Dr. Dobb's Journal December 2003
I got a lot of mail about a recent column titled "Better When I Move," all of which politely corrected me on one or the other of two assertions in that column. So I thought I'd try to explain what I meant by claiming that:
1. Dr. Dobb's Journal is still Dr. Dobb's Journal, and
2. The endpoint of the flashlight beam can move faster than the speed of light.
As many long-time readers pointed out, Dr. Dobb's Journal was once Dr. Dobb's Journal of Computer Calisthenics and Orthodontia: Running Light without Overbyte. It was pleasant to be reminded of those early days of DDJ and of the personal computer "industry" before it was an industry. None of the e-mails harked back all the way to the original title, though: Dr. Dobb's Journal of Tiny BASIC Calisthenics and Orthodontia (plus the subtitle).
The e-mails didn't just point out the name changes over the years. They spoke, often with eloquence, of the meaning of that subtitle, "running light without overbyte," and of what it was like to be a programmer back in the days of Z-80s and CP/M, or earlier, in the primordial time of the Altair, the IMSAI, the Sol, the S-100 bus, 4K RAM cards, and Tiny BASIC. Dr. Dobb's was an integral part of that era, and running light without overbyte actually meant something important.
So no, Dr. Dobb's Journal is no longer about squeezing code into impossibly small spaces and achieving marvels with ridiculously inadequate resources. Neither is the industry, or even the "industry." Moore's Law killed Running Light.
But let me quote something that ran below that subhead in one of those early issues of Dr. Dobb's:
It is this open sharing that particularly delights me...We must all do whatever we can to encourage it. The sharing of ideas...allows us to stand on one another's shoulders, instead of standing on one another's feet.
That's from Jim Warren's "Editorial" in issue 4, and that's Dr. Dobb's Journal, too. And in that sense, against some powerful forces that want to lock up ideas, Dr. Dobb's Journal remains Dr. Dobb's Journal. At least, that's how this former reader, former editor-in-chief, and present whatever-I-am sees it.
As to that faster-than-light flashlight...
I was impressed by the number of very clear explanations I received as to why nothing can travel or convey information faster than the speed of light. Some readers realized that I must have been getting at something else by what I said, but felt that I was unclear. I was, and I was.
By "the endpoint of a flashlight beam" I meant the event of the light falling on some point on some surface somewhere. Shine a very powerful flashlight at the moon and the endpoint of the beam is the space-time event where/when the light reaches the moon. Swing the flashlight briskly in a small arc, and the endpoint of the beam will, in fact, move across the surface of the moon at a speed faster than the speed of light. That's what I was getting at.
Of course, no physical object is moving in this little experiment, nor is it possible for this "endpoint of a flashlight beam" to carry any information. What the phrase defines is nothing more than a succession of events that we find it convenient to give a name to.
But that was pretty much what I was getting at in the whole column. Many things that matter to us, and that we find it very convenient indeed to give a name to, may be nothing more than a discrete succession of events. Some possible examples: An individual human life, a "thought process," the United States of America. The universe, if you believe Stephen Wolfram or Ed Fredkin. Your identity. Mine. This magazine's.
It's clear from my e-mails that many people who were reading Dr. Dobb's then are still reading it now, whether or not it is the same Dr. Dobb's as it was then. But are you the same you that you were then?
Well, apparently, I am the same me I was then. Judging by the picture at the top of this column, I haven't aged a day in 20 years. Maybe it's time to visit the photographer.
Michael Swaine
editor-at-large
mike@swaine.com