Physics and if not its force
<span>1.
</span>Cones perceive
light in color while rods perceive light in black and white.
<span>2.
</span>Rods can perceive dim light, unlike cones. The rods are located at the edges of the eyes. This is why it easier to perceive an image in the dark through
the corner of the eyes.
<span>3.
</span>The discs that compose the cones are usually
partially open to the surrounding vitreous
fluid while those of the rods are closed.
They use radiometry and pyrometry
NASA uses the Transiting Exoplanet Survey Satelite (TESS) telescope that employes this technology
This telescope measures the brightness/luminosity of stars. When this brightness drops regularly, every more or less in the same number of years, then there is the likelihood of a planet orbiting the star. The dip in brightness of the star is directly proportional to the size of the planet and the distance between the star and the orbiting planet.
The first one is 100% and the second one is 50%