# ANGULAR MOMENTUM

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#### JackBlack

• 13765
##### Re: ANGULAR MOMENTUM
« Reply #30 on: December 25, 2018, 11:51:15 PM »
According to you stopping should be easy.
So if you were to take a jet and fly it straight at a wall then it should just stop be and be perfectly fine as it is just stopping.
But this happens:

What happened to the plane? It doesn't seem to exist anymore, but according to you should be just fine.

Surely once the car stops moving forward they should just stop. Yet instead the dummies keep moving and smash into the front.

#### cikljamas

• 2174
• Ex nihilo nihil fit
##### Re: ANGULAR MOMENTUM
« Reply #31 on: December 26, 2018, 08:47:30 AM »
You don't think anyone on that boat is feeling numerous large accelerations?

In your scenario, if you're being propelled through the water at 100 mi/hr when the direction of propulsion is rapidly turned 90°, you bet your sweet bippy that anyone aboard would feel it. If you change your direction of motion, that's an acceleration, and if it's large at all you will feel it, quite violently is if's large enough. This has nothing to do with to do with whether the water is moving relative to the land or not, or whether the earth is rotating.

1. It's true that these guys (when making sharp turns while going fast on the stationary waters) are subdued to g-forces, as well, so if we compare two scenarios (flowing river vs stationary waters) solely concentrating on the amount of g-forces that would be applied on our "Alpha-box" (in both scenarios) in a very brief moment of time (a.k.a. analyzing (and measuring the amount of applied g-forces) what is happening in the very first second of an impact (due to the sharp turn executed in one fraction of a second), then we would be faced with the similar results which we would get from analyzing one typical crash test (as Jack Black has illustrated in his last post).
And i must admit that i have figured out (not before long) (after putting such scenario through it's paces (within both FORs)) that an analysis of a typical crash test is not going to yield usable results in a sense that we could easily distinguish the expected differences regarding what would happen (a.k.a. what would be measured) in two different frames of reference (inertial vs non-inertial).

2. So, we shouldn't restrain our analysis only to what could be measured in the first second of an impact (since if we jumped in a stationary water from a helicopter which travels 100 miles per hour we would endure the same consequences as in a scenario in which we jumped from a stationary bridge in the river which flows 100 miles per hour).

However, try to imagine our "wicked" racing team as attempting to perform the same kind of a maneuvers (sharp turns at 90 degrees angle IN ALL DIRECTIONS (west, east, north, south) in the streaming water which flows at the same speed at which their little green-boat is propelled by the strong force of their mighty engine. Would you say that such maneuvers would be possible in such non-inertial environment? Of course you wouldn't say that.

Only you have to ask yourself : why it would be impossible for our "wicked" racing team to perform such sharp turns in a depicted non-inertial system (in which the speed of river's flow would be the same or very similar to the speed of their mighty boat)

When going upstream their relative speed (wrt river) would be let's say 75 miles per hour, and their absolute speed (wrt land) would be 0 miles per hour, when going downstream their relative speed (wrt river) would be also 75 miles per hour, and their absolute speed (wrt land) would be 150 miles per hour.

Now, you can say that they couldn't tell the difference. I already disagree, but the real problem is going to be revealed when they try to go sideways. On the calm waters there would be no difference (in whichever direction they go), but on the fast streaming river, going sideways would be a huge problem (in some aspects even much greater problem than when trying to sail upstream).

When going sideways even if they managed somehow to travel at 75 miles per hour their forward momentum would be equal to their sideways momentum, and that would be some very serious problem that every human being should have to overcome (attempting to retain their sense of equilibration).

That is exactly the problem which i pointed out in my CONCORDE argument (forward momentum would be equal to the sideways momentum).

You can object that the air is not the same thing as the water (that the resistance of air is much lesser than the resistance of water), and that this is the reason why we can't compare the dynamics of a moving objects that sail on the waters and the dynamics of a moving objects (an airplanes) that penetrate through the air.

But, then you have to face the second part of my CONCORDE argument :

So, if the air behaved like a gas, not like a water (which presumes gradual restoration of lost INITIAL INERTIA) we should expected such outcome : Even before leaving the ground concorde would cancel out more than 50 % of it's initial inertia (momentum). What does that mean? It means that at the very moment of taking off, concorde passengers should be able to notice (very perceptibly) rotational motion of the earth beneath them assuming that the pilot of concorde right after taking off, turns concorde to the left or to the right (it doesn't make any difference), so that their direction of flight is now perpendicular to the direction of earth's rotation. Concorde passengers should be able (while concorde is restoring it's initial angular momentum (which he had before taking off)) to see VERY DISTINCTLY AND PERCEPTIBLY how the earth is turning below them from their left side to their right side (if concorde has turned to the right), or from their right to their left (if concorde has turned to the left).

Let me remind you to the first part of my CONCORDE argument :

If the air behaved like a water, which presumes INSTANT RESTITUTION/REGAINING of partially lost INITIAL INERTIA of concorde, *passengers would be subdued (in the very moment the pilot of concorde abruptly turns an airplane to the right or to the left) to an effect of enormously strong abrupt instant sideways blow which would tend to carry concorde in a direction of earth's rotation.*

You see, the second part of my CONCORDE argument deals with INSTANT restitution of partially lost initial inertia. So, INSTANT restitution of partially lost initial inertia happens in water which is a VERY DENSE medium (in comparison with the air), no matter whether we are considering fast-moving-object scenario within inertial or non-inertial FOR.

Within HC scenario (supposed closed system with "glued" (stuck to rigid earth) air) the air is treated (interpreted) more like water, than like a gas. But, we don't see such effects that would match water characteristics (within alleged non-inertial system).

No wonder, since the air is not akin to water, and the earth doesn't rotate, as well.

3. Now, i am going to show you one interesting video in which one another racing team sails 150 miles per hour upstream the river which flows at about 5 miles per hour :

At about 8 min. in the video you can see how this insanely fast boat turns 90 degrees at the full speed (for which maneuver it took them a few seconds of time, and that is why it is much more convenient example (much more similar) to our CONCORDE scenario).

Try to imagine how would such 90 degrees turn look like on a river which would flow at 50 mile per hour (1/3 of boat's speed).

At about 13 min. in the video engine fails, and the boat turns 180 degrees in a second. Try to compare this situation (that happened on the slow streaming river = 5 miles per hour), with a hypothetical situation in which the speed of river's flow would be 10 times greater, and then tell me that there would be no difference.
« Last Edit: December 26, 2018, 10:55:25 AM by cikljamas »
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#### JackBlack

• 13765
##### RE: HOW DO THINGS MOVE????
« Reply #32 on: December 26, 2018, 11:57:31 AM »
so if we compare two scenarios (flowing river vs stationary waters)
We end up with the exact same result.

different frames of reference (inertial vs non-inertial).
But you aren't discussing inertial vs non-inertial. Like I said, pick a topic and stick to it.
Do you want to discuss how Earth is not an inertial frame of reference? If so, all this BS about boats and planes is irrelevant and you should be focusing solely upon the tiny acceleration due to Earth's rotation or the tidal forces from the sun.

Would you say that such maneuvers would be possible in such non-inertial environment?
You aren't describing a non-inertial system. You are appealing to a linear movement of the water which would allow it to be an inertial system and the boat would perform fine.
If you wish to focus on the non-inertial part you would need to bring up the Coriolis effect which would have no detectable impact on these boats.

Only you have to ask yourself : why it would be impossible
No, I would have to ask you that. You are the one asserting it is.

And your disagreement means nothing. Do you know why?
Because you have nothing more than baseless assertions.

the real problem is going to be revealed when they try to go sideways.

the problem which i pointed out
No, it was and remains a "problem" that you baselessly asserted, of which there is no justification for.

Let me remind you to the first part of my CONCORDE argument :
No need. We already know it and we know it is BS.
There is no magic instant gaining or losing of momentum. There is no magic instant turn.
Instead you have a plane flying relative to the air and as such it doesn't matter if the Earth, with the air with it, is moving or stationary. The same results would be expected.

So, INSTANT restitution of partially lost initial inertia happens in water
No it doesn't.
It happens much faster than in air, but it is not instant.

So you are still yet to show any actual problem except that you don't understand how motion works.

#### rabinoz

• 26528
• Real Earth Believer
##### Re: ANGULAR MOMENTUM
« Reply #33 on: December 26, 2018, 01:06:28 PM »
Let me remind you to the first part of my CONCORDE argument :
Get this straight! YOU HAVE NO VALID "CONCORDE argument".

Until you answer the following I will continue to claim that you have no valid argument:
The atmosphere, apart from comparatively low velocity local winds, rotates with the earth.
Hence an aeroplane takes off from a runway into air moving at almost the same absolute velocity as the runway so there is never any sudden change in velocity.
This applies to all aircraft wherever they take off from.

At one of the poles the earth (ice!) is rotating at the massive rate of 0.25°/minute with an atmosphere rotating at the same rate - big deal!

At 60° latitude the significant motion of the surface of the earth is a velocity of about 845 km/hr with an atmosphere moving at the same rate - big deal!

All your Concorde arguments with your "instant restoration of an initial inertia" are nothing more than strawman arguments, presumably based on your own ignorance.

#### MicroBeta

• 2433
##### Re: ANGULAR MOMENTUM
« Reply #34 on: December 27, 2018, 12:04:11 PM »
If rotational systems shouldn't be considered as inertial systems (given the constant change of the direction of motion) then the earth shouldn't be considered as inertial system, also. Am i right?

The earth is allegedly subdued to more than two different rotational motions :

1. Rotation on it's axis
2. Orbital motion around the sun
3. Galactic orbital motion around the center of the Milky Way. Our whole solar system allegedly orbits around the center of the Milky Way Galaxy. We are supposed to be moving at an average velocity of 828,000 km/hr.

The speed of our orbital motion around the sun is not a constant.
The speed of our galactic orbital motion around the center of the Milky Way is not a constant.

And we can never feel acceleration.
Very convincing, isn't it?
If you calculate the forces due to the rotation of the earth, the orbit of the earth around the sun, and the solar system around galaxy you would see that they are incredibly small.  AAMOF, you don't feel those forces because compared to the force due to gravity they are minuscule.  The force due to the rotation of the earth is over 300 times weaker than gravity.  The other two forces are so small as to be un-measurable.

If you do the calculations you'll see why we don't feel the "acceleration" you're asking about.

Mike
Since it costs 1.82¢ to produce a penny, putting in your 2¢ if really worth 3.64¢.