Ancient Stellar Light Analysis · AI Generator #GEN-A99E6B0E

Physics · modern-physics

Problem

An astronomer discovers light from a distant star that has been traveling through space for 13 billion years. Due to the expansion of the universe, this ancient starlight has been redshifted from its original wavelength of

\lambda_0 = 500\;\text{nm}

(green light) to

\lambda = 1400\;\text{nm}

(infrared). When this infrared light hits a photodetector made of silicon, it must have enough energy to excite an electron across the band gap. Silicon has a band gap energy of

E_g = 1.12\;\text{eV}

. Will the redshifted photons from this ancient star have enough energy to be detected by the silicon photodetector?

Browse the problem library