[Yahya A.Sharif (OP)]

That explanation is not your own,

Then you should not have pretended it was, should you.

Anyway, are you really to stupid to understand padding?
People are soft; rocks are hard.

If I lie prone on a rock, isn't it the same hard surface? So why don't I experience pain or injury, unlike when the same rock is placed on top of my abdomen? In both cases, the force is mutual-an action and a corresponding reaction.

[Yahya A.Sharif (OP)]

That explanation is not your own,

Anyway, are you really to stupid to understand padding?
People are soft; rocks are hard.

I understand that texture and solidity play a role; however, placing a piece of wood under both the person's feet and the rock still yields different results. The person cannot support the rock the same way they can support another person.

[Bored chemist]

That explanation is not your own,

Then you should not have pretended it was, should you.

Anyway, are you really to stupid to understand padding?
People are soft; rocks are hard.

If I lie prone on a rock, isn't it the same hard surface? So why don't I experience pain or injury, unlike when the same rock is placed on top of my abdomen? In both cases, the force is mutual-an action and a corresponding reaction.

[/quote]


I answered that already.

I can see how it is obviously wrong: I could lie on my stomach on a concrecte block for a minute without pain with my weight 70 kg, however the opposite is also true I can put a rock of 70 kg on my stomach with the same area of contact without any damage or pain. Obviously wrong concept.
I thought I discovered basic biomechanics, how stupid I am.
Thank you
Let this idea die out who cares.

Yes, your concept is obviously wrong. It's also worse than you thought.
Let's imagine you lying down on a concrete floor.
And now, let's imagine slicing you up with a chainsaw.
First, we cut off your head.
Since it was already resting on the ground, removing it does not affect the load on your stomach.
Then we cut your legs off.
Again, they were already resting on the ground so their weight was already supported.
So removing them adds no additional load to your stomach.
We can do the same with your arms.
There's no additional weight on your stomach, because your stomach wasn't holding your arms up.
Finally, we can cut your torso in half.
Your chest still supports itself, just as it did before.
So  we finally see that your stomach is only supporting itself- far less than 70 Kg.
So its absurd to compare that it it supporting an additional 70Kg of rock.


Well, that's a bit messy, so let's imagine putting you back together again.
And let's imagine that, in the fullness of time you end up married and in bed with your wife.
Are you going to tell her it's not possible for her to support 70Kg of you lying on top of her?

Or are you going to accept that your position was always absurd?

[/quote]

[Yahya A.Sharif (OP)]

That explanation is not your own,

Then you should not have pretended it was, should you.

Anyway, are you really to stupid to understand padding?
People are soft; rocks are hard.

If I lie prone on a rock, isn't it the same hard surface? So why don't I experience pain or injury, unlike when the same rock is placed on top of my abdomen? In both cases, the force is mutual-an action and a corresponding reaction.

I answered that already.

I can see how it is obviously wrong: I could lie on my stomach on a concrecte block for a minute without pain with my weight 70 kg, however the opposite is also true I can put a rock of 70 kg on my stomach with the same area of contact without any damage or pain. Obviously wrong concept.
I thought I discovered basic biomechanics, how stupid I am.
Thank you
Let this idea die out who cares.

Yes, your concept is obviously wrong. It's also worse than you thought.
Let's imagine you lying down on a concrete floor.
And now, let's imagine slicing you up with a chainsaw.
First, we cut off your head.
Since it was already resting on the ground, removing it does not affect the load on your stomach.
Then we cut your legs off.
Again, they were already resting on the ground so their weight was already supported.
So removing them adds no additional load to your stomach.
We can do the same with your arms.
There's no additional weight on your stomach, because your stomach wasn't holding your arms up.
Finally, we can cut your torso in half.
Your chest still supports itself, just as it did before.
So  we finally see that your stomach is only supporting itself- far less than 70 Kg.
So its absurd to compare that it it supporting an additional 70Kg of rock.


Well, that's a bit messy, so let's imagine putting you back together again.
And let's imagine that, in the fullness of time you end up married and in bed with your wife.
Are you going to tell her it's not possible for her to support 70Kg of you lying on top of her?

Or are you going to accept that your position was always absurd?

That is completely incorrect. When I lie prone on a concrete block with my abdomen, my entire body weight is exerted through my abdomen-that's basic physics. If the block were replaced with a scale, it would measure my full body weight, not just the weight of my abdomen.

[Bored chemist]

You have yet to say how big the block is.
Would you like to clarify that?

I'm no artist but

Stickmen.png (39.11 kB . 843x451 - viewed 142 times)

Here we have stick man,
stickman looked at from one side,
Stickman lying down.
Stickman lying on a green block that's big enough to be comfortable
Stickman lying very uncomfortably on a block that's too small to be omfortable.

[Yahya A.Sharif (OP)]

You have yet to say how big the block is.

The block measures 0.2 meters in length and 0.2 meters in width, making contact only with my abdomen. I weigh then 63.4 kilograms and was able to lie on it for one minute without experiencing any pain or injury. Now compare that with a hypothetical scenario where a 63.4 kg block or rock is placed on my abdomen, maintaining the same contact area.

[Bored chemist]

The outcome would be the same.

[Yahya A.Sharif (OP)]

The outcome would be the same.

The outcome would be completely different - a 63.4 kg rock would cause severe pain and likely serious injury.

[Yahya A.Sharif (OP)]

In my research, I proposed conducting such an experiment on an animal. For example, a horse can lie on its abdomen on a concrete block without harm; however, placing a 300 kg rock on the horse's abdomen would cause serious damage.
Research Paper
This research was accepted as an abstract at the International Union of Physiological Sciences (IUPS) 2025 Congress.
Biological Leverage: A Novel Principle in Human Biomechanics

[alancalverd]

If you have reason to believe that an experiment would cause serious harm to an animal with no concomitant benefit, no responsible scientific body would accept your proposal or publish your findings.

You can, of course, experiment on yourself, though people might be sceptical of the result, or seek the consent of properly informed volunteers  to at least assess discomfort if the experiment is adequately designed to prevent actual harm.

Happy to advise on the ethics of a particular investigation - it's what I do.

[Yahya A.Sharif (OP)]

If you have reason to believe that an experiment would cause serious harm to an animal with no concomitant benefit, no responsible scientific body would accept your proposal or publish your findings.

You can, of course, experiment on yourself, though people might be sceptical of the result, or seek the consent of properly informed volunteers  to at least assess discomfort if the experiment is adequately designed to prevent actual harm.

Happy to advise on the ethics of a particular investigation - it's what I do.

Thank you, Alan. I can instead rely on the other two experiments-measuring acceleration and assessing maximum calf push in individuals with low strength.

[Bored chemist]

The outcome would be the same.

The outcome would be completely different - a 63.4 kg rock would cause severe pain and likely serious injury.

That's your claim. Now provide the evidence.

[Kryptid]

In my research, I proposed conducting such an experiment on an animal. For example, a horse can lie on its abdomen on a concrete block without harm; however, placing a 300 kg rock on the horse's abdomen would cause serious damage.

There's nothing profound about that. It's nothing new. I can lie on my back on top of a house and be just fine. If I lie on my back and put a house on top of me, I'd get crushed. The scenarios aren't symmetrical. In one case, I have the weight of a whole house on top of me and in the other I don't have anything on top of me.

[Yahya A.Sharif (OP)]

In my research, I proposed conducting such an experiment on an animal. For example, a horse can lie on its abdomen on a concrete block without harm; however, placing a 300 kg rock on the horse's abdomen would cause serious damage.

There's nothing profound about that. It's nothing new. I can lie on my back on top of a house and be just fine. If I lie on my back and put a house on top of me, I'd get crushed. The scenarios aren't symmetrical. In one case, I have the weight of a whole house on top of me and in the other I don't have anything on top of me.

That is not an equivalent scenario. A truly equivalent scenario would involve placing an object of the same weight on your abdomen. Hypothetically, placing a 63.4 kg block with an area of 0.2x0.2 meters on my abdomen would be fatal. However, my own body weight was 63.4 kg, I could lie on a 0.2x0.2 meter concrete block for one minute without experiencing any pain or injury.

[Kryptid]

A truly equivalent scenario would involve placing an object of the same weight on your abdomen. Hypothetically, placing a 63.4 kg block with an area of 0.2x0.2 meters on my abdomen would be fatal. However, my own body weight was 63.4 kg, I could lie on a 0.2x0.2 meter concrete block for one minute without experiencing any pain or injury.

Yes, we know that. It's because the applied pressure is different between your two scenarios.

[alancalverd]

Hypothetically, placing a 63.4 kg block with an area of 0.2x0.2 meters on my abdomen would be fatal. However, my own body weight was 63.4 kg, I could lie on a 0.2x0.2 meter concrete block for one minute without experiencing any pain or injury.

Why the hypothesis? Try it! Just find a farm gatepost (they are usually about 15 x 15 cm) and nail a 20 x 20 piece of 15 mm plywood to the top. Unless you are a trained gymnast or bodybuilder, I doubt that you would manage more then 10 seconds suspended prone by your abdomen.

Less dangerously, stack four house bricks to make a pile 215 x 215 mm x 130 mm high. Drape yourself over them, then raise your arms and legs so that your entire weight is borne by the bricks. If your paraspinal muscles aren't strong enough, just use one layer of bricks (65 mm high), get a "friend" to truss you to a pole (feet, hips, shoulders) and when you are steady, put your hands behind your head.

[Yahya A.Sharif (OP)]

A truly equivalent scenario would involve placing an object of the same weight on your abdomen. Hypothetically, placing a 63.4 kg block with an area of 0.2x0.2 meters on my abdomen would be fatal. However, my own body weight was 63.4 kg, I could lie on a 0.2x0.2 meter concrete block for one minute without experiencing any pain or injury.

Yes, we know that. It's because the applied pressure is different between your two scenarios.

Why is the applied pressure different when two equal forces of 63.4 kgf act on two equal areas of 0.2x0.2 m? This would only occur if a biomechanical advantage is involved.

[Bored chemist]

A truly equivalent scenario would involve placing an object of the same weight on your abdomen. Hypothetically, placing a 63.4 kg block with an area of 0.2x0.2 meters on my abdomen would be fatal. However, my own body weight was 63.4 kg, I could lie on a 0.2x0.2 meter concrete block for one minute without experiencing any pain or injury.

Yes, we know that. It's because the applied pressure is different between your two scenarios.

Why is the applied pressure different when two equal forces of 63.4 kgf act on two equal areas of 0.2x0.2 m? This would only occur if a biomechanical advantage is involved.

This "Why is the applied pressure different "
Is the wrong question.
 You need to start by asking "is the applied pressure different ".

Have you done that?

[Kryptid]

Why is the applied pressure different when two equal forces of 63.4 kgf act on two equal areas of 0.2x0.2 m? This would only occur if a biomechanical advantage is involved.

Oh, wait. I think I misunderstood what you posted. Yes, the pressure would be same (about 15,544 pascals), assuming that you happen to weigh 63.4 kilograms. However the way that it is applied isn't exactly the same between the two scenarios. In one, you are being squeezed between the block and the ground. In the other, you aren't being squeezed between two objects. The effect on your internal organs would therefore not be exactly the same.

However, your skin shouldn't be pierced in either scenario. A Google search shows the yield strength of skin to be between 420,000 pascals and 20,000,000 pascals. The large range results from skin having different properties in different areas of the body as well as changes associated with aging. Even the low ball figure is well above the pressure your block is producing.

[Yahya A.Sharif (OP)]

Why is the applied pressure different when two equal forces of 63.4 kgf act on two equal areas of 0.2x0.2 m? This would only occur if a biomechanical advantage is involved.

Oh, wait. I think I misunderstood what you posted. Yes, the pressure would be same (about 15,544 pascals), assuming that you happen to weigh 63.4 kilograms. However the way that it is applied isn't exactly the same between the two scenarios. In one, you are being squeezed between the block and the ground. In the other, you aren't being squeezed between two objects. The effect on your internal organs would therefore not be exactly the same.

However, your skin shouldn't be pierced in either scenario. A Google search shows the yield strength of skin to be between 420,000 pascals and 20,000,000 pascals. The large range results from skin having different properties in different areas of the body as well as changes associated with aging. Even the low ball figure is well above the pressure your block is producing.

Science does not recognize the concept of "squeezed" pressure; pressure must remain the same when the force, material, and area are unchanged.