# How fast is the Beacon of Gondor? : Dot Physics

It’s been a long summer already. How long? Physics professors, waiting around for classes to start, have enough time on their hands to answer important (to me) for questions about events in the Lord of the Rings.

In the film there’s a beautiful cinematic sequence that shows the signal beacons being lit in Gondor and then the signal fires being lit along the tops of the mountains until the alarm is raised in Rohan:

Video here.

So, a professor in Louisianna asks the same question I did when I saw it: “How long does it actually take to alert the Rhoridiim?”

Rhett Allain writes:

“Can I get an estimate of these three parameters from that movie clip? Oh, yes I can. Will it be realistic? Who knows. Here is the stuff I found.

• When Pippin lights the first signal, it takes about 12 seconds from the time he puts the fire on it until it is mostly lit.
• After the first signal is on fire, Gandalf sees the next signal only 6 seconds later. WHAT?
• The guys (or gals) at the next station must have just been sitting there staring and waiting for a signal. Oh, it was probably like 40 years since the last time it was used. I guess you can do stuff like that if you don’t have youtube. But wait, the more I think about this, the more upset I get. I am ok with invisible rings, flying dragons, glowing swords and stuff. However, it is beyond the bounds of reason to expect me to believe that some guys are sitting way on the other mountain with a hair-triggered lighting mechanism. Six seconds. Seriously.
• The next time to light is 12 seconds. That is reaction plus light time.
• The next one is at night and has a total time of about 6 seconds. At night! Don’t these guys even sleep?
• 3 seconds for the next one. Come on man.

In this last one, Aragon notices the signal in under 2 seconds. Luck or skill?”

Spoiler: The film sequence isn’t too over the top fanciful at all.

The Author

Episcopal bishop, dad, astronomer, erstwhile dancer...