 The only limits on triangulating the distance to an object are one, you have to be able to see the object in order to measure angles to it, and two, you have to be able to measure or calculate the baseline. These might not sound like serious limitations, but lightning doesn't wait around long enough to take any of these measurements, and you can't see the top of the sky. Methods for finding distances to things like these have relevance for the methods that will take us to the planets and the stars. So let's go over them. For some things, you need to know something about the physical processes at play. For example, how far away is lightning? To answer this question, it helps to know something about what lightning and sound are. For example, we know that a lightning flash is caused by a massive move of electrons across the sky. This creates a vacuum in the air, and thunder is the sound of the air collapsing back into the vacuum. We also know that sound is a wave. The speed of sound is a variable and depends on the properties of the substance through which the wave travels. For air, the speed of sound is approximately .32 kilometers per second. So all we need to do to see how far away lightning is is to start counting the seconds at the flash and stop at the sound, and multiply the number of seconds by .32 to get how many kilometers away it is. Here we have a six second delay between the light and the sound. So the lightning is 1.9 kilometers away. As we move up the distance later, we'll be using knowledge about stars and light waves in similar ways to our use of lightning and sound waves here.