# What everyday devices make could make good science lessons

**URL:** <https://boards.straightdope.com/t/what-everyday-devices-make-could-make-good-science-lessons/746935>\
**Category:** In My Humble Opinion\
**Created:** [February 24, 2016, 2:16am UTC](https://boards.straightdope.com/t/what-everyday-devices-make-could-make-good-science-lessons/746935 "2016-02-24T02:16:10Z")\
**Posts on this page:** 2\
**Page:** 2

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**Author:** ![Blue\_Blistering\_Barnacle](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/blue_blistering_barnacle/32/3386_2.png) [@Blue\_Blistering\_Barnacle](https://boards.straightdope.com/u/Blue_Blistering_Barnacle)\
**Post date:** [February 25, 2016, 12:26am UTC](https://boards.straightdope.com/t/what-everyday-devices-make-could-make-good-science-lessons/746935/21 "2016-02-25T00:26:17Z")

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> [@Urbanredneck](#):
>
> Stretch out a rubber band, then let it go back. Its suddenly cold. Never have totally figured that one out.

It’s also hot just when you stretch it. Then it cools to room temperature. When you relax it, it cools below room temperature.

It’s similar to how refrigerators work, compressing gas, cooling the hot compressed gas to ambient temperature, then allowing the gas to expand quickly and cool down.

It’s a cool thing to show kids, but I think difficult to explain, even to adults. Look up “adiabatic”- that word alone is pretty scary.

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**Author:** ![DocCathode](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/doccathode/32/18773_2.png) [@DocCathode](https://boards.straightdope.com/u/DocCathode)\
**Post date:** [February 25, 2016, 1:47am UTC](https://boards.straightdope.com/t/what-everyday-devices-make-could-make-good-science-lessons/746935/22 "2016-02-25T01:47:07Z")

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A laser pointer (I saw a bunch at the dollar store last time I visited).

Besides teaching about light and optics, you can give a very simple explanation of what a diode is. I also like to explain that when I was your age, a similar laser cost a few thousand dollars, and was three feet long.

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