Expert: Steve Nelson - 7/10/2010

Question
Hello:

I love physics and the science that goes along with it especially when it comes to outer space.  Over the past 3 months I have been watching some shows that have been on our local cable stations called "The Universe" and "Into The Universe with Stephen Hawking" among others and I have many questions but will stick to this one for now. The question has two parts.

First. The speed of light.  186,000 miles per second. On one of the shows I saw last night they were explaining that because light travels at that speed we as humans see everything in "real time".  We get to experience events as they actually happen.  So that leads me to the first part of my question.  What if the speed of light suddenly slowed down to lets say 184,000 miles per second? What would or what do you think would happen? Second part of the question is the opposite.  What would happen if the speed of light suddenly increased to 189,000 miles per second?

The reason I am using small examples and not asking "what would happen if the speed of light dropped to 50,000 miles per second?" is because I can kind of understand what the effects would be on that large scale but on a smaller scale such as going from 186,000 to 184,000, would the effects be catastrophic?  Could we survive?

Thanks,

Paul

Answer
First question:  nothing would happen, light basically governs time.  Study relativity, the question is far more complex than you're making it.  Second question:  Yes, relativistic quantum mechanics would be radically different and the effects would be both unpredictable and probably catastrophic.