As the title of this post says, I’m talking about “real time.” It’s a term used to refer to something that takes place immediately. It takes place so fast you can see and hear it happening with no perceptible lag in time between the occurrence and the recognition of that occurrence. My dictionary defines it as “the actual time during which something takes place.” (Merriam-Webster’s Collegiate Dictionary, Eleventh Edition). But with all things that “take place,” there’s always an inherent lag due to the time it takes for light to reach the eye or sound to reach the ear of the person(s) observing the action. That may not sound like much because we’re so used to the lag being so short we can’t detect it, but as distances increase, the lag also increases.
If you are tossing firecrackers around on the 4th of July, the bang of the firecracker or the rocket-powered fireworks forty or fifty feet in the air may seem to be immediate. You can’t usually tell if there’s any lag at all, though I have noticed when I’m watching a professional fireworks company set off the beautiful fireworks displays we so often have around the country, there can be a distinct delay between the point at which I see the explosion and when I hear the bang. That’s because the explosion is usually several hundred or several thousand feet in the air. Light travels so much faster than sound. But does that delay mean the sound was not heard in “real time”?
If a golfer hits a bad shot and it slices over toward the gallery, and the golfer yells “Fore!” the ball may bounce off a spectator’s head before he hears the yell. Does that violate “real time”? Does the spectator have a legitimate complaint against the golfer that he should have been warned earlier?
These examples may seem unnecessarily precise as they rarely cause any trouble here on Earth. But when the Apollo astronauts were on the moon, there was a lag time of about a second and a half in transmission time for radio communication with Mission Control. That lag didn’t seriously hamper the exploration of the moon by the astronauts, but it was obvious. But was that lag long enough to violate “real time”? A trip to Mars will involve a lag time of several minutes, and the astronauts will have to factor it into their work schedule. Real time? If you’ve seen the movie “2001: A Space Odyssey,” you may remember that communications times to the astronauts out near the planet Jupiter were on the order of several hours! I would venture to say that is probably not “real time”.
The question I’m really asking is, where does real time end, and lag time begin. After a lag of one second? One minute? One hour? If I write a story about astronauts in outer space receiving communications, what do I say about any lag? Where do I stop using “real time,” and begin talking about “lag time”? I’m not sure there’s any real distinction between the two, though there should be.