Hi. So my friend thinks he's smart, and one time, while we were talking, he asked me whether fire can produce shadow. Of course he does not know the answer, but knowing him, he asked me this question to show that I am not smarter than him. Nevertheless, his question started bothering me, because generally everyone knows that in order to have a shadow you need a source of light and an opaque object. I know how broad of a term a fire is because of its variation, considering different gases and light it produces that may either be visible or non visible. I know that there may not be any specific answer to it, so treat my question as some kind of a challenge. I know that a lot of people who visit this forum are much more knowledgeable than me when it come to physics and chemistry, and this is why I am posting this question. Feel free to discuss different kinds of flames, gases, spectrum, and all that stuff. Feel free to give me your honest opinion as well - as long as it has some physics behind it. So tell me: DOES FIRE PRODUCE SHADOW?