One of the most famous science experiemnts attributed to Galileo, was him going up the tower of Pisa and dropping two balls of different masses from a height. The experiment was meant to show that the balls reached the ground at the same time - i.e., irrespective of their differing masses.
Earlier this month, someone posted the NASA video of this experiment done on the moon. It's a very cool short clip of what really happens when you take away the effects of air resistance from this experiment. David Scott and Jim Irwin conducted the experiment on the Moon during their Apollo 15 mission.
I've embedded the video below, and you can download the original source from NASA's website.
This is a great video by the one and only David Attenborough about how crows in Japan have devised a clever way to eat nuts, a food that they naturally wouldn't be able to eat otherwise.
Air has more bacterial species than we thought it did.
New research has shown that we truly live in a sea of bacteria: the air we breathe.
Writing in PNAS, scientists reported on a 17-week study of bacterial populations over two US cities, Austin and San Antonio. They designed and built a 'DNA chip', naming it the PhyloChip, capable of detecting just under 9000 bacterial orders, i.e., all known bacterial types. (An order is a mid-level rank used in our biological taxonomy system). With the PhyloChip in hand, they then collected dailysamples near environmental monitoring stations in Austin and San Antonio, and analyzed which bacteria are found.
The results? Firstly, they were able to detect 1800 types of bacteria using the chip. This kind of diversity is usually associated with soil samples which we have long known contain a myriad of bacterial populations. Another question is whether background bacterial populations vary between cities, or whether there is a 'regional fingerprint'. Austin and San Antonio were chosen because they have similar population densities, elevation and topography, and they are only about 100 kilometers apart. After taking into account these common characteristics, the researchers found that the two cities shared a similar microbial composition.
Another finding is that the time of the year during the 17-week testing period was the most significant source of variation in bacterial population, followed by atmospheric conditions. For example, warmer and dryer conditions led to increased amounts of spore-forming bacteria. In essence, the geographical location was not a major source of variation, and the variation could be predicted. This means that if we determine a bacterial census, it will have to account for this kind of variation.
So why do this? Many reasons. Firstly, we don't know what's out there, and this is a great technology to answer questions about air-borne bacterial populations. Another aspect is bioterrorism: if we set up a network of bacterial detectors, we need to calibrate them to the already-present background 'noise' to avoid false alarms. Also, if we have a natural outbreak of an air-borne bacterial disease, we can use this technique to track its progress and hopefully implement better public health policies.
All in all, it's a great step forward that opens a new avenues of study.
Should I become anonymous? Is it going to affect my job search in a few more years?
That's a good question: how does academia perceive bloggers? Are we just a bunch lazy lab escapees who can type or are we a more serious bunch that are bringing a passionate new voice to complex technical issues? I believe we're in the latter group and here is why.
This very blog started because everyone was asking me questions when I started my PhD. Most of the questions I got were of two types:
Someone watched something on TV or read in the newspaper and just didn't get why it's important.
Someone developed their own theory to explain something in life... and wanted me to rubber stamp it.
Clearly, scientists in general are really bad at explaining to the layman what science is really about. Why are stem cells important? Just what on Earth is evolution? There is so much sensationalized misinformation out there, it's sickening! Science bloggers should be a voice that everyone can understand and trust.
So should I be anonymous? No way! Quacks hide behind a veil of anonymity. Standing behind what I say in public about important issues adds to my credibility (hopefully). I reference everything I write about, and answer every question. You can hold me accountable in the comments below every post or on your own blog.
The last point is what it's all about. Science bloggers are like teachers: I wouldn't trust an anonymous teacher I couldn't call out.
As for career prospects: sadly, academia hires based on educational pedigrees. Regardless if we blog or not, where we did our research and who we know count a lot more than our blogs.
Lactose tolerance evolved a few times independently.
An exciting story has unraveled over the past few years, and a new landmark study caps the effort of dozens of scientists around the world. The problem: why do around half the people in the world have lactose intolerance and what is different about those that can tolerate lactose? While deciphering this question, we now have very strong evidence that humans are still evolving.
In celebration of it's 50th anniversary, New Scientist asked 70 world-renowned experts and scientists about their thoughts on the next 50 years. The future-gazing writings make very good reading. Enjoy!
From the Exceedingly Cool Science department: a team of Japanese and UK scientists genetically modified two blood proteins in a way that lets them capture solar energy and break down water to its constituents hydrogen and oxygen. Hydrogen is considered a 'clean' and environmentally friendly fuel because burning it gives off just water, which is quite harmless.
The paper explains it all. Firstly, they took a blood protein, a kind of porphyrin. Porphyrins are important in the blood because they are associated with metals (like iron) which help move oxygen around and do other things. The porphyrin they used is naturally associated with iron, so the first task was to replace the iron with zinc.
The next modification was taking another protein, albumin, and modifying it to be able to form a complex with the modified porphyrin. Once that happened, they showed that the new complex can take energy from sunlight and use it to break down water into hydrogen and oxygen.
So what does this mean for you and me? We know of several decent ways to produce hydrogen fuel, but this one uses sunlight directly. Electrolysis, the closes alternative, uses electricity to break down the water. In that case, where do you get your electricity from? In this light (forgive the pun), this genetic engineering technology is much better.
Of course, as with any potential technology, scaling this to produce the large amounts of hydrogen we would need to run our cars, cities, and factories will take a lot of work. However, potentially, this one might be used on small scales, say to power a mountain cabin. Also, it uses something that's readily available, namely water, making it easier for anyone to work it. Still, it's a lab-scale technology for now, but keep an eye out for it!
Social bookmark post (digg, delicious, reddit, etc)