If I jump in the air why doesn't the ground move @ 1000MPH?

Quote from: hewholikespie on January 08, 2014, 01:20:16 PM

Sceptipoo, a question- I have two Steel balls. One is solid and half a meter in diameter. One is hollow and one meter in diameter. The hollow one is completely airtight, and has a 1 centimeter thick outer shell.

Which of these two steel balls takes more effort to get moving?

The solid half a metre ball would take a lot more energy to get it into motion than the larger airtight ball due to it having more density against the ground.

Why would it have more 'density against the ground' since under your model, it is air pressure from above that pushes objects towards the ground. Why would the object with the smaller surface area have the greater Air Pressure pushing on it?

Quote from: sceptimatic on January 09, 2014, 08:28:29 AM

Quote from: Antonio on January 09, 2014, 08:23:43 AM

Quote from: sceptimatic on January 09, 2014, 08:03:34 AM

Quote from: Antonio on January 09, 2014, 07:40:18 AM

Totally lost now.
You say that the kid is pushed backwards out of the bus. How did he get this 40 mph forward motion, as the only force acting on him was the air pushing him backwards?

He is going 10 mph less speed than the bus as he leaves the back of the bus. The bus is displacing the air as it moves through it at 50 mph so in effect the bus is creating a low pressure environment around it as it pushes through it, so as the kid jumps out, he jumps straight into the oncoming  50 mph pressure but he's hitting it at 10 mph so by the time he hits the ground, the pressure carries him in the direction of the bus, except he's going backwards.

Quote from: Antonio on January 09, 2014, 07:40:18 AM

Other question. If the back of the bus is totally opened, there is no resistance to air. How does it work then ?

Well the kid was already out of the bus and the people inside the bus will be under no extra force anyway as the bus was at a steady speed.

Still unclear. What is the kid's speed and  direction when he is just about exiting the bus ?

I've just gave you all of that info, what's your problem with it?

Well, the kid starts going backwards, and then forward. Where does the direction change ?

What do you mean, backwards and forwards?

Quote from: sceptimatic on January 08, 2014, 02:37:53 PM

Quote from: hewholikespie on January 08, 2014, 01:20:16 PM

Sceptipoo, a question- I have two Steel balls. One is solid and half a meter in diameter. One is hollow and one meter in diameter. The hollow one is completely airtight, and has a 1 centimeter thick outer shell.

Which of these two steel balls takes more effort to get moving?

The solid half a metre ball would take a lot more energy to get it into motion than the larger airtight ball due to it having more density against the ground.

Why would it have more 'density against the ground' since under your model, it is air pressure from above that pushes objects towards the ground. Why would the object with the smaller surface area have the greater Air Pressure pushing on it?

Who said it had greater air pressure pushing on it?

How about leaving it up to the people to decide. You are not their keeper, are you?

No; I'm not other members' keeper.  But that shouldn't prevent me from commenting as I have should it?  Or have I struck a raw nerve maybe?  After all, you could just ignore my comments, but you seem drawn into responding LOL.

If they decide to stick rigidly to the misinformation then fine [...]

Ahhh... but you DO have a problem with other members sticking to "mainstream" information.  That's why you consistently denigrate their viewpoints, and also their personal credibility.  You're fearful of even considering accepted science because it might just disprove your flat earth belief.

I mean, after all...who wants to go against official mainstream scientific theories, even if they can explain things but cannot be accounted for as a force and yet here's me, not only accounting for the force, I'm fully explaining it as I go along.

Can I ask you if you took the time to read the site that I linked to, and what your opinion was of the currently accepted scientific facts?  Did any of the definitions cause you to think about your own interpretations of things such as pressure or density?

You wanted me banning for being a nut, so treat me like one and ignore me and let the others decide for themselves.

Wrong again.  I want you banned because of the continual stream of insults you hurl at other people, and then complain that we're ganging up on you.  And I do not consider you a "nut".  You articulate yourself very well; it's just that you do it in such a negative manner.

You go on about disrespect and here you are being disrespectful because something doesn't suit you.

Sorry, but this comment is quite funny coming from somebody whose byword is "insults".

Do you have some kind of agenda?

Other than getting you banned?  Nope, not particularly.  Other than being able to post sensible responses without being attacked by you because you think I'm a moron, or part of some massive, imaginary scientific fraud.


My apologies to mods for posting off-topic.  Please shift if necessary

Quote from: Antonio on January 09, 2014, 09:07:20 AM

Quote from: sceptimatic on January 09, 2014, 08:28:29 AM

Quote from: Antonio on January 09, 2014, 08:23:43 AM

Quote from: sceptimatic on January 09, 2014, 08:03:34 AM

Quote from: Antonio on January 09, 2014, 07:40:18 AM

Totally lost now.
You say that the kid is pushed backwards out of the bus. How did he get this 40 mph forward motion, as the only force acting on him was the air pushing him backwards?

He is going 10 mph less speed than the bus as he leaves the back of the bus. The bus is displacing the air as it moves through it at 50 mph so in effect the bus is creating a low pressure environment around it as it pushes through it, so as the kid jumps out, he jumps straight into the oncoming  50 mph pressure but he's hitting it at 10 mph so by the time he hits the ground, the pressure carries him in the direction of the bus, except he's going backwards.

Quote from: Antonio on January 09, 2014, 07:40:18 AM

Other question. If the back of the bus is totally opened, there is no resistance to air. How does it work then ?

Well the kid was already out of the bus and the people inside the bus will be under no extra force anyway as the bus was at a steady speed.

Still unclear. What is the kid's speed and  direction when he is just about exiting the bus ?

I've just gave you all of that info, what's your problem with it?

Well, the kid starts going backwards, and then forward. Where does the direction change ?

What do you mean, backwards and forwards?

Let's start again.
You said that the air inside the bus pushes the kid backwards. So I assume he is going backwards while inside the bus correct ?
How did he gain 40mph forward, while receiving only backward forces ?

I put you on a BOLTED down seat inside a bus sized cylinder at 14.7 psi. You are sat facing the filler nozzle.
I decide to add 1 psi to that cylinder with my filler hose.
What happens to you inside that cylinder?

This scenario is totally different to your bus scenario.

The bus is open to the atmosphere.  Presumably your "cylinder is not.
Increasing the pressure in your cylinder is not the same as your bus "full" of air accelerating.  In any way, shape or form.
You're using an external pump (=work) to compress the air in your sealed cylinder.

—You need to ensure the goalposts aren't shifted midway through the problem.

Quote from: sceptimatic on January 09, 2014, 09:15:18 AM

Quote from: Antonio on January 09, 2014, 09:07:20 AM

Quote from: sceptimatic on January 09, 2014, 08:28:29 AM

Quote from: Antonio on January 09, 2014, 08:23:43 AM

Quote from: sceptimatic on January 09, 2014, 08:03:34 AM

Quote from: Antonio on January 09, 2014, 07:40:18 AM

Totally lost now.
You say that the kid is pushed backwards out of the bus. How did he get this 40 mph forward motion, as the only force acting on him was the air pushing him backwards?

He is going 10 mph less speed than the bus as he leaves the back of the bus. The bus is displacing the air as it moves through it at 50 mph so in effect the bus is creating a low pressure environment around it as it pushes through it, so as the kid jumps out, he jumps straight into the oncoming  50 mph pressure but he's hitting it at 10 mph so by the time he hits the ground, the pressure carries him in the direction of the bus, except he's going backwards.

Quote from: Antonio on January 09, 2014, 07:40:18 AM

Other question. If the back of the bus is totally opened, there is no resistance to air. How does it work then ?

Well the kid was already out of the bus and the people inside the bus will be under no extra force anyway as the bus was at a steady speed.

Still unclear. What is the kid's speed and  direction when he is just about exiting the bus ?

I've just gave you all of that info, what's your problem with it?

Well, the kid starts going backwards, and then forward. Where does the direction change ?

What do you mean, backwards and forwards?

Let's start again.
You said that the air inside the bus pushes the kid backwards. So I assume he is going backwards while inside the bus correct ?
How did he gain 40mph forward, while receiving only backward forces ?

Let's fully start again because different people gave me different scenarios and I was asked if the back doors of the bus opened whilst the kid was on his skateboard, what would happen, so I simply placed the kid facing the back so he could skateboard out.

So let's start from scratch with this and I will respond exactly to your next post, because if I don't, this is in danger of being twisted to hell.

Quote from: sceptimatic on January 09, 2014, 08:37:01 AM

I put you on a BOLTED down seat inside a bus sized cylinder at 14.7 psi. You are sat facing the filler nozzle.
I decide to add 1 psi to that cylinder with my filler hose.
What happens to you inside that cylinder?

This scenario is totally different to your bus scenario.

The bus is open to the atmosphere.  Presumably your "cylinder is not.
Increasing the pressure in your cylinder is not the same as your bus "full" of air accelerating.  In any way, shape or form.
You're using an external pump (=work) to compress the air in your sealed cylinder.

—You need to ensure the goalposts aren't shifted midway through the problem.

And what do you think the bus is using to compress the air?

Quote from: Antonio on January 09, 2014, 09:25:52 AM

Quote from: sceptimatic on January 09, 2014, 09:15:18 AM

Quote from: Antonio on January 09, 2014, 09:07:20 AM

Quote from: sceptimatic on January 09, 2014, 08:28:29 AM

Quote from: Antonio on January 09, 2014, 08:23:43 AM

Quote from: sceptimatic on January 09, 2014, 08:03:34 AM

Quote from: Antonio on January 09, 2014, 07:40:18 AM

Totally lost now.
You say that the kid is pushed backwards out of the bus. How did he get this 40 mph forward motion, as the only force acting on him was the air pushing him backwards?

He is going 10 mph less speed than the bus as he leaves the back of the bus. The bus is displacing the air as it moves through it at 50 mph so in effect the bus is creating a low pressure environment around it as it pushes through it, so as the kid jumps out, he jumps straight into the oncoming  50 mph pressure but he's hitting it at 10 mph so by the time he hits the ground, the pressure carries him in the direction of the bus, except he's going backwards.

Quote from: Antonio on January 09, 2014, 07:40:18 AM

Other question. If the back of the bus is totally opened, there is no resistance to air. How does it work then ?

Well the kid was already out of the bus and the people inside the bus will be under no extra force anyway as the bus was at a steady speed.

Still unclear. What is the kid's speed and  direction when he is just about exiting the bus ?

I've just gave you all of that info, what's your problem with it?

Well, the kid starts going backwards, and then forward. Where does the direction change ?

What do you mean, backwards and forwards?

Let's start again.
You said that the air inside the bus pushes the kid backwards. So I assume he is going backwards while inside the bus correct ?
How did he gain 40mph forward, while receiving only backward forces ?

Let's fully start again because different people gave me different scenarios and I was asked if the back doors of the bus opened whilst the kid was on his skateboard, what would happen, so I simply placed the kid facing the back so he could skateboard out.

So let's start from scratch with this and I will respond exactly to your next post, because if I don't, this is in danger of being twisted to hell.

He just did start again. How did he gain speed in the opposite direction (forward) of the force pushing him (backward)?

Quote from: ausGeoff on January 09, 2014, 09:28:57 AM

Quote from: sceptimatic on January 09, 2014, 08:37:01 AM

I put you on a BOLTED down seat inside a bus sized cylinder at 14.7 psi. You are sat facing the filler nozzle.
I decide to add 1 psi to that cylinder with my filler hose.
What happens to you inside that cylinder?

This scenario is totally different to your bus scenario.

The bus is open to the atmosphere.  Presumably your "cylinder is not.
Increasing the pressure in your cylinder is not the same as your bus "full" of air accelerating.  In any way, shape or form.
You're using an external pump (=work) to compress the air in your sealed cylinder.

—You need to ensure the goalposts aren't shifted midway through the problem.

And what do you think the bus is using to compress the air?

A real bus doesn't compress air inside of a cabin. It is not air tight like the cylinder you are talking about. As I already mentioned the same stuff happens on the back of an open trailer bed of a large semi.

Quote from: hewholikespie on January 09, 2014, 09:10:09 AM

Quote from: sceptimatic on January 08, 2014, 02:37:53 PM

Quote from: hewholikespie on January 08, 2014, 01:20:16 PM

Sceptipoo, a question- I have two Steel balls. One is solid and half a meter in diameter. One is hollow and one meter in diameter. The hollow one is completely airtight, and has a 1 centimeter thick outer shell.

Which of these two steel balls takes more effort to get moving?

The solid half a metre ball would take a lot more energy to get it into motion than the larger airtight ball due to it having more density against the ground.

Why would it have more 'density against the ground' since under your model, it is air pressure from above that pushes objects towards the ground. Why would the object with the smaller surface area have the greater Air Pressure pushing on it?

Who said it had greater air pressure pushing on it?

The larger sphere has a greater surface area. More surface area means more air to push down on. This means that air is exerting more overall pressure to the larger sphere, even if the two objects are at the same altitude.

And what do you think the bus is using to compress the air?

There is no pump being used to "compress" the air in the bus (obviously).  In fact, there is no mechanical means of doing so whatsoever.

One cannot compress any of the air in the bus simply because it's open to the atmosphere.  Imagine drilling a tiny hole in your cylinder.  You'd never be able to increase the internal air pressure by even 1psi.

The larger sphere has a greater surface area. More surface area means more air to push down on. This means that air is exerting more overall pressure to the larger sphere, even if the two objects are at the same altitude.

Atmospheric air pressure exerts a force equal at, and perpendicular to, every point on the sphere's surface.  The air pressure exerted on both sphere's is identical, that is 1 atm =101,325 Pa (in the metric system).

Just as I pumped more compressed air into the cylinder with a pump, the same can be said of the bus using it's engine to travel against the air and compressing it against it's windscreen and front and around the sides of the bus to the back.
It's created high pressure on the outside windscreen and front and around the bus, yet the back is creating a low pressure always behind it that the high pressure fills all the time.

The same happens inside, except this time the air inside is compressed onto the back window which leaves the opposite effect of low pressure on the inside front that is filled, creating more internal pressure as the bus accelerates.
It's unbalanced atmospheric forces that keep balancing out and unbalancing, etc, etc, for as long as the bus accelerates.

Once the bus reaches a set speed...the air pressure inside returns to a fairly balanced state, but outside will always be a high v low pressure  fight for as long as the bus is in motion against the outside atmospheric friction upon it.

Quote from: sceptimatic on January 09, 2014, 09:18:20 AM

Quote from: hewholikespie on January 09, 2014, 09:10:09 AM

Quote from: sceptimatic on January 08, 2014, 02:37:53 PM

Quote from: hewholikespie on January 08, 2014, 01:20:16 PM

Sceptipoo, a question- I have two Steel balls. One is solid and half a meter in diameter. One is hollow and one meter in diameter. The hollow one is completely airtight, and has a 1 centimeter thick outer shell.

Which of these two steel balls takes more effort to get moving?

The solid half a metre ball would take a lot more energy to get it into motion than the larger airtight ball due to it having more density against the ground.

Why would it have more 'density against the ground' since under your model, it is air pressure from above that pushes objects towards the ground. Why would the object with the smaller surface area have the greater Air Pressure pushing on it?

Who said it had greater air pressure pushing on it?

The larger sphere has a greater surface area. More surface area means more air to push down on. This means that air is exerting more overall pressure to the larger sphere, even if the two objects are at the same altitude.

Yes, so why are you making out I said the smaller ball had more pressure on it?

Quote from: sceptimatic on January 09, 2014, 09:33:34 AM

And what do you think the bus is using to compress the air?

There is no pump being used to "compress" the air in the bus (obviously).  In fact, there is no mechanical means of doing so whatsoever.

One cannot compress any of the air in the bus simply because it's open to the atmosphere.  Imagine drilling a tiny hole in your cylinder.  You'd never be able to increase the internal air pressure by even 1psi.

The bus itself is the pump, driven by it's own engine that drives against the external atmosphere.

Just as I pumped more compressed air into the cylinder with a pump, the same can be said of the bus using it's engine [...]

Apparently I didn't make this clear in my earlier post.  Sorry.

The bus is open to the outside atmosphere;  the cylinder is sealed from the outside atmosphere.

It's a physical impossibility to compress any gas in an open container.

Quote from: sceptimatic on January 09, 2014, 09:51:56 AM

Just as I pumped more compressed air into the cylinder with a pump, the same can be said of the bus using it's engine [...]

Apparently I didn't make this clear in my earlier post.  Sorry.

The bus is open to the outside atmosphere;  the cylinder is sealed from the outside atmosphere.

It's a physical impossibility to compress any gas in an open container.

Not if the compression is gradual as it would be on an accelerating bus against atmospheric pressure.
Think about it.

The bus itself is the pump, driven by it's own engine that drives against the external atmosphere.

It's immaterial the your bus even has an engine.  Think of it freewheeling down a steep hill with the engine turned off, and coming to rest at the bottom of the hill. 

At any rate, the buses engine—even when it's going—is not exerting any pressure on the air inside the bus.  There is no applied force acting on this air, other than the tiny force due to gravity.  There is no compressive force being exerted on the air.

Not if the compression is gradual as it would be on an accelerating bus against atmospheric pressure.

The rate of compression of a gas in a closed container is immaterial.

But again:  The bus is not a closed container, therefore the potential "compression" of the air is an impossibility.

Quote from: sceptimatic on January 09, 2014, 09:56:29 AM

The bus itself is the pump, driven by it's own engine that drives against the external atmosphere.

It's immaterial the your bus even has an engine.  Think of it freewheeling down a steep hill with the engine turned off, and coming to rest at the bottom of the hill. 

At any rate, the buses engine—even when it's going—is not exerting any pressure on the air inside the bus.  There is no applied force acting on this air, other than the tiny force due to gravity.  There is no compressive force being exerted on the air.

Let me try and put it in a simple to understand way.

You are in an open top car and it has a back window but no front windscreen. You decide to accelerate in that car from 0 to 100 mph in 5 seconds.
Question: Where would your back window be by the time you stop? would it be...
A. Still attached to the back of the car, intact like at the start.
B. A few miles back down the road.

Whichever answer  you give...tell me why.

Quote from: sceptimatic on January 09, 2014, 09:59:17 AM

Not if the compression is gradual as it would be on an accelerating bus against atmospheric pressure.

The rate of compression of a gas in a closed container is immaterial.

But again:  The bus is not a closed container, therefore the potential "compression" of the air is an impossibility.

You know this is wrong.

Quote from: hewholikespie on January 09, 2014, 09:41:30 AM

The larger sphere has a greater surface area. More surface area means more air to push down on. This means that air is exerting more overall pressure to the larger sphere, even if the two objects are at the same altitude.

Atmospheric air pressure exerts a force equal at, and perpendicular to, every point on the sphere's surface.  The air pressure exerted on both sphere's is identical, that is 1 atm =101,325 Pa (in the metric system).

I was operating under Scepti's atmospheric pressure handwavium where it somehow is not, for sake of argument. I should have specified that.

I was operating under Scepti's atmospheric pressure handwavium where it somehow is not, for sake of argument. I should have specified that.

Ahhh... okey-dokey.  No worries.

Quote from: Antonio on January 09, 2014, 09:25:52 AM

Quote from: sceptimatic on January 09, 2014, 09:15:18 AM

Quote from: Antonio on January 09, 2014, 09:07:20 AM

Quote from: sceptimatic on January 09, 2014, 08:28:29 AM

Quote from: Antonio on January 09, 2014, 08:23:43 AM

Quote from: sceptimatic on January 09, 2014, 08:03:34 AM

Quote from: Antonio on January 09, 2014, 07:40:18 AM

Totally lost now.
You say that the kid is pushed backwards out of the bus. How did he get this 40 mph forward motion, as the only force acting on him was the air pushing him backwards?

He is going 10 mph less speed than the bus as he leaves the back of the bus. The bus is displacing the air as it moves through it at 50 mph so in effect the bus is creating a low pressure environment around it as it pushes through it, so as the kid jumps out, he jumps straight into the oncoming  50 mph pressure but he's hitting it at 10 mph so by the time he hits the ground, the pressure carries him in the direction of the bus, except he's going backwards.

Quote from: Antonio on January 09, 2014, 07:40:18 AM

Other question. If the back of the bus is totally opened, there is no resistance to air. How does it work then ?

Well the kid was already out of the bus and the people inside the bus will be under no extra force anyway as the bus was at a steady speed.

Still unclear. What is the kid's speed and  direction when he is just about exiting the bus ?

I've just gave you all of that info, what's your problem with it?

Well, the kid starts going backwards, and then forward. Where does the direction change ?

What do you mean, backwards and forwards?

Let's start again.
You said that the air inside the bus pushes the kid backwards. So I assume he is going backwards while inside the bus correct ?
How did he gain 40mph forward, while receiving only backward forces ?

Let's fully start again because different people gave me different scenarios and I was asked if the back doors of the bus opened whilst the kid was on his skateboard, what would happen, so I simply placed the kid facing the back so he could skateboard out.

So let's start from scratch with this and I will respond exactly to your next post, because if I don't, this is in danger of being twisted to hell.

Experiment One:
A bus, a kid on a skateboard, placed just behind the driver, in the aisle . All doors closed.

We start with both the bus and the kid at rest, relative to the road. A starting line has been drawn on it and the kid is just above it.
Now, the bus starts, accelerating up to -say - 20 mph, when his rear end crosses the starting line.

What would be the speed of the kid just before he crashes into the rear glass of the bus, and its direction ? A rough estimate is ok.
What would be his position, relative to the starting line ?

Experiment One:
A bus, a kid on a skateboard, placed just behind the driver, in the aisle . All doors closed.

We start with both the bus and the kid at rest, relative to the road. A starting line has been drawn on it and the kid is just above it.
Now, the bus starts, accelerating up to -say - 20 mph, when his rear end crosses the starting line.

What would be the speed of the kid just before he crashes into the rear glass of the bus, and its direction ? A rough estimate is ok.
What would be his position, relative to the starting line ?

Is the bus still accelerating after it hits 20 or holding a constant 20 mph speed as the kid hits the line?

The solution to this problem depends on whether or not we consider the coefficient of friction between the floor of the bus and the kid to be zero (as he's on a skateboard).  There's be no horizontally applied external forces.

If that was theoretically the case, then the only force acting on the kid would be a vertical force due to gravity.  The kid's body would resist moving because of inertia, and therefore crash into the back of the bus at around 20 mph.

The solution to this problem depends on whether or not we consider the coefficient of friction between the floor of the bus and the kid to be zero (as he's on a skateboard).  There's be no horizontally applied external forces.

If that was theoretically the case, then the only force acting on the kid would be a vertical force due to gravity.  The kid's body would resist moving because of inertia, and therefore crash into the back of the bus at around 20 mph.

There is no such thing in reality as gravity or inertia and I swear on that. It's bogus.

Quote from: ausGeoff on January 09, 2014, 12:01:32 PM

The solution to this problem depends on whether or not we consider the coefficient of friction between the floor of the bus and the kid to be zero (as he's on a skateboard).  There's be no horizontally applied external forces.

If that was theoretically the case, then the only force acting on the kid would be a vertical force due to gravity.  The kid's body would resist moving because of inertia, and therefore crash into the back of the bus at around 20 mph.

There is no such thing in reality as gravity or inertia and I swear on that. It's bogus.

I'm afraid your constant denials about the existence of gravity and inertia are totally baseless, and also out of sync with the rest of the entire modern scientific world.

And if you accept that an object has mass, then by default you accept that it has inertia.

Or do you believe an object can exist with zero mass (and therefore zero inertia?).

I prefer to stick to density of any object of matter. I've explained quite clearly why gravity and inertia are simply bogus science.
I noticed you didn't answer the car questions. Did you over look it or do you prefer not to answer?

rld.

And if you accept that an object has mass, then by default you accept that it has inertia.

Or do you believe an object can exist with zero mass (and therefore zero inertia?).

he already accepts that air has inertia or it would move exactly in synch with a bus and there would be no pressure variance.