Hammers, Balls and Feathers

[gfellow]

I did a search on the site to see if this question had been covered, and although the subject was breached, the thread drifted off leaving what seemed to be the original intent in its wake.
Tucson_Tim's post triggered my Google Alert and I initially posted the question there. He suggested - in the kindest way - that it might be suited better elsewhere on the site, and I have taken his advice. So...

Some might consider this nit-picking, but in the spirit of Eddington, sometimes it is the minor discrepancies (Mercury's orbit, eclipse displacement of stars) that make for new directions...

Galileo's rolling balls work fine, but over distance drag from air resistance would mean that the larger, more massive ball arrives first.
The famous Hammer and Feather on the Moon demonstration also works, but dropped from an altitude of 300 miles, the feather would be subject to interference from solar wind and would - unless driven directly by the wind - arrive after the hammer.

Even in the thinnest intergalactic space, any given cubic centimeter is awash in activity. Virtual particles spontaneously come into existence, then blink out again. Radiation permeates this thinnest of space. Whole atoms, unhindered, reach such high velocities that a plethora of them pass through a given cubic centimeter at any given time.
ALL space appears to be a fabric of interference, so the laws of pressure are just as relevant in outer space as within the boundaries of our own atmosphere, just on a much bigger scale.

...so my question - in the strictest sense - is there a problem with our present reasoning about the behavior of mass and motion, if the experiments upon which we base our reasoning show discrepancies? Or am I just being too nit-picky?

Addendum: In my original posting, a senior forum member named George was kind enough to send me this intriguing link which - if this topic is of interest - you might enjoy.

[Hornblower]

Addendum: In my original posting, a senior forum member named George was kind enough to send me this intriguing link which - if this topic is of interest - you might enjoy.

Here is a long-running thread on this anomaly topic, started by one of our administrators.

http://www.bautforum.com/astronomy/7...ce-probes.html

[Wizard From Oz]

I recall one of the Luna missions. The Astronaut stood with a feather and a hammer and calmly pronounced "If these dont hit the surface at the same time, we are not comming home"

After droppping the feather and hammer, he said "By golly Gallileo was right"

[NEOWatcher]

......so my question - in the strictest sense - is there a problem with our present reasoning about the behavior of mass and motion, if the experiments upon which we base our reasoning show discrepancies? Or am I just being too nit-picky?

Well; I think that this statement explains a lot of your puzzle right there.

The reasoning is not based on experimentation.
The reasoning is based on observation. Experimentation is based on the reasoning, and, can only be as valid as the understanding of the reasoning at the time.

Experimental anomalies usually arise from an incomplete reasoning. Experiments are designed with precision limits in mind.

[R.A.F.]

I recall one of the Luna missions. The Astronaut stood with a feather and a hammer and calmly pronounced "If these dont hit the surface at the same time, we are not comming home"

I don't recall any astronaut saying anything of the sort...

Sure you're not exaggerating a bit?

[alainprice]

I found the following Apollo 15 transcript which may be helpful:
http://history.nasa.gov/alsj/a15/a15.clsout3.html

[a1call]

Some might consider this nit-picking, but in the spirit of Eddington, sometimes it is the minor discrepancies (Mercury's orbit, eclipse displacement of stars) that make for new directions...

Galileo's rolling balls work fine, but over distance drag from air resistance would mean that the larger, more massive ball arrives first.

In the same spirit, not necessarily. Drag is very complex and depends on more than just mass:

Drag depends on the density of the air, the square of the velocity, the air's viscosity and compressibility, the size and shape of the body, and the body's inclination to the flow. In general, the dependence on body shape, inclination, air viscosity, and compressibility is very complex.

A parachute and its occupant are generally heavier (more massive) than a quarter but would fall slower.

[gfellow]

Sooo,

Does this mean I can can sit back and relax? The mass/motion is in good shape and I can stop worrying?

[Nowhere Man]

I recall one of the Luna missions. The Astronaut stood with a feather and a hammer and calmly pronounced "If these dont [sic] hit the surface at the same time, we are not comming [sic] home"

That would be a real trick, since the (Soviet) Luna missions were all unmanned. Now, Apollo, on the other hand...

Fred

[grant hutchison]

Sooo,

Does this mean I can can sit back and relax? The mass/motion is in good shape and I can stop worrying?

Well, we understand drag and pressure using the same Newtonian principles (mass and motion) as we use to understand the fall of hammer and feather. The same understanding applies equally to the idealized experiment and to the messiness of the real world.
I believe you may relax.

Grant Hutchison

[gfellow]

the idealized experiment

Hi Grant - Doesn't the idealized experiment imply a locale or region somewhere in the known Universe where the experiment can operate?
Like the discovery of background radiation, isn't the absence of an absolute vacuum incredibly significant?
Does it not cast doubt on our very notions of mass and motion?
If we only know that things move in space filled with 'stuff', how do we know that anything moves in space with nothing in it?
Is space with nothing in it space, or something else?
Can a volume of nothing exist?

[WayneFrancis]

The theory is that in a complete vacuum the 2 objects will fall at the same rate.

The idea that if you dropped them from 300 miles up you would be able to see that they don't drop at the same rate do to forces like solar winds has no bearing on the original theory because that solar wind isn't part of a complete vacuum.

[Middenrat]

gfellow thanks for such an elegant and entertaining post. I think I see what you're driving at and you can sleep easy tonight - the sun is still going to come up
If you calculate the minute forces which might impart on a body in the notional 'empty space' and integrate those results into the classical equations you will simply get a more accurate result. That we can for most purposes ignore them merely reflects their tiny influence.

[Wizard From Oz]

I don't recall any astronaut saying anything of the sort...

Sure you're not exaggerating a bit?

Allanprice has posted the transcript. I dont think I did too bad for a 38 year old memory of something I only saw once.

Now ask me my wifes birthday.........I got no hope lol

[Wizard From Oz]

That would be a real trick, since the (Soviet) Luna missions were all unmanned. Now, Apollo, on the other hand...

Fred

Excuse me Are you really claiming that Luna 15 wasnt manned by a KGB trained dwarf. I hope you have some serious proof to back up this ludicrious claim

[novaderrik]

Excuse me Are you really claiming that Luna 15 wasnt manned by a KGB trained dwarf. I hope you have some serious proof to back up this ludicrious claim

it was piloted by an invisible KGB trained elf that now lives in someone's back yard..

[gfellow]

Thanks for taking the trouble to ponder my question and I appreciate the comments.
Although the explanations are obviously well informed, I'm not altogether convinced that there's not a gremlin in the mix somewhere.

If one cannot observe or propagate an absolute vacuum, then I have to take it on faith that there is continuity, and -well...it just doesn't smell like the stuff of science to me.

I have trouble with it, that's all.

Thanks everyone, I appreciate your time.

[Wizard From Oz]

it was piloted by an invisible KGB trained elf that now lives in someone's back yard..

Wow I was not aware the Soviets had developed Stealth technology. You would not happen to have a link would you

[grant hutchison]

Hi Grant - Doesn't the idealized experiment imply a locale or region somewhere in the known Universe where the experiment can operate?

No, it doesn't: if it did it wouldn't be an idealized experiment. (When Plato came up with his notion of "ideals", he quite deliberately set them in a place we can only think about, not experience.)
So the idealized experiment is a way of understanding the world in small increments: first we mentally remove all interfering influences, then we put them back in again, one at a time, and finally check to see if the mental model we have thus assembled allows us to predict reality. Which it does. Newtonian mechanics is hugely successful in that regard. And that is all there is to science.

Grant Hutchison

[gfellow]

Hi Grant,

the idealized experiment is a way of understanding the world in small increments

The limitation of the idealized experiment is the surprising tipping points that sometimes appear in nature, like cream abruptly becoming butter.

It occurres to me that since all space has something in it, does that not define space?
Would an absolute vacuum not be the absence of space?
Might not the nature of such a volume be quite different from space?

[grant hutchison]

The limitation of the idealized experiment is the surprising tipping points that sometimes appear in nature, like cream abruptly becoming butter.

And if such an abrupt tipping point were ever encountered in real-world Newtonian mechanics, then of course we'd need to re-write the theory. Something of the sort occurred when we got into motions at near the speed of light, and had to develop special relativity: that was more of gentle gradient than a tipping point, however.
But so far Newtonian mechanics has stood up to rigorous and extensive testing, every day, constantly, in millions of ways.

It occurres to me that since all space has something in it, does that not define space?

Not conventionally: that defines "space with something in it".

Would an absolute vacuum not be the absence of space?

An absolute vacuum would be "space with nothing in it", conventionally.

Might not the nature of such a volume be quite different from space?

Different to the extent that it lacks things that space conventionally contains, certainly.


I think you're perhaps wanting science to do something it just doesn't do, can't do, and should never be expected to do: to describe reality in full detail. To be true, in other words.
Newtonian mechanics should never be mistaken for "how the world works": it's just an excellent way of codifying and predicting our experience of how the world works, in certain defined circumstances.

Grant Hutchison

[gfellow]

Hi Grant,

I enjoy your concise answers - you obviously have a clear mind.
One should never expect reality in full detail from science, but it is enjoyable to occasionally see new scientific experimentation broaden our library of knowledge from time to time.

[Gillianren]

It does happen all the time. It's just that many of the experiments refine such small things that the average person--or, in fact, anyone not in that field--doesn't know about it.

[gfellow]

I was talking to a friend who was familiar with ion pumps. He was telling me it uses electrons to sweep up errant particles. He was telling me how fantastically difficult it is to produce a partial vacuum and speculated that it was impossible to produce an absolute vacuum because the energy input to approach an absolute vacuum grows exponentially.

Fascinating if true - is it?

Seems reminiscent to the explanation why mass cannot attain the speed of light.

[Jeff Root]

A plethora of processes have the feature of diminishing returns. Depending
on exactly how you define "vacuum", I'm sure a perfect vacuum can be made
as long as you don't try to make it too big. Actually, I question whether the
energy grows exponentially. The cost, however, probably does.

-- Jeff, in Minneapolis