Questions:
1. In 1643, X filled a tall cylindrical container closed at one end with liquid mercury, then turned it upside down on a basin of mercury until the container was fully vertical. The mercury in the container dropped by some height but not further, leaving behind a vacuum in the receptacle. Name X. Hint: One unit of measuring vacuum is named for him.
2. An incandescent light bulb contains a vacuum or an inert gas so that the filament doesn’t undergo a chemical reaction called _________ when it is heated to produce light. Fill in the blank.
3. The world’s first practical Y consisted of a chamber containing a vacuum, a heated cathode, and an anode. When an alternating current was applied to the circuit, electrons could only flow from the heated electrode to the unheated one. Thus Y allowed current to flow in only one direction. Name Y.
4. An important part of quantum field theory describes the vacuum of empty space as being full of _______ _________, which are subatomic particles rapidly popping in and out of existence. If these particles didn’t exist, the electron’s bare charge would be infinite. Fill in the blanks.
5. While space is mostly empty, it’s nowhere a perfect vacuum. It’s filled instead with photons — the particles of light — and _________, the second most abundant particles in the universe. Fill in the blank.
Visual:
Name the two hemispheres at the centre of the famous experiment depicted in this 1657 engraving. When they were latched, had their air pumped out, and sealed, they couldn’t be taken apart by multiple horses pulling from either side.
Answers:
1. Evangelista Torricelli
2. Oxidation
3. Diode
4. Virtual particles
5. Neutrinos
Visual: Magdeburg hemispheres
Published – December 20, 2024 11:00 am IST