# First story to mention the speed of light?

Not necessarily traveling at light speed. (Although that would certainly count, I suspect traveling at the speed of light or nearly so is a 20th century thing.)

Very interesting would be a story in which the speed of light is mentioned as the maximum speed possible, but that is so depressing to many fans as well as being fairly sophisticated that it may have not shown up until, say, the 1950s.

• No book published before 1905 can completely answer your question as that's the year Einstein determined that the speed of light could not be exceeded. (Source)
– JBH
Commented Feb 13, 2023 at 7:02
• @jbh: i do not know a couple of things: 1. whether in 1905 einstein knew that c was maximum speed and 2. whether his predecessors (like the great and underrated Heaviside) already suspected this -- as early as the 1890s (or 1880s?) time dilation (for an electron at least) was already being discussed and this might imply the ultimate speed thing. that special relativity was anticipated well before Einstein put all the pieces together needs to be understood by more people -- i was well into middle age before I read of Heaviside's (and others') ideas from the 19th century. Commented Feb 13, 2023 at 8:00
• "Ole Rømer first demonstrated in 1676 that light travels at a finite speed (non-instantaneously) by studying the apparent motion of Jupiter's moon Io." en.wikipedia.org/wiki/Speed_of_light So we should be able to find references around that time Commented Feb 13, 2023 at 20:40
• @releseabe Your question doesn't brook speculation or suspicion. You wanted to know the earliest story where c was mentioned as the maximum speed possible. There's a difference between knowing it has a finite speed (doesn't travel infinitely fast or instantaneously) and knowing there is no faster speed than X. I get your point, but stand by my date. You'll find examples of it having finite speed, but no examples suggesting a maximum speed.
– JBH
Commented Feb 14, 2023 at 5:17
• It was known from the early 1860s, when Maxwell published his equations, that there was something weird about c (the speed of light), but at that stage it wasn't clear what those equations were telling us when they said that c is a constant. By the late 1880s, the Lorentz transformation equations showed that near lightspeed mass & time don't behave according to Newton, but it was still a bit hazy what those equations really meant, until Einstein. Commented Feb 14, 2023 at 11:08

The earliest concrete reference to the speed of light in science fiction I can find is A Thousand Years Hence; Being Personal Experiences as Narrated by Nunsowe Green, Esq., F.R.A.S., F.S.S., ex V-P.S.S.U.D.S. (Ex Vice-President of the Shoreditch and Spitalfields Universal Discussion Society), published in 1882. You can find the book at the Internet Archive.

By this great discovery of cross-electric speed, we were enabled to despatch the electro-light motor into far-off space, to overtake the ordinary light on its image or picture-carrying mission. It was not, however, until the further discovery of the Duplication of the Cross-Electric that we could bring back the over-taken picture — as, for instance, that of our little earth, as it was when the light quitted it so many years or so many ages past. Indeed, the vastly greater speed thus attained made us at last regard, with something like contempt, the old ordinary light-speed of about one hundred and eighty thousand miles in a second. But what a grand field, as we may suppose, now opened upon our ancestors, in bringing back the past aspects of the world! And these, as we shall afterwards see, could be restored by high scientific manipulation, even to the actual life dimensions.

Credit to the Historical Dictionary of Science Fiction for this one.

Note that this does not acknowledge the speed of light as an absolute limit; that would have to be sometime later, at least after the development of the Lorentz Group of transformations and Einstein's formulation of Special Relativity (both 1905).

• That's funny - I read a story a few years ago about a mission traveling to a location where gravitational lensing could be used to view a civilization that had been extinct for millions of years, and I thought the idea of moving your telescope to get ahead of 'old' light was clever. Funny to hear that the idea was over a century old. Commented Feb 12, 2023 at 20:44
• Is that also pre dating radio broadcasts by about 3 years? Or am I misunderstanding the "picture carrying missing" Commented Feb 14, 2023 at 0:08

In E.E. Smith's The Skylark of Space Chapter VII "The Trial Voyage" there is the following discussion of the spaceship's possible speed.

To hold down the power-plant, so that the bar won't tear through the ship when we cut her loose," replied Seaton. "Have you any idea how fast this bird can fly?"

"Well, I have heard you speak of traveling with the velocity of light, but that is overdrawn, isn't it?"

"Not very much. Our figures show that with this four-hundred-pound bar"—pointing to the copper cylinder in the exact center of the inner sphere—"we could develop not only the velocity of light, but an acceleration equal to that velocity, were it not for the increase in mass at high velocities, as shown by Einstein and others. We can't go very fast near the earth, of course, as the friction of the air would melt the whole works in a few minutes. Until we get out of the atmosphere our speed will be limited by the ability of steel to withstand melting by the friction of the air to somewhere in the neighborhood of four or five thousand miles per hour, but out in space we can develop any speed we wish, up to that of light as a limit."

"I studied physics a little in my youth. Wouldn't the mere force of such an acceleration as you mention flatten you on the floor and hold you there? And any sudden jar would certainly kill you."

So the characters are certainly aware that Einstein had calculated that mass would increase with velocity so that it would be impossible to reach the speed of light.

In Chapter VIII "Indirect action":

Regaining his self-possession as the wisdom of his friend's advice came home to him, Seaton sat down and pulled out his pipe. There was a tense silence for an instant. Then he leaped to his feet and darted into his room, returning with an object-compass whose needle pointed upward.

"DuQuesne did it," he cried exultantly. "This baby is still looking right at him. Now let's go—make it snappy!"[531]

"Not yet. We should find out how far away they are; that may give us an idea."

Suiting action to word, he took up his stopwatch and set the needle swinging. They watched it with strained faces as second after second went by and it still continued to swing. When it had come to rest Crane read his watch and made a rapid calculation.

"About three hundred and fifty million miles," he stated. "Clear out of our solar system already, and from the distance covered he must have had a constant acceleration so as to approximate the velocity of light, and he is still going with full...."

"But nothing can possibly go that fast, Mart, it's impossible. How about Einstein's theory?"

"That is a theory, this measurement of distance is a fact, as you know from our tests."

"That's right. Another good theory gone to pot. But how do you account for his distance? D'you suppose he's lost control?"

Smith first wrote The Skylark of Space between 1915 and 1921. The quotations are from the Project Guttenburg text.

This etext was produced from Amazing Stories August, September and October 1928. Extensive research did not uncover any evidence that the U.S. copyright on this publication was renewed.

Other notes and a list of corrections made will be found at the end of the book.

https://www.gutenberg.org/files/20869/20869-h/20869-h.htm#CHAPTER_V

So any earlier science fiction mention of the Speed of light or of Einstein's theory of relativity stating that the speed of light was the absolute speed limit will have to be published before The Skylark of Space in 1928.

David W.'s answer has a mention of the speed of light, but not as any sort of absolute speed limit, from 1882.

So the first mention of the speed of light in science fiction was in 1882 or earlier, while the first mention of the speed of light as an absolute speed limit would be sometime between 1882 and 1928.

The Skylark of Space was one of the earliest stories of interstellar travel but not the very first. So there are several possibilities to check for earlier mentions of the speed of light as a cosmic speed limit.

• "we could develop not only the velocity of light, but an acceleration equal to that velocity, were it not for the increase in mass at high velocities, as shown by Einstein and others." Ouch! Didn't Smith have a PhD? Apples and oranges... Commented Feb 13, 2023 at 16:16
• @GeneralElectron That made me cringe too. I wonder if Smith was using "equal to" in the colloquial sense of "able to meet the challenge" - i.e. acceleration strong enough to reach c reasonably quickly.
– G_B
Commented Feb 14, 2023 at 22:56
• @GeneralElectron: Seems like huge variation of education among scifi writers. Some were real scientists; some knew apparently nothing. I think Wells had some science classes but did not work as a researcher -- he still managed to be very creative and prescient on more than one occasion. Commented Jun 12, 2023 at 7:09