How to Set Up an Easy Memento Mori Science Activity
Memento Mori is Latin for “Remember your death.” It may sound morbid at first, but it is important to remember that we all will die some day. In fact, as Catholics, we know that we do not need to be afraid of death because death allows us to enter into our eternal life with God in Heaven – if we prepare well. Our bodies will die and return to the earth, but our soul will live forever!
Hallowtide is a time set aside in the Liturgical year to meditate on death. Heaven and Hell do exist, and we must spend our lives preparing to enter Heaven to be united with God forever.
During the Hallowtide season (October 31-November 2), consider setting up this simple “Memento Mori” science activity to observe what happens to bones over time!
What happens to our body when we die?
Compared to how fast our body tissue (skin, muscles, etc.) decomposes, bones take a much longer time to break down. Our body (including our bones) decomposes when exposed to moisture, air, extreme temperatures, and even acid in the soil. Bones are made of many components, but the calcium in your bones (in the form of calcium phosphate) is what makes them durable and long-lasting. Even this strong mineral does not last forever. This is why incorruptible Saints are so miraculous!
Decomposing Egg Activity
The eggshell of a chicken egg is a similar composition to human bones. Eggshells have minerals made of calcium (calcium carbonate and a small amount of calcium phosphate).
In this activity, we will observe how an eggshell decomposes when exposed to vinegar. Vinegar is a weak acid that readily reacts with and breaks down calcium minerals.
The decomposition of the eggshell by the vinegar is a chemical change (or, chemical reaction). This means that the eggshell and vinegar combine and change into completely new materials. The process cannot be reversed under normal conditions. In other words, the change is permanent!
When our body and bones are exposed to various environmental conditions, physical and chemical changes occur to decompose our body. At the end of our life, our physical body will eventually return to the earth just as God told Adam in Genesis 3:19:
“…for thou art dust, and to dust thou shalt return”
Materials
1 egg
1 glass to hold the egg
enough vinegar to cover the egg in the glass
spoon
Procedure
Place the egg in the glass.
Fill the glass with vinegar. Make sure the egg is completely covered.
Observe the egg in the vinegar for a few minutes. Discuss what you see. Note any bubbles, color changes, etc. (When you observes bubbles in the liquid, this means that the chemical reaction between the vinegar and the eggshell is taking place!)
Place the glass with the egg and vinegar in the refrigerator.
Observe the egg again in 24 hours. Discuss any observations.
Use the spoon to remove the egg from the vinegar, and set the egg aside on a paper towel or plate. Dump out the vinegar.
Remove the egg from the vinegar. Rinse the egg in water, and gently try to rub off the shell. If the shell does not come off easily, return it to the glass and cover it with fresh vinegar.
Return the glass to the fridge, and allow the eggshell to react with the vinegar for another 24 hours.
Remove the egg from the vinegar. Rinse the egg in water, and gently try to rub off the shell.
Once the shell has been completely removed, observe how the rest of the egg is in tact! The egg white does not react with vinegar very much (it reacts a little bit, which is why it feels firm and rubbery, but it does not decompose in the vinegar like the shell). Discuss your observations.
Where did the eggshell go??
The calcium minerals in the eggshell react with the vinegar (which is also known as acetic acid) to form carbon dioxide (a gas that escapes into the air around you) and ions (charged particles that stay in the liquid). Just like the eggshell, our body and bones decompose into gasses and other components that return to the earth!
Hallowtide Science Extension Activities
Gently try making the egg bounce!
Consider comparing how the eggshell reacts with lemon juice, orange juice, or cola.
Try making different solutions (mixtures) of citric acid in water to see how the eggshell reacts. Put 3 eggs in 3 different glasses, and cover them with water. Add 1 teaspoon of citric acid to the first glass, 2 teaspoons to the second glass, and 5 teaspoons to the third glass. Allow eggs in citric acid solutions to sit in the fridge for 24 hours and observe as you did in the vinegar experiment.
Observe other signs of decomposition in nature such as decaying logs, tree trunks, leaves, and other vegetation.
If you carved a pumpkin, watch the pumpkin decompose over time. What signs of decomposition do you observe?
Study composting, and consider starting a compost if your family has the desire or space to use food waste to create fertile soil for your garden.
Research saints who are incorruptible, and meditate on the miracle of their bodies remaining intact for such long periods of time!