What is Gravity?

If NASA faked the moon landings, does the agency have any credibility at all? Was the Space Shuttle program also a hoax? Is the International Space Station another one? Do not dismiss these hypotheses offhand. Check out our wider NASA research and make up your own mind about it all.
hoi.polloi
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Re: What is Gravity?

Unread post by hoi.polloi » Sun Nov 17, 2013 11:44 pm

Another demonstration of forces which has been credited to our modern notion of gravity is something sometimes referred to as the Cavendish scale. I have had this explained to me as two balanced points pulled by massive objects as an attempt to 'weigh' gravity in some way. I think it would be useful to look into these things, and the above effects mentioned by kickstones, in order to begin to lay out for the average person what questions about forces exist (whether they have been answered by broader theories or not).

I am not yet prepared to call these mysterious forces by the same names as mainstream science just yet, since I have lost a lot of trust in the reliability of the consistency of pop science and their ability to separate phenomena. It seems there is a problem in modern science (perhaps just traceable back to human reason) where many different observed things are lumped together. Maybe the feeling I get from this modern 'gravity' theory started by Newton is akin to string theory hypothesizing to bridge relativity (with all its problems) to quantum physics (with all its problems) without many (any?) real ways to actually test the hypotheses. I would guess — actually, logically, I must guess until I spend time looking at it for myself — that gravity has given similar attention and clumsy lumping to various phenomena and may be one of the earlier broad attempts to 'unify' all the forces that make our world work.

Perhaps that is seen as a waste of time by most people who can't be bothered. I'm not yet sure I can be bothered with it. But for me, the revelations of CluesForum (regarding just how deeply we are hypnotized by nonsense) tell me we must re-examine, review and if possible reconduct the many basic experiments that seem too controlled (how it is recorded/conducted), shut up (locked behind guarded, closed gates and doors, frankly) and analyzed (analyzable) by some militant/zealot power that would have us believe erroneous information, or have us map the world in a wrong (maybe oversimplified?) manner.

fbenario
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Re: What is Gravity?

Unread post by fbenario » Mon Nov 18, 2013 1:33 am

hoi.polloi wrote: the revelations of CluesForum (regarding just how deeply we are hypnotized by nonsense) tell me we must re-examine, review and if possible reconduct the many basic experiments that seem too controlled (how it is recorded/conducted), shut up (locked behind guarded, closed gates and doors, frankly) and analyzed (analyzable) by some militant/zealot power that would have us believe erroneous information, or have us map the world in a wrong (maybe oversimplified?) manner.
Awesome summary of the forces arrayed against our innate common sense. Hypnotized by nonsense, indeed!

dalai
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Re: What is Gravity?

Unread post by dalai » Thu Jan 02, 2014 9:54 pm

Lately, I've been thinking about the concept of constants in physics. We all are taught to believe that gravitational force of two bodies of mass is directly proportional to the product of the their masses and inversely proportional to the square of the distance between them. But gravity is supposed to be a force. Which is kg*m/s^2. So we get a constant which translates this kg^2/m^2 to kg*m/s^2, which is conveniently m^3/kg*s^2.

The fallacy here is this: if this force depends on the magnitude of two masses, how can you later divide the result by mass? What is dividing by mass? Which mass? Which object's mass is later irrelevant? How can you take one mass as mass and the other one in absolute value? Only its magnitude but not what it is? How is this possible? What does sheer magnitude mean in physics? I think this alone proves that this effect has nothing to do with mass. I could say that it was due to their volumes m^3*m^3 and then multiply it by kg/m^5*s^2 (dalai constant I name it) and get kg*m/s^2 (force). If Newton can do it, so can I.

Two masses do not generate a force between them, at least not due to their masses. What we call gravity is actually a constant acceleration and that is all we can say about it.

This is also probably why two objects accelerate at the same rate regardless of their masses. It's because it has nothing to do with their masses. Probably the electromagnetic interaction is the only real one as someone above mentioned. Newtonian gravity was invented to cover up how big a mind fuck the heliocentric spherical model is. I also believe that nuclear energy is a hoax too. Not only the nuclear bomb, the concept as a whole. So the four fundamental interaction is down to one. There goes the unified theory. :P

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Re: What is Gravity?

Unread post by simonshack » Thu May 14, 2015 2:26 am

*


IS "GRAVITY" JUST ATMOSPHERIC PRESSURE?

This very thread started off with a number of posts by skeptics of the thesis put forth by our now apparently 'estranged' member, Sceppy - who proposed that what we call "gravity" is nothing but atmospheric pressure. As it is, I was not among those skeptics - as this concept / idea has been trotting in my mind for quite some time. I will now "boldly" try and illustrate to the best of my capacities what, hopefully, may come across as a reasonable / rational attempt at tackling what surely is one of the greatest, still unsolved mysteries of our universe. To be sure, even this world's "scientific establishment" admits that 'gravity' is a still utterly unsolved / unexplained phenomenon:
"It's the force we all know about and think we understand. It keeps our feet firmly on the ground and our world circling the sun. Yet look a little closer, and the certainties start to float away, revealing gravity as the most puzzling and least understood of the four fundamental forces of nature." http://www.newscientist.com/special/sev ... ut-gravity

"All the other forces in nature have opposites. In the case of the electromagnetic force, for example, it can attract or repel, depending on the charges of the bodies involved. So what makes gravity different?"

http://www.newscientist.com/article/mg2 ... -pull.html
For the purpose of this discourse, please make a mental note of the above words : "attract & repel".

If there is one thing I can firmly agree with - as regards to Mr. Newton's various assertions and 'laws' - it is that of his famed 'equal-and-opposite-force-reaction' observations. That is, if we can observe a force exerting a... well ... a force on something, then we must assume that an equal-and-opposite force is being exerted 'on the other end' of the same. With 'gravity', we have this force which - apparently and to the 'best' of our perceptions - is just "PULLING" us towards the ground, yet we really have no idea (or have never rationally explained) as to what sort of force exerts that apparent "pulling" effect - nor of what kind of opposite reaction (if any) is exerted at the other end that mysterious force.

We rarely think of how much air / atmospheric pressure we all have around us (we're talking about a tremendous force of some 10.000kg 'pressing in' at all times on our bodies). Here's a simple experiment reminding us of this fact:
"The atmosphere applies a pressure of about 100 000 N to every square metre on Earth's surface. We take this pressure for granted because we have the same amount of pressure pushing out. But what happens when the pressure of the atmosphere is applied to an object with no outward pressure? It implodes. In spectacular fashion."
https://www.youtube.com/watch?v=p3b9pK-O6cE
So, without further ado, let me get to the point. We can all agree that, by simply filling a balloon with hot air, we can 'suspend' or, in other words 'vanquish and nullify' gravity - and the so-called "weight" of our earthly bodies. Here's a humorous (fake yet thought-provoking) image to illustrate this fact:

Image

The above-depicted man is, technically speaking, not only weightless: since he's being pushed up and away from earth (and "gravity"), his weight is actually 'negative' - i.e. "X" amount of weight / force less than ZERO (pushing upwards). Of course, this doesn't mean that his body has lost any of its mass - it only means that it is being vectored upwards thanks to the hot air in the balloon (or what we have come to call the "buoyancy" exerted by the balloon's hot air). Now, please stop and think about it for a moment: if ALL it takes to vanquish "gravity" is a given volume of hot air, what does this tell us about the role & relevance of AIR - within the concept that we have defined as "weight" (as in the "PULL of gravity") ?

We know that balloons (filled with any lighter-than-air gas known to man - such as hot air, hydrogen or helium) will eventually stop ascending at an altitude of 50km or thereabouts (the current World Record stands at 50km of altitude or so). This, because the surrounding atmosphere-pressure at those altitudes equals the pressure of the gas inside the balloon. As it is, (aside from the claims of NASA's pathetic fable-factory) no man-made flight vessel is known to have reached altitudes beyond circa 50km. I will henceforth - playfully - call this circa 50km altitude boundary the "BARMAN LINE" (an altitude beyond which any man is barred from accessing) - which is a little word play on the well-known "KARMAN LINE" - the approx 100km altitude boundary defined as "the edge of space" where vacuum (or near-vacuum) of space sets in.

Let me now introduce you to "FAT MAN" - an imaginary man with huge lungs. Let us imagine that my FAT MAN was born with the organic faculty of filling himself with HOT AIR and thus, defy "gravity". Logically, if my theoretical "FAT MAN" filled with HOT AIR would exist, he would most certainly (due to what we know and can empirically verify with ascending hot air balloons) be hovering WAY above our earth's surface - perhaps somewhere around the "BARMAN" LINE, as illustrated below:

Image
(Yes, the "Barman line" is a play on words with the"Kármán line")

Now, would FAT MAN call the force / pressure which sustains him as he walks along the Barman Line ..."GRAVITY"?
Or would he, more logically, conclude that he is being PUSHED upwards by the pressure of earth's atmosphere - just as we earth-dwellers are being PUSHED down towards the ground (at the other end) by the very same - yet opposite - force?

On this forum we often (and justly) lament that many so-called "scientifically established cosmic facts" cannot be reproduced / experimented and verified here on earth - under empirically observable conditions. The concept of "GRAVITY" (as proposed by Mr. Newton) is certainly one of (or perhaps the foremost) such 'grey area'. However, I think we can all agree that ANY gas inside of any given pressure chamber (or pressure vessel - such as, say, the gas inside a scuba diver's oxygen tank) will exert an equal force on all of its interior walls. I hereby propose that the "walls" of our earth's atmosphere "pressure vessel" are constituted by the earth's surface (on one side) and the so-called 'vacuum of space' (on the opposite side - i.e. my above-mentioned "Barman Line").

This is when I will ask you, dear reader, to consider that we may be well be living inside a "pressure chamber" of sorts. This "pressure chamber" would be what we call the "earth's atmosphere". The bottom of this pressure chamber would be the surface of earth ("P2" in my below diagram) - while the top would be the vacuum of space ("P1" in my below diagram). Ok, so how exactly the latter (the ACTION/ REACTION of vacuum of space/ against atmosphere) would work - is probably something needing further study in order for us to fully understand. However, and as Aristotle once said, "nature abhors a vacuum" - or, in other words (and undeniably so) - vacuum REPELS air.

Image

So, we may ask ourselves, HOW was earth's atmosphere formed? Wouldn't earthly objects have flown off into space BEFORE the atmosphere (and its downward pressure) came to be? Could it be that, as mainstream science has it, oxygen (for instance) was created through photosynthesis from trees / algae and vegetation? To be sure, trees / forests are firmly anchored to the ground - and could well have resisted the initial 'problem' of a spinning earth - what with its centrifugal force (a quandary which anyone questioning the spinning earth naturally entertains). Gradually, perhaps (but who am I to know - I'm only venturing a wild guess here) the atmosphere pressure would have built up (and so providing the necessary pressure / "gravity" force for earthly matter - such as our oceans' waters - to 'stick' to earth) - and eventually allowing other (non-anchored-to-earth) life forms to develop.

In any case, I hope that my humble / tentative take on what we call "gravity" makes sound sense - insofar that it proposes a physically plausible "action/and opposite reaction force" which, on one end, PUSHES (denser-than-air-objects) down towards the earth's surface and, on the other end, PUSHES (thinner-than-air objects) up towards the "edge of outer space" (or, as I call it, the "BARMAN LINE"). Our atmosphere acts as a "pressure chamber" - and what we call "gravity" is by no means a mystical / mysterious / inexplicable "PULLING force", as cryptically postulated by Mr. Newton.

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Re: What is Gravity?

Unread post by ICfreely » Thu May 14, 2015 5:45 am

Dear Simon,

It’s important that we ‘mere mortals’ question our ‘gods of scientism’ & take nothing for granted. I’m not sure that every action has an equal and opposite reaction. Here’s some food for thought:


The Farce of Modern Physics - David Pratt
According to Newton’s third law, every action causes an equal and opposite reaction. But out-of-balance electrodynamic forces have been observed in various experimental settings, e.g. anomalous cathode reaction forces in electric discharge tubes, and anomalous acceleration of ions by electrons in plasmas. To explain this, some scientists argue that the modern relativistic Lorentz force law should be replaced by the older Ampère force law.3 But this law, too, is inadequate. Both Lorentz and Ampère assumed that interacting electrical circuits cannot exchange energy with the local ‘vacuum’ medium (i.e. the ether). In 1969 Harold Aspden published an alternative law of electrodynamics, which can explain all the experimental evidence: it modifies Maxwell’s third law of electrodynamics to take account of the different masses of the charge carriers involved (e.g. ions and electrons), and allows energy to be transferred to and from the surrounding ether. Action and reaction only balance, says Aspden, if the ether is taken into account.4 An additional problem is that Lorentz assumed that the field force propagates at the speed of light, while Ampère assumed instantaneous action at a distance. Clearly, to retain causality, forces must propagate at finite speeds, but the Correas argue that the field force, which is carried by etheric charges, is not restricted to the speed of light, and should not be confused with the mechanical force that two material charges exert on one another.5
http://www.davidpratt.info/farce.htm


Morsels of Knowledge Banquets of Ignorance: Scientific Fallacies Exposed
Physics
In a previous issue of MuseLetter [“Don’t Enshrine the New Physics... Just Yet,” Number 19, July 1993], we explored briefly some of the difficulties with quantum and relativity theories. As we noted there, physicists are fond of pointing out the limitations of the “Newtonian paradigm,” in which space is Euclidean, the Universe is (in principle) entirely predictable, and matter is made up of billiard-ball atoms. The quantum and relativity theories of the early twentieth century are often hailed as having liberated the human mind from mechanistic and dualistic assumptions, and as confirming the mystical worldviews of Eastern religions.
Unfortunately, physicists hardly ever express to the general public their perplexity and inability to reconcile the fundamental contradictions between current theories — though among themselves they occasionally admit that “Physics is now faced with a crisis in which… further changes will have to take place, which will probably be as revolutionary compared to relativity and the quantum theory as these theories are compared to classical physics.” (David Bohm) In light of a statement like this from one of the most eminent scientists of our century, one cannot help but feel a certain bemused skepticism at the attempts of some science popularizers to create a mythic worldview for the masses out of a “new” physics that is already beginning to look a bit tattered and worn around the edges.
http://www.newdawnmagazine.com/articles ... es-exposed


Admittedly Unproven, Why Does Science Accept Gravity as a Property of Matter? - PETER BROS

How does science’s interpretation of gravity demonstrate that it’s proportional to matter?
It doesn’t. It merely uses Newton’s math (more or less) to compute the amount of matter in a planet.
Newton needed to know the amount of matter, and therefore, gravity in a planet in order to compute proportionality.
What is the one tenet of science that must never be violated?
Any hypothesis must produce measurable predictions.
Is the amount of matter in a planet measurable?
Absolutely not. No one, and this was Newton’s fallacy, knows the proportion of the different densities of matter in a planet, and therefore the use of Newton’s unproven theory to demonstrate the amount of matter in a planet is inherently unscientific.

http://therealskeptic.blogspot.ca/2007/ ... ience.html


The Errors & Animadversions of Honest Isaac Newton - Sheldon Lee Glashow
http://www.iec.cat/butlleti/pdf/90_butlleti_sheldon.pdf


Isaac Newton’s sinister heraldry - Alejandro Jenkins
http://arxiv.org/pdf/1310.7494v2.pdf

kickstones
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Re: What is Gravity?

Unread post by kickstones » Thu May 14, 2015 10:05 am

simonshack wrote:*


IS "GRAVITY" JUST ATMOSPHERIC PRESSURE?

This very thread started off with a number of posts by skeptics of the thesis put forth by our now apparently 'estranged' member, Sceppy - who proposed that what we call "gravity" is nothing but atmospheric pressure. As it is, I was not among those skeptics - as this concept / idea has been trotting in my mind for quite some time. I will now "boldly" try and illustrate to the best of my capacities what, hopefully, may come across as a reasonable / rational attempt at tackling what surely is one of the greatest, still unsolved mysteries of our universe. To be sure, even this world's "scientific establishment" admits that 'gravity' is a still utterly unsolved / unexplained phenomenon:
Simon, while the subject of physics is that of limited understanding in my education , I do try and improve that understanding by paying attention to different theories out there, including those that differ from "scientific establishment" viewpoint.

Recently, a differing viewpoint which caught my attention, was by a fella called Edward Leedskalnin. His main writings concerned magnetic current.

Now, while I'm not putting forward what he writes as fact, it does make for interesting reading. Especially as he backs up most of his claims with simple experiment.

Here's a little what he writes about gravity:

Gravity

Gravitation must be caused by the matter in the middle of the earth, and more concentrated than Uranium. When Uranium atoms burst they release the North and South pole individual magnets that held the atom together, then the magnets scatter all around, they can only pass from the middle to the outside. When the North and South pole magnets are running alongside each other and in the same direction, they have no attraction for the other kind. They only attract if they are running one kind against the other kind. When the magnets are running out of the middle of the earth, as soon as they meet an object they attract it, on account of the fact that in any object there is both kinds of magnets in it. It can be seen by rubbing hard rubber or glass until they get hot., then they will attract sand, iron filings, salt, and other things. To see how it functions, move a salt crystal a little, if it happens to get on a different magnet pole, then it will jump away. Another way is to rub hard rubber until it gets hot, then it will be a temporary magnet. The difference between the rubber magnet and the steel magnet is both North and South poles are in the same side of the rubber and the magnet poles are small and there are many of them close together, but the surplus magnets in the circulating magnet that was put in it. Attract the iron filings with the rubber magnet, then approach with the steel magnet, Change the poles, then you will see some of the filings jump away. This means the steel magnet changed the magnet poles in the iron filings, and so they jumped away.

http://www.leedskalnin.com/index.html

http://www.leedskalnin.com/Leedskalnins ... RRENT.html

Thinktwice
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Re: What is Gravity?

Unread post by Thinktwice » Fri May 22, 2015 5:56 pm

Very interesting theory about atmospheric pressure and gravity. One thought I had is that, if it were true, then gravity would seem to be weaker on a passenger airplane, as you are above a significant mass of air that would no longer be pushing down on you. I have never personally noticed a significant change in gravity at cruising altitude.

I wanted to discuss a few more models for gravity.

While walking around my neighborhood thinking about gravity, I realized that in my experience of gravity while walking, it feels to me as if the ground is pushing up, rising up to meet me at every moment. We feel a very firm pressure on the bottom of our feet. Historically, gravity has been defined as a falling down, but it could also equivalently be viewed as a pushing from below.

Einstein argued this very same point a century ago. From the point of view of the observer, there is no way to tell the difference between an observer on a stationary chamber on earth experiencing gravity, versus an observer ascending in an elevator (so long as the elevator accelerates at the correct acceleration). The observer should feel the same force in each case. Now, maybe we could argue with that equivalency, but for now we will accept it as Einstein did.

Thinking along these lines, I think we could even explain gravity and a flat earth at once, in a very startling (and hopefully amusing) worldview. Let's say the earth is flat like the UN flag, and mounted on the top of a giant rocket ship accelerating at 9.8m/s/s forever. Any observer on this rocket-earth would experience a force identical to the gravity we experience on Earth. You experience a constant force pushing up on your feet. You throw a ball in the air, it flies up, but the earth-rocket accelerates toward it and the the earth-rocket catches up to the ball and slams into it.
Clearly no cluesforum members will be supporting a rocket-propelled model of the earth! But it is just a thought experiment which allows for a mechanism for gravity on a flat surface.

What if we live on the inside of a round ball? You could explain gravity like a spinning carnival ride, where the centrifugal force pushes anything on the inside of the ball against the walls of the ball. But, in this case, gravity would be zero at the poles, and very strong at the equator, not to mention if you were standing at 45 degrees from the equator you would experience gravity pulling you at a 45 degree angle rather than straight down. This model of gravity does not work very well.

What if we do live on the outside of a round ball? How can we use this idea to explain gravity?

Whatever you think of him (I am still trying to figure that out myself), Miles Mathis proposes a mechanism to explain gravity on a globe as a push from below, not a fall from above. The basis of Mathis' gravity theory is his idea that all matter in the universe, every single proton, is constantly expanding. I'm not here to defend Mathis or his model of the universe, so I won't go into more detail on his theory. But he uses this idea to explain gravity as the expansion of mass, specifically protons. The earth is very big, in this theory we are treating it as a sphere, and it is made of many protons. Since each proton that makes the earth is expanding, the earth herself is expanding as well, and at quite a rate. Anything on the surface of the expanding ball is going to experience a pushing force as the ball expands. Because the protons that make up our bodies expand, too, we actually push a tiny bit back against the earth. Also notice that all scales still stay exactly the same, because every proton expands at the same rate, including the protons that make up the measuring stick. (Mainstream physics says it is not matter but space which is expanding.)

You may ask, "If everything on the ball experiences a pushing force outward, then why doesn't everything keep moving outward due to inertia and fly off the earth?" I believe the answer is that the expansion is accelerating. The earth is not growing at a fixed rate, it is growing faster at every moment. As a surface object gets pushed outward, the object flies away for a brief moment, but the expanding globe catches up because its rate of expansion is constantly increasing. We know rate of expansion is increasing because the value of gravity is an acceleration, so that's what our actual data tells us. We know the answer, we just have to figure out the mechanism. 

So basically, gravity is like a bouncer pushing you out of a club. You're just minding your own business, when the bouncer starts inexorably pushing you toward the door. Let's say you are very difficult and the club is very large, so it takes an hour for the bouncer to push you out the door. For that entire hour, you experience a force where his body contacts yours, and you appear to be stuck to him as long as he is pushing you. What is the mysterious force attracting the bouncer to you? Is there a pulling force at all anywhere here? The only force is the pushing force directed from the bouncer outwards. Similarly, this push in perpetuity is enough to make it look like we are "stuck" or "attracted" to the earth.

Edit: removed unrelated paragraph on Mathis, perhaps better suited for the Mathis thread

Thinktwice
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Re: What is Gravity?

Unread post by Thinktwice » Mon May 25, 2015 5:37 pm

I was thinking about my thought experiment from my last post. I remarked, about Simon's atmospheric pressure theory of gravity, that this would result in less gravity while flying in a plane due to smaller atmospheric pressure above you pressing down, so there should be a smaller gravity force. But I don't think that is right.

It occurs to me that the lift on the plane's wings is pushing the floor of the airplane up against anything in the plane. The plane is experiencing an upward force, lift, as it cruises through the air. The body of the plane therefore presses this upward lift force against your feet. This lift force would be experienced to anyone on the plane as gravity. 

It is like the parabolic vomit comet plane. When the plane ascends and has a great lift force, the plane floor pushes very hard against the items inside, and the "gravity force" experienced in the plane is very high. But when the plane starts going down, there is negligible lift force pushing the wings upward, in fact the plane is dropping quickly, so the floor can no longer make contact with your body and can no longer impart a "gravity force".

Why the difference gaining altitude vs dropping? Well, gaining altitude requires a strong lift force which would create the gravity force. Dropping very slowly may result in a negligible change in forces, as the lift and downward movement may balance somewhat. But dropping very quickly would overpower any lift still felt by the wings and cause the "gravity force" to disappear as the floor literally drops out below you and can no longer impart its upward push on your body.

Therefore, my objection to Simon above is actually wrong. You would still feel gravity on a plane. My thought experiment was sloppy. 

However, it did bring up another question, a challenge for myself: in the "pushing from below" theory of gravity, which I am trying to evaluate, why would you feel any weight on an airplane? Since the plane is not in contact with the ground, it is not subject to the pushing force as a result of the expansion of the earth. But I believe my explanation above solves it. In this theory, the earth is growing very fast and will eventually grow up to meet the plane flying at cruising altitude. So if the plane coasts without gaining altitude, it will strike the earth. This gaining of altitude results in an upward lift force on the wings of the plane, and this force pushes the plane up against anybody inside, resulting in a feeling of gravity, again so long as there is a lift force on the plane.

hoi.polloi
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Re: What is Gravity?

Unread post by hoi.polloi » Mon May 25, 2015 9:19 pm

How about a helicopter, though?

pov603
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Re: What is Gravity?

Unread post by pov603 » Tue May 26, 2015 9:20 am

The plane is a pressurised can and so would already be subject to a set amount of air pressure which isolates you from the air pressure outside irrespective of its fluctuations/changes.

pov603
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Re: What is Gravity?

Unread post by pov603 » Tue May 26, 2015 9:32 am

Though I'm not convinced that air pressure would explain gravity, it got me thinking about the force of gravity currently considered as a pulling/attracting force.
If so, and if it is in the same way as a magnet, why is it that when a magnet attracts a metallic object there is no 'bounce' as there is/would be if an object 'falls' from a great height to the Earth [as in a rock from a mountain or a child skipping along the footpath]?
I realise that this bouncing ability reduces after each subsequent bounce but presumably the added force of plummeting to the Earth should compliment the existing force so that one 'sticks' to the ground with ever more [initial] force at the time of landing.
Considering that the whole of the 'magnet' known as Earth, is currently occupied with voluminous layers of things 'attracted' to it, there does not seem to be any diminishing of the pulling power of this 'magnet' whereas it should be reasonable to assume that the more layers of 'crud' that adorn this magnet would eventually, over millenia, begin to erode its 'pulling' power as would presumably happen to any magnet once it was covered in hundreds of thousands of [let's say] paper clips?

simonshack
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Re: What is Gravity?

Unread post by simonshack » Tue May 26, 2015 3:15 pm

pov603 wrote:Though I'm not convinced that air pressure would explain gravity, it got me thinking about the force of gravity currently considered as a pulling/attracting force.
Dear pov,

Indeed, most people refer to 'gravity' as a pulling force from somewhere below our feet (the centre of the earth?). Quite frankly, I cannot see this being the case at all. If this were the case, how then would a hot air balloon vessel full of people (weighing, say, 300kg) rise up and away from the earth? It rises because it is 'attached' to a balloon full of lower-density air and thus, quite simply 'defeats' what we call the 'force of gravity'.

If you dive into the ocean, you won't continue being pulled downwards towards the centre of the earth. If you only breathe normally, your lungs will make you 'levitate' upon the surface of the water. One could well say that you are now 'weightless' and that you're 'flying' on top of the ocean and, to be sure, no pulling force from below is acting on you. Yes I know, it's called 'buoyancy' - a term which we just accept at 'face value' ("it's just a fact of nature!") - yet, without thinking much more about what exactly it implies. It most certainly implies that because a human body (unlike a rock) has air containers which are able to balance your 'net body weight' between (1) the force pushing you downwards from above - our atmosphere - and (2) the force pushing you upwards from below (i.e. the water's density - which is about 784 times denser than air at sea level).

Magnetism, as I see it, is something different altogether - and has nothing to do with objects 'sticking' to our earth's surface / or being 'pulled' downwards. Again (returning to my hot air balloon), if magnetism were an 'absolute' pulling force ruling all earthly objects (and their apparent 'attraction towards the centre of the earth') - why would it not affect that 300-kg-vessel rising up and away from earth? Is it not plain obvious that what makes that heavy object rise - is the simple fact that its hot air is "alleviating" the force of the atmospheric air pressure which keeps pushing us down - at all times - towards the earth's surface?

As for your question regarding 'why don't we feel lighter inside an airplane cabin', please know that the standard pressure / air density maintained inside commercial airliners is similar to the air which you can find at about 5km of altitude (or 5000m, which is about the height of the Mont Blanc mountain peak in the Alps). That isn't far enough away from sea level that you could tell any difference. BUT - and here's an important point : as you rise up higher and higher through the atmosphere, the air density will decrease exponentially. For instance: at 5km of altitude, the air pressure will be around 50000 (fifty thousand) Pa - about half of the air pressure at sea level. Whereas at 50km of altitude (only 10X higher), the air pressure will drop to about 80 (eighty) Pa. Ergo, with altitude increasing by only a 10X factor - the air pressure will decrease by a whopping 625X factor! Hence, the idea of "zero gravity" and "weightlessness in space" may not be so fanciful after all. The question is, has mankind the means to reach such (50+ km) altitudes? I personally do not think so.

PRESSURE AT ALTITUDE CALCULATOR: http://www.calctool.org/CALC/phys/default/pres_at_alt

This, of course, makes me wonder: have any manned balloons ever reached such altitudes - and have these men reported feeling lighter than at sea level? This deserves a separate investigation, as the current 'world record holder' ("39km of altitude") is that "Red Bull" / Felix Baumgartner clown which we have roundly exposed on this forum as a silly fraud / publicity stunt. Next on the "world record rostrum" is a claimed "34,6km ascent" (in 1961) by a pair of US Navy officers, one of which reportedly died as "his pressure suit filled with water as he landed at sea after his record breaking flight"...

"Altitude of the Highest Manned Balloon Flight": http://hypertextbook.com/facts/1997/CassandraEng.shtml

sceppy
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Re: What is Gravity?

Unread post by sceppy » Tue May 26, 2015 4:13 pm

simonshack wrote:
pov603 wrote:Though I'm not convinced that air pressure would explain gravity, it got me thinking about the force of gravity currently considered as a pulling/attracting force.
Dear pov,

Indeed, most people refer to 'gravity' as a pulling force from somewhere below our feet (the centre of the earth?). Quite frankly, I cannot see this being the case at all. If this were the case, how then would a hot air balloon full of people (weighing, say, 300kg) rise up and away from the earth? It rises because it is 'attached' to a balloon full of lower-density air and thus, quite simply 'defeats' what we call the 'force of gravity'.

If you dive into the ocean, you won't continue being pulled downwards towards the centre of the earth. If you only breathe normally, your lungs will make you 'levitate' upon the surface of the water. One could well say that you are now 'weightless' and that you're 'flying' on top of the ocean and, to be sure, no pulling force from below is acting on you. Yes I know, it's called 'buoyancy' - a term which we just accept at 'face value' ("it's just a fact of nature!") - yet, without thinking much more about what exactly it implies. It certainly implies that because a human body (unlike a rock) has air containers which are able to balance your 'net body weight' between (1) the force pushing you downwards from above (our atmosphere) and (2) the force pushing you upwards from below (i.e. the water's density - which is about 784 times denser than air at sea level).

Magnetism, as I see it, is something different altogether - and has nothing to do with objects 'sticking' to our earth's surface / or being 'pulled' downwards. Again (returning to my hot air balloon), if magnetism were an 'absolute' pulling force ruling all earthly objects (and their apparent 'attraction' towards the centre of the earth') - why would it not affect that 300-kg-vessel rising up and away from earth? Is it not plain obvious that what makes that heavy object rise - is the simple fact that its hot air is "alleviating" the force of the atmospheric air pressure which keeps pushing us down - at all times - towards the earth's surface?
I said I wouldn't post on here but I felt I had to, to let you know that you seem to be getting it with this gravity.
A little tip for you. Try and also look at it without global thoughts because that will scupper you.
I know you and others took me as a looney when I mentioned all of my stuff about a dome. I'm serious when I say it. It fits with gravity being atmospheric pressure and also fits with how Earth atmosphere is just another sea of buoyancy.

Gravity is what I've re-named it. It's denpressure.
That's my opinion of course.

simonshack
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Re: What is Gravity?

Unread post by simonshack » Mon Jun 01, 2015 9:48 pm

*


Excentrifugal Forz

(Just borrowing the title of a good ol' Frank Zappa song for this little 'musing post' of mine - hope Frankie doesn't mind.) <_<

So, I was wondering this morning at breakfast ( and feeling rather embarrassed about my old self) : what on Earth has made me wonder, for most of my life, why the "centrifugal force" of this spinning planet doesn't fling us all out into space? Now, I know I'm not alone to have entertained such a silly thought (which is of meager solace) - but anyways, here's the sort of mindless puzzlement my mind has harbored for far too long:

Here's what I remember telling a friend of mine - back in the days... :rolleyes: (*rolleyes* and *blushing* for my youthful silliness) :
"Hey, if I'd put a few ants on top of an orange - put a shaft through it and spin it fast enough, wouldn't the ants be flung off the surface of my orange?
Image

Also, I remember wondering: "Hey, if you take a joyride on a rollercoaster, you'll experience some pretty wild centrifugal / centripetal forces! What's up with this world spinning at about 1000mph at the equator - and we're not feeling any of these forces?" Oh well, I was probably thinking of my "American Revolution" ride at Magic Mountain / Six Flags (California) - many, many years ago... That rail pushing on my butt in that 'death loop' - and keeping my balls from flying off into space - was a pretty memorable experience :

Image

Alright - so let's see if my mind is working a little better nowadays. Heh - you'll be the judge of course - but I hope the following makes a little more sound sense - and may be helpful to those who've shared (or still entertain) my above-mentioned youthful musings. Firstly, let us imagine if we had a really fast train - speeding around earth at 1000mph. Now, would all the passengers of this train be flung up from their seats and be squished onto the train's ceiling ?

Image

Of course not. They'd be tranquilly sipping their tea or coffee - and feel just as comfortable as in their own living rooms. Indeed, if they'd close their eyes - and if the train were silent / sound-insulated enough - they wouldn't even notice that they were MOVING AT ALL ! Also, if a mosquito were flying around in the train carriage, it would be carried along in the train's "atmosphere" - completely oblivious and undisturbed by the fact that it was actually moving along at 1000mph (+ or - its own flight velocity as it flew back and forth in the cabin). As it is, the mosquito would fly back and forth just like an airliner does in our earth's pressurized atmosphere. The mosquito would, of course, employ the same time to cover the length of the train carriage - in EITHER DIRECTION. Alright, so I can hear someone (a flat earther, maybe?) objecting: "hey, so WHERE'S THE CEILING of our earth's atmosphere? That is actually a good question, and I do not pretend to have a perfect / definitive answer for that. However, I think it is absolutely undeniable that our atmosphere can be considered as a unique, pressurized environment - just like the unique atmosphere inside that speedy, 1000mph-train.

Now, let's take a quick look at our spinning earth - but before I get on, let me just tell you that I now have firm mathematical proof (which I will soon present on this forum) that it DOES NOT travel around the sun at the claimed speed of 107.000+ km/h (as of the Copernican solar system model).

However, I think we can safely say that Mother Earth does one revolution on itself - every 24 hours or so. I know, some folks will opine that this is very, very fast (and "unbelievably" so), as it would compute to a speed of about 1000mph (at the equator). Yet, I will ask those folks to think again. Why would this speed / motion be felt by us earth dwellers - given that our pressurized atmosphere is (in my honest opinion) quite similar / comparable to that inside the afore-mentioned train ? As for those folks even questioning that we live on a spherical planet - well, I salute your healthy skepticism, but please do not blame me for following my own intuition - or for trying to make sense of the accumulated observations gathered by all of our forefathers and foremothers!

I've (jokingly) put my orange at the center of Mother Earth - just to show that my youthful "orange-and-ants-theory" was quite foolish / misguided: my ants would certainly not be flung off my orange by "centrifugal force" - if it were rotating only once every 24-hours !
Image

To finish off this little thought exercise, I will now take Mother Earth and drop it inside a giant fishbowl, fill it with pressurized air - put a lid on it - and place it on a turntable that revolves (360°) ONLY ONCE every 24 hours. Do you think that (if it weren't for the stars indicating this fact) the living beings on earth would actually notice that they are revolving once every 24 hours? Really?
Image

But of course - anyone is free to believe that it is actually the stars that are circling around us, clockwise over one side of the earth - and counter-clockwise over the other! Good Heavens... and good luck with that one, you flat/concave / pyramidal earthers ! ^_^

roastrunner
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Re: The MOON HOAX

Unread post by roastrunner » Mon Jun 01, 2015 10:59 pm

*If* you are willing to accept that a large object exerting a gravitational force exists (such as the Earth), then orbital velocity follows logically.

The force of gravity towards the center of mass of the large object is one leg of a right triangle; the force propelling the "spacecraft" at a constant speed (orbital velocity) away from the planet is another leg, and the hypotenuse is the tangent line to the large object. As the spacecraft accelerates at 9.8 m/s^2 towards the Earth (or whatever) it also remains moving away from the Earth along the other leg's vector and maintains equal distance from the planet. This continues for eternity. No work is being done so it's a system at rest.

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