free debate

March 30, 2011

A Case of Mistaken Identity

Much of the fossil record is confusing. There are tons of fossils that look a lot like normal rocks, and quite a few normal rocks that look like fossils. This makes a paleontologist's job tricky, with any fossil in any time period. However, the most challenging are microfossils. Microfossils are fossilized single-cell organisms or colonies: bacteria and algae, usually. Prior to the explosion of multicellular life in the Cambrian, microfossils are all paleontologists find. To date, the oldest bacterial fossils that have been discovered are about 3.5 billion years old.

However, microfossils are particularly controversial because they are microscopic and often lack much detail. There are several geologic processes that create structures that look a lot like these microfossils. There is also a risk of contamination: modern bacteria can slip into cracks in the rock and die there, looking for all the world like a fossil.

One of the oldest fossils discovered were 3.5 billion year old cyanobacteria in the Apex Chert of Australia. At least, that's what the research team thought they were. Other raised questions, though. In some places, the fossil had strange branching structures, that seem inconsistent with life. Analysis suggested the structures were carbon-based, which also suggests life... but graphite and organic compounds could leave similar structures without life. And that's assuming the initial analysis was correct. A more recent look, by Craig Marshall and his collegues at the University of Kansas, suggests that the "fossils" are actually just crystal-filled fractures. The original research team is planning to respond to this study, so there's certainly no solid conclusion yet. Ancient microfossils are still an active, highly debated, and very important, field of study.

Now, if you read this blog regularly, some of the things above might sound familiar. "Cyanobacteria", preserved in ancient rock, suggesting origins of life, but could easily be a case of misinterpretation... it's very similar to the debate over the alien meteorite. That's because they pose the same problems. Here on Earth, we know from other lines of evidence that cyanobacteria, or something similar, first appeared around 3.5 billion years ago. That's when free oxygen first starts to appear, and cyanobacteria are the only organisms on Earth that can produce that free oxygen. So, it's reasonable to try and find fossils of them. In space, though, we have no such evidence that cyanobacteria, or any other type of life, has developed. It's certainly possible, but it will take a lot of proof to be accepted as fact. If we can't even verify that microfossils are real microfossil on Earth, we have a long way to go before we can accept extraterrestrial microfossils.

Source: LiveScience- Most Ancient Fossils Aren't Life, Study Suggests

March 28, 2011

Funky Fossil Finds

New fossil species are discovered all the time. Each individual specimen provides new information to the scientific community. Sometimes, these fossils are of species we've seen before. Other times, we find things that are totally new. There have been a couple new species published over the past couple of weeks, that I find fascinating and bizarre, that I'd like to share.

(c) National Geographic
Easter's in about a month. Instead of your common bunny rabbit, how would you like Naralagus rex for the Easter Bunny? This new species of rabbit, found in Spain, weighed in at an estimated 26 pounds (12 kilograms), and would have been about 6 times the size of the common European rabbit. It had no natural predators, which allowed it to get so big. It also didn't look or act much like a rabbit; due to its stiff backbone, it would have been unable to hop about. It also had very short ears, making it look more like a giant guinea pig than a rabbit. It lived about 4 million years ago, and likely went extinct due to changes in climate and environment.

from LiveScience
Now, as weird as gigantic rabbits are, they still look somewhat like their modern cousins. The other bizarre new find looks like nothing alive. The so-called "walking cactus," discovered in China, looks exactly like its nickname.
(c) National Geographic
Diania cactiformis has a long, thin, spiky body and jointed legs. It is these legs that are particularly exciting; most creatures 500 million years ago, at the start of the Cambrian period, had fleshy "legs", not rigid jointed structures. The legs of the walking cactus resemble a crude form of the arthropod leg, exemplified in modern crabs and insects. This strange animal could be the ancestor of all bugs and crustaceans today.

Finding weird creatures like these are part of what makes me excited about paleontology. It reveals the unexpected, the bizarre, and the wonderful history of life on Earth, and how much this planet has changed over the past 4.6 billion years. We live in a tiny snapshot of this ever-changing world, and so cannot pretend that this is how it has always been and will always be. If discoveries like these two teach us anything, it is that the world is far stranger, and more spectacular, than we can ever guess.

March 23, 2011

Medical Technology is Amazing

Burns can easily be some of the worst injuries a person can sustain. The most well-known type of burn is a thermal or heat burn, caused by touching something hot or by fire. Most people have had a first-degree burn; sunburns fall under this category. They are usually characterized by pain, redness, and some blistering. First-degree burns aren't particularly serious, and can usually be treated at home. Second-degree burns are also common, but are much more severe. When a person has a second-degree burn, the outer layer of skin has been burned away completely, and the dermis (the live skin underneath) is partially burnt. These burns are very prone to infection, as the outer layer of skin is the body's first defense against bacteria, viruses, and fungi. Without it, painful and serious infections are easy to get. There are also third-degree burns, in which both layers of skin are completely burnt away, and muscle can sometimes be burnt as well. Those are the worst type, and are much less common because of their severity. For now, though, I'd like to focus on second-degree burns.

In the past, treating second-degree burns was a long process, and infections were hard to avoid. To replace the lost outer skin, grafts have to be grown, either artificially or taken from another part of the patient's body. These grafts are very thin, a sheet only a cell thick. These grafts are easily damaged, are prone to infection, and take weeks to fully heal a burn. A new prototype technology, the skin gun, may make the healing process a lot less painful.

It's an amazing innovation, but a simple idea. Stem cells develop rapidly into all the necessary types of cells, and are ideal for this sort of application. National Geographic made a good video explaining how this works, and featuring a real patient who has had the procedure done. The results are spectacular. I've embedded the video below; however, take note that it does contain graphic images of second-degree burns, which are not for the faint of heart or stomach. Click to see the video below.

March 21, 2011

Updates from Space

Image credit: NASA/JPL/SSI
There has been some exciting news from space over the last week. Here are some of the highlights.

Things are looking dim for the Martian rover Spirit. We haven't heard from this hardy rover in almost a year. Sounds like they will keep trying for a few more months but things don't look good. For a rover that was designed to last 3 months, 5 years is not bad.

On a brighter note, the Messenger spacecraft has dropped into orbit around Mercury. There it can now study Mercury's strange magnetic field. Messenger will also image the 5% of Mercury's surface that has yet to be mapped.

Thought Earth was the only place in the solar system to get spring showers, think again. Scientists using the Cassini spacecraft have gathered evidence of rain showers on Titan. At almost -300 degrees Fahrenheit, Titan's rain is likely a mix of liquid methane and ethane. This weird moon never ceases amazing me.

March 18, 2011

Putting Nuclear Power in Perspective

With the nuclear reactor crisis in Japan, the Internet is a-buzz with the dangers of nuclear power. I don't want to go into the details of the situation in Japan because I think that has been done well other places already. If you are interested in that, I recommend Live Science and Georneys. What I wanted to talk about is the real dangers of nuclear power in some context.

from National Geographic
Nuclear power is generated by fissioning radioactive elements. This process produces radiation and heat. That heat is then usually used to heat water into steam that drives a turbine. The reactors themselves also need to be cooled by some means to control the speed the fission occurs. Problems happen when the fission starts producing heat in a uncontrolled chain reaction. This can lead to a meltdown of the reactor and leaking of large amounts of radiation. It is that radiation that causes so much concern among nuclear power detractors. Despite these fears, nuclear power currently generates about a third of our power in the United States.

There is no doubt that there are dangers to nuclear power. The two worst disasters on record are Three Mile Island and the infamous Chernobyl. While most people view these as some of the greatest disasters in the last century, they actually come nowhere close. At Three Mile Island, I could find no evidence of any deaths from either the initial meltdown or the subsequent radiation. In fact, radiation would have had to be thousands of times higher than the numbers reported for the people living in the area to have encounter any measurable health effects. Chernobyl is a slightly different story. With such a controversial issue, the number of people affected varies wildly depending on who you ask. The data I am giving here is from a 2005 report by the World Health Organization (WHO). I recommend you read the report, as the story has a lot of nuance. Still, they concluded that approximately 4000 people will likely die in total from Chernobyl and its after-effects. As of right now, the meltdown in Japan is somewhere in between these two.

So let's compare the worst nuclear power disasters to some other current events. Dam failures in the last fifty years have claimed tens, if not hundreds of thousands of lives. In the US alone, about fifty people died in coal mining accidents last year. In 2007 Scientific American reported the following, "In fact, the fly ash emitted by a power planta by-product from burning coal for electricity-carries into the surrounding environment 100 times more radiation than a nuclear power plant producing the same amount of energy." While this is still not deadly levels of radiation, it is still worth noting. In addition to this, more than 150 people are killed each year from lightning, tornados, and hurricanes. Natural disasters can dwarf these numbers, with the tsunami in 2004 killing well over one hundred fifty thousand people.

I do not want to trivialize the importance of safety in dealing with nuclear power or the deaths of above. Still there is a reality that everything we do has risks. Nuclear power is no exception. Over the last few decades, it has been getting safer and safer. Three Mile Island is actually a testament that even when things do go wrong, we can control the damage to prevent any deaths. Like most things, nuclear power is not a magic bullet or a monster of pure evil. The reality lies somewhere in between.

March 16, 2011

Dynamic Earth: Earthquakes, Tsunamis, Supermoons, and Japan

Tsunami Wave
from National Geographic
Earthquakes occur all the time; look at the USGS list of earthquakes in the past 8-30 days. There are a few hundred entries, most around a magnitude of 4 or 5. The plates that make up the Earth's crust move about constantly, so these minor tremors are quite common. A 4 on the Richter scale is strong enough to be felt, but not strong enough to cause much concern or damage. There are a couple thousand of these a year. Anything less than a 4 is a microquake; these are too weak to be felt, and are only recorded on local seismometers. Anything more than a 7 or 8 is a "great" earthquake. These are far less common; usually, there are only one or two great earthquakes per year. These earthquakes are the ones that cause trouble when they hit populated areas.

The earthquake that hit Japan last Friday was undeniably a great earthquake. It ranks as a 9.0 on the Richter scale, making it the 4th largest earthquake to occur in the past century. It caused a lot of damage, and in some places moved the crust by as much at 8 inches. Like the strong Chilean earthquake a year ago, it also shifted the Earth's axis slightly, shortening the day by about 2 microseconds (source). It also triggered a massive tsunami that hit Japan, Hawaii, and the US west coast, causing even more damage. Currently, Japan is still on alert as the Fukushima nuclear power plant threatens meltdown from damaged caused by the quake and tsunami. Evelyn, one of the Skepchicks, has been following this crisis with her father, a nuclear engineer, and has some great information up at her Georneys blog. It was truly a devastating quake, and needs to be seen to be truly understood.

This is a major natural disaster, and Japan need support and assistance from the rest of the world. What they do not need are a lot of pseudoscience explaining why the earthquake occurred or how recovery efforts should be run. One of the first pieces of nonsense was the supermoon idea. On March 19th, the moon will be closer to the Earth than at any other point during the year, and will also be full. Some astrologists claimed that this would increase the tidal forces to the point where the continental plates moved. This is simply wrong. First off, no matter where the Moon is in its procession and cycle, the tidal forces aren't strong enough to cause anything more than a microearthquake, if that. Second, the quake did not occur on the supermoon day; it occurred a week before, where the Moon is not at the minimum distance from the Earth, and when it has the weakest tidal forces in the monthly cycle. There is simply no way that the Moon had any causal effect on last Friday's earthquake.

The second, somewhat disturbing, piece of pseudoscience is the homeopathic groups distributing their medicines for nuclear radiation. Homeopathy, for those that don't know, is the concept of diluting a substance repeatedly, supposedly increasing the strength of the remedy each time it is diluted. (Mad Art Lab did an excellent job of illustrating the idea.) How this works for radiation, I don't know. These groups are trying to help, but are doing so with nonsense, and will likely cause more harm than good.

If you want to help the recovery efforts, first educate yourself; there is a lot of information available, both good and bad. If someone makes a claim about a natural disaster, check science sources, such as the USGS Earthquake page, to find out the facts, and sites like ScienceDaily and LiveScience to find out what the experts are saying, without as much of a media spin. Searching skeptical sites is also a way to sort the wheat from the chaff. Then, look into how you can help. There are some other groups doing real work. Doctors Without Borders and the Red Cross both do very good work, and are engaged in Japan right now. These groups provide shelter, real medicine, food, and materials to those affected by the disaster.

March 14, 2011

Alien Update

I want to quickly revisit the alien meteorite from last week. Here are some good links to take a look at if you are curious.

I was wondering what NASA was going to say about this. Here is their official statement. If this research really carried some weight, I would expect NASA to be publicizing it to no end. Instead, they are distancing themselves.

This is the best review of the science in the paper I have seen so far. They also a fairly good job of reviewing the journal itself.

I know I linked to Bad Astronomy before but I am going to do it again. He does a nice job laying out the criticisms made other places in a very understandable way.

After reading all of the follow-up here and other places, my original opinion still holds. The science here is just not nearly enough to prove the claim being made.


Today is March 14, or, as it's better known to mathematics enthusiasts, Pi Day!
Pi (π) is one of the most important constants in geometry and advanced mathematics. It stands for the ratio of a circle's circumference to its diameter. This works for any circle; if you measure the circumference and the diameter, and take the ratio, it will always simplify to approximately 22/7, or 3.14159265358979323846264338327950288419716939937510...

Pi is an irrational number, and has an infinite number of non-repeating decimal places. Currently, over 1 trillion digits of pi have been calculated, but we will never reach the end. However, for most applications, 3.14 is a good enough approximation. As March 14th is abbreviated 3/14, we celebrate this handy constant.

So have a slice of pie, and a happy pi day!

To learn more about Pi, check out

March 7, 2011

Aliens Exist: Proof Pending

Last week I mentioned how I wanted to do some posts talking about the possibility of life in the solar system. Well, apparently that is going to be a waste of time, since this Saturday Yahoo News released an article reading in its first line "Aliens exist, and we have proof." Fox News was no better with their first line "We are not alone in the universe -- and alien life forms may have a lot more in common with life on Earth than we had previously thought." How much did we think we have in common with alien life forms before? Anyway, both articles discuss a paper done by NASA astrobiologist Dr. Richard Hoover who claim that he has found evidence for fossil alien bacteria in a meteorite. With a news story like this spreading across the Internet, I couldn't help but do some digging.

First, I went looking around my usual astronomy news sites. As of Sunday evening, I couldn't find a thing mentioning it. This is really peculiar and made me that much more skeptical. The one article I could find was on Bad Astronomy by Phil Plait. It is a good review of the paper and makes several of the same points that came to mind for me. Still, the vast under-reporting of this breakthrough in the specialized media is a point I think is worth mentioning. If you ever see something in the mainstream media, look to see what the people who deal with that subject on a regular basis have to say. While not always true, I have found that breakthroughs tend to go from the specialized media to the mainstream; nonsense tends to flow the opposite way.

With no luck in the space news, it was time to go to the paper itself. The largest problem this paper faces is in that pesky relationship between claim and evidence. If you are going to claim extraterrestrial life, you need a mountain of evidence to back you up. Dr. Hoover works hard in the paper to rule out any earth-based contamination. He is quoted in the journal press release with the following.
"What is both exciting and extraordinary is although many of the bacteria resemble and can be associated with generic species on Earth, there are others which are completely alien. Neither I nor other experts who have seen the evidence have any idea what these creatures might be."

It could be true that no one who has studied the rock has been able to identify the bacteria inside. This does not mean however, that they are necessarily alien. In the paper itself, he tries to use the specific chemistry to the meteorite and the "fossils" to rule out abiotic causes and earthly contamination. I do not have the technical knowledge to delve into these details, so it will be interesting to see what the editors of paper said when those are released.

In the end, I think this paper falls short. I want to see how the scientific community responds over the next few days and what, if anything, comes of this. That is part of what makes science so interesting. Now the paper is published and the real critique can start. For now I remain unconvinced but eagerly await to hear what story will come from this.

March 4, 2011

Science from the Artist's Perspective

It's a common misconception that art and science are totally separate fields: scientists aren't interested in "pretty things" outside of their field of study, and "artsy" people are simply not interested in science. From my own experience, though, this is totally false. There are whole branches of art that devote themselves to science. One in particular that I am familiar with is paleoart, or art about prehistoric creatures and the distant past of planet Earth.

Scientific Illustration of a Trilobite
(c) AB Paleoart
Most paleoart falls into two main categories: scientific illustration, and reconstruction. Both of these are extremely valuable, but for very different reasons. (Continued below the break...)

March 2, 2011

Scientific Unknowns: Life on Mars

The question of how much life there is in the universe is one of the most fundamental questions in astronomy, and possibly all of science. While we are just now on the brink of finding Earth-like planets around other stars, the possibility of life existing on planets very different from our own still remains. While scientists have dismissed the old notions of grand civilizations on Venus and Mars, there is tantalizing evidence of microbial life throughout the Solar System. This is a first in a series of posts I will do over the next few weeks looking at some of the top contenders.

Of all the places we look for life in our solar system, none seems to have the mystique of Mars. The search for life on Mars has deep historical roots. Percival Lowell infamously reported his evidence for a grand civilization on Mars with a grand irrigation network. This and other stories firmly set Mars as the home of extraterrestrials in science fiction. While scientists are no longer searching little green men on the surface, microbes on the red planet have become hot topic of debate. Mars surface is bathed in radiation that would likely prevent anything from living on its surface. Liquid water also can no longer exist on the surface of Mars. These both come from the fact Mars lacks the thick atmosphere and magnetic field we have on the Earth. So planetary scientists are now searching for microbes under the surface of mars. For those scientists there are three main lines of evidence.

1. Recently, there has been a growing consensus that a few billion years ago, Mars had at least a some running water on its surface. The Earth appears to have developed life fairly quickly once the oceans formed. The thinking goes that if Mars had conditions similar to that of the early Earth, it is reasonable to assume that it would have developed life in a similar way. Mars has changed so much over the last few billion years to become the dry and harsh world it is today, that it is not surprising that we don't see the abundance of life we now have on the Earth. This idea gives hope that possibly some microbial life was able to take hold on Mars during the planet's youth and maybe still be surviving under the surface.

2. If life ever existed on Mars, we could maybe find evidence of it the same way we find evidence of past life on the Earth: fossils. It is well accepted that large impacts from meteorites on the surface of Mars can lob chunks of the Red Planet into space. The Sun can then pull those into the more inner part of the solar system where they collide with the Earth. What is controversial is a claim made by a group of scientists in 1996 that one such Martian meteorite contained a fossilized bacteria. If true, this would be sure evidence of at the very least past life on Mars. After 15 years of research however, the scientific community is still far from a consensus.

In science, extraordinary claims require extraordinary evidence. Life on Mars is certainly an extraordinary claim. Unfortunately, the evidence has yet to match. Without going into extreme technical detail, the core issue is whether or not the meteorite in question, Martian meteorite ALH84001, could have plausibly formed without life. Scientists look at a multitude of characteristics, mostly based around the various minerals including their isotopes, distribution, and texture. I think it is safe to say that our current results have been inconclusive. There are scientists with strong points on either side. In the end, the evidence is just not there to make a solid decision.

3. The final hint of life on Mars is methane. This is something I touched on briefly in the past and the basic story is this. The chemistry of Mars atmosphere is such that methane breaks down over time. We have found large quantities of methane in Mars atmosphere, so we know it must be replenished by some ongoing process. At this point all we have is the observation of the methane itself, and speculation about what is causing it. The reason people get excited is because one of the ways methane is produced here on Earth is by bacteria. Scientists, however, are also quick to point out that we know of geologic processes that can produce methane in the quantities we seen on Mars. Again, this line of evidence seems tantalizing, but non-conclusive.

So, what is the final story for Mars? I have to say that, while there is good reason to continue looking for microbes under the surface, we can't say we know they will be there. Either we will see exciting geology or revolutionary biology. Regardless, Mars continues to be a place worth exploring with mysteries lurking just beneath the surface.