Scientists use many kinds of physical models to predict and understand that which they cannot observe directly. Physical models range from the Bohr model of the atom to models of the universe, which illustrate planets' orbits around the sun. Usually, models make something very small larger or something large smaller.
While the Bohr model of the atom is not accurate in its portrayal of the nature of the orbits of the electrons, it was the first physical model that incorporated quantum theory and provided an understanding of electron behavior, according to Encyclopedia Britannica. Each physical model has its own limitations and does not always provide a complete representation of what occurs in nature.
The double-helix is a physical model of DNA that aids scientists in visualizing the structures of DNA and its function in gene reproduction. The creation of this model, like many others, was dependent on the use of experimental data.
Scientists often use computer generated models in conjunction with physical models. Although there are limitations, computer generated models can provide greater detail than physical models. For example, a computer model of the universe, described by The Atlantic, is rendered as a cube with 350 million light years on each side, built from 12 billion three-dimensional pixels. Attempting to capture the universe's size with a physical model would yield a much less impressive result.