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April 29, 2011

Scientific Unknowns: Life on Titan?

Sunlight reflecting of one of the lakes of Titan
Image Courtesy: NASA/JPL/University of Arizona/DLR

Of all the places we look for life in the solar system, there is one that has captured my imagination more than any other. Maybe it is because of this obscure moons weirdness, or the possibly of an entirely new biology. Either way I could not discuss life in the solar system and leave it out. So what plausibly and evidence is there for life on Saturn's largest moon? The answer may surprise you.

Here on Earth all life requires water. Water makes a great solvent. This simply means a large variety of different molecules can be taken up by the water. Suspended in liquid water, those molecules can move around to do the things of life. This works great here on Earth and water may even be a good solvent for possible life on Europa. Titan however, is a balmy -290 oFputting water out of the picture. Luckily Titan is covered with another liquid that may be able to fill the same role as water, liquid methane. I need be clear in saying that we have no idea if life can form in liquid methane. Maybe it forms easier in methane than it does in water. While there are some good reasons to think water may be the liquid of choice, we simply don't know. This is what make Titan such an interesting world to explore.
An infrared image of Titan showing Titan's Northern Lakes
Image Courtesy: NASA/JPL/Space Science Institute

So now we have a feel for the plausibility of life on Titan, but what about the evidence? Often in science you test a hypothesis by building a model that produces predictions. Then you test those predictions to see if the model reflects reality. In 2005 a team of astrobiologists published a paper making some suggestions about what we might expect to see if some sort of methanogenic life were enjoying the orange haze of Titan. In 2010 data from the Cassini Huygens probe matched those predictions. So what does that mean? Well it means that this model deserves strong consideration. That said, we should not be quick to accept any claim of alien life. There are a huge multitude of processes not involving life that can change the chemistry of an atmosphere. This evidence is a exciting starting point, but it is not proof.
So when it comes to Titan, even more so than Mars or Europa, I can only say we have no clue if there is any life present. Titan is a moon we have only recently gotten a good look at. Astronomy has a history of dismissing early speculations of life with future observations. Will that pattern hold true on Titan? We need more scientists and more spacecraft to find the answer. Right now I can only say that I don't know, but that I am extremely excited to see the discoveries made as we hunt down the solution.

April 26, 2011

A Visual Look at Radiation 25 Years After Chernobyl

Today is the 25th anniversary of the Chernobyl disaster. I don't want to delve into the details of what happened but with all the talk of radiation recently I thought it was important to again, put things in perspective. The image below was created a little while back but I think it is still a good visual way to understand radiation levels.

Click on image to enlarge
The creator of this image is Randall Munroe, who is also the author of the web comic xkcd. If you haven't already, I recommend you give it a read.

April 22, 2011

The Potential of Algae

Every once in a while, I find a story on the potential of algae for biofuel or for waste cleanup. Back in 2009, I wrote about both the potential of "milking" oil from diatoms, and about hydrogen-producing algae, which could make hydrogen fuel cells a possibility. In 2010, a breakthrough suggested that we could pressure-cook algae to create crude oil, which would then be refined into gasoline, which is at least more sustainable than drilling and poses many fewer risks. By now, the hurdle is not can we create algal biofuels; the technology is there. The larger issue is how much we can reasonably produce. The one thing algae needs a lot of is water; it's planktonic pond scum. They also only live on the surface of water, so they require a lot of land. Algae farms, therefore, use up a lot of two important resources to create one. Is this a smart trade-off?

Source: Wikimedia Commons
Enter Mark Wigmosta and other researchers at the Department of Energy's Pacific Northwest National Laboratory. They conducted a study on how much land and water algal farms would actually require, and where they are best located to minimize the inputs (land and water) and maximize the outputs (biofuel). As it turns out, algae could easily replace 17 percent of the oil currently imported. The land requirements aren't awful; it would require water surface approximately equal to the size of South Carolina, assuming only open, fresh water farms were used. As algae can be grown on salt water and in closed farms as well, there's a potential for reducing the amount of land surface used. The bigger problem is water: for every mile driven on a tank of algal biofuel, 8-50 gallons of water was used. While this is equivalent to current biofuels from corn and soybeans, it's much larger than the amount from drilled oil, which is about 0.5 gallons of water per mile driven. Still, on land use, algae is much more efficient than corn, producing 80 times as much oil per hectare than corn. Plus, people don't eat algae, so there's no competition between biofuel and food.

Diatoms, a type of algae
Source: Wikimedia Commons
So, algae's still a definite contender in making our oil consumption sustainable, until alternative energy sources are set in place, such as wind, water, solar, and nuclear. Oh, and in case you're still concerned about nuclear power, particularly the waste, algae may help there, too: at least one species can specifically create biomolecules from strontium. While some tests still need to be run, there is a chance that these single-celled organisms could take up Strontium-90, one of the most radioactive waste products of nuclear energy, and convert it to harmless forms.

Basically, algae is proving more and more to be a key player in any of our alternative energy solutions. They may act as the transition between fossil fuels and sustainable, clean energy; they might create that clean energy; or they may help clean up any unwanted byproducts of sustainable energy. The potential of exactly how much pond scum can do is still being discovered, and will likely prove to be far more than anyone would have guessed. And on that note, Happy Earth Day!

April 13, 2011

Religion and Politics in the Science Classroom

Ever since the Scope's Monkey Trials in 1925, there's been a political debate raging about the teaching of creationism and evolution in the science class. There's a lot of claims flying about: "Teach the Controversy", "Evolution is just a theory", "Intelligent Design is a science too!" Thus, so far this year, 7 different states have proposed bills that directly attack the teaching of evolution and other sciences.

As I mentioned before, this is hardly a new problem. Anti-evolution legislation is proposed every few years, and we've discussed it before. Every time, the National Center for Science Education presents its solid stance that evolution is a science and is fundamental in understanding biology; creationism, however, is not a science and has no place in the science classroom. Normally, this is enough to prevent the bill from being passed.

Man is But a WormThis year, however, there's more of a problem. In Tennessee, an anti-evolution (and anti-global warming) bill passed in the House of Representatives. It aims to let teachers "question" the sciences, and proposes they teach the alternatives. They fall into the trap I hear a lot, that "evolution is just a theory." This is not true in any sense. Evolution is a fact; we know for certain that animals change over time. We've watched it happen. The theory is Darwin's theory of evolution by natural selection, which was accepted by the scientific community over a century ago. There is zero controversy among the scientists; the "controversy" is only created by political and religious groups.

It's this made-up controversy that causes around 60% of high school biology teachers to be wishy-washy, at best, with the teaching of evolution. Many of these are not creationists themselves (although, unfortunately, some are). However, it's easier to play it safe and avoid the issue than deal with unhappy parents or school boards. Less than 30% of science teachers are willing to take the necessary strong stance that evolution is a scientific fact, and deserved to be taught as the central tenant of biology that it is.

I do think that religion can be taught in schools... in a comparative religions class. Single religions can even be taught... in private religious schools. But religious doctrine, based on texts written millennia ago, don't have any place in the empirical, ever-adapting realms of science and the science classroom. I find it very sad that, despite every rational argument that's been made for the teaching of evolution, despite a century of scientific acceptance, and despite the fact that intelligent design/creationism/creation science has been repeatedly proven to not be a science, there's still this yearly battle over such a central fact of how the world works.

April 11, 2011

Why Museums Matter

I grew up in a museum.
Ok, so there's a bit more on a nuance to it than that. I was homeschooled from elementary school through my sophomore year in high school. My "official" courses were online, through a virtual public school. I did my work at home, at the ice skating rink where my brothers practiced, at my other brother's violin studio, or where ever I happened to be on any given day. That was all great, but the place I really considered my school, and my second home, was the Denver Museum of Nature and Science. I took classes there within months of moving to Colorado. If my parents asked me where I wanted to spend the day, I would invariably say "the Museum." As soon as I was old enough, I started volunteering there. With how many hundreds of hours I spend within that building, you'd think I would have gotten tired of it. Quite the contrary; I couldn't get enough of it. I still can't. In any city or state, I feel most at home at a science museum. They spark my interest, make me ask new questions, and remind me that this universe is a fantastic place.

I was pretty pleased, therefore, when I ran across a news article titled "Surveys confirm enormous value of science museums, 'free choice' learning." Apparently, I am far from the only one whose excitement about science came from a museum. The study focused on a single museum in Los Angeles, California, recording who came there, what they thought about the museum and the role of science, and what they thought about "free choice" learning, which is the idea that the bulk of science knowledge comes not from school, but from self-education: using the Internet, watching documentaries or science programming, going to the museum. Instead of trying to present facts and figures through rote memorization and textbooks, this "free-choice" style inspires people to look further, to try to solve problems on their own, and to understand not only what science has discovered, but also how the scientific process works.

For a museum geek like me, this seems like common knowledge. But, my anecdotes do not count as scientific evidence supporting the value of museums and alternative schooling. This survey, covering over a decade and millions of people, confirms what seems basic to me: that those who have access to scientific facts in a clear, engaging way, get excited by science. And that's the first step to appreciating the natural wonders of our universe.

April 8, 2011

Storm: An Introduction to Skepticism

Tim Minchin is a fantastic comedian/musician from Australia, and a few years ago came out with a 9-minute beat poem called "Storm." Since then, over the course of two years, an animation production team has worked diligently to animate this wonderful work. It's got a very strong skeptical slant throughout, and an inspirational message at the end. Some language might not be appropriate for little kids, but past that is absolutely fantastic. Absolutely worth a watch.

Tim Minchin's Website
Storm Movie Official Website

April 6, 2011

Scientific Unknowns: Life on Europa

Europa as seen by the Galileo Spacecraft. 
When we think of aliens we often think of a place similar to Earth. We think of creatures with similar body plans and similar needs. But what about the possibility of creatures that have never seen the Sun? This is the kind of life that could be hiding on Europa, Jupiter's fourth largest moon.

There are two sides to every claim, plausibility and evidence. Some claims, like many new medical drugs, start with a high plausibility but the evidence never bears them out. Others, such as quantum mechanics, start with low plausibility but the evidence becomes overwhelming until they are accepted. Right now, to my knowledge, there is no evidence of life on Europa. What makes it exciting, however, is how plausible it is that life could exist there.

Europa's entire surface is covered with ice. Located almost a half billion miles from the Sun, there is nowhere near enough heat from the sun to melt Europa's ice covered surface. Still many, if not most, scientists agree that there is likely a ocean under that ice. As Europa orbits around Jupiter, it is squeezed and stretched. This is what creates the cracks you see on the surface. This also heats Europa's core in the much the same way playing with Silly Putty will warm it up over time, creating a layer of liquid water. There is a lot of debate between scientists on how thick this ocean is. Right now, it seems likely that the ice is tens of kilometers thick with an ocean that is between 25 to 100 kilometers thick. So the question is could anything survive in the ocean?

A cutaway view showing Europa's interior. Notice the
inner rocky core surrounded by liquid water and capped
 off an outer layer of ice.
Credit: NASA/JPL
If there is any life in Europa's ocean, it have had to have formed and survive with no sunlight. The ice above this ocean is just too thick to allow in enough sunlight for any organism to use that as a source of energy. So scientists have looked to the Earth for creatures that can survive without the Sun. Probably the most similar environment to Europa here on Earth is the ocean under the Antarctic ice. When scientists have drilled into the ice there we have found life. In fact scientists have found entire colonies of organisms called black smokers that live in some of the harshest conditions on the Earth. These organisms live off of hydrothermal vents at the very bottom of the oceans where there is no light at all. Some scientists have even speculated that this is where life on Earth originated in the first place. These unique adaptations of life here on the Earth make it reasonable to think similar creatures could survive on Europa.

A hydrothermal vent on the
Mid-Atlantic Ridge. Credit NOAA
So when it comes to life on Europa we have a really good story. We have solid reasons to think the ocean is there and that life could possibly survive in that ocean. What we are missing is the evidence. A detailed study of Europa is high on NASA's priority list, but without the proper funding it could easily still be more than a decade away. At this point, we don't have the evidence to say if life exists on this icy moon or not. I hope in my lifetime a spacecraft arrives at Europa and drills through that ice. What we find in that ocean could change how we think about ourselves and the universe we live in.

April 4, 2011

Ancient Writing From a Garbage Heap

Long before I was interested in science, I had dreams of being a history professor. That interest in history has never faded and this weekend I saw an article that caught my eye. Around the year 1400 B.C.E., a sun-dried clay tablet was throw in the garbage heap by a Greek in Iklaina. That tablet was probably of not much importance at the time. I doubt anyone thought much of it when the trash caught fire. That blaze hardened the table allowing archaeologists to find it more than 3000 years later.

Writing seems to have originally developed in Mesopotamia, Egypt, and China around 3000 B.C.E. What makes this discovery exciting is it is the oldest credible example of writing found in Europe. It is written in a script called Linear B which seems to stem from a older undeciphered writing called Linear A. Linear B was eventually replaced with the Greek alphabet, which evolved into the language you are reading now.

Each discovery like this adds more detail to our understanding of the past. This find gives us greater insight into the history of writing and the power structure of ancient Greece.
“Iklaina could potentially challenge what we know about the origins of states in ancient Greece,” Michael Cosmopoulos, the Professor of Greek Studies at University of Missouri–St. Louis and director of the Iklaina Archaeological Project. “Not only does it push the origins of those states back in time by at least a century and a half, but the tablet shows that literacy and bureaucracy appeared earlier and were more widespread than what we had thought until now. We still have a lot to learn about the ancient world.”

History is a subject that I have always found humbling and a nice way to grow perspective for modern issues. Understanding the long and arduous journey writing took to get what we have now gives a greater appreciation for it. That appreciation is, in my opinion, one of history's greatest contributions.

April 1, 2011

More Amazing Medical Science: Regeneration

It's been an idea in science fiction for years. What if people could regrow their own body parts? The extreme example, and my personal favorite, comes from the British TV show Doctor Who, where the main character, an alien Time Lord, can replace every single cell in his body after suffering some fatal injury, thereby cheating death. He's also been known to regrow a hand, if cut of within the first 13 hours of his regeneration cycle. The idea is similar to a real phenomenon in nature: some animals can regrow body parts if those sections are lost, Think the tails of lizards or sea star arms. Unfortunately, humans do not share this handy ability to revive lost or diseased tissue, so we rely currently on the imperfect process of organ donation. The waiting list to receive an organ donation is over 100,000 people long, and many of these die before a good match becomes available. Even if they do get a replacement, the match is often not perfect: the new organ is from a different person, and so has different DNA. Sometimes, these replacements are rejected. The patient's body does not accept the new tissue as part of itself, and the immune system attacks it, potentially causing the organ to fail again, putting the person in the same, if not worse, condition then before the replacement.

Here's where new medical technology could step in to save the day. Bioartificial organs are created by taking healthy cells from the sick organ of a person, and using a scaffold - a synthetic or organic frame to make sure the cells form correctly - to grow a new one. This would solve the rejection problem: the immune system would recognize the replacement as part of the individual, because it is. The technology to complete this process is also fascinating. It's similar to a 3D inkjet printer: the cells are placed, one by one, like drops of ink into the shape of the new organ. This is incubated to encourage it to grow like living tissue, instead of dying, and then can be transplanted just like any other organ. The main researcher for this technology, Dr. Anthony Atala, discussed it in more detail in a TED talk.

I've known several people who became organ donors, and several others who have needed organs. It's a tough process on either end, and often risky for both donor and recipient. Technology like this could help make the process a bit easier, and improve the success rate. It's truly a testament to what medical technology can do to improve our lives.