What is the problem with using pulse for time and what is the difference between pulse and a watch?

Question

1) One of the timing devices Galileo used was his pulse. Drop a rubber ball from a height of about 2 m and to try to determine how many pulse beats elapsed before it hits the ground. What was the timing problem that Galileo encountered?

2) Now measure the time it takes for the rubber ball to fall 2 m, using a watch or a clock with a second hand or seconds display. Did the results improve substantially?

3) Roll the hard ball down an incline that makes an angle of about 10 degrees with the horizontal. First use your pulse and then your watch or a clock to measure the time of descent.

4)Do you think that during Galileo's day it was possible to get useful data for any of these experiments? Why? 

Answer 1

The best way to answer this question is to perform the experiment.

1. Find a rubber ball
2. Measure a distance of 2 m
3. Find your pulse
4. Drop the ball and measure how many pulse beats it takes for the ball to drop 2 meters (repeat 2 more times for accuracy)
5. Do the same as above but with a stopwatch

I think it will be obvious in your results why the stopwatch is more reliable than your pulse. Especially since your pulse can speed up or slow down depending on your mood, what you ate, etc