The author of a legendary equation illustrating the probability of alien civilization, Drake suggests that we should listen more.Read the rest
The last place you expect to meet a creationist is at the annual American Geophysical Union conference. I don't know how I got so lucky.
Yesterday morning, I wandered through the posters presented at the event, with a thought to translating their scientific jargon into something interesting to read. Since my background is biological, I thought that discipline would be the obvious place to start—in particular, something about microbes doing interesting things under the surface of the Earth.
A title caught my eye. It was one of the first posters in the aisle, so prominent to the casual passerby:
A COMPARISON OF δ13C & pMC VALUES for TEN CRETACEOUS-JURASSIC DINOSAUR BONES from TEXAS to ALASKA USA, CHINA AND EUROPE WITH THAT OF COAL AND DIAMONDS PRESENTED IN THE 2003 AGU MEETING
Dinosaur bones and diamonds! My brain, attracted to both old and shiny objects, sent me in closer to investigate. As I was trying to interpret the densely-packed board of letters, numbers, and figures printed in incredibly tiny print, I was approached by a slight, elderly man in glasses. A name badge declaring him to be Hugh Miller, the first author on the poster.
He asked if I had any questions. I asked if he could just give me a quick summary of the work. He talked about performing mass spectrometry on samples of various dinosaur bones that produced age estimates ranging from 15,000 to 50,000 years. My spidey-sense tingled. I peered over his shoulder, searching for bullet points to figure out what was going on here.
That's when I read it: "humans, neanderthals, and dinosaurs existed together."
The poster was challenging radiocarbon dating using Carbon-14 (C-14) isotopes. It suggested that their data, comparing coal, diamond, wood, and dinosaur bones, were sufficient to throw all of geology into question. Namely, that based on their data, the age estimate of the dinosaurs was off by some 2000x.
Moreover, humanity must be increasingly concerned about asteroid strikes to the Earth, because that age estimate error would influence our estimate of the size of the whole universe (since we look at the size of the universe through the lens of time), which would mean that everything in our solar system is more densely packed. Hence, we are more likely to be hit by asteroids because they are so much closer to us than thought.
This makes about as much sense as the Indiana Jones movie with ancient alien archaeologists.
I don't know if Hugh saw the quizzical look in my eyes, but when he was interrupted by someone asking for something, I quickly backed away.
Now, here's the thing about Carbon-14 dating. This isotope has a very short half-life (the time necessary for the element to reduce in mass by half) of only 5730 years. Since it decays so quickly, it is useless for dating objects more than about 40-50,000 years old. The background levels of C-14 radiation in the laboratory have to be compensated for.
According to the NCSE website:
"This radiation cannot be totally eliminated from the laboratory, so one could probably get a "radiocarbon" date of fifty thousand years from a pure carbon-free piece of tin."
And, this is pretty much what the poster presented.
When looking at fossils preserved in sedimentary rock, the fossil itself can be dated, but often a technique called "bracketing" is used where the igneous rock on either side of the fossil is dated with radioactive isotopes that have half-lives on the order of millions of years. This give scientists a range of time in which the animal could have lived. The poster authors, Hugh included, were basing their attack on one technique in the geological toolkit, and disregarding all other evidence that would have undermined their conclusions.
How did this abstract get past the selection process? I have no idea, but I hope that people at the conference were able to see that it was not science. It was an example of belief masquerading as scientific inquiry.
By adding a little sampling to their adventures out in the wild, explorers in hard-to-reach locations could lend a big hand to scientific research.
An organization called Adventurers and Scientists for Conservation hopes to bring the two professions together in the name of science.
This week, I sat in on a session at the American Geophysical Union meeting in which the speakers discussed the merits of citizen science and the potential impact that explorers could make on scientific data collection.
Many scientists are explorer and trek across the globe, but often they have responsibilities that keep them tied to the institutions where they work with limited opportunities to get into the field for data collection. If sampling techniques can be simplified and standardized so that anyone can learn how collect the necessary bits of rock, water, flora, etc. at particular sites, why not ask the people who are already out there to help out?
Additionally, those out exploring are often on the front lines of witnessing changes to our planet, and are passionate about wanting to help in some way.
Not all science can utilize the citizenry, but for those projects that can, this seems like an amazing resource on both sides of the equation.
The Earth is full of water. Not just lakes, river, streams, and oceans on the crustal surface, or even aquifers close to the surface—the planet literally holds water inside itself.
Deep inside the mantle, where the temperature and pressure are so high you would think it impossible, viscous crystalline rocks potentially trap the equivalent of the Pacific Ocean.
Last year, scientists found a diamond with the tiniest speck of an olivine mineral called ringwoodite in it that was 1.5 percent water by weight. Ringwoodite only exists at great depths, some 550-660 km beneath the surface of the Earth, where phase transitions alter the structure of olivine into something that is more capable of holding water.
Convection within the mantle could conceivably bring water held in olivine back to the surface. In the case of the ringwoodite-containing diamond, the process was rapid and explosive, but it is more likely to be slow and gradual. The inner-Earth's water cycle is thought to take on the order of 250-500 million years.
There are chemical processes at work around undersea vents and volcanoes by which water gets incorporated into rock in the Earth's crust. The crust is constantly moving, with separate plates jockeying for position, rubbing up against one another, and sometimes getting subsumed underneath each other.
When one crustal plate dives beneath another, that's called subduction. This process is thought to take rocks, and the water held in them, down into the mantle.
At about 100-150 km down, the rocks start to break down under the pressure and increasing temperature. Water gets released during the breakdown process, but it's not entirely efficient. A lot of water remains tied up in the minerals as they break apart, and recombine through chemical reactions. They head ever deeper.
We know that ringwoodite can hold water, but it has been determined that below 660 km, ringwoodite transitions into yet another form of olivine called bridgmanite, which can't hold much water. However, seismic mapping experiments have detected areas of melt, melted material held within the crystalline solids that differ in their chemical composition, and which are possibly indicative of water, at depths of 760 km. This is 100 km deeper than water should be able to venture.
So, how does the water get there? And, how is there still water deep down there if the cycle keeps taking the stuff back to the surface? What is the missing step?
Wendy Panero, PhD, an Assistant Professor at Ohio State University, has been addressing these questions with her graduate student, Jeff Pigott. Together, they created computer models of the lower mantle, and came up with an answer.
Garnet. The burgundy-colored mineral is stable at depths beyond what ringwoodite can handle, and well into the lower mantle. It is possible that garnet could be a water-carrying missionary into the land of bridgmanite.
If the mechanism is correct, it puts another link in the chain of Earth's inner water cycle, and when connected to the oceans and atmosphere, it puts the duration of a complete cycle on the order of billions of years. Additionally, it constrains the amount of water that could be contained within the Earth by specifying the minerals that are in the chain, and determining their respective contributions to the cycle. Whereas previous estimates have put the amount of water in the mantle at 1-3 times the amount of water on the surface, this study brings that quantity down to a single ocean. Regardless of the reduction, this is still substantial considering that all of the water could have originated from geochemical processes alone.
The interior of our planet is something we can't touch, unless it spits itself out at us. Our technological abilities allow us to mimic it ever more precisely with each passing advancement. The lab Dr. Panero has created contains a piece of equipment called a diamond anvil cell, which squeezes minerals between two diamonds in order to apply immense amounts of pressure, and then fires a laser to bring up the heat to subterranean levels. Her lab just might have the burn marks to prove it. She also gets to take that diamond anvil cell to a synchrotron where she and a team of physicists fire high-energy x-rays at it.
Dr. Panero is also a planetary scientist in addition to investigating our Earth's geochemical pathways, and she suggested that plate tectonics might be the key to Earth's abundance of water. The mantle probably plays an influential role in the amount of water that is in our oceans, and consequentially the amount of carbon that it can store. However, Panero mentioned that this finding raises more questions than it answers, as we know very little about the content of these melts at great depth, the other things they could carry within them, and exactly how they move through the mantle's circulation.
If we want to get a better idea of our planet's formation and modern state, rather than simply considering the Goldilock's zone as the place where water can be liquid, we need to look at our and other planets with a broader eye toward what Panero called the "geochemical Goldilock's zone"... that place where all the chemical and physical processes on and in a planet can allow for the culmination of something like oceans and an atmosphere.
Maybe we are even more lucky than we thought.
NASA scientists reported results from the Mars Curiosity roving science lab at the American Geophysical Union to a packed room of press chomping at the bit for a big story. It turns out Mars has gas. It burps methane "sporadically, and episodically," according to Curiosity co-investigator, Sushil Atreya.
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NASA scientists, at the American Geophysical Union’s annual meeting, revealed images from space of humanity—and our wonderful cultural behaviors.Read the rest
Right now, it's cold in the Arctic. Days are dark, and ice grows to cover the dark sea. Come summer, lengthening days and warming temperatures will reverse that process. This is the ebb and flow of the Arctic, a natural cycle.
However, over the past several decades we have seen summers melt more and more of the ice that forms during the cold winter months. As a result, more and more dark seawater is exposed to the light of day.
NASA researchers, using several instruments on three separate satellites, has been collecting data for 15 years to find out why the ice is melting, and to be able to predict trends in future ice formation and melting. They reported on this data at the 2014 American Geophysical Union annual meeting, saying that 15 years worth is the absolute minimum amount of information needed for them to begin making long-term predictions. Climate trends, as opposed to weather trends, are averaged over 30 years, so they are about halfway there at this point in time.
The project to observe the Arctic is part of NASA's Clouds and the Earths Radiant Energy Systems (CERES) mission. They measure the Earth's reflected solar radiation, emitted thermal infrared radiation, and all emitted and reflected radiation.
The results so far indicate that the Arctic is absorbing energy from the sun five percent faster now during the summer months than it was when they first began monitoring in 2000. This is important because the rest of the Earth is still absorbing energy at pretty much the same rate.
Put into energetic terms, this means each square meter of the Arctic Ocean is absorbing approximately 10 more watts of solar energy than everywhere else. Interestingly, this is not uniform, and is regionally specific. For instance, the Beaufort Sea has been measured at 50 watts per square meter.
All this extra energy has an impact on sea ice melt. The Beaufort Sea is one of the more dramatic ice melt examples. And, the rate of ice loss in September in the Arctic overall is 13 percent per decade. Let me spell that out... the Arctic is absorbing more energy, the air temperature is warming, and the rate of ice melting is being multiplied over ten times each decade.
So, why is this happening? It partially has to do with albedo, or reflectivity. Ice and snow reflect the sun's light and energy, while dark oceans absorb it. Less summer ice means that things are going to warm up faster, creating a feed-forward cycle that will potentially lead to even further warming and melting.
Walt Meier discussed differences in the ice itself that contribute to this process. He said that young ice melts more easily than old ice due to surface features and salinity. This results in much more rapid melting each year, which exposes more old, thicker ice to the suns rays. Each year more old ice is lost only to be replaced during the winter with easily melting young ice. The Arctic has lost 1.4 million square kilometers of ice over the past 15 years.
Young, thin ice makes the Arctic more vulnerable to further summer melting. Further Jennifer Kay, said that cloud cover is not related to the observed absorbed radiation.
Arsenic. Hearing the word in America usually brings up black and white mental images of the film "Arsenic and Old Lace." Yet, it is not an old issue. People around the world are exposed to dangerous levels of arsenic in their water.
Speaking today at the American Geophysical Union, Lex van Green discussed the issue of arsenic in well water in the Asian sub-continent, primarily in Bangladesh and Bihar, India. His concern is that even though people are aware of the problem, very little is being done to address it.
People continue to drill new wells without determining their safety (safe levels are set at less than 10 micrograms per liter of water). Van Green's data, collected from 2012-13, show that 50% of people in the area assessed drink water containing arsenic at unsafe levels. However, 100% of people live near safe wells. Additionally, only about a third of people who become aware that their wells are contaminated switch to new wells by either drilling new wells or using their neighbor's wells.
The difference between a safe well and an arsenic contaminated well is depth. Sedimentation by ancient arsenic rich waters along river deltas left layers of arsenic containing soil near the surface of the Earth. To get past the arsenic to clean aquifers, one has only to drill deeper than 100 meters down. However, wells are expensive to drill, and the deeper the well, the more expensive it will be.
So, the problem in these areas where there is no infrastructure to deliver treated water to people boils down one of inequality. Only the wealthy are able to afford a deep enough well. And, although the government has initiated subsidy programs to help with the digging of wells, research suggests that the wells end up clustered within a small subset of villages where the inhabitants are wealthy and support the political party in power.
In response, he and a team of researchers have developed affordable field test kits that can be used by private individuals or organizations to test wells for their arsenic content. The test results can be localized using GPS and smartphones. One of his collaborators is using Formhub, a system for mobile data collection, to improve data collection itself, quality control, and dissemination of information to impacted areas and individuals.
It's already looking like technology will speed up the spread of awareness about arsenic levels in wells and the availability of tests. Van Green showed a couple of slides supporting this point with data collected in the past week that visually demonstrated that many more people are beginning to take advantage of the testing compared to the 2012-13 test period.
This project, while important in the developing world where many millions more people are affected, could also be useful within the United States and Canada. The USGS has collected data on arsenic in water, and based on that information it is estimated that more than 40 million people in the U.S. are drinking arsenic laden water, many at levels well above 10 micrograms/liter.
The test kits do contain strips laden with mercury bromide, so there are concerns about their use. No one wants a baby getting one of the little strips in their mouth. But, there is no reason to think that an affordable, at home solution to testing for arsenic shouldn't be implemented if safety concerns are properly addressed. The risk from ingesting arsenic is much more serious and pressing.
So, do you know how safe your well is? You should, and you can.
Dr. Kiki Sanford on how scientists are predicting outbreaks from an unusual new vantage point.Read the rest
Reporting this week at the annual American Geophysical Union, scientists from UC Irvine discussed air quality results from samples taken during the 2012 and 2013 Hajj.
The annual pilgrimage brings between 3-4 million people to the holy city of Mecca. Isobel Simpson, the lead researcher on this project, stated that, "The problem is that this intensifies the pollution that already exists. We measured among the highest concentrations [of smog-forming pollutants] our group has ever measured in urban areas – and we’ve studied 75 cities around the world in the past two decades.”
The worst locations were tunnels leading into the Grande Mosque where carbon monoxide levels were up to 300 times higher than baseline measurements, and pedestrians were often walking in large numbers alongside idling motor vehicles. Increases in carbon monoxide are linked to increased numbers of hospitalizations and deaths from heart failure. In addition to carbon monoxide, the team found elevated levels of benzene, black carbon, and other fine particulates that can affect lung function.
The main culprit here that can be addressed by the Saudi government is a lack of regulation over automobiles, gasolines, and exhausts. Currently, there is a significant lack of public transportation in the area, and nearly everyone owns a car. Those cars don't have the devices that are currently required and built into vehicles in the Unites States to limit pollution.
The easiest thing to fix would be separating pedestrians from cars in the tunnels, or at least spreading vehicles out more evenly among the tunnels leading to the Mosque, so that pollutants don't build up as much and negatively affect those walking in. Alternatively, improving ventilation in the tunnels would reduce deadly carbon monoxide build-up.
In the meantime, if you are planning to join the Hajj in the near-future, consider bringing an air-filtering face mask.
Have you ever been on a plane during a thunderstorm that experienced a direct lightning strike? While most commercial airliner will do their best to avoid thunderclouds delivering the wrath of the atmosphere, it's estimated that every plane in the U.S. is struck more than once per year.
Large commercial planes are equipped to route the electrical current from a lightning strike so that it avoids sensitive electronics, and most passengers may not even realize that a plane has been struck when it does occur. However, the electrical current and loud clap of thunder are not all that is produced by a bolt of lightning. It's only within the past 20 years that research has confirmed that lightning also emits x-rays and gamma-rays.
One source of x-rays is normal lightning, under normal atmospheric pressure that occurs near the ground. These x-rays are measured at strengths analogous to the energy range commonly emitted by CT scanning devices used in the health care industry. Then there are gamma-rays, high energy x-rays usually seen emitted by particle accelerators, exploding stars, and black holes, that have been detected as a continuous kind of glow within clouds. Additionally, a separate class of gamma-rays, called terrestrial gamma-ray flashes or TGFs, are even more powerful, brief bursts that can be seen by spacecraft and satellites in low earth orbit. TGFs are the most energetic phenomena on the planet, and are thought to be caused by intracloud lightning (lightning that occurs between clouds). TGFs appear all over the world where there are thunderstorms, but nobody understands exactly why or how.
Scientists at the University of Alabama in Huntsville reported in a press conference today at the 2014 American Geophysical Union that they have been delving into the world of these high energy particles associated with the bursts of light, and have concluded that these TGFs can be produced by any type of storm from the "garden variety" to more extreme events. That weaker or moderate strength storms would produce TGFs was totally unexpected based on earlier theories.
While lightning strikes some 50 times per second around the globe, TGFs fire up to 1100 times per day based on data from NASA's FERMI Gamma-ray Burst Monitor (GBM). Separation of positive and negative charges between layer in the clouds leads to lighting, and sometimes when lighting does fire a surge of electrons is deflected upward. Those energetic electrons cause gamma ray flashes when they bump into other particles in the atmosphere. The TGFs that are measured by craft in low-earth orbit like NASA's FERMI GBM form between 7-9 miles high, but TGFs are likely to form at lower altitudes well. Although, because of attenuation in the atmosphere those at lower altitude are harder to detect from space, so the total numbers of TGFs are probably vastly underestimated.
In order to address this issue, researchers attempted a gutsy experiment in which they actually flew an Airbus plane into a thunderstorm. The plane was equipped with a system called ILDAS to measure various properties of lightning strikes. The plane entered the thunderstorm to measure the radiation coming from the storm at approximately 10,000 feet, and over five hours experienced extreme turbulence and more than 20 direct lightning strikes. The data from the flight corroborates previous ground-based measurements linking gamma-rays and x-rays to lightning strikes. As long as there are enough brave pilots, this type of in-storm research will be one way that the scientists can get a better understanding of lower altitude TGFs.
There are many questions remaining about how and why these high energy particles are produced by storms, and how they influence other atmospheric phenomena. What we do know now is that x-rays and gamma-rays that are detected can be tracked back to their source, the lightning, to help us learn more about the dangerous, dramatic, and mesmerizing flashes of light.
Imagine never having to take a pill again for anxiety, depression, or your heart condition. Imagine epilepsy or Parkinson’s disease being managed by the patient without drug interventions. What if control of these conditions were possible with a thought? Kiki Sanford reports on the advent of mind-genetic interfaces.Read the rest
This week we started the This Week in Science podcast on a low note talking about the climate, or as we like to call it on TWIS, 'Climytia.'
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If you’ve ever watched this video, you might wonder whether an astronaut’s suit is too ungainly to be graceful, or alternatively, if astronauts might just lack coordination. Read the rest
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Kiki Sanford on a strange scientific study comparing the effects of caffeine to zapping your brain tissue with electricity.Read the rest