![Boy looking through telescope at night](/sites/default/files/styles/resource_card_image_360x300_/public/2020-02/telescope-boy-night.jpg?itok=13zWe-Od)
Optical Telescopes
Backgrounders
Learn about the history of telescopes and the function of refracting and reflecting optical telescopes.
![Radio Telescope array at night](/sites/default/files/styles/resource_card_image_360x300_/public/2020-02/radio-telescope-at-night.jpg?itok=Xj9MDhpb)
Radio Astronomy
Backgrounders
Learn about radio astronomy, a type of astronomy that studies objects in space using radio waves and radio telescopes.
![Ultrasound treatment on knee](/sites/default/files/styles/resource_card_image_360x300_/public/2020-02/ultrasound_treatment_knee.jpg?itok=093wi43j)
Ultrasonography
Backgrounders
Learn about the history, function, uses, benefits and risks of Ultrasonography as a medical imaging technology.
![Adult and children looking through telescope](/sites/default/files/styles/resource_card_image_360x300_/public/2019-09/adult_and_children_looking_through_telescope.jpg?itok=eKeL_YGd)
The Optics of Telescopes
Backgrounders
Learn about telescopes, how they work & why they're important to astronomers.
![Two faces each with one eye visible](/sites/default/files/2022-06/two%20eyes%20to%20see.jpg)
Why do we need two eyes to see?
Hands-on Activities
Ever wondered why we have two eyes (and not one, three or more)? Find how your two eyes work together in this hands-on activity.
![Why is everything so small down there?](/sites/default/files/2019-08/why-is-everything-so-small-down-there.jpg)
Why is everything so small down there?
Hands-on Activities
Explore how we see things far and near and from different angles. It's all about perspective!
![The Electronic Sackbut Synthesizer](/sites/default/files/styles/resource_card_image_360x300_/public/2020-01/Electronic_Sackbut_Synthesizer.jpg?itok=jubC6sRr)
Who Created the Electronic Synthesizer?
STEM Explained
A Canadian researcher built the first voltage-controlled synthesizer in the 1940s.
![Sound waves](/sites/default/files/styles/resource_card_image_360x300_/public/2020-01/Sound_wave_icons.jpg?itok=GMAHUQyT)
What is Sound and How do we Hear it?
Backgrounders
Learn how sound travels in waves and how it is measured in this backgrounder.
![Circle of colours](/sites/default/files/2019-08/what-is-white-light.jpg)
What is white light?
Hands-on Activities
Find out what happens if you spin the colours of the rainbow in this hands-on activity.
![A pot of gold at the end of a rainbow](/sites/default/files/styles/resource_card_image_360x300_/public/2019-09/A%20pot%20of%20gold%20at%20the%20end%20of%20a%20rainbow.jpeg?itok=qHjgEPrQ)
What's in a Rainbow?
STEM Explained
Rainbows are beautiful examples of optics in nature. We see them thanks to the reflection and refraction of visible light and water.
![Artist’s interpretation of astronaut in space](/sites/default/files/styles/resource_card_image_360x300_/public/2019-12/Astronaut_in_space.jpg?itok=650F3G6e)
What are the Different Types of Radiation?
Backgrounders
Learn about the different types of radiation, how they interact with atoms and how they can affect you.
![Sound waves and sound-producing devices. Image © jop_pop, istockphoto.com](/sites/default/files/styles/resource_card_image_360x300_/public/2019-09/Sound%20waves%20and%20sound-producing%20devices.jpg?itok=6ATkmIUM)
Sound vs. Noise
STEM Explained
What is the difference between sound and noise? How do they affect your hearing? And is noise always a bad thing?
![Replica of the earliest wooden model stethoscope](/sites/default/files/styles/resource_card_image_360x300_/public/2020-02/stethoscope_replica_ingenium.jpg?itok=RgHTg8L2)
Stethoscope Replica
Interactives
Using stethoscopes, doctors can use sound waves to detect various health issues. Learn how this device has evolved since it was invented in 1816!
![Water: A Natural Reflector Water: A Natural Reflector](/sites/default/files/styles/resource_card_image_360x300_/public/PM_Water_Reflector.jpg?itok=0C01YEYB)
Reflectors
Picture Collections
7 images of some objects that can reflect light such as mirrors, Mylar balloons and water
![Is a green apple always green?](/sites/default/files/2019-08/is-a-green-apple-always-green.jpg)
Is a green apple always green?
Hands-on Activities
What does light have to do with colour? Observe some colourful fruit under different conditions to learn why we see the colours we see!