MythBusters Episode 39: Chinese Invasion Alarm
Air Date: October 19, 2005
The ancient Chinese were able to detect an invading army tunneling beneath the ground by using a drum submerged in a shaft.
plausible
Kari was able to hear Jamie and Tory’s digging in an underground mine shaft in two of the three tests. She actually detected them better by listening to the drum compared to Grant’s use of modern geophone equipment.
The "five-second rule" is valid when it comes to food dropped on the floor.
busted
This myth yielded a varied number of results, but in the definitive test where the only variable was time the myth was definitively busted. There was no real difference in the amount of bacteria collected from 2 seconds exposure as there was from 6 seconds exposure.
The toilet seat is the cleanest place in your house.
confirmed
Adam tested this myth just out of curiosity and when the results were compared to the bacteria samples from the "five-second rule" tests, the toilet seat actually proved cleaner than all other surfaces tested.
A dog’s mouth is cleaner than a human’s.
partly confirmed
The sample collected from Adam’s mouth had much more bacterial growth than the sample collected from Lulu the dog. Jamie suggested, however, that the bacteria from the dog may be more potent.
I believe that the dog’s mouth myth is hard to test. I’m pretty certain that a dog has different types of bacteria than a human’s mouth, thus not being able to compare “cleanliness.”
June 25, 2007 at 3:38 PMYeah, kissing dogs isn’t my thing. I mean the people who do that normally have other germs anyway, or other STD’s. It is interesting with all of the technology that we try to remove germs from areas that are actually created to deal with these things.
June 26, 2007 at 9:53 AMHuman bites to human limbs lead to greater infection rates than dog bites to human limbs. So it seems that a dogs mouth is cleaner than the human mouth.
August 22, 2007 at 3:34 PMAbout the Chinese Invasion Alarm… in the myth it is stated that an army was tunneling beneath the ground. In the MB test there were only two people tunneling. Wouldn’t the army, with more people tunneling at the same time, put off more vibration and cause the drum to emit more and louder sound? It’s been a while since I have seen that episode, but that question has been nagging at me ever since I watched that episode. I’m just thinking that maybe Adam and Jamie should try that myth again with as many people tunneling that they can get.
October 15, 2007 at 5:01 PMI don’t understand why the myth is “Plausible”. The experiment was a success… What more can they do to prove it than that??? It’s not about the history; it’s about the science in historical context.
November 23, 2007 at 12:19 AMPlausible because this method would work if they were tunneling in just the right spot, but a tunneling force could come from so many directions it’s not confirmed that this would be successful enough to have been the best method. That’s what I think anyways.
December 30, 2007 at 6:45 PMI agree with Ninja on the dog’s mouth myth. Dogs have different bacteria on their mouths than humans, and they have very different imune sytems than humans. (I mean, it’s not every day you see a person getting into a cat litter box or an animal carcas the way a dog would) And on Keith’s note, another reason alot of human bites lead to greater infections than dog bites is because humans carry alot of diseases that dogs don’t, such as AIDS, herpes and other defilements that can be carried be people.
January 2, 2008 at 2:11 PMBy the way, sorry for the long comment.XI
Remember kids an amry of 10,000 tunneling will probably make more noise than an army of 2 MB’s. Thats why its plausable. Its like that whole thing with two people talking and 2000 people talking. Alot more sound, alot more vibration.
August 27, 2008 at 12:17 AMIm doing a science fair project on who’s mouth is cleaner a dog or a human.your research has been alot of help.Im a sixth grader.
January 18, 2009 at 10:17 PMI totaly belive that dogs mouths are cleaner than humans! (It depends though on what they eat)
April 28, 2009 at 11:03 AMGo mythbusters!
I would say that the Chinese Invasion alarm should be considered confirmed not plausible. In this episode, it was stated that no evidence was found that it was ever used. It was actually used in 1552 by István Dobó commanding a small contingent of men, women and children in Eger Hungary to defend the Eger castle against the invading Turkish army of 40,000+. This is considered by many as the greatest military victory in Hungarian history. A few years ago I toured the fortess museum in Eger and have seen the equipment still installed in its original place in the castle. The guide explained that the large drums placed into the numerous nooks along the passageways under the castle were used to listen for invaders tunneling from the outside. The guide also indicated that Istvan had brought in a specialist to upgrade the defenses of the fortress prior to the seige. This individual had come from another country (Germany or Prussia I believe) and the fortifications he put in place(including the alarm system) were state of the art at the time (1500s).
June 13, 2009 at 11:14 PMits not the number bacteria that counts its the type.plus a dog licks its arse all day that cant be good
September 8, 2009 at 7:28 AMLove the site! The 5 second rule episode has me wondering. Jamie and Adam pressed the samples onto the floor for the timescales stated, they didn’t just let them fall and pick them back up again, which is in my view a fairer scenario. Ergo, the results would be different from reality. Thoughts?
November 6, 2009 at 1:15 PMmy friend and i are also doing an experiment on which household pet has a cleaner mouth. we’re comparing them to humans and this site has been tons of help. :) thanx a million
January 19, 2010 at 10:27 AM