I have found squirrel-cage fans are quieter than box fans, but are generally bulkier. Some box fans are quieter than others, usually the ones with less blades. They may have specs for noise so that you can compare.
I've heard of cases where the builder didn't put in return ducts where they should have. You need a thermostat in the upper floors that determines when the AC unit runs, and you need one in the lower floors to determine when/if to open a duct to the lower floors. In the winter it will be...
As one who has had posts deleted, this is a strong put off. That's why I seldom get on this site. I think it would be better to reply to the person, "this did not contribute to the thread" rather than delete the post and the thumbs up that came with it.
How many times in the history of science has the current understanding been wrong, only to be changed by future discoveries? Take the Big Bang theory for instance. The recent JWST discoveries have challenged that.
Space without matter still has fields: electromagnetic field, gravitational field, Higgs field, etc. It also has energy, so "empty" space isn't nothing.
Alpha waves and other types of waves are involved with dreams and consciousness. There is much to be learned about the human brain. Here is a start:
https://www.sciencedirect.com/topics/neuroscience/alpha-wave
Certainly I did. From the link in the OP:
"Early VTOL experimental aircraft operated from open grids to channel away the engine exhaust and prevent thrust loss from HGI.
The Bell X-14, built to research early VTOL technology, was unable to hover until suckdown effects were reduced by raising...
If the antenna has no ground radials, then the ground on the end of the coax is an important part of the antenna. Otherwise it is only for lightning protection. A 10' piece of chain-link fence pipe is cheaper than an 8' copper rod, and will make a better ground. A hammer-drill will work well for...
The diode serves no useful purpose and looks to be in backwards, but no polarity of voltage is shown. There is little current limiting in the circuit, so the transistor may fail from excess current, except that the transistor has no bias. The inductor is a very poor antenna. How does it work...
Unknown. I take it the signal has not been re-observed.
https://www.msn.com/en-us/news/technology/alien-hunters-detect-mysterious-radio-signal-from-nearby-star/ar-BB1c3rJU
They didn't give the bandwidth. That would be an interesting fact. But it has no modulation and it drifts. Those facts don't suggest ETI, so it's most likely natural. It sounds like they have almost ruled out Earth sources. If they do, it is something that will teach us something with enough study.