From the Classroom to Outer Space
I. Spectroscopy
Student Activity #1-part 3
| Exploring
Our Universe: From the Classroom to Outer Space I. Spectroscopy Student Activity #1-part 3 |
Could We Measure a Googol Anyway?
If there isn't a googol of matter (atoms) in the universe, what about a googol of space? Use the following numbers and estimate the volume of the visible universe:
radius of the visible universe = 13 billion light-years
one light-year = 9.46 trillion km
[formula to calculate the volume of a sphere = 4/3 
R³]
Your Answer (approximate volume of the Universe) = _____________
Not quite at a googol yet? Maybe that's because the unit we used to measure volume is cubic kilometers (km³). What if we tried a smaller unit, like cubic meters? To do this, convert the distance of one light-year from kilometers to meters (knowing of course that 1 km = 1000 m), then recalculate the volume of the visible universe:
1 light-year = 9.46 trillion km = ______________ m
Your answer (volume in cubic meters) = ____________________
If you are still not quite at a googol, continue to change the unit
used to measure one light-year, reducing it to a smaller and smaller
unit (like cm, mm, 
m, etc), until your answer turns ot to be at least a
googol:
Final answer for the volume of the Universe = _________________
What's the point of repeating so many calculations? One reason is to see that measurements of the same thing look bigger or smaller simply by changing the unit. Pay careful attention to units, whenever you do calculations, or whenever you read information containing statistics. Numbers are meaningless unless you know what is being counted!
Extension Activities:
If you would like to read more about a googol, googolplex and other really big numbers, visit the following website on the Internet: