Albert Einstein

Albert Einstein was a renowned scientist of the 20th century. According to the First Doctor, there was "none more famous". (PROSE: The Long Step Backward)

Einstein was best known for devising his Theory of relativity. (TV: Four to Doomsday) The Doctor called the theory "absurd", and said he'd "tr[ied] to explain the realities to poor old Albert, but he would insist that he knew best." (TV: The Stones of Blood)

Sherman thought that Einstein came close to the theory of time travel, but lost it with the "three rivers" theory. (AUDIO: The Way Forwards)

History
In 1905, Albert Einstein came up with the mathematical scientific conclusion of E=MC². (TV: The Lie of the Land)

From 1911 to 1912, Einstein held the position of professor of theoretical physics at Charles University in Prague. (PROSE: The Long Step Backward)

The Fourth Doctor claimed to have met Einstein. (TV: The Stones of Blood)

At some point, Einstein had a non-denominational wedding, officiated by the Doctor. As the Thirteenth Doctor recalled, Einstein's parents did not approve of the union. (TV: Demons of the Punjab)

Einstein worked with other scientists at the Kaiser Wilhelm Institute in Berlin, Germany. However, by January 1933, he had left Germany and travelled to the United States of America in response to the rise of Adolf Hitler and the Nazis. (AUDIO: The Alchemists)

In the 1940s, kidnapped Einstein and brought him to Lakertya so that his genius could be used to help create her time brain. Afterwards, the Seventh Doctor boarded him on his TARDIS in order to bring him back to his right time; the curiosity of the scientist was aroused by the console room, and the Doctor promised to his old friend that he would "explain how it work[ed] later". (TV: Time and the Rani)

The Eighth Doctor mentioned knowing Einstein. (PROSE: The Eye of the Tyger)

The Eleventh Doctor once claimed to have attended a party at Frank Sinatra's hunting lodge with Einstein and Father Christmas. He produced a photograph of them as proof. (TV: A Christmas Carol)

Other encounters between Einstein and the Eleventh Doctor included Einstein trying to steal the Doctor's TARDIS and having his toothbrush taken by the Doctor and "exterminated" by the Daleks. Einstein also left his bicarbonated processing machine somewhere in the TARDIS.

While working on a malfunctioning time machine of his own in 1945, Einstein was accidentally brought onboard the TARDIS in an accident involving the TARDIS console and the Doctor's new fez (which Einstein had been the original owner of) along with his fez and a flask of experimental liquid which he hoped was bionic fusion liquid. Einstein was momentarily transformed into an Ood by his liquid, before being changed back and returned home by the Doctor; the mishap had resulted in Einstein's hair standing on end, a look which the Doctor recommended he keep as "more sciencey". (TV: Death Is the Only Answer)

The Eleventh Doctor later said he liked Einstein, as he was a bow tie wearer. (TV: A Night with the Stars)

Other references
Ian Chesterton once told the First Doctor that he "rattle[d] off explanations that would have baffled Einstein." (TV: The Executioners)

The Third Doctor told Tom Osgood that the device he had built to penetrate the heat barrier surrounding Devil's End was as simple as Einstein's Theory of relativity. (TV: The Dæmons)

In 1979, Kerensky tried to quote Einstein to answer-back Count Scarlioni's requests. (TV: City of Death)

Peri Brown said, "You don't need to be Albert Einstein to find the off switch" of the Master's control box, conveying she was able to. (TV: Planet of Fire)

The Sixth Doctor used the alias "Albert Einstein" when meeting with Charles Darwin in the Galápagos Islands in 1835. (AUDIO: Bloodtide)

Plotting to destroy Earth's solar system in 1639, the Eleven noted that, among others, Albert Einstein would never be born. (AUDIO: The Satanic Mill)

Chris Parsons told the Doctor that he didn't believe they just travelled hundreds of light-years, since according to Einstein, it was impossible to travel faster than light. The Doctor replied that he had a lot to unlearn. (PROSE: Shada, AUDIO: Shada, WC: Shada)

Some compared the child prodigy, Nathan Goss, to Einstein, while others believed his potential exceeded Einstein. (TV: The Lost Boy) Luke Smith could spot flaws in Einstein's theory of relativity. (PROSE: The Lost Boy)

When Mr Smith was about to self-destruct, Clyde Langer asked Luke Smith what would Einstein do. Rani Chandra reminded Clyde that Einstein "didn't have an alien computer in his room that turns into a bomb". (TV: Prisoner of the Judoon)

Criticizing the Ninth Doctor's clothing style, Jackie Tyler questioned if he ever showed up to meet Einstein "without a stitch on", and wondered how Einstein would react. (AUDIO: Retail Therapy)

In 2010 London, the Tenth Doctor discussed about Einstein's Theory with Spike and other boys whose brains were enhanced by the alien Brainy Crisps. (PROSE: Code of the Krillitanes)

The Eleventh Doctor used Einstein as an example of great people who had dyslexia in order to encourage Elliot Northover to continue trying. (TV: The Hungry Earth) He mentioned Einstein as one of humanity's finest minds who had been drawn to Prague. (COMIC: The Broken Man) He once defined himself "a time traveler with an IQ as big as Einstein's quantum pants". (COMIC: The One)

After the Monks took over Earth they began altering people's memories so that it looked as if they had always been there. Amongst altered history was Einstein's conclusion of E=MC² to make it look like the Monks helped him. (TV: The Lie of the Land)

Behind the scenes
Jim Norton played a holographic version of Einstein in Star Trek: The Next Generation.