• 2 people
• Identical coins (the heavier, the better) - 2
• Glass of ice water
• Glass of warm water (not hot water)
• Towel

1. Lay down and close your eyes.
2. Have your partner put one coin in each cup and leave the coins there for one minute.
3. After a minute, your partner should take the coins out, quickly dry them with the towel and place them about three finger-widths apart on your forehead. Which coin feels heavier-- and why?

Your skin does more than just hold your insides in ... it helps you feel things, using your sense of touch!

Throughout your skin, you have special structures called nerve cells. These are special cells in your body that feel cold, heat, pain and pressure. In this experiment, one coin triggers your cold receptors and one coin triggers your heat receptors. Human pressure receptors lack selectivity, so the pressure receptors also respond to coolness.

The cold coin and the warm coin are of equal mass, but the cold coin will feel heavier since it is mistakenly detected by the pressure receptors.