At least two or three times a month, I see back in time.

Sometimes I’m even able to overhear entire conversations.

I know it sounds hard to believe, but it’s true.

I’ve been able to see New York City in 1911 as people and cars dart about... and Paris in the 1890s when horse-drawn carriages were everywhere.

I’ve watched in horror as thousands of French soldiers marched back home after the worst battles of World War I.

Once I was even able to see what San Francisco looked like right after the earthquake of 1906.

I’ve used my time-searching device to spy on Woodrow Wilson in the Oval Office in 1917... and to watch Winston Churchill deliver his “The End of the Beginning” speech in 1942.

The time-travel technology I use does have its limits, however.

For one thing, it can only see back about 140 years to the 1880s.

The visual clarity is sometimes stunning but the audio is usually quite poor.  

Yet this technology is truly a window back in time.

I am referring, of course, to the tens of thousands of historical videos now available on YouTube.

While my family and friends use YouTube for many different reasons, I usually watch high-definition, colorized, speed-corrected home movies and newsreels taken by photographers in the late 19th and early 20th centuries.

Until very recently, to see footage such as this you had to travel to government archives and museums in faraway cities, and you often needed credentials as a scholar or journalist.

It could take days, even weeks to see a single newsreel.

Now, you can watch thousands of these precious snippets of lost time on your favorite smart phone.

The things you can find are astonishing.

Among my favorites are the Go-Pro-like travelogues, taken by cameras mounted on automobiles, around Berlin, Paris and New York around 1910.

The scenes of Berlin in 1910... and in the weeks right after the World War II stopped in 1945... will amaze you.

The Germans took high-resolution film images, sometimes in color. As a result, the people you see in these videos seem eerily contemporary, like people you could meet out on the street.

The earliest surviving video record you can see is of traffic over a bridge in Leeds, England, in October 1888.

I’ve used my pocket time machine to watch the Wright Brothers’ plane take off from an airfield in 1908.

I’ve seen Babe Ruth hit his 60th home run in 1927 against the Washington Senators.

I’ve watched Japanese fighter bombers attack Pearl Harbor on December 7, 1941.

 And then there are the conversations!

I’ve spent probably dozens of hours watching and listening to conversations with figures I used to know solely from books, such as Leo Tolstoy, Ernest Hemingway, George Orwell, Evelyn Waugh, James Baldwin, Bertrand Russell, Albert Camus, William Faulkner, Jean-Paul Sartre, Vladimir Nabokov, and on and on.

For some famous writers, we only have footage of them reading from their works, such as T.S. Elliot. With James Joyce, we have film footage of him strolling about Paris but audio only of him reading from Ulysses.

There is even an audio recording of America’s great poet Walt Whitman reading from his poem “America,” taken from a wax recording taken in the late 1880s. And there is video footage, but no audio, of Mark Twain taken by Thomas Edison in 1909.

Yet despite some frustrating gaps, what we actually have available through the pocket time machine boggles the imagination.

If you want, you can ‘hear and often see some of the most important people in history speaking directly to you, including Albert Einstein, Mahatma Gandhi, Thomas Edison, Winston Churchill, Theodore and Franklin Roosevelt, Ronald Reagan, and many more.

Ever been curious what the real Lawrence of Arabia was like?

Thanks to the time machine in your pocket, we have video footage of him with Arab sheiks.

The same is true of great generals such as George Patton, Dwight Eisenhower, Erwin Rommel, and Bernard Montgomery.

In fact, we have literally hundreds of hours of film footage – often in color – of the great battles of the past century, from the Battle of Somme in World War I and D Day in World War II to the Assault on Hamburger Hill in Vietnam and the Battle of Fallujah in Iraq.

In other words, rather than learning about events solely second-hand from historians and journalists, we can, thanks to this amazing time machine, often see at least some things for ourselves.

If you’re curious about Communism, you can hear interviews, unfiltered, with the people who tried to create communist societies, such as Joseph Stalin (his final speech of 1952), Che Guevara, Fidel Castro, and Pol Pot.

If you want to know why people fought so ardently against Communism, you can also listen to interviews with anti-Communist activists, including Sen. Joseph McCarthy, Whittaker Chambers, Aleksandr Solzhenitsyn, and Ayn Rand.

As a writer of popular history, I find the time machine in my pocket to be one of the most amazing resources imaginable.

But as an interested citizen of the modern world, I think this video archive is invaluable for other reasons.

If it’s true that those who fail to learn from history are condemned to repeat it, then I think it’s crucial we access the people, events and battles of the past in any way we can.

One way we can do this is with our pocket time machines, watching YouTube videos with film footage taken as much as 140 years ago.

It is time well spent.

Robert J. Hutchinson writes frequently on the intersection of politics and ideas. He is the author of the upcoming book, What Really Happened: The Lincoln Assassination.