Test your knowledge of physics and C

This C program measures acceleration due to gravity.  When run without any arguments, it prints the exact value of g in SI units (m/s²).

Instructions: download the program text, save it to a file, compile and run it. It is very important that you preserve the formatting: if you delete or add a single newline, the program will not work!

#define O +\
__LI\
NE__\
,46-\
__LI\
NE__
char
g[]
={
46
O       O









        O

        O







        O







        O






        O



};main(   ){puts(g);}

To understand the program, print out the source and look at it from some distance.  The apparatus at the top is the particle dispenser; O's are falling particles, and at the bottom there's a photodector connected to a very precise timer.  The program works by measuring the time it takes for a particle to fall from the top of the program to the bottom.

You can reproduce Galileo's famous experiment by changing O to another letter and verifying that the value of acceleration doesn't change.

FIXME: current version of the program works only on Earth; support for other planets will be added in later revisions.  If you live on Mars and want to be a beta-tester, please contact me.

😉