Image Questions
What is this an animation of?
What are these horses doing.
Image Answers
Caption: Cartoon of gas molecules motion at finite temperature.
Credit: User:Greg L.
Image linked to Wikipedia.
Permission: Use under GNU Free Documentation License
Caption: Otto von Guericke (1602--1686) famous demonstration that teams of eight horses could not pull apart two copper hemispheres of diameter 51 cm which had been evacuated and were being held together only by ambient air pressure.
The force of air pressure sealing the hemispheres is about
pA = about (10**5 Pa)*pi*(0.5**2) = about 10**5 N = about 2000 lb.Consider that in modern horse pulling (which is not the sport of kings) pair of draft horses can pull with up to about 5000 lb of force for distances of some tens of feet, von Guericke's horses must have been feeble beasts---ponies?, nags ready for the knacker.
See Horse Pulling Records and Midwest Dynamometer Horse Pulling for horse pulling records and images.
Credit:
Permission: Public domain at least in USA.
Image linked to the Museum of Vacuum.
Videos
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Hydrogen economy videos:
- The Promise and Challenge of the Hydrogen Economy Good. Too long for the classroom.
- Artificial Leaf at MIT The artifical leaf is an example of artificial photosynthesis. In the case of the artificial leaf, one has specifically photocatalytic water splitting or photoelectrolysis. It's not quite as bad as watching paint dry. Suitable for the classroom.
- Hindenburg Disaster Footage (With Herbert Morrison Commentary) The full show. Too long for classroom.
- The Hindenburg Explosion Newsreel style. Suitable for classroom.
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Nuclear bomb videos
- Tsar Bomba - Largest Nuclear Device Ever Tested (50MT) It's a lot like Dr. Strangelove (1964) for real.
- Atomic Bomb Footage Light heat flash before the shock wave arrives. Short enough for classroom.
- Christmas Island Atomic Bomb Test Short enough for classroom.