An objective measure of how majestic a mountain is

Ever since our days in Seattle, I have been endlessly fascinated with mountains like Rainier and Denali - mountains that stand much taller than their neighbouring mountains thereby offering dramatic and spectacular views, often from long distances. It turns out there is an objective measure that measures this quality: topographical prominence (thanks to a Windows screen saver photo of Mt. Kilimanjaro which led me to this Wikipedia page). Some really high peaks (like K2) don't have as much topological prominence as they are surrounded by mountain masses that are also very high.

By Muhammad Mahdi Karim - Own work, GFDL 1.2, Link

The definition of topographic prominence is a bit tricky but makes intuitive sense if you think about it. Wikipedia defines it as " the height of a mountain or hill's summit relative to the lowest contour line encircling it but containing no higher summit within it". Basically:

1. Find the maximal land area surrounding the peak which contains no higher peak. 
2. Find the lowest point in that area. 
3. Topographic prominence is the height of the peak from that point. 

Now, which mountain do you think is #1 in terms of topological prominence? As per another helpful Wikipedia page on the Ranking of Mountains by Topological prominence, it is indeed Mt. Everest. Well, no surprise there, you might say. But I was actually surprised. I knew that you need to get to a very high altitude before you even see Everest. The base camp for a mountaineer making an attempt at Mt. Everest is at a whopping 17000 ft. So I would have thought Mt. Everest's topological prominence would be around 12000 ft, not that high. I thought even Mt. Rainier might beat it, Denali for sure. You can see Denali from 100 miles. 

But then if you go back and read the definition again, Mt. Everest gets the top nod based on a technicality. You see, as per step 1, you need to find the maximal area surrounding the peak which contains no higher peak. Since there is no higher peak than Everest, the maximal area is the Earth's entire landmass (or at least Eurasia if you want to be very precise). And the lowest point in that area (step 2) is sea level. Hence the topological prominence of Everest is its entire height from sea level, all 29000ft of it. So the measure actually doesn't really work that well for the tallest mountain in the world because it is no. 1 by definition, but it works well for others. So none of the high peaks in the Himalayas other than Mt. Everest  come up in the top 10, because they are surrounded by really high contiguous landmasses that includes higher peaks  and they don't stand out as much. 

Not surprisingly, Mt. Aconcagua and Mt. Denali the tallest mountains in South and North America respectively are 2nd and 3rd in the list. And Mt. Kilimanjaro, the highest mountain in Africa is fourth.  And my favourite neighbourhood Mt. Rainier comes in at a respectable 21st  in the list. 

- Balaji

BSVI, diesel cars and air quality

Overdrive magazine has been serving the needs of my inner car-buff, replacing Car and Driver from earlier days. Recently they have been publishing some good primers on automobile technology including one on electric cars. In the latest issue they have a good in-depth article on the new BSVI (BS-6) emission standards (http://overdrive.in/…/everything-you-need-to-know-about-bs…/) that is going to come into effect from April 1, 2020. What this means is that all new vehicles (big and small, 2-3-4 wheelers) sold after this date have to comply with BSVI emission requirements which are much more stringent than BSIV (BS-4) which was adopted in 2017. BSVI is based on the European standard Euro 6.

BSVI impacts diesel cars more because diesel engines pollute more and car-makers will have to equip diesel cars with cleaner running engines and more importantly install post-emission devices like DPF (diesel particulate filters) to meet the standards. This means that diesel cars will get more expensive. Also, in order to meet BSVI, diesel cars also need to use BSVI diesel. Indian gas refineries have been working on producing the cleaner burning diesel which should become available throughout the country by April 1st. Cars sold before the date of course can continue to run and they can use the BSVI diesel and will emit a bit less. BSVI implies significant reduction in nitrous oxides, sulphur content and particulate matter (80-90% reduction) all of which have been linked with respiratory and other illnesses. It will perhaps take years to see any noticeable improvement in air quality as more BSVI vehicles replace older cars. But it looks like a good thing.

In a nutshell, cleaner diesel, less emissions from new diesel vehicles, more expensive diesel cars.

Spreading positivity - kudos to Indigo Airlines

So, for a while now, when I read the newspaper in the morning, I get depressed because almost everything being reported is negative. This happens to some extent in social media as well. I recently participated in a Mindfulness workshop where people echoed this concern. So I have made a resolution to do my small bit and spread positivity around.

The first one I want to do is to appreciate Indigo Airlines for their on-time performance and how seriously they take it. I have been taking some late evening flights recently; while it is par for the course for most airlines to accumulate delays over the day, I was impressed how Indigo was on-time even in these evening flights. They seem to obsess about it to the point which causes some inconvenience to passengers (like they put you in the bus and go wait in the tarmac while the arriving passengers from the plane you're about to board are still disembarking; this helps parallelize and shorten the deboarding/boarding process); but I will take this minor inconvenience any day over waiting in the airport for a flight that got delayed by 2 hours. They also do smart things like adding some buffer to their flying time. This surely implies that they are not jamming in as many flights as they possibly could in a day at the cost of on-time performance. 

And there are some signs that this may be infectious. In the last GoAir flight I took, they started asking the passengers to help in getting the cabin ready for the next flight to shorten the time they are on the ground (something Indigo has been doing for many years). 

- Balaji