an expanding universe...
What is the difference between the three pictures?
The first one was taken in 1888. The first ever picture taken by humans, of a spiral galaxy...
Isaac Roberts (27 January 1829 -17 July 1904) was a Welsh engineer and business man best known for his work as an amateur astronomer, pioneering the field of astrophotography of nebulae. He was a member of the Liverpool Astronomical Society in England and was a fellow of the Royal Geological Society. Roberts was also awarded the Gold Medal of the Royal Astronomical Society in 1895.
Most consider Roberts's magnum opus to be a photograph showing the spiral structure of the Great Nebula in Andromeda, taken on December 29, 1888. His long exposure of the Andromeda Nebula revealed that it was actually a spiral nebula, which was quite unexpected at the time. Photographs such as this changed astronomy by revealing the true form of nebulae and clusters. He published his celestial portfolio in a large format book  that is the first popular account of celestial photography of the deep sky.
The second would have been taken in the 1920s from the Yerkes Observatory in the USA.
and the third in colour was taken in the 21st century...
The quality of the image has improved somewhat, but the wonder of the space in which we live started way way back, before the greeks and the Egyptians astronomers... Going in the outback of Australia on a clear night, one can feel one could touch the stars... But the star closest to ours — the sun — is already too far...
These images are those of the Andromeda Galaxy...:
The Andromeda Galaxy is a spiral galaxy approximately 2,500,000 light-years (1.58×1011 AU) away in the constellation Andromeda. It is also known as Messier 31, M31, or NGC 224, and is often referred to as the Great Andromeda Nebula in older texts. Andromeda is the nearest spiral galaxy to our own, the Milky Way, but not the closest galaxy overall. As it is visible as a faint smudge on a moonless night, it is one of the farthest objects visible to the naked eye, and can be seen even from urban areas with binoculars. It gets its name from the area of the sky in which it appears, the Andromeda constellation, which was named after the mythological princess Andromeda. Andromeda is the largest galaxy of the Local Group, which consists of the Andromeda Galaxy, the Milky Way Galaxy, the Triangulum Galaxy, and about 30 other smaller galaxies. Although the largest, Andromeda may not be the most massive, as recent findings suggest that the Milky Way contains more dark matter and may be the most massive in the grouping. The 2006 observations by the Spitzer Space Telescope revealed that M31 contains one trillion (1012) stars, more than the number of stars in our own galaxy, which is estimated to be c. 200-400 billion.
While the 2006 estimates put the mass of the Milky Way to be ~80% of the mass of Andromeda, which is estimated to be 7.1 × 1011 solar masses, a 2009 study concluded that Andromeda and the Milky Way are about equal in mass.
At an apparent magnitude of 3.4, the Andromeda Galaxy is notable for being one of the brightest Messier objects,light pollution. Although it appears more than six times as wide as the full Moon when photographed through a larger telescope, only the brighter central region is visible with the naked eye. making it easily visible to the naked eye even when viewed from areas with moderate
When the light we see today left that far away corner of the universe, we, humans, were still hunched hairy beasts, having barely fallen off our trees. Just letting you know. And in two days time, Mr Roberts died 106 years ago...