Tag: allotrope

In search for life through the twists of light

Akshat RathiLeave a comment

Finding Earth-like planets is common place now. What about detecting life on them?

Two centuries ago a French engineer noticed something special about light from the sun. As it reflected from the window and passed through a crystal of calcium carbonate, depending on the angle at which the crystal was placed, the image it created grew stronger or weaker. Étienne-Louis Malus had discovered a phenomenon called polarisation of light. The simplest example of this can be seen in the above images whereremoval of certain polarised light increases the contrast with clouds.

Sunlight is unpolarised which means that the electromagnetic waves that make up sunlight are not restricted in their spatial orientation. But when this light interacts with biological molecules like sugars, amino acids or chlorophyll it changes its spatial orientation, and, more importantly, we are able to detect the change and measure it.

This week researchers using the Very Large Telescope in Chile used this characteristic of light to show the presence of water, clouds, and vegetation in Earthshine – the sunlight that’s been reflected off of Earth to the dark portion of the Moon’s face and then back to our planet – through a method dubbed spectropolarimetry. Michael Sterzik, an astronomer at the European Southern Observatory in Santiago, Chile, said that the state of polarisation contains a lot of information that hasn’t been used very often.

Comparing their measurements of Earthshine with models of how various land and sea surfaces reflect polarised light, the researchers could discern which part of our planet was covered with oceans and which with land mass. They also identified the biosignature of chlorophyll which showed up when land masses on Earth were illuminated.

The upshot is that it might be possible to use this technique to spot the presence of water and other biological molecules on the many Earth-like planets that have been discovered recently. The techniques currently available can only detect the presence of water and other simpler molecules which is not enough to ascertain the existence of life. The occurrence of biological molecules on the other hand increases the probability of finding life by many factors.

But as these planets are usually many light years away, the light received from them is very faint. Researchers will have to wait for the next generation of telescopes, such as the European Extremely Large Telescope planned for 2022, to gather the required data. But possibly, within a decade, the twists of light will help us seal the fate of life beyond our planet.

First published on Science Oxford Online.

Reference: Sterzik, M., Bagnulo, S., & Palle, E. (2012). Biosignatures as revealed by spectropolarimetry of Earthshine Nature, 483 (7387), 64-66 DOI: 10.1038/nature10778

Through twists of light

Akshat RathiLeave a comment

Two centuries ago a French engineer noticed something special about light from the sun and discovered the phenomenon of polarisation of light. Now using that property of light scientists have developed a  technique to spot the presence of water and other biological molecules on the many Earth-like planets. With more powerful telescopes being built, they might just be able to search for life through the twists of light.

In search of light through the twists of light – Science Oxford, 20 March 2012

The Over-simplification Conundrum

Akshat RathiLeave a comment

I believe that those of us involved in science communication have at some point wrestled with this issue: In being able to effectively communicate the science as we know it, we are often blamed for over-simplification to reach the masses or going into too much detail to ending up not reaching the masses.

Not losing your audience’s interest is the goal of any communicator. But when it comes to writing about scientific issues, we scientists have a tendency to try to get the facts straight and be as clear about what we know and what we don’t know. And rightly so, we’ve been trained to pay attention to detail that is part of our jobs. But a friend recently said to me, ‘We scientists pay so much attention to details sometimes, that we fail to recognize the peril in it!’

The conversation began because someone shared the image above. It’s part of advertisements made for Mercedes-Benz. I had read about the left-right brain myth and kindly pointed it out to my friend, when he came back with that retort. Although I appreciate the artistic beauty of the image and that the over-simplification done in this case causes no ‘real’ harm to the society, I am against over-simplifying just to be able to make something popular.

My friend interjects, ‘If you tell a common person that “Oh, this is all a myth. Everything is integrated to every other part of the brain” the common man soon looses interest and in the end does not get anything out of it. But if you can take one step at a time after talking about the left-right dichotomy, he may feel interested.’

As a matter of fact, the only thing a common man may get out knowing about the left-right brain is to pleasure of learning something new (because the ‘methods’ I know that have been ‘developed’ to help someone improve their left brain by doing left brain activities are bollocks). If the ‘something new’ you have taught the reader isn’t even right, and he discovers that later, then you have (or worse, science has) lost a loyal listener.

Make things as simple as possible, but not simpler. – Einstein’s Razor

Looking at the bigger picture, it is important to help people have the most accurate beliefs from the beginning. Thus, when communicating scientific matters, one must not sacrifice details for artistic/populist reasons. The solution, of course, is to give as accurate a picture as possible to anyone but do it in a manner that is attractive (may be by tailoring it to your audience or using audio-visual aids or consulting with experts who usually have a neat explanation). This is definitely one of the main reasons why science communication is hard but also why it is worth doing it.