In September 2005 (for the 50th anniversary of the atomic clock and 100th anniversary of the theory of relativity) we took several cesium clocks on a road trip to Mt Rainier; a family science experiment unlike anything you've seen before.
By keeping the clocks at altitude for a weekend we were able to detect and measure the effects of relativistic time dilation compared to atomic clocks we left at home. The amazing thing is that the experiment worked! The predicted and measured effect was just over 20 nanoseconds.
I will not even try to understand the science here, but this story looked delightful. This fellow strapped cesium clocks into the family van along with his kids for a road trip to Mt. Rainier on what he termed Project GRE2AT - the General Relativity Einstein/Essen Anniversary Test.
In September 2005 the kids and I took several very accurate cesium atomic clocks from home and parked 5400 feet up Mt Rainier (the volcano near Seattle) for a full two days. The goal was to see if the clocks actually gained time, even if billionths of a second, as predicted by Einstein's general theory of relativity. Does gravity really alter time and can this weird phenomenon be detected with a family road trip experiment?
Judging from the pitcures, I think these kids my have a geeky Dad, but theya re lucky to have him!