Alcohol lamp
oten
Because it makes the apparatus black when heating
sun is the primary source of heat and light......
The sun is the source of heat and light for plant-life.
We're modestly familiar with the source of heat and light. And we know that heat and light both exist and are real. Cold and darkness do not exist. They merely describe the lack of heat and light, respectively.
The main source of light is the sun
the sun?
Yes, the sun is the origin of heat and light in our biosphere.
A light source is a form of energy produced by heat.
both
The planet get its light from their internal heat source.
sun