Viswanathan K's Thoughts

Pranay Kotasthane’s post on the history of how the water situation in Bangalore has evolved was highly informative. “First, half of the city’s water supply comes from Kaveri, which is 90 km away and 350 m lower.” That “350 m lower ” part is very significant. First, it means the water has to be lifted. The electricity bill for lifting comes to ₹3 crores per day. Second: “Before independence, Bengaluru, due to its elevation, relied largely on the rainwater stored in nearby lakes. But as the city population grew, the engineering marvel of pumping water up from the Kaveri was dreamed and realised.” In turn, that led to a decrease in the dependence on lakes. As the lakes fell into disuse, encroachments began to increase. Since the lakes had begun to matter less (at that point), the pushback against encroachment was proportionally low.   Historically, the other half of the city’s water needs were met by groundwater. But, as the city began to grow with tech parks followed by ...

In an earlier blog , we looked at why Mars doesn’t have any water. How about our neighbour on the other side – Venus – why doesn’t it have any either? The knee jerk answer (it’s closer to the sun, so it’s hotter) doesn’t hold up on closer inspection. In his book, H2O , Philip Ball points out that Venus’ surface temperature is 500˚C, far, far more than what its proximity to the sun should dictate. So what happened to Venus?   Well, the volcanoes of Venus released a huge amount of CO2. This led to the greenhouse effect, which then caused whatever water was on the planet to evaporate. It isn’t as well known, but water vapour too is a greenhouse gas, i.e., it raises the temperature. A vicious loop had been set off: the evaporated water added to the greenhouse effect, leading to even faster evaporation of water: “With nothing to hold this process in check, the entire oceans boiled dry… This is the greenhouse effect taken to its terrifying conclusion.” Further, even the evaporate...

When I turn a globe such that the Pacific Ocean is facing me, it’s possible to adjust it such that no land is visible. The opposite isn’t possible though: there is no orientation of the globe where I can see only land. That’s a perfect visualization for Philip Ball’s line from his biography of water, H2O : “We call our home Earth – but Water would be more apt.”   Why does Earth have (so much) water, whereas Mars doesn’t? After all, our theories say that when the planets were being formed, ice-laden comets were bombarding planets all the time, so why shouldn’t Mars still have water? The answer has two parts. And both parts are based on the same root cause: “The key is size.”   The first consequence of the smaller size? “ Being smaller than Earth, Mars cooled off sooner from its fiery youth.” As it cooled, its volcanic activity seized up. And: “Without the churning of a hot mantle, Mars developed no plate tectonics.” The (initial) water on Mars eroded its roc...

Water is the liquid we see everywhere, and thus the one we take to be representative of liquids in general. Which is why we don’t realize how “profoundly odd” water is, how un-representative of liquids it is, writes Philip Ball in H2O . He compares it to using the lives of the residents of Buckingham Palace as representative for British life in general! “They’re probably the most written-about family in the country – but you could scarcely have chosen a less representative household.”   Let’s see the ways in which water is atypical. Most liquids become denser when they freeze. Not water. Ice is famously less dense than water. Which is why ice floats on water, whereas the solid forms of other liquids sink to the bottom of their respective liquids. (This, by the way, has enormous implications for life. Ice is formed at the top of oceans, not bottom. And so when summer comes, the ice at the top melts. If instead, ice had sunk to the bottom, it would never un-freeze and progress...