For a detailed lesson template with learning outcomes, keywords etc. click here.
This second lesson is for people who would like to explore the tool further. It looks at the "Pole in the Barn Paradox" in three different situations. This seeming paradox results from confusion around simultaneity and space contraction. It is a slippery concept and well worth going through a couple of times.
Each student will need a copy of the Spacetime Grid for each of these excercises.
Interactive
Lecture (20 minutes)
The PowerPoint presentation Space
Fight takes the students through a scenario with two passing spaceships.
Ali thinks that he is going to fire a harmless warning shot at Brenda. The co-pilot
says that Brenda will be hit by the shot because of space contraction. Who is
right? This would be a good question to work on with whiteboards.
For this to work, you need to photcopy a Spacetime
Grid in reverse onto a transparency that you clip onto the white board.
By photocopying it in reverse, you prevent the whiteboard markers from erasing
the printed lines. (The problem used here is a modification of a problem found
on page 79 of "Spacetime Physics" by Taylor and Wheeler.) The physics
is brought back to Earth by considering muons produced by cosmic rays in our
atmosphere.
Worksheet (30
minutes)
The Alien
Parking Problem has Aliens visit the Earth and looking for a parking space
for their ship. The spot provided by the Earth's welcoming committee results
in the ship crashing becasue the space was too small. This is a major diplomatic
disaster! Only a relatvistic diplomat can save the day. The answers are provided
in Alien Parking Answers
and Alien Parking Grid .
The final question, #14 would be a good whiteboard
question. You could have two small groups join up to make a two-whiteboard presentation
to the class.
Worksheet (30
minutes)
The Lightning Strike
looks at the standard scenario that is used to explain the realtvitiy of simultaneity.
Putting this problem on a spacetime diagram can help it be much more convincing.
The answers are provided in Lightning
Strike Answers and Lightning
Strike Grid.
1) Al’s Relativistic Adventures www.onestick.com/relativity/, This is a cute but very accurate storybook version of special relativity.
2) This is another animated explanation of Special Relativity. It is available
in English, French and German. http://www.cell-action.com/einstein/index.html
(Thanks to Laure Ghia (Hamilton) for the suggestion.)
3 ) www.cco.caltech.edu/~phys1/java/phys1/Einstein/Einstein.html,
This contains some very simple, clear animations along with the relavant spacetime
diagrams.
Last Updated July 2010