I couldn't sleep so I was watching History Channel documentaries on hulu (I know, History Channel is not a good source, that's why I'm asking here) this one was about Ancient Egypt. The series is "Ancient Top 10" and it's S1E1 Secrets of Egypt. In this episode they do a countdown of the top 10 secrets in Egypt and #2 was the Lighthouse of Alexandria. There were two claims they made in this video that seemed a bit stretched: The first one was this quote below, saying that the mirrors on the lighthouse could destroy ships in the harbor.
"There are actually ancient sources that say the lighthouse could focus a lethal beam of light and aim it at enemy ships, burning them"
This seems utterly ridiculous to me but they do mention sources, but they fail to link them anywhere. Is this factual at all, or is it the History Channel saying "probably not but if it was wouldn't we get lots of ratings on this episode"?
The second one was that the lighthouse's light could be seen from 30 miles away, which the show claims hasn't yet been matched by modern technology. I'm assuming that both of these ideas are bogus, but I was so intrigued by how ridiculous they sounded that I wanted to find out the truth. I'm even more skeptical because all of their "experts" just have titles that say "Historian" or "Factual TV Host" and they don't cite any sources at all. Reading between the lines it seems like they are using fanciful tales told by travelers as proof for these claims.
Thanks much, love this sub!
That's a fascinating mangling of the original. The claim of a 'death ray' that used mirrors as a method to focus sunlight to burn targets (same principle as a magnifying glass) is A Thing...but that's set in Syracuse, specifically being one of Archimedes' many inventions to combat the Roman siege of the city of 213-212 BC. History Channel appears to have displaced the story across the Mediterranean. As to whether it worked or whether it was An Actual Thing instead of a story, I'll leave that to u/QuickSpore in their assessment in this previous post - though as always, if anyone else wants to put their own oar in, please don't let this post stop you!
I can't help on the second claim, unfortunately, though it seems a relatively straightforward physics question.