World Science Scholars

### 34.4 The Pole in the Barn: Spacetime Diagrams - Bart's Skateboard

Discussion
• What do you think will happen in this version of the Pole in the Barn Paradox? Bart is riding a skateboard whose rest length (between the front and back wheels) is 1 meter at a velocity so high that those on the sidewalk say his skateboard is contracted to a hundredth his rest length, 1 centimeter. Directly on his path is a sewer drainage cover, embedded in the road, with gratings that are 10 centimeters apart. Observers on the sidewalk think he’s going to fall in. But from Bart’s view, his skateboard is still 1 meter long and it is the separations in the drainage cover that are Lorentz contracted down to .1 centimeters apart, so he can simply skate right across them. What happens?

• Bart will simply ride on it

• Bart will ride like a champ.

• Bart will skate across them.

• Bart will not fall he will cross it

• The sidewalk viewers will post process to understand that at Barts velocity the gratings, from his point of view, will be Lorentz contracted to .1cm and, even at only 1cm long he will ride his scateboard across the drain with style 🙂

• According to him, he would ride over the grate

• I can say for sure that Bart will ride over it but I don’t know what is the reason behind this. If I take a guess then it would be as follows,” The force which will pull Bart has something to do with mass and I think at some place the famous formula E=mc^2 will come into picture”.

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