The Fall of the Walls of Jericho - Myth or Mechanical Resonance?

"Joshua at the Walls of Jericho" giclee print available at AllPosters.com

According to Joshua 6:2-5, the three simple instructions given to the Israelites were:

1. March around the city once a day for six days.
2. March around the city seven times on the seventh day.
3. After the marches are complete, the priests blast their horns and all the people shout together.

We know quite a bit today about scientific principles unknown at the time of the Israelites' attack on Jericho. Specifically, the Jericho story references the principle of resonance: mechanical resonance and acoustic resonance, the two forces that collapsed the walls of Jericho.

Every object has a unique natural frequency of vibration.

A periodic force occurring at the same frequency as the natural frequency of vibration of an object may cause the object to vibrate. This is called mechanical resonance.

The force and the object being affected must come into physical contact for mechanical resonance to occur.

Mechanical resonance may cause objects to fail.

In certain applications, particularly in civil and mechanical engineering, an understanding of mechanical resonance is essential to prevent the failure of materials.

from Saskatchewan Education

Basically, when two objects that are touching each other vibrate together, the result can be increased vibrations or decreased vibrations, depending on the frequency at which each object is vibrating. Vibrations can increase to the point of destroying the objects vibrating.

Days Count by FaithOut

The Angers Bridge in Angers, France, collapsed on 18 April 1850 when 478 French soldiers marched across in lockstep; 226 soldiers died in the river below. "Because the soldiers were marching together, they caused the bridge to vibrate and twist from side to side, dislodging an anchoring cable from its concrete mooring." [read more]

The Tacoma Narrows Bridge in Tacoma, Washington, collapsed in 1940. This is commonly attributed to mechanical resonance but is now known to have been due to aeroelastic flutter, unrelated to any sort of resonance.

The Manhattan Bridge reacted dynamically to two recent mass pedestrian exoduses from the island. The cables groaned and the bridge swayed visibly from side to side as masses of pedestrians crossed the bridge after 9-11 and again during the blackout of 2003.

"Contrary to logic, pedestrian traffic is actually heavier than vehicular traffic. Pack people into the same square footage of a car or SUV, and the humans weigh more than the vehicle. What's more, pedestrian movement interacts with a bridge - vibrating it, in the words of several engineers - in a much more chaotic and little understood way. While cars and trucks move their weight in a smooth, uniform manner, pedestrians constantly shift weight from side to side and strike the bridge in an up-and-down motion. Witnesses observed the bridge reacting to both types of pedestrian stress on the day of the blackout.

"Allan McRobie, a lecturer in engineering at Cambridge, says flatly that bridges are not designed for the dynamics of crowd interaction. He called pedestrian traffic and bridge engineering "a gray area" where a complex web of action and reaction is at work. "The basic point is that engineers don't know what happens when a crowd walks over a bridge," he says.

"Ochsendorf of M.I.T. says he wondered about the bridge's load and reaction when he watched the blackout coverage on television. For a decade, engineers have learned how foot traffic vibrates a bridge. "The problem of lateral vibration has been noted for more than a century, but no one has become concerned about it as a design problem until the last couple of years." "

from Point of Collapse

Nikola Tesla established a laboratory in New York. While experimenting with mechanical oscillators, he allegedly generated a resonance of several buildings causing complaints to the police. As the speed grew he hit the resonance frequency of his own building and belatedly realizing the danger he was forced to apply a sledge hammer to terminate the experiment, just as the astonished police arrived.

The Discovery Channel's popular MythBusters show examined Tesla's claim that he had created an "Earthquake Machine" in their 60th episode. They tested the physical phenomenon known as mechanical resonance on a traffic bridge, which today are built to withstand such forces. While a single I-beam of steel was deflected several feet in each direction by their oscillator, and they reportedly felt the bridge shaking many yards away, there were no "earth shattering" effects. It is worth indicating that, in the time of the event undertaken by Tesla, buildings were not built to withstand such resonance.

from Wikipedia

Heart Cross by FaithOut

No Fear in Love by FaithOut

Consider the story as outlined in the book of Joshua:

Thousands of men marching lockstep six times, over a space of six days, around a city wall constructed of baked mud: mechanical resonance.

Thousands of men marching lockstep around the same walls seven times in a single day: mechanical resonance.

A unified blast from the ram's horns as thousands of men raise their voices and yell in unison: a shattering blast of acoustic resonance to walls weakened over a week's worth of mechanical resonance.

Notice too that every man charged straight in - which means that they didn't batter down a section of the wall, but all the walls shattered at once - like a glass shattering under acoustic resonance, so that everyone in the long line had access to the city immediately.

I don't really expect this little lens to convert anyone to my way of thinking. But I'd be happy if you would just take this away with you: a document universally agreed to be thousands of years old (whether it is believed to be true is another matter, but even naysayers agree that it is very, very old) has just described a perfect application and effect of an instance of mechanical and acoustic resonance; perhaps not in scientific terms but certainly accurately enough to be recognizable.

How ever on earth could anyone from that era have known to make up a story using just those circumstances, if it were not true?

I do not believe there is any conflict between science and the Bible. I know there are true believers on both sides of that statement who will disagree with me violently! I stand with St. Augustine: "Miracles are not contrary to nature, but only contrary to what we know about nature." God created nature and the laws of nature. Science is the study of nature; therefore science is the study of how God did what He did, and not being afraid of what is uncovered. Remember, the medieval church was afraid of Galileo's scientific discovery that the earth revolved around the sun and thought it would break people's faith. My God weathered that storm as He will weather many more.

So does understanding the principles of mechanical and acoustic resonance make the fall of Jericho somehow less of a miracle? Far from it - in fact, the reverse in my mind. Yes, it is a miracle that a guiding principle of the universe may have been built around accommodating this single week of history!

This is not so much saying that God has to, or does, work within the laws of nature, as it is saying that the laws work around what He wants to happen. In other words, what God wants to happen ARE the laws of the universe. Think about it: if God created the universe with Legos, He doesn't have to stick a Tinkertoy in somewhere to make happen exactly what He wants to have happen. God doesn't need to - nor does He - break His own laws.

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