The answer is apogee my dude
Vacum flask has inner layer of glass and outer body of plastic.the glass has a reflective metal layer..when a hot drink is poured into the flask it prevents conduction.tight lid stops the convection.when radiation tries to leave the hot drink the reflective layer of the glass reflects it back so no heat can escape.
Is there a equation or something so I can do the math of how many flowers there are at the end of the two monthsm
C.
Explanation: Because mirrors are lighter, and they are easier than lenses to make perfectly smooth.
