On this episode they are forgetting one thing. They need to research when this saying first started and then they need to have socks and shoes for that time period to use in their experiments. Since footware of all kinds have changed drastically since say the 1920's then they may not be doing this experiment justice!

Just my 2 cents

use the ankle socks

I think you need to worry more about the speed then the force... with the first test you came close but with the slower moving ram it didn't work.. remember objects at rest tend to stay at rest.. the faster you hit it the more likly it is that the sock will stay there.

on this episode, adam was using a paintball marker to mini the experiment. his conclusion was that the paintball were at fault. id like to point a few things out.

first, what was the air source? Co2 is less consistent than HPA (high pressured air).

the regulator is next, possibly causing an inconsistent FPS (feet per second) on the paintball is likely the cause. normally the lower end markers will give you a FPS spread of +/- 20 FPS, where as a higher end marker is +/- 3 FPS.

the quality of the paintball. use cheap paint, get cheap results. not to mention the way the paintballs were stored.

btw, play paintball!

-jp

quote:

Originally posted by Midnightcat6:
On this episode they are forgetting one thing. They need to research when this saying first started and then they need to have socks and shoes for that time period to use in their experiments. Since footware of all kinds have changed drastically since say the 1920's then they may not be doing this experiment justice!

Just my 2 cents

My comment exactly, socks used to be slouchy, remember garters, socks have come a long way baby

The Problem I have with this Episode is that when that saying "knock your socks off" was first used Socks didn't have elastic bands in the ankle to keep them tight to the leg. They need to revisit the myth using socks from different periods in world history. I socks now-a-days are less likely to slide down or off as their ancient counterparts.

The time period comment is a good point - we were using garters and girdles to hold our socks and stockings up into the 1960s. They might have a very different result if they used silk stockings, nylons, or wool socks without any elastic. I think they need to do this again using garters and girdles and see what happens then.

i think the mythbusters should have also used prosthetic feet molded in different positions in the first two tests of "knock your socks off". Busters feet were flexed during both experiments. When hit by the forces tested in the myth, a human foot might be pointed giving the socks an easier path to come off.

The biggest issue here is that the rigid dummy foot used in the test does not AT ALL resemble the human foot, which is essentially bones in a very flexible bag of liquid. The amount of deformation the foot experiences is amazing. In engineering, if you make a 'rigid body' assumption, you better confirm it. In this case, the 'rigid body' assumption is completely invalid. I love Mythbusters and have watched for years. But this was the FIRST time that I was so disgusted that I had to actually write in to object to a myth.

The Mythbusters need to learn the difference between Impulse and Force during a collision. What matters for a short collision is the impulse which is the average force times the time over which it is applied. The presentation in the "Knock your socks off" episode got this all wrong.

If the myth was about a boxer being knocked out of his socks then I think the experimental method was lacking. I personally don't box but it appears to be a very high exertion sport which it likely to involve the participants sweating ... a lot. Since the subjects stand during boxing that sweat likely runs down into their socks and shoes.

This sweat has three major effects:
1) Lubrication: decreasing sock-skin friction
2) Decreasing effectiveness of elastic
3) Increased sock mass due to wicking

These three effects would make it substantially easier to remove a person's socks. Had Buster gone 3-4 rounds in the boxing ring before the test, not only would the first punch test have succeeded in removing him from sweat sodden socks, those previous rounds of boxing would have tired him out to the point he might have failed to block or dodge that punch.

Add sweat, socks slide right off.

What me that this was in Holland (especially in the area of leiden city) is also a saying, with varieatie's shoes, slippers and clogs and or of course be blowing you off.
The word actually always talks to a supporter used said "yeah if you tailor that happens is not well off you"
But we are now convinced of.
Greetings marco.

quote:

Originally posted by Midnightcat6:
On this episode they are forgetting one thing. They need to research when this saying first started and then they need to have socks and shoes for that time period to use in their experiments. Since footware of all kinds have changed drastically since say the 1920's then they may not be doing this experiment justice!

Just my 2 cents

It is in Dutch
a proverb and now confirms what you do not want to happen.

The saying "knock your socks off" predates wide use of elastic in socks. The tests done should have included well worn non-elastic socks the type found in the early 19th century. Also socks would have often fit very loosely as they were not always made for the person who used them (Hand me downs etc). Furthemore sneakers were not the common footwear of the time.

Lastly the term "sock" or soccus is MUCH older, dating back to Roman times as a loose fitting shoe which I would assume had to be fairly easy to knock off.

Why was a saying that can be traced back to at least the 19th century, maybe further, tested with modern materials anyway?

Usually the science in Mythbusters is pretty good(and at times outstanding), but this time they got it wrong. Here, we are dealing with two things. First is the friction of the socks on skin, secondly, we are also dealing with inertia of the socks.

Friction keeps the sock on, but since we can take socks off, we know that a certain amount of force will take it off. Now, the trick of knocking off socks is that the force created by inertia(in this case: objects at rest will stay at rest unless force is applied) is greater than that of the friction to stay on.

When they went from the piston to the swing, they were thinking in the right direction, need more force, but they got it wrong. They had to think of the force applied to buster. His mass stays the same regardless, that means the acceleration needs to increase.

Think of it this way, I could hit buster with a block of lead that is 1,000,000,000,000,000,000,000,000,000,000 kilograms going 1 meter/second. That is a huge huge huge huge amount of momentum. Or I can hit him with a block that's 1,000 kg traveling 1 kilometer/second which has a lot lot lot lot less momentum (momentum = mass x velocity). Which hits him with more force? The second one does because his velocity change is much greater.

When they went to the swing, they did hit with more momentum, but looking at the footage, I'd say it actually hit with less force.

In this myth, change in buster's velocity is everything.

The fastest recorded punch I could find was just under 7 m/s. If the heavy pendulum rig had a cable length of 10 meters and was raised to an angle of 75 degrees it would have a velocity of just over 12 m/s, 70% faster than the fastest punch. With all of that mass behind it it carried much more force than any punch could and could accelerate Buster much faster than a punch.

quote:

Originally posted by Dastmal:
I think you need to worry more about the speed then the force... with the first test you came close but with the slower moving ram it didn't work.. remember objects at rest tend to stay at rest.. the faster you hit it the more likly it is that the sock will stay there.

Exactly. The second test was beyond pointless. The amount of energy contained in the moving ram was irrelevant -- it was moving as slow as mud. You'll notice that after the impact the ram was not moving at a noticeably different speed -- most the energy remained in the ram.

The had the exact same failure to understand highschool-level physics when they did the experiment with the girl who was supposedly launched from a seesaw by a free-falling man. They thought that using a heavier weight with a lower drop distance (thus the same kinetic energy) would be equivalent. A seesaw cannot transfer all the kinetic energy in that case. At the best case, it will transfer the speed.

They really need someone with a better grasp of physics on their staff.

Yeah, I could have made my point alittle clearer. When dealing with force, it's mass x acceleration. When dealing with the amount of force imparted upon an object, it is that target object's mass and it's acceleration that you use in your calculations, not the object applying the force.

The see-saw is another example. could drop a 100 ton weight from a foot off the ground and hit with more momentum or kinetic energy, but that girl wouldn't go anywhere. When dealing with this sort of physics, you actually need to use vectors in your calculations, because velocity and mass aren't necessarily interchangeable. Also, you have to take into account what other forces are in play. For instance, the ground also acts as a force against the weight being dropped.

Guys, we are missing a big factor, physiological response of a human after trauma/shock.
Humans respond by clenching some muscles, so your feet are straightened and toes curled.
Check out the data from vehicle vs. pedestrian accidents, how many people lost their shoes and socks? I have seen this phenomenon in real life, real weird.
So, unless it is a live human, this can not be replicated, so can not be busted.

B-Rad

They should be using feet made from a skeleton structure and gel so it'll flex like a real foot. the rubber and plastic feet won't felx as much, making it less likely for the socks and shoes to be knocked off. This myth needs to be revisited!