#### benben

##### Active member

I've really enjoyed listening to the recent RSR programs on the speed of light. As a YEC the light-time travel problem is one that's fascinated and stumped me for years.

A while ago I read one of Lisle's books wherein he proposed the ASC (infinite one-way speed of light convention). I liked the idea, but something about it never felt right. After thinking through this again I've concluded that the one-way speed of light can't be infinite.

If the one-way speed of light in a given direction is truly instantaneous, then no time passes during which light traverses a given distance. To put it another way, the same light (i.e. photon) is in two places at once. Only God can be in multiple places at once, so the idea that a photon can also is a problem.

There's also a fascinating implication of a photon being in two places at once. When light is bounced off a mirror, the initial photon of light would pop into existence at the source AND be reflected off the mirror at exactly the same moment. Sounds cool, but again, none of this makes sense.

And there's another problem. The equation for speed is speed = distance / time. Therefore, a speed of infinity would require time to be 0 (infinity = distance / 0). But division by zero leads to absurd and clearly false expressions like 0=1.

To illustrate this, let's say that on a one-way trip, light travels 100,000 miles in an instant. Therefore infinity = 100,000 miles / 0. Multiply both sides of the equation by 0, and you get 0 miles = 100,000 miles. You can do this with any distance and will always get 0 = whatever distance you use.

Of course, we can get around these problems by saying that the one-way speed of light in one direction is some real number so fantastically large that it might as well be infinity. However, the idea of the speed of light being different in different directions seems counterintuitive, like the results of the double-slit experiment but much weirder. That alone isn't a reason to dismiss it, but it raises a number of even more difficult questions such as how light "knows" what direction it's going or whether it's being measured on the return trip.

Anyway, change my mind

A while ago I read one of Lisle's books wherein he proposed the ASC (infinite one-way speed of light convention). I liked the idea, but something about it never felt right. After thinking through this again I've concluded that the one-way speed of light can't be infinite.

If the one-way speed of light in a given direction is truly instantaneous, then no time passes during which light traverses a given distance. To put it another way, the same light (i.e. photon) is in two places at once. Only God can be in multiple places at once, so the idea that a photon can also is a problem.

There's also a fascinating implication of a photon being in two places at once. When light is bounced off a mirror, the initial photon of light would pop into existence at the source AND be reflected off the mirror at exactly the same moment. Sounds cool, but again, none of this makes sense.

And there's another problem. The equation for speed is speed = distance / time. Therefore, a speed of infinity would require time to be 0 (infinity = distance / 0). But division by zero leads to absurd and clearly false expressions like 0=1.

To illustrate this, let's say that on a one-way trip, light travels 100,000 miles in an instant. Therefore infinity = 100,000 miles / 0. Multiply both sides of the equation by 0, and you get 0 miles = 100,000 miles. You can do this with any distance and will always get 0 = whatever distance you use.

Of course, we can get around these problems by saying that the one-way speed of light in one direction is some real number so fantastically large that it might as well be infinity. However, the idea of the speed of light being different in different directions seems counterintuitive, like the results of the double-slit experiment but much weirder. That alone isn't a reason to dismiss it, but it raises a number of even more difficult questions such as how light "knows" what direction it's going or whether it's being measured on the return trip.

Anyway, change my mind

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