Slo-Mo Popcorn

I came across this fantastic video of popping corn in slow motion from Warped Perception and had to share it with you.

So, how does popcorn actually pop?

First of all, there are a few types of corn that are grown. But only one kind can be popped. Popcorn.

And the reason that popcorn can be popped is that the outer layer, the hull, is thicker than any other type of corn. This comes in handy when the kernel is heated up.

You see, each kernel of corn has a small amount of water inside as well as a little blob of starch. When the water is heated up it turns into steam.  Super heated steam. The steam mixes with the starch and changes it into a gel like substance.

Now the steam continues to heat up and expand, this causes pressure on the hull of the corn kernel. Since the popcorn hull is thick, it contains the heat for a slightly longer time than other corn, giving the starch time to form into that gel like substance.

Once the pressure gets too high, the hull bursts open and the starchy gel expands outwards, cooling as it goes, forming the puffy, yummy substance we love to eat.

Fun Facts

  • Popcorn can jump up to 3 feet/1 meter into the air.
  • There are two types of popped popcorn, Snowflake and Mushroom shaped.

 

  • The oldest ear of popcorn was found in a bat cave in Mexico in 1948. It is believed to be over 5,000 years old.
  • A kernel will pop when it reaches a temperature of 175 degrees Celsius.
  • Popping popcorn is one of the most popular uses for microwaves.

Unbreakable Prince Rupert’s Drops

Listen to this:

I came across these awesome glass drops in a video by Destin Sandlin from Smarter Every Day.

When you drop a piece of molten glass into cold water, the result is a tadpole shaped piece of extremely hard glass.

Three Prince Albert drops
Prince Rupert’s drops

Well, at least the head of the drop is very strong. The tail is actually quite delicate.

A shattering Prince Albert drop
A shattering Prince Rupert’s drop

The reason Prince Rupert’s Drops are so strong is that the outer layer of glass hardens almost straight away, while the inside takes a bit longer. When hot glass cools down (and this happens with water turning into ice too), the glass shrinks. This means that the inside of the glass drop is cooling down and shrinking but the outside is already cold and hard so the glass pulls towards the centre of the drop and makes it really, really strong inside.

Before we look at a really cool video of Destin from Smarter Every Day trying to break one of these drops using a bullet, take a look at his video that shows you how the drop is formed.

Right, now you have seen how the drop is formed and that hitting it on the head with a hammer won’t break it but if you nip the tail then the whole thing explodes.

Destin takes it a step further and shows us that even a speeding bullet won’t actually break the head of the drop itself.

Tip: try watch this on a large, high resolution screen for an even better experience.

How cool was that?!

Marshmallows in a vacuum

Marshmellows
Listen to this:

Hi everyone, its the mom here, with my first Stuff to Teach Our Kids post.

I really like baking, the kids like mixing and licking the bowl. I also like teaching them how and why we mix the ingredients together and the reactions that take place when certain things mix. Baking really is just science. So I went looking for some fun baking experiments we could try.

I came across this video by The Crazy Russian Hacker about what happens to marshmallows in a vacuum. It looks like a really fun experiment to try at home and you can find a vacuum box like the one he uses on Amazon here. You can also make your own vacuum box using a wine bottle and a wine saver pump/stopper (instructions here).

According to Physics.org the science behind the growing marshmallows is as follows:

Marshmallows have small bubbles of air trapped inside them. These bubbles are at atmospheric pressure. When the air inside the glass container is sucked out, the volume of the container remains the same although there is much less air inside – so the pressure is reduced. The air bubbles inside the marshmallows are therefore at a much higher pressure than the air surrounding the marshmallows, so those bubbles push outwards, causing the marshmallows to expand. When air is let back into the glass container, the surrounding pressure increases again, and the marshmallows deflate back to their normal size.

As soon as we get the vacuum boxes we are going to try this out for ourselves and I will post a video of our results. Please let us know if you try it out too.

Image credit: Marshmellows by Maryam Abdulghaffar, licensed CC BY 2.0