Living Things

No matter how old you are, you will no doubt have noticed that time moves forward, and as it does, living things grow and change. This is the aging process. No matter how many cosmetics we use, special diets we try or surgeries we endure, everyone ages. And, sadly, everyone will one day die. In a sense, this is a good and necessary thing. The world would have long ago been overcrowded had past generations all possessed philosopher's stones or the like.

Having said that, scientists have discovered strains of living bacteria thought to be about two hundred million (200 000 000) years old. They were trapped inside rocks at the bottom of a mine shaft (from the Nova series "Origins"). Now that is old!

The Disappearing Eggshell Trick

Here's a science experiment that you can try with either a hard-boiled egg, or a raw one. It is best not to eat the egg afterward, especially if you choose the raw one.

Materials:
wide-mouthed glass jar with lid (a mayonnaise or pickle jar works well)
white vinegar or pickling vinegar
a raw or boiled egg
a spoon

Use the spoon to gently lower the egg into the jar.

Fill the jar with white vinegar (pickling vinegar, which is slightly stronger will work a little faster, but regular white vinegar will also work).

Fasten the lid loosely on top, and let it sit for 2-4 days. What do you see? If you used a raw egg, what did you expect to happen? What really did happen?

Eggshell is mostly calcium carbonate, which is easily dissolved by vinegar. You can also use this to help your eggs not to crack during boiling by adding a few drops of vinegar to the cooking water. Any tiny cracks will reseal themselves this way.

Unboiling an Egg: Molecular Gastronomics and Entropy

Transfiguration is the art of changing one thing into another. When you boil an egg, you will find the inside is quite different than the inside of an uncooked egg. But can you uncook it?

When you cook an egg, the proteins change in a way that can't be undone. The protein chains unravel then coagulate much as they do in curdled milk. Can you think of other examples of things that don't easily change back?

The universe is in a state of entropy. This means that things are moving towards a state of disorganisation. (It also means the loss of available energy according to the second law of thermodynamics, but we'll leave that one for later). For example, if you drop a glass onto the sidewalk, chances are pretty good it will shatter. Chances are not so good that a shattered glass will bounce up and reassemble itself. (Do not go out and shatter a glass to prove this--your parents might not approve!).

Getting back to unboiling an egg, according to one site on the internet, Hervé This, one of France's most famous chemists and the founder of the field of molecular gastronomics, has managed to unboil an egg. He explains that when an egg is cooked, the protein molecules unroll themselves, link up and enclose the water molecules. In order to 'uncook' the egg, you need to detach the protein molecules from each other. By adding a product like sodium borohydride, the egg becomes liquid within three hours. For those who want to try it at home, vitamin C is also supposed to work.

I have yet to try this, but will let you know what happens when I do. Maybe there will be lots of us non-chemists foolishly pickling eggs all around the world, or maybe there really is something to this!

Egg update:

We tried this using some vitamin C crystals we had in our cupboard. First we boiled an egg, let it cool, then peeled it. Next, we sprinkled some vitamin C crystals on it. After a couple of hours, we found that the crystals were quite wet, and the egg yolk was becoming slightly visible on one side. The next day the yolk was very visible (and the typical hard-boiled light yellow colour), but beyond that there were no changes. We added a bit of water and stirred it, hoping to speed things up. This didn't seem to make any difference.

Two days later, about half of the yolk became visible, and the egg white was clearly shrinking. The liquid around the egg (vitamin C, water and perhaps dissolved egg white) is more watery than the normal consistency of raw egg whites. The yolk is turning a bit darker yellow in places as well.

Our conclusion: to "unboil" an egg with vitamin C takes a very long time to accomplish. The vitamin C did seem to pull water from the egg, but whether this was causing the protein molecules to rearrange themselves remains undetermined. It might be significant to note that our vitamin C crystals were quite old, so may not have been as potent as fresh vitamin C. If we try this again, we will try and find a way to test the liquid for protein.

If you decide to try this and send me an email with your results, I'll post them here. (click on "me" to send me an email). Also, whatever you do, don't try and eat the egg!

If you find this intriguing, you may want to investigate Hervé This (pronounced "Tess") and the science of molecular gastronomics.

For further discussion about protein chains and coagulation, try this link explorebiology.com.

Mobius Magic: the Science of Topology

This activity is adapted from the book Big Ideas for Small Mathematicians by Ann Kajander.

You will need:
a wide strip of paper that is a different colour on each side (paint ofr colour one side if necessary)
a pencil, crayon or marker
tape
a pair of scissors

Pick up and explore your strip of paper. Try bending and twisting it in different ways (but do not fold it). Now see if you can figure out how to solve the following problem: your friend has a hamster, we'll call her Fufu. Fufu is a hamster of unusual intelligence, and as such, she has become bored with just running in her wheel. She wants to do things a little differently. She has tried running on the outside of her wheel, but keeps falling off. Still, she knows there must be a way she can run on the outside and the inside of her wheel, without falling off. In fact, if her wheel is created in a specific way, she can run continuously on the wheel (without getting off or climbing over the edge) yet run on both the inside and outside edges.

Can you use your paper strip to make a model of such a wheel?

What you have created is a mobius strip. (If you haven't figured it out, watch the first YouTube video below).

Now, try this: take a pencil and draw a line down the centre of the strip (as if your strip is a road, and your line is the centre line). Continue the line until it joins up where you started. What do you think will happen if you cut along this line?

Poke a hole in the line and begin cutting. What really happens? Were you surprised?

Try drawing another line like you did the first time. What do you notice is different this time? How do you think that will affect the outcome if you cut it? Test your theory by cutting it again. Were you right?

Explanation: The strip of paper appears as a 2-dimensional object when it lies flat on the table, as its third dimension (the height when it lies flat) is thin enough that it is easily ignored. When you picked it up and started manipulating it, the third dimension became more obvious (you can't do that with 2-dimensional objects!). When you made the mobius strip, you took this 3-dimensional object (the strip of paper) and folded the third dimension back on itself. This gives the shape some unusual properties, as you discovered.

The field of science (mathematics) that studies shapes in this way is called topography. The study of dimensions is very relevant to physicists too, especially those who study string theory. String theory attempts to bring quantum mechanics and relativity together into a Unified Field Theory. String theory predicts the existence of many more dimensions than the basic four that we know about (length, width, height and time). If string theory holds true, maybe some of those dimensions are hard to see because they twist back on themselves like a mobius strip.