1. 1 “Nothing Hidden” A Science Demonstration “Be sure your sin will find you out.” (Numbers 32:23)

2. 2 “All things are naked and opened unto the eyes of him with whom we have to do.” (Hebrews 4:13)

3. 3 Sam Kelly

4. 4 Friedemann Wulff-Woesten

5. 5 scienceheath

6. 6 These two types of water are very different, but we cannot easily tell them apart. One is what we call soft water, and the other is what we call hard water. The hard water has dissolved calcium, magnesium, or perhaps iron in the water. Because the mineral atoms are in solution, they are invisible to the eye.

7. 7 You can do this demonstration at home. Put each type of water in a separate jar that has a lid, filling halfway. Add a few drops of dishwashing detergent to each jar, attach lid, and shake well for about thirty seconds. The difference between the two types of water should be evident.

8. 8 SOFT WATER Lots of suds on top Soap is dissolved Water quickly clears Looks clean HARD WATER Has a “bathtub ring” Little suds Soap left over Water is milky

9. 9 The impurities in the hard water prevent the soap from performing properly. Instead, a messy white precipitate forms, sometimes known as bathtub ring. A little bit of soap dramatically reveals the difference in the water types.

10. 10 Likewise, people may be similar in outward appearance. We cannot see within the heart to determine what a person really stands for, but God can. We may fool others and even ourselves with hidden motives, but everything is open and apparent before God’s eyes.

11. 11 Explanation If samples of hard and soft water are left out in the open to evaporate for a couple of days, a difference becomes apparent. White scale material forms around the sides of the evaporating hard water. This white residue consists of calcium, magnesium, or iron. It is actually dissolved rock powder that precipitates with the loss of water.

12. 12 Using hard water may lead to a number of difficulties. The soap-hardness precipitate may leave a gummy residue behind during hair-washing. In cooking, hard water will make food taste slightly “tough.”

13. 13 Over time, hardness scale may completely plug hot water pipes, which is what happened in the ancient city of Laodicea.

14. 14 Water pipe to Laodicea

15. 15 Adapted from Science & the Bible, By Donald B. DeYoung