Egg in a Bottle

Today, we perform a feat of scientific ingenuity, and shove an egg into a bottle which is too small for it, without even touching the egg!


It's amazing! It's incredible! It has useful and important applications which will benefit society!

Uh...well, it's fun anyway.

You will need:
A hard-boiled egg
Very hot water
A bowl of very cold water
A glass bottle with an opening which is just slightly too small for your egg.  I used a Starbucks frappachino bottle with a large grade AA egg.
A bit of butter or oil

An adult!  Yes, because of the hot water, you must have an adult.  Hot water is very dangerous, and can give you burns--yes, burns, like fire--if it's not handled carefully.

Alrighty, let's get started!  First, empty out the bottle and grease the top and a little ways inside with the butter or oil, to make it super slippery for the egg.  Now, set the egg on top of the opening.  Have an adult tilt the bottle and hold it under the faucet, while you're running water as hot as possible.  Gasses expand when they're heated, so the air in the bottle will push out, popping the egg up ever-so-slightly to escape as the hot water heats it.

Once the air is good and hot, and lifting the egg up a teeny bit doesn't seem to let any air out, the adult can hand the bottle over to you.  Plunge it into the ice water.  If hot water heats up the air and makes it expand, what do you think cold water does?  It shrinks!  FUMP, the egg is pulled into the bottle!  This time, instead of wanting to push on the egg to let air escape, the cooling air shrinks and sucks on the egg.  It sucks and sucks, but the egg is a good seal--it doesn't let air past--so the only option is to suck the egg all the way in!

This project is good fun!  There are other things to do, too.  You can pop the egg back out again by having your adult hold the bottle upside-down under the hot water--the air expands again and pushes that sucker out!

If your goal is to baffle people, here's a very fun variation.  Instead of hard-boiling the egg, let the shell soften in vinegar for 12-24 hours.  The rest of the project is the same--but when the shell dries out, it hardens again! Now you have a normal, hard egg in a bottle with people wondering how on earth you got it in there!

Where do plants breathe?

Where do plants breathe--that's the question we tackle with today's project.  I hope you still have some Vaseline from the blob slide, because we'll be using it again in this investigation.

Plants do definitely breathe.  In fact, they breathe carbon dioxide and make oxygen--people and other animals breathe oxygen and make carbon dioxide.  We help each other that way.  If we had only plants on Earth forever, they would use up the carbon dioxide and die.  If we have only people and no plants, we'll use up the oxygen.

So they do breathe, but the question still isn't answered--where?  They don't have mouths or noses.  So how does the air get it?

To find out, you will need:
Three small, leafy potted plants
Petroleum jelly (Vaseline)

No adults required--although you might want permission to use the plants.

Air can't get through the petroleum jelly, so anywhere we put it on the plant definitely won't be able to breathe.  If we block a place with the jelly, and the plant does just fine and doesn't seem to care, then it must not breath there.  If we block a place with jelly and it drops down dead instantly then we've covered the only place it has for getting air.  The jelly is clear, so it won't block sunlight--only air.

On the first plant, carefully spread jelly on the undersides of all the leaves.  Label it "Plant 1."

On the second plant, spread the jelly on the tops of all the leaves.  This one will be "Plant 2."

Finally, on the third plant, we don't put any jelly on at all.  This is our control.  We compare the other two to this plant to see if the jelly made them better or worse, and by how much.

If you want, you can add more plant to the experiment and check other places--like the stems, for example.

Water all the plants normally and watch them over the next few days.  Which is doing the best?  Which is doing the worst?  What does that tell you about where plants get their air?  Do plants get all their air from either the top or bottom of the leaves, or is it a mixture?  If they get some air from both, do you think they get the same from each or is one side more important for breathing than the other?

Mini Monday: Blob slide

Hello girls, and welcome to the blob slide!  You might have noticed that in the hot summer, black asphalt is absolutely scorching, but light gray is better.  Today, we are going to harness that power, and bet on a race of penny blobs sliding down a tin can--based on our scientific knowledge, of course.

But first, materials!

You will need:
Petroleum jelly (Vaseline)
Two pennies
An empty tin can
A lamp without the lampshade
A black sharpie or black paint
Tin foil

You may want an adult for this one--the tin can can get very hot, very quickly!

First, color or paint half of the inside of the can black.

Next, make a little tin foil sunhat for your light bulb.  The open end of the can will sit on this.

Jaunty, no?

Next, but one blob of jelly on each penny.  Make the blobs as close to the same size as you possibly can.  Using the sticky jelly, stick the pennies on the outside of the can.  Put one penny on the side that's black inside, and one on the side that's not black.

Now, put the can on the light bulb hat and watch the blob slide begin!  Which side won?  Write down whether it was the black side or the light side, and hold at least three races.  Which side won the most?  Why do you think that was?

Black absorbs more heat than any other color, and white absorbs the least.  The black side of the can, then, should have gotten hotter than the light side, and melted the jelly on the penny faster.  Faster-melting jelly would make the black-penny slide down faster and win more often.  Did that happen in your experiment?  If not, what reasons can you think of that might have been more important than color, letting the light side win?  Maybe the light side was closer to the bulb, or had less jelly to melt.  When you figure out reasons for something unexpected in an experiment, that's real science!