Split Thread The validity of classical physics (split from: DWFTTW)

[Modified]

Cool, I worked on some cockpit avionics for the F22, C130, and CH46. Moving map displays, waypoints and navigation stuff, artificial horizon, compass bearing, heads up display, targeting info. Everything you can put on a digital display on LCD screens. stuff like that.

What did you work on?

My guess is cup holders.

 

[sol invictus]

Too many assumptions. The answer is interdeterminate, yet I can make it be whatever I wish.
a) You are assuming that the kites are identical. What if they are not?
b) The cyclist may stop for lunch, or may start drafting behind a truck.
c) A bird may pick up one, or the other, kite.
d) Either kite may be struck by lightning.
e) One of those "boys" may in fact be a girl.
f) Once the strings break, the Nebraskan may get on his motorcycle and in a couple of minutes he will be around the track, or more!
g) One of the kites may actually be a treadmill. HAH! You won't fool me that easily! A treadmill is not a kite!
h) The altitudes may be different in the two states, and thus the air density will whether only some by.
i) Any fool knows that the Nebraska kite will never reach the ground, it will continue to be blown along like a feather, while the Kansas kite will plummet like a hammer dropped on the moon. It is the same as a bullet fired from a gun, compared to one dropped onto a treadmill. That is why the sky is now littered with kites, and the sunlight no longer reaches the ground, and we all dwell in the darkness like moles, or the chiropterids that I am still trying to evict from the church. I remember in my youth when we could still see the sunshine, and I long for those days. And we didn't have to crawl on our bellies back then, either, because there were no bullets perpetually whizzing around at chest height. There is supposedly a government program to teach butterflies to eat the kites, but I haven't seen any results thus far.

This was a masterwork - pure 100% humoronic (and very humorous). You're getting humber and humber with every post. Soon, you may achieve the humberist!

 

[spork]

Poll update:

Does humber really understand physics more than is apparent in this thread?

And the results:

Yes:
Clive: He Understands Much But Excludes Reason.
recursive prophet: but qualified
Semper: Yes, but not much.
humb: Of course he does. In addition to the wealth of information that he has provided you with, I have no doubt that he has comparable expertise in other branches of physics.
John Freestone: with reluctance


NO:
spork: his confusion is legit
subduction zone: only a true believer would keep this nonsense up for 65 pages and over 2,500 posts.
mender: I believe that humber is presenting things as he understands them.
Dan O.: humber doesn't have the background to be faking it.
Michael C.
Fredriks: Humber don't know more physics than it seems to but it is possibly that he to some extent know that everything he says is incorrect but that he like to write nonsense on the internet anyway.
GregLondon: I'm not a gambling man, but I'd wager a sandwich that Humber doesn't know physics more than he has revealed in the thread.
RossFW: Doesn't know how a kite works

 

[sol invictus]

Poll update:

I think humber is your sock puppet - so he only knows what you tell him .

 

[ThinAirDesigns]

Poll update:

Does humber really understand physics more than is apparent in this thread?

I'm sticking to John's Goldfish theory.

JB

 

[Dan O.]

I think humber is your sock puppet - so he only knows what you tell him .

I believe you said that in jest. But if anyone has any evidence of sock puppetry, they should report it to the moderators or admins. Having only one account is partly intended to make people think about how they present themselves here. You can't just start over after playing a fool, you have to live with your past.

 

[recursive prophet]

Book 'im, DanO.

 

[humber]

It is one of those things that "ordinary people" might expect, that if we race along the ground pulling something (airborne or otherwise), then let go, it will have momentum that will carry it forward in such a manner as differentiates it from the other scenario - standing still with something (air) pulling on an object, which we then let go of.

Then they are right. That object will be carried forward by its momentum. If ti looses no energy, then it will continue at the same velocity. If not, and it looses energy to friction, then it will slow, and come to a stop when all of the KE is dissipated.

Ordinary people (and some extraordinarily vocal ones) imagine that a body moving with respect to the earth has momentum, absolute momentum, and not one that is stationary w.r.t. the earth. As we have discussed for months now, velocity is relative to a position, the Earth has no special place, and hence humber's latest (recycled) argument still fails.

It has momentum. That is all that it needs to know. If you always need to add 'relative to' before accepting that it can be moving, then you are denying that object's independent existence.

If one doubts this, he only has to imagine that the "killoon" is extremely massive, has no area to be dragged by the air, yet is held up by a mysterious force while pulled (in the way a kite is held up by the air).

Then that object can't exist.

Then, when the Earth-motion-in still air one is let loose, its enormous momentum will cause it to continue to move, following the cyclist or whatever, be accelerated due to gravity, and, since it is not dragged by the air, will land right at the back wheel, assuming it was held vertically above the back wheel. Both cyclist and object will continue to travel together. The Earth-stationary one will simply fall, a dead weight, landing vertically underneath where it was held.

Fiction. A story about an imaginary object.

 

[mender]

If the first remark is true, then my scenario is also good.

Yes, it is just fine, it is your preconceived conclusion that is wrong. I focused in on the part that you are getting wrong every time you draw.

Hey, is this humber physics or Charlie Brown physics?

The treadmill is flawed and that is a fact.

Your arguments about the treadmill are flawed and that is a fact that only you can change.

I have added more details again and gain, and now there is a balloon example. I will not address anything else.

I see you avoiding answering questions by changing the subject again and again whenever you can't come up with more than a smart remark.

 

[mender]

Fiction. A story about an imaginary object.

This from the guy who invoked Anubis and his magic flying kite.

 

[humber]

All those words and yet not a single attempt to answer the 2 simple questions:

1) Which kite hits the ground first?
2) Which kite is the greater distance from its owner when it hits the ground?

JB

I wrote an answer because I though it was from jjcote, but then I saw it was from you.

 

[humber]

Wow, the number of posts in a day is amazing.



Cool, I worked on some cockpit avionics for the F22, C130, and CH46. Moving map displays, waypoints and navigation stuff, artificial horizon, compass bearing, heads up display, targeting info. Everything you can put on a digital display on LCD screens. stuff like that.

What did you work on?

Airbus LCD's.

 

[jjcote]

All those words and yet not a single attempt to answer the 2 simple questions:

1) Which kite hits the ground first?
2) Which kite is the greater distance from its owner when it hits the ground?

JB

I wrote an answer because I though it was from jjcote, but then I saw it was from you.

And for some reason you think I'm not still here, waiting for an answer?

 

[humber]

Newton would find your assertion that there is motion toward the observer in all frames quite fascinating, I suspect. You don't know what a frame is, and apparently never will, because it would be impossible to utter such an inane statement if you did.

(1) The belt observer will see it ( motion w.r.t to the balloon), unless you think that the balloon becomes invisible when released.
(2) The balloon observer will see if for the same reason. (otion w.r.t to the belt observer)
(This must be true, if for no other reason than the air is common to belt and balloon)
The treadmill observer can see both the balloon and the observer, so he will see that motion as relative motion between observer and balloon, giving the same result as in (1) and (2). It is not necessary to define the motion as towards the observer, but that the (relative) difference is smaller or larger. The "windspeed" observer must see it, because the motion must be relative to the air. Seems solid to me.

Heavens no, you've got our rapt attention now. Please expound for us on how you can keep an inert, untethered, heavier-than-air object aloft indefinitely in a horizontal wind.

Tunny

Aren't gliders heavier than air?
It does not have to be indefinitely, but longer than the treadmill. I think that should be no problem. Even air-filled party balloons can stay aloft in the wind.
You are right of course, a heavier than air balloon will fall to the ground in still air, which is why it does so on the treadmill, but the real wind is a continuous source of energy that can provide lift, and the force to drive the balloon along with it, whereas treadmill "wind" is only energetic when powered by belt, and that stops once the string is released.
A test using a device that relied solely on aerodynamic lift would show an even greater difference, I suspect.

Earlier, I had been assured that all wind-borne objects would reach windspeed, but now it is doubted that even a balloon will stay aloft, at any speed.

 

[jjcote]

Assuming no thermals, can a glider stay in the air over a flat landscape for longer on a calm day or a windy day? And on the windy day, does it matter which direction the glider flies?

 

[humber]

partial post.

 

[humber]

And for some reason you think I'm not still here, waiting for an answer?

You can't find the answers within the text of my previous post, jjcote?
So let's plug that rabbit hole.
(1) The balloon pulled by the bike will fall first. (Kansas)
(2) The balloon in the wind will travel the greatest distance. (Nebraska.)

(a)The last case is not the same as the treadmill, because when the balloon falls to the belt, it travels with it. It does not remain behind as on the ground as in Kansas.

(b) This is because there is no separate road and ground on the treadmill.

(c) The fixed length of string is not something that can force a condition. The string can be removed as needed

 

[humber]

Recursive prophet, do you still think humber is carrying on a many-leveled parody, or is his concept of physics the parody on many levels?

"Tell me it can't be done. If you should succeed, I will find another object."

Humber, your game play won't allow you to actually learn from your mistakes. You need to find someone that you trust and show them your diagrams. Hopefully they will be able to change your mind. I obviously can't.

I am not making any mistakes, Mender.
That I can find as many exceptions as I wish, is a failure of the treadmill.

 

[jjcote]

You can't find the answers within the text of my previous post, jjcote?
So let's plug that rabbit hole.

Hey, check it out, gang! humber actually answered a question! Good show! You're making progress! Let's see how he did:

(1) The balloon pulled by the bike will fall first. (Kansas)

Wrong! Same time to the ground.

(2) The balloon in the wind will travel the greatest distance. (Nebraska.)

Wrong! Well, the statement could be considered true, but it isn't what I asked. I asked which will be the greatest distance from its owner. The Nebraska kite will travel further as seen by an observer stationary on the ground, but that will be matched by the distance that the bicycle travels in Kansas.

(And yes, they were kites, not balloons. If they were balloons that were on strings well above the kids' heads, then they would presumably float upward when released, which is an entirely different situation.)

(a)The last case is not the same as the treadmill, because when the balloon falls to the belt, it travels with it. It does not remain behind as on the ground as in Kansas.

That is quite true. But not at all relevant to the question that I asked, which was only about what happens before the kites hit the ground.

(b) This is because there is no separate road and ground on the treadmill.

Anybody know what this means?

(c) The fixed length of string is not something that can force a condition. The string can be removed as needed

Or this?

 

[humber]

A meteorological balloon doesn't stay airborne because of the wind, it stays airborne because it's lighter than the air. If it's heavier than the air, it descends, wind or no wind. The balloon doesn't care what the speed of the air over the ground is: it is only affected by the air around it. If you've ever ridden in a balloon, you'll have noticed that you don't feel any wind. It doesn't matter how much wind is measured at ground level: in the balloon no wind is felt because the balloon moves with the air.

No, the balloon needs only to get enough lift, or force to drive it. The mass/area ratio is important, but making the gas less dense than air is not necessary to staying aloft in a moving wind.

That's news: one balloon is real and one isn't? Since we're trying to make equivalent scenarios here, the two balloons are identical. You said that they are "not quite buoyant". They are therefore slightly heavier than the air, and will both slowly descend. They will both reach the horizontal speed of the air at the same time.

That is good enough. The only lift required, is to overcome the small pull of gravity. In still air, the balloon will fall even if only just shy of buoyant. The wind can easily provide enough lift to keep the balloon aloft. Bubbles can take a long time to settle to ground, but eventually do. However, even a small air current will keep them aloft.

You could test this easily with a helium-filled balloon from a novelty shop. Hang just enough weight on it so that it slowly descends to the floor when you release it indoors. Now go out on a day without wind, run a few metres while pulling it along, then let go. Note how long it takes to descend to the ground.

So we should compare the room air with still external air. That is a common factor to belt and wind. Still air is possible in the real world, but always so at windspeed.

When there's a day with a wind speed about the same as your running speed, hold it in the wind at the same height as when you were running with it, then let go. If you find that the balloon takes significantly longer to reach the ground in the second case, please alert NASA, the JREF and indeed the whole scientific community: you are capable of defying the laws of physics.

Why not. The vertical decent is due to gravity. A little lift can easily overcome that. Lift, force is not available to the balloon on the treadmill, once it is released.
If you hold to your position, then the balloon attached to the observer, will fall to the belt, and travel at a fixed distance to the observer, with no motion relative to the belt surface, but only if the string remains attached.

The problem is easily resolved. Make the balloons lighter than air, but different masses. That was the first balloon post. Those balloons will behave according to the formula in the meteorological book.
The two balloons are still lighter than air, but accelerate at different rates. They are the same distance apart when tethered, and remain essentially so when released from the belt mounting, but continue to move further apart when in the wind.