On fireflies and luminescent flowers!

We have all probably seen fireflies glowing in the dark. How does this happen? There is some fascinating underlying chemistry involving a compound luciferin. Luciferin combines with oxygen, and light is emitted as a result of this reaction. The same mechanism exists in some deep sea jelly fishes which send out periodic flashes of light in the pitch dark depths of the ocean. A fascinating experiment conducted by some Israeli scientists was to transplant the genes responsible for the production of luciferin into orchids. The result was luminescent orchids which glow in the dark!

The time may not be far when you will be able to sit in the evening in your garden surrounded by chemiluminescent roses and other flowers. This indeed is the strange and wondrous world of science!

Auroras – what causes them?

Did you know that the sun is responsible for the spectacular bright lights in the night sky seen near the two poles of the earth? The sun throws a magnetic hurricane, comprising a hot gas of charged particles, with associated magnetic fields and electric currents, in the direction of the earth. This hurricane blows over the earth at a terrific one million miles per hour. However we hardly feel it because it is largely defected by the earth’s magnetic field (“magnetosphere”). However it does cause distortions in our magnetosphere causing a shower of high energy particles which light up the night sky. When there is a high intensity storm the sky lights up brightly with many colours, the green and red light being produced by the collision of the cosmic particles with oxygen, while blue light appears due to the interaction of the cosmic particles with nitrogen. Fortunately for us the magnetosphere acts a protective shield, protecting us from the cancer-causing cosmic rays.

Ever heard of “e-cigarettes”?

I was sitting on a plane last month on my way back from a conference in Trieste when I noticed a passenger on my left who was smoking a battery powered “cigarette”. The tip glowed red due to a fitted LED light every time he puffed but very little smoke came out of his mouth. The cigarette does not contain tobacco but allows the smoker to inhale a few micrograms of nicotine. Invented by a company in China the device costs about US$60 while nicotine cartridges cost about US$1.5 each. Tobacco contains certain cancer-causing nitrosamines which are largely absent in e-cigarettes (except from some minor contamination in the nicotine).

Are we all made up of tiny strings?

Arguably the two greatest breakthroughs in physics were quantum mechanics and Einstein’s theory of general relativity. Quantum mechanics tells us about the fuzziness of nature on the atomic scale while Einstein’s theory of general relativity addresses the physics involved at the macro level (such as planetary motions, gravitation etc). However while quantum mechanics works well at the atomic level it cannot be applied at the macro level. Similarly Einstein’s theory of general relativity cannot be applied at the atomic level, clearly emphasising the need to have a unifying theory — a “theory of everything”. To unify these two great frontiers of physics Ed Whitten from USA proposed that the smallest building blocks of matter may not be atoms but much smaller loops or strings which vibrate in a space with 10 or 11 dimensions. We may therefore be made up of tiny dancing strings — difficult, if not impossible, to prove!

Are there other planets with life?

Does life exist on other planets? This question has puzzled scientists for centuries. Such “alien earths” need to be at the right distance from the sun so that water can stay in a liquid form - if they are too near then water will exist as steam, while if they are too far then it will be frozen. The Kepler space telescope launched by Nasa in March this year in an orbit around our sun may provide some answers. It is now about 11 million kilometers from earth and proceeding on its planned course.The Kepler space telescope will be monitoring the existence of planets by the decrease in brightness of some 100,000 stars as planets pass in front of them. Meanwhile the European satellite “Corot” has discovered an earth-like planet about 390 light years away from us which has a diameter twice that of earth. However its surface temperature is over 1000 0C which is too hot for life to survive.

Source: Dawn News