Build your own spectrometer (with help from Twilight Sparkle) · 8:59pm Sep 6th, 2014
In this post Twilight will show you how to build your own spectrometer, to split light into all its constituent colours. Like those used by professional astronomers to study distant stars and galaxies.
Checklist! You will need:
One breakfast cereal box
One old CD
Aluminium foil
Sticky Tape
Pair of scissors and a sharp knife (take care not to cut yourself)
A triangle to measure a 60° angle
Some friends to help
Get your friends help to finish the cereal so you have an empty box:
Cut a slot in the box at an angle of 60 degrees as shown below:
Cut holes in the box in the positions shown below:
Tape some aluminium foil to the hole to the side, leaving a narrow (1mm) slot to let the light through:
Take the CD and slide it into the slot as shown. Note it will not be possible to retrieve the CD without breaking your spectrometer, so make sure to choose a CD which nobody will want to play again. Let light shine onto the slot on the side, and look through the hole on top of the box. The spectrometer splits the incoming light into all the different colours.
This is what you will see when looking at different light sources:
Sunlight contains the full rainbow. As does the light from an old tungsten light bulb. Modern energy-saving bulbs emit a mix of individual colours instead of a continuous spectrum. Sodium street lamps produce a narrow band of yellow light.
By looking at lines in detailed spectra from distant stars, astronomers can tell what elements they are made from, and what elements lie in the interstellar space in front of them.
How does it work? We'll answer that question another time.
There are many variations of this fun project. This version is based on the one described in this video.
Very cool stuff, Thanks Twi and co.
If you look at the energy efficinet bulb, with its well defined and seperated lines of colour, you can see how having a little keyboard, where fingers of cardboard, say, slide over each colour to block it, folowed by the parts needed to reverse the behaviour of the light, gives you modern multiple frequency optical comunications. Using Roman and Newtonion, 400 year old technology.
But, thats for another time as it involves taking apart a pair of binoculars or such.
If you add the right sort of cheap webcam, it can pick up infra red and ultraviolet bands as well, giiving you up to a 300% increase in range of colours.
Wow, neat!
Tungsten bulb, those are the older style filament bulbs?
That's a HELLA big cereal box.
Hmm, tungsten, for some reason, puts me in the mind of brass and bronze, despite not being remotely related to either alloy.
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Yes, tungsten was the metal used to make light bulb filaments, as it is very durable at high temperatures. It's also sometimes used in jewellery instead of platinum.
I love projects like this. You take seemingly random materials that border on trash and you make SCIENCE out of them!
Also, it seems wrong that Dash isn't the one looking at the rainbows, though maybe that's just me.
SCIENCE!
This is awesome
Nice!
But the Tesco Multigrain Hoops (TM) Mouse is going to give me nightmares.
Conjuring rainbows inside cereal boxes?!
BEGONE WITH YOUR BLACK MAGIC!!
Usinga CD as a diffraction-grate is cool.