how do you make it have good acoustics? what do you have to do?
Depends on the wavelength of the I.R. Visible wavelengths are 400-700 nm or 0.4-0.7 microns. I.R. from 0.7 microns to around 3 or so microns is mostly transmitted through glass. I.R. at longer wavelengths than this is mostly absorbed by glass. If a detector is sensitive only to this longer-wave I.R., it will not detect objects behind glass. However, detectors that are sensitive to near-I.R. can detect objects behind glass. As for you question about greenhouses: Room- and body-temperature objects emit I.R. at wavelengths considerably longer than 3 microns, so this radiation is trapped by glass in greenhouses. An object as hot as the sun emits mostly visible and near-I.R., so the sunlight passes through the greenhouse windows and is absorbed by objects inside the greenhouse. Hope this helps.
In the same time when babies most often wore cloth diapers which necessitated the safety pins, it was also most common for clothing to be hung out on a line to dry instead of in a clothes dryer. And since newborn babies pee, poop, and puke all over themselves, moms had a lot more laundry to do.
