Abstract
We developed this project in different classes of primary school students (aged 10-11), in classes of middle school students (aged 13-14) and in several scientific improvement
groups in secondary school, where the students are 18 years old and also for teaching Italian and European teachers...
We ask the students How can I study distant objects?
and they answer I observe through a binocular or a telescope
, so we builded a simple telescope.
The students asked us How can an Astronomer understand stellar composition?
In next section, we'll answer to this question: we'll show how to build a very simple spectroscope.
Description
We describe how to build a very simple spectroscope.
Material needed
- Paper tube: the inner tube of a toilet paper roll;
- 2 squared pieces of black cardboard (8x8 cm);
- glue and a cutter;
- scissors, black sellotape;
- diffraction grating (2x2 cm): a piece of an old CD-rom.
Procedure
- Cut a slit 0.2 cm x 1.5 cm in the centre of one of the cardboard squares. The slit obtained in this way will be very thin and neat.
- Glue this square to one of the basis of the paper roll. Make sure the glue has dried up, then cut the square, just as large as the cylinder base. Not to let light in, seal the round piece of cardboard to the edges by using the sellotape. Light should pass only through the slit.
- Cut a 1-cm-square hole in the centre of the second squared piece of black cardboard.
- To prepare the diffraction grating you need the piece of CD included in the set bag. It has been obtained by peeling off the silvery and coloured film in the upper part of a CD. Be careful not to scratch it as it is very delicate.
- Fix the diffraction grating (the little piece of the CD ) to cover the squared hole in the piece of cardboard. Seal it to the edges by using the sellotape paying attention not to cover the diffraction grating.
- Glue this squared piece of cardboard to the paper roll, on the side of the paper roll which is still free.
Now your spectroscope is ready. Look through it. Point the slit towards the source of light, with the diffraction grating close to your eye. What can you see?
We observe
- If you look at a filament lamp, you can see a contnuum spesctrum.
- If you look at a gas lamp, you can see a gas lamp, you can se a spectrum with lines.
- If you look at the solar light, you can see an absorbtion spectrum...
