I was talking to my brother the other day, and he asked me a question that completely threw me off guard. He asked "Do you think it's possible to see beams of light, and actually be able to track their movements, and translate it to a macroscopic scale?". At first, I said that it was impossible due to the actual speed of light. But, I thought on it, and I remembered something back when I visited a physics convention. I remembered that the speed of light slows down once it exits a vaccum, and furthers when it passes through certain objects (Like glass, perhaps?). So, I was wondering, is it THEORETICALLY possible to slow light down enough to track it's movements using one of our most powerful high speed cameras by lining up enough objects that slow light, and shooting a beam of light (for all intents and purposes, let's say it's a green laser) through them? I'm not very experienced with Optical or Particle Physics (I'm more of a Quantum Mechanics, and Astrophysics guy), so I would appreciate some insight with this problem that seems to be an enigma at the moment.