The Guardian publishes a physics-based puzzle about keeping a room cool during a summer heatwave, focusing on how curtains affect heat flow. The puzzle asks how drawing curtains all day can reduce the temperature inside.
In the solution, the outlet describes a room with curtains over windows. When sunlight is present, the Sun’s energy enters through the windows and is absorbed by the curtains. As the curtains warm up, they eventually reach an equilibrium temperature where their own radiation balances the rate at which they absorb heat.
The explanation adds that at this equilibrium, the curtains radiate the absorbed energy back in two directions: roughly half of the radiated heat goes back toward the window and roughly half goes into the room. By blocking direct solar heating of the interior surfaces and by redistributing how the absorbed energy is released, the curtains reduce the net heat entering the room compared with leaving the window uncovered.
The article presents the scenario as a conceptual “think like a physicist” exercise rather than a new scientific study.
