Posts tagged Science
Posts tagged Science
Astronomers searching for the building blocks of life in a giant dust cloud at the heart of the Milky Way have concluded that it would taste vaguely of raspberries.
The unanticipated discovery follows years of work by astronomers who trained their 30m radio telescope on the enormous ball of dust and gas in the hope of spotting complex molecules that are vital for life.
Finding amino acids in interstellar space is a Holy Grail for astrobiologists, as this would raise the possibility of life emerging on other planets after being seeded with the molecules.
In the latest survey, astronomers sifted through thousands of signals from Sagittarius B2, a vast dust cloud at the centre of our galaxy. While they failed to find evidence for amino acids, they did find a substance called ethyl formate, the chemical responsible for the flavour of raspberries.
“It does happen to give raspberries their flavour, but there are many other molecules that are needed to make space raspberries,” Arnaud Belloche, an astronomer at the Max Planck Institute for Radio Astronomy in Bonn, told the Guardian.
Curiously, ethyl formate has another distinguishing characteristic: it also smells of rum.
The astronomers used the IRAM telescope in Spain to analyse electromagnetic radiation emitted by a hot and dense region of Sagittarius B2 that surrounds a newborn star.
Radiation from the star is absorbed by molecules floating around in the gas cloud, which is then re-emitted at different energies depending on the type of molecule.
While scouring their data, the team also found evidence for the lethal chemical propyl cyanide in the same cloud. The two molecules are the largest yet discovered in deep space.
Dr Belloche and his colleague Robin Garrod at Cornell University in New York have collected nearly 4,000 distinct signals from the cloud but have only analysed around half of these.
“So far we have identified around 50 molecules in our survey, and two of those had not been seen before,” said Belloche.
Last year, the team came tantalisingly close to finding amino acids in space with the discovery of a molecule that can be used to make them, called amino acetonitrile.
The latest discoveries have boosted the researchers’ morale because the molecules are as large as the simplest amino acid, glycine. Amino acids are the building blocks of proteins and are widely seen as being critical for complex life to exist anywhere in the universe.
“The difficulty in searching for complex molecules is that the best astronomical sources contain so many different molecules that their ‘fingerprints’ overlap and are difficult to disentangle,” Belloche said.
The molecules are thought to form when chemicals that already exist on some dust grains, such as ethanol, link together to make more complex chains.
“There is no apparent limit to the size of molecules that can be formed by this process, so there’s good reason to expect even more complex organic molecules to be there,” said Garrod.
this is why I fucking love space so much
Was Earth’s most devastating mass extinction caused by a single microbe?
Around 251 million years ago, over 90% of the species on Earth suddenly went extinct. Their killer may not have been a devastating meteorite or a catastrophic volcanic eruption, but a humble microbe.
The prevailing theory is that the mass extinction at the end of the Permian period was triggered by volcanic eruptions over a vast area of what is now Siberia. This led, among other things, to a dramatic rise in greenhouse gas emissions.
But the scenario just doesn’t fit the facts, says Daniel Rothman of the Massachusetts Institute of Technology. From his analysis of an end-Permian sediment sample from China, Rothman says carbon levels surged much too quickly for geological processes to be at work.
Microbes can generate carbon compounds that fast, though. When Rothman’s group analysed the genome of Methanosarcina - a methanogen responsible for most of Earth’s biogenic methane today - they discovered that the microbe gained this ability about 231 million years ago. The date was close to that of the mass extinction, but not close enough to suggest a link.
But Methanosarcina needs large amounts of nickel to produce methane quickly. When the team went back to their sediment cores, they discovered that nickel levels spiked almost exactly 251 million years ago - probably because the Siberian lavas were rich in the metal. That suggests Methanosarcina did trigger the extinction, Rothman told the American Geophysical Union meeting in San Francisco last week.
Other geologists remain to be convinced. “[But] it’s a fascinating idea that the evolution of a new life form led to an extinction,” says Anthony Barnosky of the University of California, Berkeley. Today’s mass extinction of biodiversity is similar, says Barnosky, because it is largely driven by our species.
A recent study by a researcher at the Centre for Studies on Human Stress (CSHS) at the Hôpital Louis-H. Lafontaine and professor at the Université de Montréal suggests that bullying by peers changes the structure surrounding a gene involved in regulating mood, making victims more vulnerable to mental health problems as they age. The study published in the journal Psychological Medicine seeks to better understand the mechanisms that explain how difficult experiences disrupt our response to stressful situations. “Many people think that our genes are immutable; however this study suggests that environment, even the social environment, can affect their functioning. This is particularly the case for victimization experiences in childhood, which change not only our stress response but also the functioning of genes involved in mood regulation,” says Isabelle Ouellet-Morin, lead author of the study.
A previous study by Ouellet-Morin, conducted at the Institute of Psychiatry in London (UK), showed that bullied children secrete less cortisol—the stress hormone—but had more problems with social interaction and aggressive behaviour. The present study indicates that the reduction of cortisol, which occurs around the age of 12, is preceded two years earlier by a change in the structure surrounding a gene (SERT) that regulates serotonin, a neurotransmitter involved in mood regulation and depression.
To achieve these results, 28 pairs of identical twins with a mean age of 10 years were analyzed separately according to their experiences of bullying by peers: one twin had been bullied at school while the other had not. “Since they were identical twins living in the same conditions, changes in the chemical structure surrounding the gene cannot be explained by genetics or family environment. Our results suggest that victimization experiences are the source of these changes,” says Ouellet-Morin. According to the author, it would now be worthwhile to evaluate the possibility of reversing these psychological effects, in particular, through interventions at school and support for victims.
I went on a walk this morning up the hill and on my way back down, I stopped to notice these really cool ice crystals sticking up out of the snow. I went and got my camera and took some pictures. I thought now would be a great opportunity to talk about the structure of frozen water!
Water freezes in a hexagonal shape because of where the bonds lie in the water molecule.
When water is at room temperature, or at a liquid state, all the molecules bunch up together and try to fill every crevice they can. It looks like this:
But, when water freezes, the molecules rearrange themselves along the hydrogen atoms and bond there. This structure is more organized than liquid water is:
This accounts for why ice floats on top of water in your drinking glass - there is more space between the molecules in a solid state, which means it is less dense than water in a liquid state. The shape of this model is also hexagonal - the molecules arrange into a tetrahedral shape so every hydrogen atom is bonded to another oxygen atom via a lone pair of electrons. This naturally forms a hexagonal shape, thus the spectacular forms of snowflakes!
Postcards featuring the Space Shuttle Enterprise.
Let’s get something straight!
Bill Nye, the famed “Science Guy,” found himself the center of attention this week after a video in which he saidcreationism should not be taught to childrenwent viral.
“I say to the grownups, ‘If you want to deny evolution and live in your world that’s completely inconsistent with everything we’ve observed in the universe that’s fine,” Nye says in the video. “But don’t make your kids do it.’”
Of course,the Twitterverseand many viewers had a strong response. The Huffington Post reached out to Nye to ask him more about science, religion and teaching creationism in school.
What’s the best scientific argument against creationism?
Unlike science, creationism cannot predict anything, and it cannot provide satisfactory answers about the past. The examples would be nearly limitless. Why does radioactive dating indicate that the world is 4.54 billion years old, if radioactivity is not a feature of nature?
Should teaching creationism be against the law?
Teaching creationism in science class as an alternative to evolution is inappropriate.
Tax dollars intended for science education must not be used to teach creationism as any sort of real explanation of nature, because any observation or process of inference about our origin and the nature of the universe disproves creationism in every respect. Creationism provides no insight whatsoever into nature. Creationism might be taught in a philosophy, psychology, or history of science class, for example.
Is religion inconsistent with science?
If your religion is inconsistent with science, consider tempering your beliefs. For me, the claims of creationism are completely unreasonable.
Judge Jones in Dover, Pennsylvania, used the expression “breathtaking inanity,” meaning so empty, so silly that it took his breath away. The age of the Earth is very close to 4.54 billion years rather than a millionth of that time. The idea that fossils were buried in the Earth by some hidden deity to test ones faith is completely unsatisfactory. We can observe the processes of evolution, physics and especially geology everywhere every day. To deny what I see around me is unacceptable to me. Science is the acceptance of what you observe and seeking the natural laws that cause these effects.
How can science-minded people make it “safe” for believers to acknowledge that evolution is real?
The bible that is often cited as a guide to natural law has been translated from other ancient languages. There must be countless subtleties and nuances that are literally lost in translation. I got into good bit of controversy, when I showed an audience in Waco, Texas, USA that the bible, as translated into English, claims that the Sun lights the day, and the Moon lights the night. I pointed out that this translation is unsettling. To my ear, it doesn’t seem as though the author realized that the Moon’s light is reflected sunlight. It seems to me that many ancient people may have realized that the Moon casts reflected light, but it’s lost in translation. This being but one example.
Will anything good be lost if creationism disappears?
Because of the robustness of our historical records, creationism will probably never disappear as such; instead, creationism can be used in classrooms and conversations to illustrate the process of science.
To wit, people once accepted an idea that the Earth was built in a week. In recent centuries, we have discovered the actual nature of nature. The process of science debunked and disproved the old idea, so it was cast aside for a better idea.
Did you ever believe in creationism? If so, what changed your mind?
The biblical stories were presented to me, but they never seemed reasonable.
I remember asking about Noah’s ark. Did he look after the invertebrates: the bees, for example? What about the yellow-jackets? And, the black wasps that stung me a few times? All those ants? There’s no mention of the most numerous organisms in my world. As a kid, I remember imagining a series of barges full of soil to be pulled like trailers behind this big boat. Grownups explained that it was just a story (whatever that meant). I remember asking, what was the point of the story? What was this guy’s idea to get animals two-by-two? What did he hope to accomplish, if all the bees, worms, oak trees, and rosebushes were gone? Let alone the question: why did he let the poison ivy come back? He missed a huge opportunity, etc. It was never satisfying to my mind.
If you could speak directly to the children of creationists, what would you say?
Hang in there.
There is another amazing, exciting, inspiring way to know the world, one that will fill you with joy and reverence. Pick your battles with grownups. These creation ideas are important to the grownups in your life right now. Accept that.
Do your views place your personal safety in jeopardy?
We’ll see. You don’t get shot down, if you’re not flying.
We are at a turning point, a crossroads in human history. Climate change or an asteroid impact can only be addressed with science. Shooting the messenger is not going to make creationism able to explain anything in the natural world. It still will be completely unsatisfactory and useless to anyone trying to solve an engineering problem in the real world. No science; no asteroid deflection.
Do you have any superstitions?
None that I know of. I change my socks often, because I had bad bouts of athelete’s foot fungus infections as a kid. I may be able to change socks less frequently and not get the fungus. But, I’d rather not run the test to determine just how infrequently I could change socks. I don’t feel superstitious about it.
Who is your favorite scientist?
Don’t make me pick.
Michael Faraday was amazing. He clearly realized that his discovery of a means to generate electricity, would change the world. I have great admiration for my physics teacher George Lang and my old professor Carl Sagan; he changed the world. My dad was no slouch, either. My older brother Darby continually showed me wonderful scientific principles.
The big step comes when you can convince yourself of the truth of a natural law. It changes the way you think of everything around you.
There’s no science in this post. I just know we’re all gonna want to save this picture for future reference.