If anyone claims it is all about air pressure then they should do some real tests to prove it.
Agreed. Also, I've read through all 78 pages of this thread, but I'm not sure if the following question has been answered yet.
Let's go back to the bus example. Scepti, if the reason that people are pushed into their seats upon acceleration of the bus is due to the air from the front moving to the back because of air pressure, why do we not feel a rush of air hit us upon acceleration? If the air was truly rushing toward the back of the bus fast enough to push us into the seats, then we'd feel a rush of air hit us.
Because the air is compressed against you. It's in a container (the bus).
It is not blown against you as is passing you by as if you were on top of the bus.
Okay, if it's pressed against you, why do we not feel any compression in the front of our bodies? Surely if the pressure is enough to push us back against the seat, we'd feel the air being compressed against our bodies.
Have you ever been on one of these?
#" class="bbc_link" target="_blank" rel="noopener noreferrer">#If you have, you will notice that the pressure on you feels mild, but it's enough to make you stick to the wall when the floor drops.
This is very similar to when you travel in a vehicle that gradually gains speed. It's a gained pressure that simply pushes against your full body.
On a bus, you do not feel it on your body to the point of really noticing but take the head rest away and you will feel it on your neck muscles.
If there's a sharp acceleration, then there will be a sharp jerk of air onto you in COMPRESSED state, not as wind, like you would feel if the wind blew on you, because that wind can pass around you and over you which you feel as it's pouring friction all around your body by deflecting the pressure directly at you, around your body. The opposite effect is if you were riding a motorbike into that air friction.
Once that outside air hits you, it can do only two things. It can knock you off your bike , except that you have hold of the handle bars....or hit you and pass around you, so you feel that force by your body and the friction of it as it's deflecting around you, stretching your face, clothes and whatever.
In A bus, it's like you are put into a compressed air cylinder before being filled, knowing that it's at equal pressure.
It's then as though someone is adding pressure but as a build up that cannot pass around you because the back of the cylinder is closed, so it simply compresses the air and you towards the back of the cylinder.
At low speed, you barely notice it in motion of slow acceleration, except for the IMMEDIATE start off, which your body is not ready for, which you feel as a kick back...and as the acceleration builds up, your body is geared for it and you are reacting to it naturally, because that's how your body is geared to react to anything...it just isn't geared to react to SUDDEN movement.
It's like walking up a hill. You know what's coming as you walk, so your body changes angle to balance the forces.
Our bodies are equipped for the pressure we live under, or are born under and growing under, so we are equalized to that pressure and think it's nothing, It's anything BUT nothing. it's extremely strong which can be seen if you unbalance that force by creating a higher or lower pressure by whichever means you want to.
You can make a 10 foot flask of which you know that some of the air is evacuated from it. If you were to whack a hole into that flask, you would be pushed into it, because the atmosphere would immediately want to equalize the low pressure inside that flask and to get in, it would have to get past you, forcing you into it as well.
It's an extreme example but it would be a real scenario.
Then you have a compressed air cylinder that is under higher pressure than the air outside...so the air inside if the cylinder was whacked with a hole, would be explosive decompression of that and I think you've seen what that can do.
Can you see what I'm getting at?