To build a fire...

The book recently for my smallest students has been about the weather, so I've had the chance to further damage my vision by demonstrating "the power of the sun" with a magnifying glass and assorted petroleum-based objects. In one class, the game today was to say, "The sun makes fire," when I pointed to that picture. The other two pictures were to prompt "The sun is hot" and "The sun is toooo hot," but since two grammar patterns was too much for most of them in a game, the fire pattern devolved into "The sun is fire." Which got me thinking. The fire created by the beam through the magnifying glass really is the sun's heat. It is a way of concentrating the literal flames of the sun into a small enough space to ignite what would ignite at much closer distance to the sun. But my quandary is this: which flames of the sun are actually causing the ignition under the magnifying glass? It's not the flames erupting "right now" as I hold the glass, since the energy from those flames won't reach earth (and my lens) until eight minutes later. But if it is the flames from eight minutes before, can we really say those flames were emitted in order to create a small ignition on earth in a kindergarten playground? My point is that at the time they erupted from the sun, the solar rays which eventually started my little fire did not have as one of their causal functions (or causal ends) "to ignite waxy paper 93,000,000 miles away." At the time those rays left the sun, they lacked the causal power to ignite the paper under my lens, since the paper and the left wouldn't be in hand in the sunlight at that time. The lens and paper would only be ready for ignition eight minutes after the rays began their flight. And yet clearly it is nothing less than those rays which cause the ignition on earth. So the question is, how large is the sun? It seems that it's causal powers extend well beyond its 'immediate' solar dimensions (qua "the sun"), since its energy causes ignitions eight minutes away in spacetime.

I intend to write more about this when I get a chance to sit down, but my main concerns for the moment are 1) in what spatiotemporal frame of reference should we consider the rays as they pass through the lens, 2) in what spatiotemporal frame of reference should we quantify the sun, and 3) how should we understand the causal powers of solar rays if they can assume unpredicted new powers outside their own spatiotemporal so to speak frame of existence? At the moment the rays were emitted, there was no way an observer could really say they 'contained' the power to ignite Teacher E's waxy paper on earth, since, at that time, the waxy paper etc. were not 'there' to 'participate in' the solar rays' causal impact.