How Can You Make a Plastic Bottle Cave In Without Touching It? Frugal Friday.

How Can You Make a Plastic Bottle Cave In Without Touching It?

Air Pressure Crushing a Plastic Bottle

Have you ever seen a plastic bottle crumble without anyone touching it?

There are three ways to make a plastic bottle cave in without touching it.

In all three cases, you are going to make the temperature inside the bottle warmer than outside the bottle.

Hot to Room Temperature

The first, and easiest way is to run water as hot as you can get it.

Do not do this trick with boiling water. It will melt the plastic bottle.

Pour the hot water into the empty plastic bottle.
Swish it around for a minute or so
Pour out the water and quickly put the top back on the bottle.
Put the bottle on the counter or a table.
Watch the sides cave in.

If you open the bottle cap, it will go back to normal.

Click here to read about this on a homeschooler’s blog, written by a Mom of six, where we first saw this neat trick, in 30-Second Science.

Her kids love doing this at breakfast.

Cold to Room Temperature

You can see the same effect whether the cold air is room temperature or freezing.

Empty a plastic bottle and put the cap back on.
Put it into a freezer for about half an hour.
When you take it out, the sides will be caved in.

If you open the bottle cap, it will go back to normal.

Click here to read more about it on ehow.com.

Hot to Ice

This one is the fastest and most dramatic.

Fill a large bowl with ice water.
Fill a plastic bottle with water as hot as you can run it, without boiling it.
Swish the hot water around the bottle for a minute.
Pour the water out. Put the cap back on the bottle.
Plunge the bottle into the ice water.
The sides will cave in.

If you take it out of the ice water and take off the cap, the bottle will go back to normal.

Who Is Charles and Why Does He Have His Own Law?

Jacques Charles discovered in the 1780s that gases expand when heated. This was later discovered to apply to all gases, including air.

In the early 1700s, another French scientist, Guillaume Amontons, had discovered that gas pressure rises with a rise in temperature.

Thus, when the air inside the plastic bottle is heated, it expands.

This is the key. Some of that volume of heated air escaped the bottle before it was capped, but the volume of air outside the bottle is the same.

Similarly, the volume of room temperature air is lower than that in the freezer.

As the temperature inside the bottle is increased with hot water or is room temperature, and the outside of the bottle is cooled in ice water or the freezer, the air pressure outside increases, relatively, compared to the volume or pressure of air inside the bottle and the bottle caves in.

Taking the top off the bottle equalizes the pressure on the inside and the outside, thus returning the bottle to normal.

We write about fun things to do with your grandchildren every Friday.

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To you and the endless discoveries you share with your grandchildren.

Carol Covin, “Granny-Guru”

Author, “Who Gets to Name Grandma? The Wisdom of Mothers and Grandmothers”

http://newgrandmas.com