Time is a mysterious thing, it runs out on us quickly. If you really want to experience the relationship between space and time, a sand clock is one way to go. If you have children, you can build a sand clock with them, as part of a learning experiment.

Most online sites provide information on how to make sand clocks with plastic bottles. Sand clocks made of plastic bottles are not that attractive as the design provided in this article.

Here is what you will need: Sand, two light bulbs (to be emptied), some transparent tape or transparent adhesive, small piece of aluminium foil and wood to make a support.

*Step one: Empty the light bulbs with a normal screwdriver and a needle nose pliers. Emptying a light bulb is not difficult, just do it with caution. You need to empty the light bulbs so sand can flow through with ease. The light bulbs need to be transparent. Watch your hands and your eyes when emptying the light bulbs.

Note: Emptying light bulbs should be done with caution. Children should not do this experiment without adult supervision.

*Step two: Fill ¼ or ½ of one of the empty light bulbs with sand. What sand is best? Don’t use white beach sand, use river sand. You can also use marble dust, other rock dust or rock flour.

*Step three: Make a hole to a piece of aluminium foil. Now place that as the lid on one of the empty light bulbs. Sand should be able to pass through this hole. The bigger the hole the faster sand will flow. You can make this hole in other paper or use a plastic lid. The important thing is that the sand should be able to flow. Test it.

*Step four: Put the light bulb lids together. Hold them together with transparent tape.

*Step five: Time your sand clock. Add more sand if you want your sand clock to be longer.

*Step six: Once you get the sand clock to run as long as you want, paste the lids permanently together. You can do this with transparent tape, or with transparent glue or adhesive.

*Step Seven: Build a support with a wooden or plastic base. Paste the light bulb to the bases. Make sure they are straight. If not sand will not flow correctly.