Watch–and especially listen–to the above clip. It is the opening scene from the 1997 film Contact, directed by Robert Zemeckis and based on the novel by Carl Sagan, and it’s one of the most epic openers in movie history.

It’s also a trip through history. In this amazing scene, created almost entirely with CGI, “you” are moving away from Earth at greater than the speed of light, and you’re passing through the Earth’s “radio bubble”–an expanding spherical cloud of radio transmissions that is rippling outwards from our planet at the speed of light. This is not science fiction. It’s real. If you were to move through the radio bubble, as depicted here, and were listening on a radio, you could hear transmissions from Earth in what seem like real time, but which in fact happened decades ago, the longer ago the farther away you get.

In the opening scene of Contact, for instance, amid the audio clutter you might make out:

  • The song “God Shuffled His Feet” by the Crash Test Dummies (1990s)
  • The theme from Dallas (1980s)
  • “Obviously a major malfunction…” Broadcast of the space shuttle Challenger explosion (1986)
  • The song “Broken Wings” by Mr. Mister (1985)
  • The song “Longer” by Dan Fogelberg (1980)
  • The Mounds/Almond Joy “Sometimes you feel like a nut” commercial (1970s)
  • “Well, I’m not a crook…” Richard Nixon press conference (1973)
  • “Free at last!” From Martin Luther King’s “I Have A Dream” speech (1963)
  • “A sniper has fired at President Kennedy’s motorcade…” Broadcast of the JFK assassination (1963)
  • “Have you ever been a member of the Communist Party?” McCarthy HUAC hearings (1950s)
  • “Yesterday, December 7, 1941…” FDR’s declaration of war speech on Japan (1941)
  • A broadcast of Adolf Hitler giving a speech (1930s)
  • Dot-dash Morse code transmissions (1910s-1920s)

The sounds get progressively softer, as they would as the signals grow weaker. At the end of the scene it’s just silent, which is what space sounds like.

The beautiful gas formations you see toward the end of the clip are also real. They’re called the “Pillars of Creation,” located in the Eagle Nebula, about 7,000 light years from Earth.

It’s a common trope of science fiction–and reasoned speculation about extraterrestrial contact–that civilizations on other planets might be alerted to the presence of intelligent life on Earth by hearing radio broadcasts from the bubble. What they’d be hearing now would depend on how far away from us they are. For example, the star Fomalhaut is 25 light years from Earth. If it’s inhabited, and if they’re listening to us, right now they might be hearing George H.W. Bush give his infamous “Read my lips” ultimatum at the 1988 Republican Convention, or they would be just starting season two of Star Trek: The Next Generation.

But is anybody listening? There is some debate, scientifically, over whether this “radio bubble” really would be strong enough to be discernible years or decades after the signals leave Earth. After all, we can no longer detect radio signals from Pioneer 10, a manmade probe which left the solar system 30 years ago. In listening for signals from the stars, we’ve had (arguably) one close call, but that’s about it. If we can’t find anyone to listen to, is it reasonable to expect they’d be listening to us?

I don’t know the answer to this. Personally I do believe there are inhabited worlds out there somewhere, and we may make contact with them someday. (I do not believe that aliens are presently visiting Earth in flying saucers). Will it be because of our radio bubble? Time–and the heavens–will tell.