What was John Tyndal's scientific contribution in 1859?

John Tyndall's significant scientific contribution in 1859 was his experimental demonstration of the selective absorption of radiant heat (infrared radiation) by various gases. He showed that gases like water vapor, carbon dioxide, and ozone are strong absorbers of this radiation, while major atmospheric gases like oxygen and nitrogen are not. This work was crucial for understanding the greenhouse effect. The apparatus he used functioned to measure the absorption of radiation by gases, which is analogous to what a spectrophotometer does.

The correct option is the first one.

• He developed a spectrophotometer that could determine whether a gas was a greenhouse gas, and the intensity of the greenhouse gas.