1. Dmitri Mendeleev, Periodic Table. Dmitri Mendeleev (1834–1907) wanted to organize the 65 known elements somehow. He knew there was a pattern to be discerned, and it had something to do with atomic weight, but the pattern remained elusive. Then, Mendeleev later reported, "In a dream I saw a table where all the elements fell into place as required. Awakening, I immediately wrote it down on a piece of paper.” Mendeleev’s words were quoted in "On the Question of Scientific Creativity,” by Russian chemist B.M. Kedrov.

This was how the periodic table was formed. The arrangement he saw in his dream was so accurate, it even revealed that some elements had been incorrectly measured; they were placed in his periodic table according to their atomic weight, which wasn’t even known yet.

2. Niels Bohr, Atomic Model

"Niels Bohr [1885–1962]reports that he developed the model of the atom based on a dream of sitting on the sun with all the planets hissing around on tiny cords,” according to a paper titled "Pillow-Talk: Seamless Interface for Dream Priming Recalling and Playback,” by Edwina Portocarrero at the Massachusetts Institute of Technology (MIT) and co-authors.

3. Elias Howe, Sewing Machine

Elias Howe (1819–1867) is often credited with inventing the sewing machine, though in reality he significantly improved previous designs and received the first U.S. patent for a sewing machine using the lockstitch design. It was a major development in creating the modern sewing machine. Before a breakthrough came to him in a dream, however, he was stuck on the problem of where to place the eye of the needle.

His dream is recorded in a family history titled, "The Bemis History and Genealogy: Being an Account, in Greater Part, of the Descendants of Joseph Bemis of Watertown, Massachusetts:” 

"He almost beggared himself before he discovered where the eye of the needle of the sewing machine should be located. … His original idea was to follow the model of the ordinary needle, and have the eye at the heel. It never occurred to him that it should be placed near the point, and he might have failed altogether if he had not dreamed he was building a sewing machine for a savage king in a strange country.

"Just as in his actual waking experience, he was perplexed about the needle’s eye. He thought the king gave him twenty-four hours in which to complete the machine and make it sew. If not finished in that time death was to be the punishment. Howe worked and worked, and puzzled, and finally gave it up. Then he thought he was taken out to be executed.

"He noticed that the warriors carried spears that were pierced near the head. Instantly came the solution of the difficulty, and while the inventor was begging for time he awoke. It was 4 o’clock in the morning.

"He jumped out of bed, ran to his workshop, and by 9, a needle with an eye at the point had been rudely modeled. After that it was easy.”

4. Albert Einstein, Speed of Light

"Einstein said his entire career was an extended meditation on a dream he had as a teenager,” explained the Rev. John W. Price in an interview with John H. Lienhard, professor emeritus of mechanical engineering and history at the University of Houston, on the radio show "Engines of Our Ingenuity.”

"He dreamt that he was riding a sled down a steep, snowy slope and, as he approached the speed of light in his dream, the colors all blended into one. He spent much of his career, inspired by that dream, thinking about what happens at the speed of light.”

5. Friedrich August Kekulé, Molecular Structure of Benzene

Friedrich August Kekulé (1829–1896) developed a structural theory in chemistry (related to the bonding order of atoms in a molecule) that was integral to the development of organic chemistry.  Dozing on a bus, a vision that provided a starting point for this theory appeared to him, as recorded in "Serendipidty, Accidental Discoveries in Science,” by Royston M. Roberts:

"I was returning by the last bus, riding outside as usual, through the deserted streets of the city. … I fell into a reverie, and lo, the atoms were gamboling before my eyes. Whenever, hitherto, these diminutive beings had appeared to me, they had always been in motion. Now, however, I saw how, frequently, two smaller atoms united to form a pair; how a larger one embraced the two smaller ones; how still larger ones kept hold of three or even four of the smaller, whilst the whole kept whirling in a giddy dance. I saw how the larger ones formed a chain, dragging the smaller ones after them but only at the ends of the chains. …The cry of the conductor, ‘Clapham Road,’ awakened me from my dreaming; but I spent a part of the night in putting on paper at least sketches of these dream forms.”

Neuroscience Is Born

Dr. Otto Loewi, hailed as the "father of neuroscience,” had a theory that there might be a chemical transmission of the nervous impulse. But he couldn’t envision how to prove it.

In 1920, he had two dreams over the course of two consecutive nights in which the design for an experiment to prove his theory appeared to him, according to the BBC. This started him on a course that would win him the Nobel Prize for medicine in 1936.

A Cosmetic Recipe That Made History

Madame C. J. Walker was the first African-American millionairess in America. She said the secret to her success came to her in a dream. At the turn of the 20th century, she began selling Madam Walker’s Wonderful Hair Grower, a scalp conditioning and healing formula. She had begun to lose her hair and after trying products already on the market without success, she developed her own.

She told a reporter, according to the book "Madam C. J. Walker: Entrepreneur” by A’Lelia Perry Bundles, "[God] answered my prayer, for one night I had a dream, and in that dream a big black man appeared to me and told me what to mix up for my hair. Some of the remedy was grown in Africa, but I sent for it, mixed it, put it on my scalp, and in a few weeks my hair was coming in faster than it had ever fallen out. I tried it on my friends; it helped them. I made up my mind I would begin to sell it.”

A Strange Fish

Biologist and geologist Louis Agassiz (1807–1873) studied an obscure impression of a fossil fish in rock without gaining significant insight as to its characteristics. He was hesitant to chisel away the stone without an idea of the fish’s structure in case he were to irreparably damage the specimen.

He had three dreams over three consecutive nights in which he saw the fish with all its original features restored, reported his wife, Elizabeth Agassiz, in "Louis Agassiz: His Life and Correspondence.” On the first two nights, he couldn’t hold the image in his mind upon waking. But on the third night, he was prepared with paper and pencil to record the vision.

His wife wrote: "He hastened to the Jardin des Plantes, and, with his drawing as a guide, succeeded in chiseling away the surface of the stone under which portions of the fish proved to be hidden. When wholly exposed it corresponded with his dream and his drawing, and he succeeded in classifying it with ease. He often spoke of this as a good illustration of the well-known fact, that when the body is at rest the tired brain will do the work it refused before.”

Indian Village Boy’s Visions Make Him a Famed Mathematician

Srinivasa Ramanujan was born to a poor family in South India in 1887. Legend has it that a goddess appeared to him in his dreams to give him mathematical formulae, which were not understood by people he showed them to in India, but which stunned G.H. Hardy of Cambridge University in England to whom Ramanujan wrote a letter in 1913.

Indian-American mathematician Krishnaswami Alladi wrote about these events in his paper "Srinivasa Ramanujan: Going Strong at 125″ in the December 2012 Notices of the American Mathematical Society. He also described Ramanujan as "a self-taught genius, … one of the greatest mathematicians in history, and one of the most romantic figures in the mathematical world.” 

Ramanujan’s mother also had a dream that made her son’s success possible. Thayer Watkins, an economics professor at San José University, wrote in a paper titled "Srinivasa Ramanujan, a Mathematician Brilliant Beyond Comparison,” of a dream that allowed Ramanujan to go to Cambridge: "Ramanujan’s mother had a dream in which she saw her son sitting amongst a group of Europeans with a big halo surrounding him. This convinced her that it was alright for her son to travel to England.”