Category Archives: Engineering

Q: Could the tidal forces of the Sun and Moon be used to generate power directly?

The original question was: If a machine enclosed in a building could, as I think it could, detect the tidal forces of the sun and moon upon the Earth could the effect be used to extract useful energy from those … Continue reading

Posted in -- By the Physicist, Astronomy, Engineering, Physics | 5 Comments

Q: Does opening a refrigerator cool down the room?

Physicist: Briefly yes, or no, not at all.  If you think of the room as including the inside of the refrigerator, then opening the door does nothing.  Otherwise, it does almost nothing.  But ultimately, if you leave the door open … Continue reading

Posted in -- By the Physicist, Engineering, Entropy/Information, Physics | 10 Comments

Q: How are voltage and current related to battery life? What is the difference between batteries with the same voltage, but different shapes or sizes? What about capacitors?

Physicist: Chemical batteries use a pair of chemical reactions to move charges from one terminal to the  other with a fixed voltage, usually 1.5 volts for most batteries you can buy in the store (although there are other kinds of … Continue reading

Posted in -- By the Physicist, Engineering, Physics | 9 Comments

Q: How many people riding bicycle generators would be needed, in an 8-hour working day, to equal or surpass the energy generated by an average nuclear power plant?

Physicist: A person on a bike can optimistically generate around 200 watts, and an average nuclear power plant generates 800 MW of power (although a big nuclear power plant generates many times more power than a small one). Given those … Continue reading

Posted in -- By the Physicist, Engineering | 1 Comment

Q: Since the real-world does all kinds of crazy calculations in no time, can we use physics to calculate stuff?

The original question was: I’ve heard somewhere that they’re also trying to build computers using molecules, like DNA. In general would it work to try and simulate a factoring algorithm using real world things, and then let the physics of … Continue reading

Posted in -- By the Physicist, Computer Science, Engineering, Entropy/Information, Physics | 6 Comments

Q: Can light be used to transfer energy instead of power lines?

The original question was: Is it possible that, when more efficient methods of harnessing light energy are established, light could be used as a means to transfer massive amounts of energy (for instance, enough to power a city) without physical … Continue reading

Posted in -- By the Physicist, Engineering, Physics | 6 Comments