It could be a Siemens hearing instrument, patented in 1924 or a Western Electric Model 34A Audiphone Carbon Hearing Aid (pictured below).

And the same explanation for this video from 1938, showing a crowd exiting a factory in Massachusetts, 1938:

(via Hearing Aid Museum)

The time slip of Air Marshal Sir Robert Victor Goddard over the former Royal Air Force station Drem Airfield in 1935

"In 1935, while still a Wing Commander, he was sent to inspect a disused airfield near Edinburgh at a place called Drem. He found it in a very dilapidated state with cattle grazing on grass that had forced through cracks in the tarmac.

Later that day, he ran into trouble while flying his biplane in heavy rain and decided to fly back to Drem to get his bearings.

As he approached the airfield the torrential rain abruptly changed to bright sunlight. When he looked down he saw the airfield had been completely renovated and was now in use. There were mechanics in blue overalls walking around and four yellow planes parked on the runway. One of these was a model which, for all his aviation experience, he completely failed to recognize." – according to Time Travel: A New Perspective, by J. H. Brennan

Four years later, RAF began to paint their planes yellow and the mechanics uniforms were switched to blue.

(via Planes and Choppers and Scotlands Places)

The man often called Time Traveling Hipster from the reopening ceremony of South Forks Bridge in Gold Bridge, British Columbia, Canada, 1941

That type of sunglasses with leather side shields were used since the 1920s and he's wearing the sweater of a hockey team instead of a modern T-shirt, but it's still a cool photo!

(via Forgetomori)

The Philadelphia Experiment, 1943

There were no such experiments, of course, but some reports stated that U.S. Navy destroyer escort USS Eldrige travelled back in time for about 10 seconds on October 28, 1943.

(via Wikimedia Commons)

Henry Fonda and Shirley Temple checking their stagecoach route on an iPhone in the movie Fort Apache (1948)

We promise that they used Google Maps instead of Apple's Maps app.

The Fentz legend, 1950s

This urban legend is about a man in his early thirties named Rudolph Fentz, who was hit by a taxi and fatally injured at New York City's Time Square in mid-June 1950, dressed in the fashion of the late 1800s. In his pockets there were a copper token for a beer, a bill for the care of a horse and the washing of a carriage, a letter from 1876, 70 dollars and business cards, all without any signs of aging. A NYPD policeman found a person who was disappeared in 1876 in the age of 29.

The story originated in a 1951 sci-fi short story by Jack Finney, but the legend has been reported since the 1970s as an evidence for the existence of time travel.

(via Transpress NZ)

The Mountauk Project conspiration theory

The Montauk Air Force Station reportedly has a real time tunnel in its subterranean laboratory that allowed scientists to travel back to 1943. This story started with two men, the author Preston B. Nichols and Al Bielek in the 1980s, when they had begun to "recover repressed memories of working in the lab".

(via Wikimedia Commons)

Time-traveler busted for insider trading, March 2003

The story originated with the Weekly World News, but appeared in some newspapers after Yahoo reprinted it two weeks later:

[…]"The fact is, with an initial investment of only $800, in two weeks' time he had a portfolio valued at over $350 million. Every trade he made capitalized on unexpected business developments, which simply can't be pure luck."

"The only way he could pull it off is with illegal inside information. He's going to sit in a jail cell on Rikers Island until he agrees to give up his sources."

The past year of nose-diving stock prices has left most investors crying in their beer. So when Carlssin made a flurry of 126 high-risk trades and came out the winner every time, it raised the eyebrows of Wall Street watchdogs. […] Carlssin declared that he had traveled back in time from over 200 years in the future, when it is common knowledge that our era experienced one of the worst stock plunges in history. Yet anyone armed with knowledge of the handful of stocks destined to go through the roof could make a fortune.

"It was just too tempting to resist," Carlssin allegedly said in his videotaped confession. "I had planned to make it look natural, you know, lose a little here and there so it doesn't look too perfect. But I just got caught in the moment." […] – according to a Yahoo Entertainment article, found in the Internet Archive here.

(via Engelcast and Snopes)

The story of John Titor

A man, appeared on some online bulletin boards in 2000 and 2001, and claiming to be a time traveler from 2036. He made numerous predictions about events after 2004 and often described his time machine.

None of those events have happened yet.

(via Stranger Dimensions)

The story of Håkan Nordkvist, who just met with an older version of himself, 2006

Nordkvist slipped through a wormhole in his kitchen and met an older man who had the same tattoo as Håkan. He just knew that no one's going to believe this — so he filmed the encounter.

As everyone later discovered, this was just part of an advertising campaign of the Swedish insurance company AMF, made by Forsman & Bodenfors.

(via Forsman&Bodenfors)