tissue sample from the head of this poor dead human-faced lamb for DNA tests, quick!! If real, this is highly valuable! The genetics behind this mutation, in combination with stem cells, could someday be used to help people grow new face parts to repair damage from accidents, and more! Science is still decades away from understanding how genetics form various features of human faces. By the way, did you know that DNA samples from crime scenes may someday be used to determine the facial features of the criminal?!
If things pan out… genetic information from a crime scene may provide information about the perpetrator’s face that could be used to prop up other evidence in court or provide useful hints during investigations. Because there are so many different human populations around the world and a huge amount of variation in facial features, he cautioned, it may take decades to describe and understand all normal human facial variation. Still, Shriver is confident that researchers can collect enough information to be useful for forensics in the US in the next few years. – genomeweb
If this is lamb with a human face is the real deal and a rare mutation can turn a sheep face into a human face, how many evolution deniers will have trouble sleeping tonight? Answer: none. That’s the beauty of denial, you can deny any evidence you like, even when it is staring you in the face.
Posted by Xeno on January 15, 2010
Alligators betray their distant ancestral roots by breathing like birds, scientists have discovered.
Researchers found that, just as it does in birds, air flows in one direction as it loops through the lungs of alligators.
The breathing method is believed to have first appeared in ancient reptiles called archosaurs which dominated the Earth 251 million years ago.
In contrast, mammalian breath flows in and out of branching cul-de-sacs in the lungs called alveoli.
Archosaurs evolved along two different paths, one of which gave rise to the crocodilian ancestors of crocodiles and alligators. The other produced the flying pterosaurs and eventually birds.
The research on alligators suggests that bird-like breathing probably evolved earlier than previously thought, before the archosaur split.
It may explain why archosaurs became so dominant in the Early Triassic Period which followed a devastating mass extinction known as the ‘Great Dying’.
Prior to the extinction event, which killed off 70% of all land life and 96% of sea life, reptile-like mammals called synapsids were the largest animals on Earth.
After it, mammals were overshadowed by reptiles in the form of archosaurs and, later, dinosaurs.
As the Earth recovered from the ‘Great Dying’ conditions were warm and dry, with oxygen levels almost half what they are today.
But despite the lack of oxygen many archosaurs were capable of vigorous activity.
‘Lung design may have played a key role in this capacity because the lung is the first step in the cascade of oxygen from the atmosphere to the animal’s tissues, where it is used to burn fuel for energy,’ said lead researcher Colleen Farmer, from the University of Utah in Salt Lake City, US.
Posted by Xeno on January 15, 2010
Laboratory experiments in the last few decades have shown that some things can appear to move faster than light without contradicting Einstein’s special theory of relativity, but now astrophysicists have seen real examples of superluminal speeds in the form of radio pulses from a pulsar.
Superluminal, or faster than light, speeds are associated with anomalous dispersion, which is a process in which the refractive index of a medium increases with the wavelength of light passing through it. If a light pulse (consisting of a group of light waves at different wavelengths) passes through such a medium, the group velocity of the pulse can increase to a velocity greater than any of the waves within the pulse, but the energy of the pulse still travels at the speed of light, which means information is transmitted in accordance with Einstein’s theory.
Astrophysicists, led by Frederick Jenet of the University of Texas at Brownsville, have been monitoring a pulsar, PSR B1937+21, which is about 10,000 light years from Earth. They used the Arecibo Observatory in Puerto Rico to obtain radio data over three days at 1420.4 MHz with a bandwidth of 1.5 MHz. They found that pulses closer to the center arrived earlier than the normal timing, which suggests they had travelled faster than the speed of light.
A pulsar is a neutron star that is spinning rapidly and emitting a rotating beam of radio radiation as it spins, which is observed on Earth at regular intervals rather like light from a lighthouse. The pulses of radiation can be affected by several factors as they travel through the interstellar medium (ISM). Their polarization can be rotated if they pass through a magnetic field, for example, and they can be scattered if they encounter free electrons, and can be absorbed by neutral hydrogen in the ISM. Jenet and his colleagues think anomalous dispersion also affects the pulses.
According to Jenet and colleagues, the pulses from the pulsar traveled through a cloud of neutral hydrogen, which has a resonance of 1420.4 MHz — the exact center of the bandwidth studied. Passing through the cloud caused anomalous dispersion that resulted in a superluminal group velocity, and pulses with frequencies closest to the resonance frequency arrived earlier than other pulses.
The scientists believe the pulses appear to travel faster than light because of an “interplay between the time scales present in the pulse and the time scales present in the medium.” The faster-than-light pulses do not violate Einstein’s theory because technically the pulse carries no information. The effect has been known in laboratory experiments, but these observations were the first in an astrophysical context. …