The ratio of the power of a light source $S_{1}$ to that the light source $S_{2}$ is $2 S_{1}$ is emitting $2 \times 10^{15}$ photons per second at 600 nm . If the wavelength of the source $S_{2}$ is 300 nm , then the number of photons per second emitted by $S_{2}$ is $\times 10^{24}$.