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is the theory of reality real??
(i have read "a brief history of time" & "theory of everything" i understood it but is it PRACTICAL??)
- sri kanth (age 14)
I'm guessing that you meant to ask "is the theory of relativity real??" (We have nothing to say on the philosophical question about "reality".)
The effects predicted by relativity are extremely real. Special Relativity plays an enormous role in lots of fairly routine physics. For example, the electrons in a high-powered electron microscope go fast enough to require relativistic calculations to get them to focus properly.
General Relativity plays a role in some practical physics. For example, it affects the timing of the satellite clocks used in GPS systems, If those effects were ignored the position calculations would pick up an error of about 10 km per day.
(published on 04/11/12)
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