Conservatories use bent glass to blend the beauty of an exterior garden with an indoor atrium. A conservatory is a structure with a glass or plastic roof and frequently glass or plastic walls. The conservatory is heated using incoming visible solar radiation from the sun, which is then absorbed by plants, soil, and other things inside the structure. Bent glass is transparent to this radiation, therefore the warmed structures and plants inside the conservatory re-radiate this energy in the infra-red, to which bent glass is partly opaque, causing that energy to be trapped inside the conservatory. Although there is some heat loss due to conduction, there is a net increase in energy, and therefore temperature, inside the conservatory. Air warmed by the heat from hot interior surfaces is retained in the building by the roof and wall. Bent glass can be used in conservatories as a barrier to airflow to trap energy within the conservatory, which results in heating both the plants and the ground inside it. This warms the air near the ground, and this air is prevented from rising and flowing away.