Science Smarts: To eat or not to eat, that is the question
By PATTY ROOKS on April 15, 2022.
I do not know about you, but I will be boiling a lot of eggs over the next few days. The problem is that when I get busy, I tend to forget which ones are boiled and which ones are not. There must be a way to use science to figure this out so no one ends up with a raw egg on the egg hunt! Let’s get started! Remember to ask an adult before doing this experiment. Materials • 1 hardboiled egg • 1 raw egg • Plastic egg filled with plasticine or silly putty • Plastic egg filled with water Procedure • Examine the two eggs. One is hard boiled and one is raw. Can you tell just by looking at them? Make some predictions. • Examine the two plastic eggs. Can you tell which egg has the water in it and which one has the silly putty? Make some observations and predictions. • Let’s experiment on the plastic eggs now. Spin them. Observe what happens. • Spin the plastic egg, but this time, stop it with your hand and then let it go. Observe what happens. Make note of which one has the plasticine in it and which one has water in it. Do you notice any differences? • Now take the real eggs and try the same experiment; spin the eggs and observe what happens. Spin the real eggs, stop them and then let it go. What happens? • Now guess which egg is hard boiled and which one is raw. • The moment of truth – find out which is which! What is going on? A raw egg tends to “weeble” and “wobble” all over the place. It does not spin very well at all! This is because the liquid yolk and white are different densities, flowing from side to side as the egg spins. A solid, hard-boiled egg, on the other hand, will spin smoothly. There is nothing “sloshing” around inside the egg shell to slow it down. When it is hard boiled it is completely solid inside of that shell with nothing to move around. If when you spun the egg it remains at a complete, abrupt stop, it is hard-boiled. But if it begins to move again after you take away your hand, it is raw. Why? To a physicist, this is an example of Newton’s third law of motion, the one that says for every action there’s an equal and opposite reaction. When you stop a spinning raw egg, the shell applies force on the liquid inside. The liquid, in turn, applies an equal and opposite force on the shell, nudging it back into motion – as long as you remembered to let go! Newton’s first law (Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it.) also applies here. The liquid part of the egg continues to move after you stop them and thus a force is applied to the shell. Keep an eye on our social media as we have officially kicked off our 30th anniversary celebrations this week. We cannot wait to have you take part. Patty Rooks, Senior Scientific Consultant PRAXIS, “Connecting Science To The Community”. Contact Praxis at praxis@praxismh.ca, http://www.praxismh.ca, Tweet or follow us @PraxisMedHat, or friend us on Facebook. Address: #12 826 11 Street S. E., Medicine Hat, Alberta, T1A 1T7 Phone: 403.527.5365, email: praxis@praxismh.ca. 22-21
