Hacker Samy Kamkar is debuting his own open source version of a laser microphone—a spy tool that can invisibly pick up the sounds inside your home through a window, and even the text you’re typing.
if this yahoo from the internet I found in a search is right then its both:
“Glass will bock low frequency IR (red hot), but allow the passage of high frequency (white hot) IR. Hence, the heat of the sun will easily pass into a greenhouse, but once this energy is converted into low frequency heat by the objects within that absorb it, then the resulting low frequency heat is trapped. Hence, the Greenhouse Effect.”
if this yahoo from the internet I found in a search is right then its both:
“Glass will bock low frequency IR (red hot), but allow the passage of high frequency (white hot) IR. Hence, the heat of the sun will easily pass into a greenhouse, but once this energy is converted into low frequency heat by the objects within that absorb it, then the resulting low frequency heat is trapped. Hence, the Greenhouse Effect.”
That makes a lot of sense, thanks for doing the homework!