The first word in the headline is Spanish and the second is French. They, taken together, simply mean, ‘Only the Sun’. The Earth is just a fragment of the Sun, a tiny one, which was formed after the Big Bang, and which subsequently over millennia, contracted gravitationally, went through several cycles of heating and cooling, to reach the unique combo of atmosphere+hydrosphere+pedosphere+lithosphere+biosphere it is today. And it is continuing to change…owing to climate change.
Lord Rama in the Ramayana, is said to have prayed to the Sun God, before embarking on his battle against Ravana in Lanka. It worked out well for Him…even an incarnation of Lord Vishnu, revered the Sun and was aware of its power and beneficence. A hidden lesson for us when we read Valmiki’s epic!
Taking the Sun for granted?
Most of us take the Sun for granted. But up here in the northern latitudes, where this writer is based at the time of writing this piece, a series of cloudy days in the winter months creates angst, and when the Sun peeps out from behind the clouds for a few minutes/hours, everyone is out there to get his/her free dose of Vitamin D. We know very well what deficiency of Vitamin D can lead to. It is also said to be one of the drivers for cancer…Imagine what the absence of solar energy would do to plant life, and thereby to all the components of the food chain downstream, right up to us, Homo Sapiens. An acquaintance of my mother’s once remarked, ‘When the sky is cloudy, my mind seems to close too. Psychologically, I feel depressed.’ There you have it then. The Sun’s role in our physical, mental and psychological (read holistic) well-being. It gets even more holistic actually, if you factor in from a scientific and philosophical point of view the vitality of the Sun (its gravitation and its electromagnetic energy) for material well-being and economic prosperity.
Mankind has been thriving on the fossil-fuel trio – coal, oil and natural gas – for many years now. It has been quite like the Hindu Trinity – Brahma, Vishnu and Shiva – or the Christian one – The Father, The Son and the Holy Spirit – if I could try to invoke the religious aspect here; as this piece is not merely scientific, but rather metaphysical and spiritual. Now, evidently, the dependence on fossil fuels is bound to continue, though the talk is that slowly but steadily and surely (they say so), natural gas will displace more and more of coal in the economy. Let us wait and see though, what actually happens.
If you flash back several millennia, and do a kind of a material flow analysis of coal, oil and gas (over time), you get back eventually to the Sun! Photosynthesis, carbon dioxide from the atmosphere (Lord Vayu there for you), water (Lord Indra with the rain and Lord Varuna with the hydrosphere sustained by the rain) and you had the organic matter (some of which was then fed on by the higher living organisms). When they, at the end of their lives, were subjected to high pressure and temperature, they metamorphosed into the fossil fuels you get to use now. A complex material flow analysis one would say…but surely puts things in perspective. And more important, makes the Sun even more prominent!
But now, Bhoomadevi (Mother Earth, or Gaia or Tellus) who has been supplying humans with coal, oil and gas generously, is no Kamadhenu! She has Her limits. And within reasonable timeframes, coal, oil and gas are certainly not renewable resources. One could adopt Carbon Capture and Storage, for sure, but when these would yield fossil fuels in the distant future, would be hard to tell…and who knows what will happen to the human race. That makes me a cynic, I am sure; a doomsday prophet as many would say. Yes, those of us who belong to this camp know that we are poised inexorably on a watershed now. And those who counter us (Donald Trump, for example?), may call themselves techno-philic optimists. There are just these two camps…you belong to one of these, or you do not belong at all.
Take direct solar energy itself. Less than one percent of what is incident on the earth’s atmosphere, is utilised by plants on terra firma (and that is how we have our biofuels – additives to gasoline and diesel – and biomass-energy (firewood essentially): the former in the richer world, and the latter has been sustaining the poorer inhabitants of Mother Earth for ages now. While 30 percent of what is available does not reach the Earth at all (gets reflected from the upper echelons of the atmosphere), the remaining 70% warms the oceans, the lower levels of the atmosphere, and the pedosphere itself. A great deal of this energy is then slowly radiated back to outer space, as long-wave infrared radiations. (Note that when these are trapped in the atmosphere by greenhouse gases, we have global warming).
The direct use of solar energy
We will see later how some of the solar energy which warms up the hydrosphere and atmosphere is being put to use indirectly. But the point here is to try to use the energy directly wherever possible. We have been doing it of course, by installing solar heaters, availing of solar-powered devices and solar photovoltaics. Some countries have shown the way…trendsetters so to say, Germany standing out in this regard, as it has always done while setting trends in science, engineering and technology. Evidently, much more can be done. Else, the solar energy simply heats up things, and the energy is then re-radiated and lost to outer space…an increase of entropy without an attempt being made to use more of the exergy. We, in India, can do more and more of this ‘solar energy harvesting’, just as we have been trying to do ‘rainwater harvesting’.
There was a reference in the previous paragraph to the fact that some of the 70% which warms the spheres of the earth is actually put to use, consciously. This is how it goes…through the wind energy and wave energy which we have been harnessing or at least trying to harness. We know very well that winds and waves (the former in the atmosphere which gets heated up by the Sun; and the latter in the hydrosphere which gets heated up by solar energy incident on it) are consequences of thermal energy additions from the Sun! Take tidal energy and you would, prima facie, feel that this has nothing to do with solar energy. Perhaps you are right. You would attribute that to the gravitational pull of the Moon (Lord Chandra – there you have another deity) on the waters of the Earth. It is said to make some of us loony (ask astrologers for explanations), but it surely provides us with a source of green energy if we are smart enough and resourceful enough to harness that. But yet, we know that the gravitational pull of the Sun also plays a small part here…so, it is not solar thermal energy but solar gravitational energy, if one may put it that way.
Geothermal energy, they say, like nuclear energy, has nothing to do with the Sun. It is a result of the gravitational contraction of the earth which generated a lot of heat trapped deep below the earth’s crust. And also due to the radioactive decay processes happening in the core of the earth (very similar to a nuclear reactor). Yet, if we could trace back the genesis of coal, oil and gas to the sun, we could do the same for geothermal and nuclear as well…the earth after all, came from the Sun, did it not? And nuclear fusion, if that gets commercialised, we would simply be duplicating what has been happening in the heart of the Sun (the source of all the energy we have been thriving on)…
Those of you who chant the Gayatri Mantra, do recall the messages of this article, when you do so….for this is not just backward religious dogma…it is simply an expression of gratitude…which would follow after facts have been comprehended.
bhr bhuvasva
tát savitúr váre(i)ya
bhárgo devásya dhmahi
dhíyo yó naprachodáyt
(“Let us adore the supremacy of that divine sun, the god-head who illuminates all, who recreates all, from whom all proceed, to whom all must return, whom we invoke to direct our understandings aright in our progress toward his holy seat” – as paraphrased by Sir William Jones, an 18th century Welsh philologist.)
