An Artist’s Studio Constructed Entirely Out Of Cardboard

Five TED Talks that converge the worlds of art and tech

Here’s Olafur Eliasson on the nature of human perception…

Be inspired by our other selection…

Technology has altered our social and political world… 

AM & FM: How Radio Works 

Lately I’ve been thinking about how the things I use every day actually work, and since I listen to a lot of podcasts, you can guess where this post is going: radio. 

In a studio, a microphone converts sound waves from a person’s voice into an electronic audio signal. If this was sent out by itself, it would only travel a few metres in air before it faded out. To get radio waves to travel long kilometres to a receiver, we have to combine it with a “carrier wave”—an electromagnetic wave. 

Electromagnetic waves are made up of oscillating electric and magnetic fields, just like visible light, but radio waves are right down on the lower end of the spectrum, so their wavelengths are very long—around 300 metres. 

(Image Credit: NASA)

Sound information is combined with the wave by altering or modulating the wave’s properties, like changing its amplitude, frequency, or phase. There are two ways to combine the audio signal with the carrier wave: amplitude modulation (AM) or frequency modulation (FM). 

AM radio changes the overall amplitude or strength of the wave, varying its height in order to incorporate the sound information. FM radio works a little differently, because it changes the frequency of the wave rather than the amplitude. The frequency is the number of wavelengths that pass by a given point per second—physically, a high frequency wave would look squashed up, and a low frequency wave would look stretched out. 

(Image Credit: Wikimedia Commons)

Both kinds of waves are susceptible to variations in amplitude as they zoom off through the air, but since FM radio relies on changes in frequency rather than amplitude, these variations don’t matter—they can just be ignored, and so the sound quality is usually super clear. But AM radio relies on the amplitude to convey information, so when the amplitude is varied a bit, this results in interference or static, which will be a familiar idea if you’ve ever listened to AM radio on a rural country road. The upside of AM radio is that it travels much further than FM radio, which is probably why you’re listening to it on that rural country road in the first place. 

So once these radio waves—whether AM or FM—hit a radio receiver, their oscillating fields induce a current in the conductor. The sound information encoded into the waves can be extracted, and converted back to sound waves to grace your ears with your favourite music or talk show. 

(Bonus: if you want to use science to learn more cool science, my fave podcasts are Radiolab, the Infinite Monkey Cage, and Big Picture Science.)

Nikki 10th grade Charleston, SC

Nikki comes to computer science class every day with 5 questions, 3 things to show her teacher, 2 articles on cool technology and about 15 features she wants to add to her year’s project — a site that teaches American citizens about their civil rights. Check...

Five Ways Your Holidays Might Be Similar to the Crew on the Space Station

The holiday season is here! You might think that your celebrations are WAY different than what is done on the International Space Station, but you might be surprised…Here are a few ways your holidays might be similar to the crew on the space station:

1. You’re Instagramming All Your Decorations

Yep! Just like on Earth, the space station crew has the capability to use social media while on orbit. If you don’t follow them, you should check it out and get an out of this world perspective of what life is like on the International Space Station. (Expedition 34 crew members assemble in the Unity node of the space station for a brief celebration of the Christmas holiday on Dec. 24, 2012.)

2. You Have to Make Sure to Call Your Relatives

You don’t want to forget to wish Aunt Sue “Happy Holidays”, she might not send you a gift next year! The crew on the space station have the ability to talk to their loved ones every day. (Cosmonaut Mikhail Tyurin, and astronauts Michael E. Lopez-Alegria and Sunita L. Williams conduct a teleconference on Dec. 25, 2006.)

3. The Family Photos Never Seem to End

The crew on the station might not be related by blood, or even country of birth, but they share living space, meals and time together just like a family on Earth. And when it comes to the holidays, you bet they’ll be snapping pictures to capture the moments. (The six Expedition 30 crew members assemble in the U.S. Lab aboard the space station for a brief celebration of the Christmas holiday on Dec. 25, 2011.)

4. Meal Prep is a Task Shared by All

When you’re making food for multiple people, everyone needs to pitch in and help…the crew on the space station included! (Astronauts Michael Fincke, Sandra Magnus and cosmonaut Yury Lonchakov, pose for a photo as they prepare to share a Christmas meal on the space station on Dec. 25, 2008.)

5. Eating Cookies is a Must

What would the holidays be like without eating cookies? They even have the chance to eat them in space…pretty cool! (Astronauts Michael Fincke and Sandra Magnus hold Christmas cookies while posing for a photo near the galley on the space station on Dec. 25, 2008.)

For more pictures from the holidays on the International Space Station, check out our Flickr album: HERE. 

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

'A Conspicuous Fishing Village' Dubai, UAE

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The Burj Khalifa (Downtown Dubai, UAE)

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