In cellular biology, the concept and scientific discovery of the cell nucleus originated with early microscopic observations, culminating in its formal identification and naming by the Scottish botanist Robert Brown in 1831 when examining orchid tissues. Etymologically, the word derives from the Latin term "nucleus," meaning the kernel of a nut. In physics and astronomy, the atomic nucleus was later discovered by Ernest Rutherford in 1911, while galactic nuclei describe the dense central regions of galaxies.