# uncertainty

# Dot Physics

# Category archives for **uncertainty**

I just got back from judging elementary level science fair (this is like kids in 6th grade or something). Here are some quick notes in no particular order. Please, please do not have a 20 item list of supplies that you used on your board including things like thumb tacks, tape, paper and poster board.…

I previously talked about measurements (some) when I looked at the uncertainty in the distance to the Sun. One of the simple ways of determining the uncertainty of a calculated quantity is to use the uncertainty of the measured variables and find the max and min that calculated quantity can be. The example I used…

Some time ago, I wrote about the awesome things the Greeks did in astronomy. Basically they calculated the size of the Earth, distance and size of the moon and distance and size of the sun. The value obtained for the distance to the sun was a bit off, but still a bang up job if…

Previously, I talked about science fairs. One of the problems is that students don’t really have a good understanding of data analysis. For me, statistical analysis is just something to do with data. It isn’t absolutely true. So, it doesn’t really matter that students use sophisticated tests on their data. The important point is they…

Suppose I am working on a problem and I wish to calculate the density of something. I measure the mass to be *m* = 24.5 grams and the volume is *V* = 10 cm3. In this case the density would be: ![Sigfig 1](http://scienceblogs.com/dotphysics/wp-content/uploads/2008/09/sigfig-1.jpg) ALERT! ALERT! ALERT! This is not a test!!!! Something is drastically wrong!…