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The speed of light is $2.998 \cdot 10^8 \mathrm{\frac{m}{sec}}$. This means that it travels $2.998 \cdot 10^8$ m in one second (one light-second).
However, light travels $2.998 \cdot 10^8$ m by traveling one meter at a time. So, it takes $\frac{1}{2.998} \cdot 10^{-8} \mathrm{sec}$, which is $3.336 \cdot 10^{-9}$^{ }(3.3 billionths) sec to travel one meter.
Light also travels one light-second by traveling one millimeter at a time. Light therefore would travel one millimeter, which is $\frac{1}{1000}$ meters ($1 \cdot 10^{-3}$ m), in $\frac{1}{1000}$ the time that light takes to travel one meter.
In the same vein, light would travel one micrometer $1 \cdot 10^{-6}$ m) in $\frac{1}{1000}$ the time it takes to travel one millimeter. It would therefore take approximately$3.336 \cdot 10^{-15}$ seconds for light to travel one micrometer. (Check this.)
But light nevertheless travels one light-second in one second, or one light-year in one year, or a billion light-years in a billion yearsâ€”all the time traveling one micrometer at a time! It just travels a very large number of micrometers in a very large number of really small bits of time.
The dimensions of a dollar bill are 15.5956 cm by 6.6294 cm by 0.010922 cm. The U.S. federal government spent $3.8 trillion in fiscal year 2011.
How high, in km, would be a stack of dollar bills that contains the same amount of money as spent by the U.S. federal government in 2011?
An Olympic swimming pool is 50 m long, 25 m wide, and 1.5 m deep. How many Olympic pools would be filled by the dollar bills spent by the U.S. federal government in 2011?
A $100 bill has the same dimensions as a $1 bill. An episode of Breaking Bad shows three wooden platforms that each held a stack of $100 bills measuring approximately $1 \mathrm{m^3}$. What, approximately, would be the value of those three stacks if they contained real $100 bills?