Tie a string around a fairly large rock, and suspend it from a spring scale. Record the weight of the rock. Leave the rock suspended from the scale. Immerse the rock in a container of tap water, and record the weight of the rock.

Now immerse the rock in a container of ocean water or water with 1 ounce of table salt dissolved in each quart of water, and record the weight of the rock. Look for differences in the recorded weights.

Water has a force that pushes up objects, and this force is stronger in ocean water than in tap water.

Is that why people can easily float in salt water? Everybody has read about people lying about on the surface of the water at the Great Salt Lake in Utah.

I used to know a huge, fat man, who used to float on the surface of a fresh-water lake, and read! It seems that fat people can float much more easily than thin people. I don’t know why that is. Do you?