Why dinosaurs hate meteors

I ride my Road King at 653 mph, I do it every day, and trust me, you also do it every day. Actually, we can not call it riding, as we are standing still, at a red light, or in congestion, and still travel at this high speed.

653 mph is the rotational speed of the earth in London, so while we stand still, we actually move quiet fast. At the equator, the circumference of the Earth is 40,070 kilometres, and as the day is 24 hours long, the speed is 1670 kilometres/hour (1037 mph). This decreases by the cosine of your latitude, so that at London’s latitude of 51 degrees, so cos(51) = .629, thus the speed is .629 x 1670 = 1,051 km/h, or 653 mph.

I only bring this trivia to your attention as introduction to my real issue, the speed differential, or speed delta. It is not so relevant how fast you ride, but how fast you ride in relation to another reference, this is the critical figure. If this difference is high, the danger increases exponentially.

In many aspects of our riding we should be aware of the speed differential. Travelling on a country road, the speed differential between you and the big oak tree, is… your speed. The delta is most pronounced in traffic coming towards us, as the speed differential is the sum of both vehicles speeds. My advise, better not touch the truck. But when you travel on a highway at 60mph alongside a truck, you could touch it without great risks.

Take the German Autobahn, when all travel at 130mph, all is fine, when however some bimble along at 60mph, and others are allowed to travel at 130mph, greater care must be taken, and some basic rules should be observed. The practise of Undertaking becomes a lethal threat, as participants sharing the road are moving at substantial different speeds, and different speeds best stay in their assigned lane.

So, if in the UK we all ride at the same speed limit on a free M25, it doesn’t really matter if we do this at 70, 80 or 90 mph. But in the city, when cars at 30mph meet cyclists at 10mph and pedestrians at 3mph, the food chain becomes clear and the problems start.

It is not the speed itself that matters, it’s the speed differential. To avoid a collision, you need to do is bring your speed differential to zero, not your speed.

Same applies for filtering. Riding at 50mpg through long lines of stationary cars is dangerous. One dreamer moves over or open his car door, you are doomed. But doing this when the cars move at a snail speeds of 30 mph is much less risky, because the differential now is just 20 mph. You can break easily and quickly reduce this speed differential to zero, eliminating all delta, coming to a virtual standstill against the moving cars.

Speed differential is the reason why dinosaurs hate meteors



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