The speed of light is too slow. I read an article a few years back about latency, not just about switching decisions at the router level, but due to the actual

The speed of light is too slow. I read an article a few years back about latency, not just about switching decisions at the router level, but due to the actual physical distance the light/electrons in the physical media need to travel; the HFT servers need to be very close to the exchange.