After the series of very interesting lectures on Nueral Networks, I just suddenly revived my interests in physics.

Just a few years back, probably during army days, I was reading on all these things about relativity and seriously, I could hardly understand any of it all. Somehow, after going through university, everything seems crystal clear this time around. Much to my own surprise, I realised the first time I ever spontaneously thought about relativity on my own was during my secondary school days about the “A housefly in a bus” problem, I still recall relating the problem to friends who probably only took slight interest in the topic.

Basically, I was kind of intrigued by the observation that houseflies seems to fly at their normal speeds in a moving bus. A search in google tells you housefly fly at 2m/s, that’s defnitely slower than the bus! I had always wondered why they do not get hit by the rear of the bus, which is moving much faster in the forward direction. Furthermore, there are other problems:

  1. If we assume that the bus and housefly travel at the same forward speed of 60km/h, which is approx 17m/s, how did the housefly manage to accelerate so fast to maintain that speed?.
  2. If now the houselfy is flying in an arbitary circular path, how does the fly so amazingly manage the precise flight control system, accounting for the difference in “relative” (secondary school physics sense)velocity?
  3. If the bus comes to an emergency stop, how does the fly even know to detected and react to the suddenly change in relative velocity when it is in mid air, particularly, how it decelerates so fast?

Although Theory of Special Relativity may seem like an easy way out, actually, even now it still feels weird and I don’t really understand how. It may well be that my observations are wrong and housefly really just stick to the windows. Anyhow, I won’t do an experiement on that.