Pew pew pew. The physics of your favourite blaster sound.

I came across this awesome video from SKUNK BEAR explaining how the sound engineers on the Star Wars movies came up with the sound of those iconic blasters and I knew I had to share it with you.

Now I also want to go throw stones at a frozen lake and dig out a slinky.

Basically the sound the blasters make comes from sound waves dispersing along a metal wire. The sound waves expand and as they do that iconic sound is heard.

Take a look at the video for a much better explanation that I could ever give.

 

 

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.

Seeing our planet from the International Space Station

Our planet from the space station

Listen to this:

NASA publishes a large collection of photos and videos of our planet as seen from the International Space Station. They offer a truly spectacular view of our home.

What really stands out, particularly when you watch the videos, is that you don’t see borders and the many differences that divide us. Instead, what you see is the one, beautiful planet that we all share.

A wonderful example of this is astronaut Jeff Williams’ video of the Earth as he passed overhead during a recent visit to the International Space Station. This video, titled “Jeff’s Earth” is mesmerizing on a big HD TV:

This 2012 video titled “Earth Illuminated: ISS Time-lapse Photography” is another wonderful opportunity to see what the astronauts see from the ISS as they orbit the Earth:

It is easy to forget that the Earth is the only home we have and that we share it. Fortunately, photos and videos from organisations like NASA help remind us of what we have in common.

Here are some photos from the NASA Johnson Space Center collection on Flickr:

Featured image credit: NASA Johnson Space Center

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?!

Will a bowling ball fall faster than a feather?

Listen to this:

If you dropped a feather and a bowling ball at the same time, which would hit the ground first? You would probably say that the bowling ball would hit the ground first, right? After all, a bowling ball is so much heavier.

It turns out that the relative weight of the objects doesn’t make a difference to which object will hit the ground first, as strange as that may sound.

One of the parents in our class chat group shared this terrific video from the BBC that explains what really makes a difference and, surprisingly, that a bowling ball and a feather will hit the ground at the same time under the right conditions:

So, as you can see, the factor that makes the difference in normal conditions isn’t the objects’ weight, it’s air resistance! When you remove the air, both objects fall at the same rate and hit the ground at the same time.

Image credit: Pixabay

What happens when lightning strikes an airplane?

This morning our daughter asked me what happens when lightning strikes an airplane. She is a little afraid of storms and she was concerned about the passengers of airplanes when there are lightning strikes.

Understanding lightning better

Lightning is, at the same time, an awesome and terrifying phenomenon. It seems to affect us on a very primal level. Understanding it better helps us appreciate its awesome beauty while making sure we are safer during lightning storms. I found a great video from SciShow Kids about lightning:

National Geographic also has a great video that explains lightning:

Lightning moves pretty quickly so we don’t always see lightning in more detail. I found this terrific video on Wikipedia (your browser may not play the video if it doesn’t support .ogv formats).

So what happens when lightning strikes an airplane?

The prospect of lightning striking an airplane can be scary. I was fascinated to learn that planes are engineered to handle lightning strikes in an interesting way. Here is a video from the Smithsonian Channel:

If you are interested in reading more about how airplanes are engineered to withstand lightning strikes, also read an article on Scientific American titled “What happens when lightning strikes an airplane?”. Here is an extract from the Scientific American article that answer my daughter’s questions about passengers’ experience of a lightning strike:

Although passengers and crew may see a flash and hear a loud noise if lightning strikes their plane, nothing serious should happen because of the careful lightning protection engineered into the aircraft and its sensitive components. Initially, the lightning will attach to an extremity such as the nose or wing tip. The airplane then flies through the lightning flash, which reattaches itself to the fuselage at other locations while the airplane is in the electric “circuit” between the cloud regions of opposite polarity. The current will travel through the conductive exterior skin and structures of the aircraft and exit off some other extremity, such as the tail. Pilots occasionally report temporary flickering of lights or short-lived interference with instruments.

Thunderstorms are impressive and powerful natural phenomenon and it’s usually a good idea to keep your distance, regardless of your mode of travel. At the same time, it is good to know what even when you are suspended in the air, traveling through a storm, you are probably safe.

Featured image credit: Pixabay