Is Natural Frequency Perpetual Motion?

When a piece of quartz is subjected to a current of frequency matching that of the natural resonance frequency of the piece of quartz it will oscillate. In this situation you have to add electrical energy to the quartz which converts the energy to kinetic energy. Unfortunatly the law of conservation of energy cannot be broken. You are not creating or destroying energy it is merely converted to a different type of energy.

Another example of this is when you apply a stress to the material it will oscillate. This is know as piezoelectric effect but once again you are inputting energy to the system.

As for harnessing this effect, we do this already. Your wrist watch is doing it right now.

In general when the words perpetual motion are mentioned the answer is always the same-you cannot get something for nothing.

Would like to see what other readers have on this subject though. I studied applied physics at uni but this is a subject I have never studied in depth.

I am presently offshore on the Tern Alpha just about to fly off into sunny Scatsta Aint it a small world . Given time we could have met for a beer and discussed this thread in greater detail. But like you I would rather get home.Ha Ha.

Scatsta as in Shetland?Do you know Sandwick. If so it really is a small world as thats where I'am.

Let me address natural resonance frequency for a moment.

Everything and everybody has a natural frequency. In quartz, it's oscillation is so great that we sometimes think this is an anomaly. Not so.

To check for natural frequency in, say a motor or a machine, I attached an accelerometer to the motor and wailed on it with a big ass sledge hammer, (can you say "big ass" on CR4?). Anyway the accelerometer peeked at 60 Hz. That explained why the motor was shaking itself to death when we ran it at 3600 rpm. (60Hz). We had to redesign the motor to change the natural frequency to more then 10% difference from the running speed.

When motion matches your natural frequency you get sick to the stomach, we call it car sickness, motion sickness, sea sickness... to fix it, you can either get taller, get shorter, gain weight, or loose weight. That is why kids get car sick, then they "grow out of it." The really didn't grow out of anything, their natural frequency just changed.

...That is why kids... their natural frequency just changed...

Now, that was overshot, just a tiny bit...

Not that they don't have any

It is known however, that every piece of matter from a mountain to a molecule will resonate in it's "natural frequency", as if it was a string.

"A string"! Who would have thought of that!

String! That could be the basis for a theory!

My wife and three kids would get car sick everytime we drove through the mountains going home. So, I fed them Dramamine and changed their natural frequency and we all lived happily ever after.

"Everything and everybody has a natural frequency"

Near Oban in Scotland , locals report a low frequency boom type sound being heard at night . It doesn't happen every night , but when it does can go on for hours . This does not cause annoyance (as far as I know ) , but does provide for speculation and debate. The widest held view is that this has some thing to do with large scale resonant oceanic effects (no not the tide !) .File this under 'strange ,but true' , unless anybody out there can explain. Kris

...low frequency boom type sound...

This goes into the calculation of electricity pole dimension.

In European countries, 50 Hz resonance and it's overtone harmonics, have to be considered, in other countries 60 Hz taken into account.

...large scale resonant...

Earthquake aftershocks, very low frequency there, big crust plates.

O.K, re-bounce of shockwaves too.

Hi Labguy,

"When motion matches your natural frequency you get sick to the stomach, we call it car sickness, motion sickness, sea sickness... to fix it, you can either get taller, get shorter, gain weight, or loose weight. That is why kids get car sick, then they "grow out of it." The really didn't grow out of anything, their natural frequency just changed."

I must disagree with your reasoning about what causes motion sickness.

The human brain uses two primary methods to determine which way is up. Firstly there is vision, your brain looks for the boundary between the sky and the ground and defines this as level.

Secondly there is the inner ear or labyrinth. This consists of a series of circular passages roughly aligned at right angles to each other, and a small sack. These passages are lined with tiny hairs and filled with a fluid. The small sack also contains microscopic bone flecks.

Now what happens with the sack is the tiny bond fragments will sink to the lowest point due to gravity and by pushing on the tiny hairs you know which way down is. The circular passages are a sort of inertial navigation system that detects the rotational motion of your head.

What happens with motion sickness is the multitude of small motion inputs can cause the system to become disoriented. In certain situation the fluid in the circular passages may actually start moving as well. This is what happens when you get giddy.

Once the inertial method of balance is upset the brain instantly tries to use the eyes as the primary balance system, however, in a car it's common to not be able to fixate on a ground sky boundary that is stationary. When you can't fixate on this boundary the brain then uses the confused, perceived motion information from the inner ear to scan the eyes in the opposite direction to the way it perceives you are moving. This is what causes a room to appear to spin.

If you can't find some stationary object to fixate on then the brain throws up its hands in disgust and gives up. This is usually followed by the stomach going out in sympathy and throwing up as well.

If you look at the size and volume of the system in a child, it's considerably smaller and that makes it more prone to becoming upset.

There has also been some research that has shown, in some people the size of the small flecks of bone are not uniform. As a result they do not receive consistent signals from the inner ear and this makes them more prone to motion sickness.

So, as you can see it doesn't have anything to do with the fundamental frequency of your body. It could have something to do with the natural frequencies of the labyrinth but these would be fairly high frequencies as the labyrinth is very small.

Hi Masu.

I think you have a good grasp on the inner ear and it's functions, but there are several cases (documented) where people lost there sense of direction and didn't throw up. Underwater divers, when not on the bottom or near the surface, say working on a oil rig, ofter have had to follow the air bubbles to know which way is up. People caught in snow avalanches have been know to have to dig a small hole then watch which direction the snow fell in order to determine which way is up so they know which way to dig themselves out.

To my original point, when the motion of a car, boat, or plane matches the natural frequency, it is the brain, the inner ear and the eyes that will stall of the upset stomach, but for only so long. The feeling of nausea becomes overwhelming.

thoughts?

Hi Labguy,

In certain situations and with training, you can learn to ignore the input from you inner ear and rely solely on your eyes for balance. A classic example of this is a ballet dancer doing pirouettes. If you watch closely they keep their head stationary and fixated on a distant point. When they can no longer maintain the visual lock they quickly spin their head round and grab another visual lock.

I have done some aerobatic flying in gliders and this is another place where you are taught to switch off the inner ear and rely completely on a visual fix.

Astronauts are also taught to ignore their inner ear as they can have massive problems with space sickness. They have particular problems with the sack that you use to determine which way is up. In space the little bone flakes float and depending how you move your head, they bounce around inside, giving you the impression that down keeps changing direction.

Not everybody can ignore their inner ear and the people that can't ignore it are more prone to motion sickness.

"To my original point, when the motion of a car, boat, or plane matches the natural frequency, it is the brain, the inner ear and the eyes that will stall of the upset stomach, but for only so long. The feeling of nausea becomes overwhelming."

I think the main problem with motion sickness it the inner ear becoming inoperative for a variety of reasons:

· Continually varying short movements that cause the fluid in the labyrinth to start rotating, thus giving the impression that you are spinning. There may be some harmonic type things going on here with the vibrations causing the fluid to rotate. It is certainly know that certain low frequency sounds can cause disorientation and giddiness.

· Inconsistent size in bond flecks in the inner ear. Recently it has been found that there is a genetic defect that causes the bone flecks to have a range of sizes, rather than all being the same. The inconsistent size in the flecks causes inconsistent signals of which way is up and as a result you become disorientated.

· Static electricity. This is only a theory and there is no evidence that it is what happens but the static build up may be causing the bone flecks to repel each other and cause inconsistent signals to which way is up.

· Changes in fluid density. Slight changes in hydration levels can affect the density of the fluid in the labyrinth and this can cause the tiny hairs that detect the motion to float or sink and give spurious signals.

An interesting thing about nausea is that it is literally all in your mind. There is a small section of the brain that is associated with nausea. This area can also be stimulated by the inner ear, nerves in the stomach and certain drugs like pain killers. You can learn to block the signals going to this area but once it is stimulated you will get nauseous and the only way to fix it is remove the stimulus that is causing it or sedate the area with a drug like Stemetil.

There may be some sort of resonance happening with the rocking motion of the body causing the inner ear to start sending spurious signals to the brain. There are several reasons that I can think of that children get motion sick more readily than adults.

· Children are smaller and hence will bounce around more in a car. Their inner ear is also smaller and therefore more susceptible to the effects of vibration etc.

· Children are more susceptible to dehydration than adults and hence more prone to the fluid in the inner ear changing density.

· Children have a lower level of concentration and are less capable of ignoring the signals from the inner ear and relying on eyesight

· They are just inexperienced and hence havn't developed the skills to be able to cope with motion sickness.

Motion sickness is fairly complex and has a myriad of causes. There may well be some sort of resonance problem as well as the causes I have listed but I have never heard of it. That certainly doesn't mean that it doesn't happen it just means I haven't heard about it.

...switch off the inner ear and rely completely on a visual fix...

Is it possible in darkness or night flight?

In instrument flight (complete darkness or in the clouds, so there is no visual reference) the pilot must ignore what the inner ear is telling him, and relies only on the instruments. Initially this is surprisingly difficult. An early instrument student, upon ending a relatively long stable turn and resuming straight flight, will usually be convinced that the plane is now turning in the opposite direction. The unschooled response is to roll the plane into a turn to "correct" the erroneous sensation. This is what leads untrained pilots to crash when they inadvertently enter instrument conditions.

The actual sensation felt, although generated by the inner ear, seems to be from the entire body. The instruments (correctly) say straight and level, and your whole body says (incorrectly) "Straighten this thing out, we're gonna crash!"

Hi Yuval,

Is it possible in darkness or night flight?

Just to add to what Blink, in zero visibility it is absolutely essential that you completely ignore the inner ear and use only the visual aids given by the instruments.

In 1992 there was a Boeing 737-204 in South America flying on instruments and trying to dodge thunder storms. There was a fault in the artificial horizon instrumentation that told the pilots that they were flying straight and level when in fact they were banking the aircraft at a steadily increasing angle. The ultimately lost control of the aircraft, ripping the wings off and causing a complete in flight break up of the aircraft.

These were experienced, commercial pilots, each with several thousand hors at the controls. They were unable to detect that the aircraft was banking at an ever increasing angle until it was too late to save the aircraft.

Then how do you back-up your artificial horizon for redundancy requirements?

What kind of technology they use anyway, is it some mechanical pendulum?

Hi Yuval.

Then how do you back-up your artificial horizon for redundancy requirements?

What kind of technology they use anyway, is it some mechanical pendulum?

The basic artificial horizon is gyroscope mounted on a gimbal that has its axis or rotation aligned vertically.

The secondary instrument is the bank and turn indicator. This also consists of a gyroscope that is aligned vertically plus a device that is used to determine which way is down. It depends on the instrument but the older units used a small spirit level while other used a pendulum. Note that if the pilot is doing his/her job properly down should always be perpendicular to a line that passes through each wing tip.

These were the original primary instruments and depending on the manufacturer they can either be powered by electricity or a vacuum. It is normal for them to each use a different power source within a single aircraft. For example if you have an electrically powered artificial horizon you would have a vacuum powered bank and turn indicator. This was to give redundancy, for example if both were electric and you lost the electrics you would be stuffed.

On the 737-204 that crashed you have two attitude indicators that are and electronic display that combines the input of the directional indicator, bank and turn indicator and artificial horizon, air speed plus a host of other things all on two screens, one for each of the pilots. There are two sets of electronically based instruments that are used to drive these screens. Normally each set of instruments drives one screen. But you can drive both screens of one set of instruments in the event of a failure.

On top of this they have three separate mechanical artificial horizons, one for each pilot and a third emergency one.

For some reason the pilot had set the attitude displays to both run off the same set of electronic instruments and while they were in flight the signal from this instrument failed, just as they were coming out of a turn and leveling off. As a result both attitude indicators showed that the aircraft was in level flight, but, in reality it has gone past level and started to roll the other way. This roll continued to increase and the rate of turn increased so as far as you senses knew down was still directly through the floor even though the wings were banked at around 45°. By the time they realized what was happening the aircraft had stalled and entered a speed spin that ultimately resulted in the break up of the aircraft in flight.

The only good thing about the crash is that more than likely everybody was unconscious and most likely dead before the aircraft broke up. To rip the wings of a 737 you need to pull about 10 g, you loose consciousness at around 5 g and die at about 7-8.

The two separate attitude displays should have been operating of separate electronic instrument sets to specifically avoid a situation like this. Unfortunately the weren't and to this day nobody know why.

Here is a link that describes the basic flight instruments the artificial horizon or attitude indicator and the Boeing 777 glass cockpit.

If you look at the B-777 cockpit you will see 5 screens which are from left to right:

• Pilot's Attitude Display This is a combination of the artificial horizon, air speed indicator, altimeter, and a host of other thing to do with actually controlling the aircraft.
• Pilot's Navigation Display This is a combination of the direction indicator, and the navigation system that is used to navigate the aircraft as well as display weather information.
• Engine Instruments This displays all the engine data like temperature, fuel flow, speed etcetera.
• Co-Pilot's Navigation Display Same as pilot's navigation display but normally runs off a separate set of instruments.
• Co-Pilot's Attitude Display Sam as pilots attitude display except it runs off a separate set of instruments

If you look closely between the pilot's navigation display and the engine display, you will see a set of instruments that are the same as basic flight instruments. These are the backup instruments and work exactly the same as the good old steam gauges that you see in any aircraft.

It varies between aircraft and the options that have been selected but that sort of covers how the instruments are backed up and cross connected. It's just unfortunate that in the case I was talking about the pilots had selected to run the flight displays of the same gyroscope and that gyroscope failed at a critical moment. It certainly should not have happened.

...gyroscope mounted on a gimbal...

Sure, "some mechanical pendulum" was silly of me, it's subject to positive and negative G forces...

It's not that silly as the pendulum part is used in some bank and turn indicators and the g meter.

Do they use magnetometers to relay the plane's orientation to to ground, i.e, as a "3D compass", or is it to feeble to be reliable?

They do not us magnetometers in a normal aircraft for navigation purposes but there are highly specialized aircraft that do. Mining survey aircraft and submarine hunter trackers have very sophisticated magnetometers but they are normally mounted in a pod that protrudes from the tail of the aircraft. This is to keep them as far as possible from things like the shafts in the engines tat are nearly always made from ferrous metals.

They do actually have a compass but it is not a primary navigation aid and is normally only used to set the direction indicator at start up. The direction indicator is another gyroscope that is aligned north south. The direction indicator is however aligned with true north not magnetic north and when you set it you need to know the difference between true north and magnetic north at that location.

Can you electronically deduce your compass-orientation, from your trajectory in conjunction with GPS info?

Setting the DG may be something we do differently in the US versus Australia. Here we set it to magnetic north, and do any corrections for true north or local variation either mentally or with notes jotted on the chart.

Note that if the pilot is doing his/her job properly down should always be perpendicular to a line that passes through each wing tip.

I might add for Yuval's benefit that "down" is a relative term. For instance, the ball in the turn and bank indicator will stay centered in a well-controlled 60 degree banked turn. In this case "down" would, from the perspective of someone on the ground look more like "to the side".

The turn and bank indicator is also called a turn and slip indicator (probably a better name). If the aircraft is slipping or skidding (meaning too much or too little rudder for the turn rate) the ball will go to one side or the other of center. The correction is: "step on the ball" meaning add right rudder pressure if the ball is to the right of center. Yet another name for the same instrument is a "turn coordinator."

When the ball is out of center, you can feel it in the seat of your pants: the plane actually feels like it is "leaning", whereas in a coordinated turn, the force is always straight down into the seat. One time when this leaning is intentional is in a crosswind landing: in a slow plane and significant crosswind the lean can be substantial -- if I am not the person doing the flying, it makes me squirm in my seat.

...slip indicator (probably a better name...

I read that banking and pitching may have dis-orientating (for the plane, not the pilot) delay. In that sense?

You may have read about the effect of bank and pitch on a standard compass. A standard gimballed compass will indicate incorrectly while the plane is in a turn. The directional gyro, on the other hand, reads correctly. If the DG fails, then you resort to the compass, and if you haven't practiced lately, your turns will overshoot or undershoot depending upon the direction you're headed and the direction of the turn.

...overshoot or undershoot depending upon the direction...

Hence Fly-By-Wire feedback iterations (?). What brilliance.

It looks like this fighter technology would be best of all worlds, if implemented widely. Today's avionics and servo are cheap enough to justify it.

About the above mentioned landing gear: This must be super-heavy-duty, especially for big birds. What are these made of?

Hi Yuval

There are several questions I am going to answer in one post.

"Can you electronically deduce your compass-orientation, from your trajectory in conjunction with GPS info?"

Most GPS receivers will give you the bearing of you track or direction of travel so yes you can deduce the compass orientation from the GPS. Another way to do it is to enter a waypoint that is either at the magnetic or true north pole and ask for a direction to fly indication. This will tell you which way you need to fly to reach that point on the globe.

Keep in mind though magnetic and true north are not the same thing. The north magnetic pole is quite a distance from the geographic north pole and moves position by up to 40 Km each year. There are also regions on earth like the South Atlantic Anomaly that cause a magnetic compass to deflect even further from true north.

"Setting the DG may be something we do differently in the US versus Australia. Here we set it to magnetic north, and do any corrections for true north or local variation either mentally or with notes jotted on the chart. "

That's interesting. As I said there are other anomalies that can affect a magnetic compass as well and the DG is immune to these. There are plenty of ore bodies in Australia that can give you a serious deflection in a magnetic compass that don't appear on maps and that may be the reason we set our DG to true rather than magnetic. It makea interpreting World Aeronautical Charts WAC, En Route Charts ERC and Visual Terminal Charts VTC a whole lot simpler because only the VTC have magnetic deviation contours on them. It may also have something to do with the average trips being longer in Australia and therefore being affected more by the difference between the two north poles during a single flight. Another thing is that all headings to fly are given as true so there is room for confusion there as well.

By setting the DG to true north you can avoid having to apply any changes to the bearings given by ATC or from your map. Another thing is that if you have two aircraft one that takes of from say the west coast and another that takes off from the east coast they will have two different settings on their DG and will need to use two separate conversion factors. I must admit I do not find setting the DG to magnetic north rather than true north a good idea. There is too much chance for misinterpretation. Also when you move to a glass cockpit you will find that the heading display is always true rather than magnetic.

There is another instrument that is far more sensitive than the bank and turn indicator that most private pilots will not be familiar with. Jet fighter and glider pilots use this highly sensitive and sophisticated instrument all the time.

I am of course referring to the yaw string, which usually consists of a short piece of wool, preferably orange. Stuck to the center of the canopy with a piece of electricians tape. Unfortunately on single engine propeller driven aircraft you can't use one because the prop wash upsets it.

The yaw string tells you which way the aircraft is orientated with respect to the flow of air. This is highly critical with high performance aircraft like fighters and gliders and the idea is to keep the aircraft flying cleanly through the air, by keeping the yaw string aligned with the axis of the aircraft. Basically if the string is off to the right of center you need more left rudder and vice versa. It is fare more sensitive than the bank an turn indicator and in a glider one of your primary instruments.

"About the above mentioned landing gear: This must be super-heavy-duty, especially for big birds. What are these made of?"

The whole idea of side slipping on landing is to set the aircraft up so that it is aligned with the runway and traveling along the axis of the runway. The following diagram shows what I mean.

What we have are the two ways you can approach the end of the runway when there is a cross wing blowing from the left and shown by the blue arrows.

The aircraft on the left is flying straight and along the line shown by the red arrow. The wind is now blowing the aircraft off course along the blue arrow, the resultant ground track is along the green arrow and is in line with the runway. The only hassle is the aircraft is not pointed in the direction that it is traveling along the ground and when it touches down there would be a considerable side way or lateral forces applied to the undercarriage.

With the aircraft on the right the same thing is happening, the aircraft flies through the air along the red arrow, is deflected by the wind along the blue arrow and track across the ground along the green arrow. The big difference is, this time we are actually flying the aircraft sideways through the air in a way that its ground track or green arrow lines up this the axis of the aircraft as well as the runway. The result is that when the aircraft touches down the wheels are pointed straight down the runway and are not subjected to the lateral forces.

This is called a side slip landing and is done specifically to avoid applying lateral forces to the undercarriage.

There is one aircraft that can actually land sideways and that is the B-52. In this aircraft they fly according to the diagram on the left and rotate the undercarriage so that it is aligned with the runway. The reason for this is that with a side slip landing you need to dip or lower the wing on the side the wind is coming from. If you did this with a B-52 the wingtip would hit the ground before the main wheels did.

Another technique that is commonly used with big aircraft is to fly as the left hand diagram indicates and at the last moment kick in a stack of rudder and align the aircraft with the runway just before it touches down. Large aircraft use this technique as their huge mass will keep them traveling along the runway even though the wind is trying to push them to the side. Most glider pilots use this technique because of the huge wing span but if you practice you can use the side slip approach in gliders as well.

masu,

I've seen the yaw string in glider cockpits, but didn't know what it was.

Just as I've seen the metal strips attached to the perspex canopy of fighters, only later told it was a pyro-cutter for escape.

Are you a flight avid?

Hi Yuval,

"Are you a flight avid?"

I have always been interested in aircraft and flight. I got my private pilots license in 1978 but let it slip due to work commitments and the ever increasing cost. I Got involved in gliding in about 1987 with the plan to use it as a stepping stone for getting back into powered flight. I ended up enjoying it too much and never went back to powered flight. I also became involved with the administration of the sport of gliding and was the secretary of the gliding club that I belonged to for six years. I also served on the committee that successfully bid to hose the inaugural sports class World Gliding Competition in 2000.

I guess that means the answer to your question is yes.

I was always fascinated by flight, but flying lessons here are ridiculously high, an given the dimension of this tiny country, full of airforce installations and patrols, flight paths here are complicated, and not really encouraged for private flight.

Other than Bernoulli's principle (which doesn't even apply to inherently unstable modern fighters), I never got into the intricate workings of flying machines, unless was fascinated by some trivial amazing this or that gizmo.

Only once did I fly on a small plane, in SA, and I was elated. I just loved it, kept the sensation for months, afterwards. Loved it.

Hi Yuval,

I met a compatriot of yours that flew gliders in Israel, he was a professor at one of the universities but I can't remember his details at the moment.

He found the freedom we had quiet amazing, especially since we were only 45 Km away for the city center of Adelaide, the capital of South Australia. Evidently air space violations in Israel can have fatal consequences. We had a special relationship with the Royal Australian Air Force where they would release a block of their military control zone for us to use. We could have pretty much whatever sky we could use and the only proviso was that we kept a radio tuned to a specific frequency and if required landed within 20 minutes of a call. We never got a call to vacate the airspace while I was involve. In return we would do the flight training of the Air Cadets, it was a mutually beneficial arrangement that made many people envious.

After being accustomed to having as much sky as I liked I am not sure I would appreciate flying in airspace as restricted as yours.

I am not currently active as a pilot due to health reasons, but if you ever get to Australia I can, if you wish, organize a flight in a glider. It really is the closest you will come to soaring with the birds. It's another story but I have literally soared with an eagle, close enough to see the mottling on the feathers.

Flying is the thing I miss the most and I do plan to get back in the air sometime in the future, once infected by the flying but there is no cure.

...active as a pilot due to health reasons...

I have a Friend, Eli Geffen, who was the graphics director for the Air Force's Monthly, taken on a photo shoot onboard a two-sitter F4.

This was his firs supersonic experience, and he was not properly briefed for this, and didn't have proper knowledge of correct breathing during high G turns. He torn a hole in his right lung

...literally soared with an eagle...

Spiralling a thermal I can only guess... (pure envy of a sigh )

I hear that panting and heavy pelvic contraction helps to counter act the effect of g. Is this so ? Perhaps it explains why female pilot can take a higher 'g' than men. The ability to Chanel blood flow is perhaps related to child-birth and contractions. I would be interested to know - perhaps pilot candidates should be all female ?

...I would be interested to know...

masu? MASU?

Hi Kris,

Yes, I was told I can be intense at times.

Some even called me "dense" on occasions.

Blockhead is what Ian Dury would call it...

Me too . Ya know why girl fake it ? - They think guys care ! Ouh - sorry to all those of the female type , I m sure you have worse.

...They think guys care...

How can you tell a Jewish princess comes?

- She drops her nail-file / remote-control

Brit translation for Essex - ' .....drops her kebab.'

I was about to go on with terrible jokes but paused . What a great thread somewhere - "what did your girl drop ?" . My worst transgression was pausing to hit 'record ' on the radio/tape player . For some reason she thought my mind was elsewhere. Well , it was a good song. I will desist , since I enjoy access to cr4. (Also I hate to think what jokes girls tell).

...about to go on with terrible jokes...

I just did, some half an hour ago, and was culled by the admins.

It referred to a word in the title of the book you mentioned with a picture.

Don't sweat it. Express yourself and be redeemed.

...What a great thread somewhere - "what did your girl drop ?"...

Are you kidding? This could be great!

Only the admins will send us to forced labour camp for two years, on the grounds of defacing their site's reputation.

I'm an angel. See?

I have a great 'oldie ' book entitled "Mind if I Smoke". It's hilariousl 1950's style, but I'm saving it for a good occasion . Today public smoking was banned in Wales , but I don't know of any welsh members. Tony and George may make it apt. soon .... oops , me and my big mouth !

Erectum -! deliberate spell-checker mistakes could become a whole new language .

Don't Re-Erectum me you shmuck !

Copying is the sincerest form of fartery .

misspelling i s grate fun when bord.

Is ther e a limy 2 how far we cud indent a convo ? Wat is numba 4 ginis buk of rekords ? Aaaagh , i'm getting a 'serious ' spasm , 17387³ + 50135³ = ..... Oh my god , I'll be back soon

...Is ther e a limy 2 how far we cud indent a convo ? Wat is numba 4 ginis buk of rekords ?...

Kipup da goodwork and turna spellchekaoff. - This sound like a day in Johannesburg

I met up with some long distant friends there once . A few hours into the evening and we really did sound like that . Friend 'a' had made a head start and whilst enjoying a meal his head dropped splat onto his plate . Myself and another administered medicinal 'refreshment' before going to a club. Oddly I don't remember the rest .

...distant friends there once...

I lived there for a few years, in a neighbourhood called "Yeoville", of all possible names. Took endless stream of silly jokes from Israelites.

There is even Yeovil in Somerset UK. Both accents are hard to copy - I can't imagine how the two would communicate . It would have been a good 'Python' sketch.

Hi Yuval & Kris,

Sorry I dropped out of the discussion, it was 04:00 where I am and time to get some shut eye.

"I hear that panting and heavy pelvic contraction helps to counter act the effect of g. Is this so ? Perhaps it explains why female pilot can take a higher 'g' than men."

From what I have heard the main reason that women can tolerate higher G forces than men is the distance between their heart and brain is normally less. A shorter distance between the brain and heart means that when you are upright the hart doesn't need to work as hard to keep the blood flowing to the brain. That means that women can cope with slightly higher G loads than men, but only when sitting up. When lying down like in a spacecraft there is little difference between the two.

The process of GLOC (g induced loss of consciousness) is not fun. The first symptoms at the loss of peripheral vision, it's sort of like looking down a tunnel or pipe. Then you have that sort of tingling light headed feeling in you head and you loose your colour vision. Finally it is sort of like somebody laying sheet after sheet of translucent material over your face, everything goes grey and the next thing you remember is regaining consciousness. That is of course if you aren't the pilot flying the aircraft in which case you never regain consciousness. If you ever get to the tingling light headed point it is definitely time to stop doing whatever you are doing pronto.

The idea of tensing the muscles in the abdomen and legs, like you are trying to clear a really bad bout of constipation, is that this forces the blood out of your legs and increases you blood pressure up. Higher blood pressure means a greater resistance to the effects but only to a point. Obviously going to high can cause things to break so you really need to be careful as you can cause an aneurism. You also need to be careful, because like Yuval's friend, like lifting heavy objects, you can easily give yourself a hernia.

A G suit is a combination of hernia belt and series of bladders that inflate and as the G forces you are subject to increase. This helps you by giving you something to strain against and by squashing your legs, forces the blood up into your abdomen and head. You need to be careful when putting a G suit on as wearing them incorrectly can have a dramatic effect on certain parts of make anatomy. Incorrect use can bring the strongest an bravest men to their knees with tears in their eyes.

There is a maneuver that I love to pull on those macho guys that think they can cope with everything. You set the glider up in straight an level flight then give it forward stick till you hit about 95 Kt. You then pull back on the stick till you hit 3 g and hold that till you are about 45 degrees past vertical. At this point if you get the controls just right you can experience 0 g for a few seconds. The result is that you end up experiencing weightlessness while viewing the world from upside down while everything that isn't bolted down floats past your face.

The sight of the world being upside down with respect to you and the cockpit combined with weightlessness is enough to confuse the living daylights out of most people and it can take some time to figure which way up is. It's not necessary but a follow u spin or two usually ensures that they still havn't figured it out which way is up by the time you land. When the try and stand up they fall over, then, after trying to compose themselves, stagger off weaving from side to side like a drunken idiot. This is often followed by a replay of the last meal.

I can be a really sinister sod when I put my mind to it.

That's a fantastic detailed clarification masu . I shall be wary of short people - especially if coming at me in a Mig . Perhaps the days of pilots are limited ? The process is mostly there. I was told that when I see fighter pilots ground-hugging the mountains up in Scotland that they're usually flying on computer whilst the pilot concentrates on targeting . Whatever , it's pretty weird when they look at you on the same level (probably figuring how much they can blow you over! ).

...Perhaps the days of pilots are limited...

In the fighter's cockpit, that is.

Not in the ground control station.

Not just the mighty US is R&D'ing Unmanned Fighters, but the tiny Israel does, and probably dozen other countries as well.

Why? The human limited tolerance to G forces.

It can be much smaller, cheaper, and more agile with negligible radar signature, yet able to carry effective weapon systems

Now, isn't that funny? - Robots will fill the skies, long before they'll fill your coffee-mug.

On second thought, why am I not surprised?

Why? The human limited tolerance to G forces.

Some might say it's because a pilot is too valuable to risk outside of a game console environment . Also swarmed miniature remotes could have superior tactical advantage in some situations.

Now, isn't that funny?

funny ha-ha , or funny peculiar ?

Not sure where you're going with reference to coffee-mugs . More off-topic than me possibly.

Kris, kris, kris:

...a pilot is too valuable to risk outside of a game console environment...

The pilot is not yet out of the loop. He's safe on the ground, with his horse rampaging out there. It's flight by proxy, only more automated, to allow free the pilot of danger and physically demanding exhaustion, to be at his best whispering in his horse's ear what he wants done.

...funny peculiar...

I was just only sarcastic. Isn't it amazing that the most exciting technologies of human invention, always pop up first, to serve armies and killing or destruction in general, as if destruction being the greatest motivator. Geeeze, take my head of...

P.S: Off-topic "Perpetual Motion"??? Are you insane?

How can you possibly be off-topic perpetual motion I wonder... Not even with aliens on your plate can you be off-topic Perpetual Motion...

"Klaatu barada nikto"

Serves me right, with the last one overshot like that, especially with the bold stressed like a painted whore.

My bold stress, not yours, which was perfect. Just mine. Sorry.

Hmmm... I need to tone down, I know, but with the lack of so much intention in my early childhood , I've got to redeem myself with some occasional bull-cheese. if only to feel somewhat alive

Will you ever forgive me? please?

Nothing to forgive my friend !

Let me illustrate with a completely off-thread story ;

A man is in his garden one evening , and hears an owl call . Out of interest he makes a noise in reply . The Owl calls back to him ! Much excited he builds up his evening conversation with the Owl . Some weeks later , his wife has a friend visiting for coffee . The friend regales them with a fantastic story -'some weeks ago my husband was in the garden and.......'

Variation - 2 dogs chatting in the park : 'these humans are great . I bring him a stick , and every time he throws it to see how far it will go . He loves it bless him'

My metaphorical point - we are all guilty of misinterpreting each other, even if joined at the hip . I love your style of writing and humour . My day would be dull without it.

Kris

So true, so true.

I had a friend in the front seat in the glider with me one day and after about 20 minutes of stooging around he asked me to show him what the glider could actually do. I confirmed that he really wanted me to put the aircraft through its paces and he said yes he was sure.

I wicket it into a step turn to the left and after a full turn rolled it into a right hand turn with close to an 80° bank, it was about this time that he stopped talking to me.

When we got back on the ground I checked the g meter and it said we pulled a 5 g turn and he couldn't remember much past saying that he was certain that he wanted me to show him what the glider could do.

The moral of the story is, never ask a pilot to really show you what an aircraft can do, he might just do it.

...never ask a pilot to really show you...

Or any serious professional for that matter.

"...Be careful of what you ask for, you might just get it..."

I was however in a similar situation, asking a driver to show his skills while I remained, foolishly, with him inside the car. I was sick for two hours, and always gave some excuse to avoid car riding with him ever since. I'm still sick recalling this ride.

Hey ,like I'm gonna go up in a bunch of twigs and then risk pissing off the guy/gal flying the thing . If you've got the conrol you have my full attention . ( If I was a whingeing pom you'ld have my full support - spare the rest of us . p-l-e-e-e-z-e ).Oz pilot , Brit passenger - We're gonna die !!!

I must admit I do not find setting the DG to magnetic north rather than true north a good idea. There is too much chance for misinterpretation.

To some extent, I agree. However, here, as in Australia, VFR flight levels are referenced to magnetic headings, so setting your DG to true north would mean you'd have to apply several un-corrections.

Also, around the world, ATC headings are to be given in magnetic, not true, with the only exceptions being in polar regions. So, if you set your DG to true, then every time ATC says, "Turn left, heading 120." you'd need to apply un-corrections, too, adding to workload. On approaches, where ATC is expecting you to fly magnetic headings, and when they may be giving you headings very frequently, flying with your DG set to true headings would be problematic, and potentially dangerous.

And of course, runways are named for magnetic headings, so having your DG set magnetically makes finding the correct wind correction angle easier.

All this stuff came from the days when a compass might have been the only nav instrument on board.

Remember Jerycho?

Are the ruins of this city available to visitors?

There is no such thing as perpetual motion!

There is no such thing as perpetual motion!

There is no such thing as perpetual motion!

There is no such thing as perpetual motion!

There is no such thing as perpetual motion!

Say it!!

Actually, perpetual motion does exist, but not of the type that we could harness any energy from. For example, Brownian motion occurring in liquids. Another example: vibrations of molecular dipoles (this occurs even at absolute zero temperature). But unfortunately the 2nd law of thermodynamics ("entropy of a closed system never decreases") prevents us from tapping such motion. I call this type of perpetual motion "perpetual motion of the trivial kind". A device that could violate the 1st or 2nd laws of thermodynamics would be called "perpetual motion of the 1st kind" and "perpetual motion of the 2nd kind", repectively. As far as I know, no one has ever succeeded at violating thermodynamic law.

If this topics interests anyone, check out these two Yahoo groups:

http://tech.groups.yahoo.com/group/free_energy/

http://tech.groups.yahoo.com/group/Maxwells_Demon/

Sir, I can't prove there is, but you can't prove there is not!!!!!!!!!!! It's all about dreams, remember a man can't fly either. Thank God and mrs. Mr. and Mrs.Wright for giving us someone who did DREAM !!!!!

...you can't prove there is not...

Also there is no proof that Jimmy Hoffa is not having the fun of his life on Alfa Centauri.

Let's make it much simpler, according to "Occam's Razor":

It's been searched for, since the down of history. Everyone wants an engine which will produce infinite motion with no cost whatsoever. Anyone managing to produce one, even as a working prototype, is likely to richer than Microsoft overnight.

Any volunteers?

I like the double negative Yuval .

There is proof about Jimmy Hoffas whereabouts - we just don't have it in the public domain yet. Even if he 'sleeps with the fish' (instead of a foundation) there is proof somewhere. Time on it's own will still not prove his existence or otherwise. Philosophy is 'intellectual trouble-making' (not sure who said that) , but is still interesting .

When I said I would like to know more in my last post I meant more about piezoelectric effect etc NOT perpetual motion. Perhaps I made the wrong assumption that people would realise that a degree educated person in physics (like myself) would already know perpetual motion is contrary to the laws governing the universe as we see it.

Hi MACA,

Bhankii wasn't referring to your post, he was responding to the original posters question about whether or not such oscillations are perpetual motion. If you take a look at the post number in the right, you'll see that there is not "In reply to #x" there, so it's in response to the original poster.

Silas Marner

Perhaps a more specific question to match your high degree of education would have been a better choice. Science is all about the details is it not? Just a thought for you. Also the laws governing the universe as we see it might in the future seem pretty lame

Dear Guest,

Perpetual it's not, as nothing is, but most precise it is indeed.

Molecules have their "Dance" which is amplified, divided, and made to be displayed to the incredible accuracy of a few seconds per year.

A "quartz" wrist watch is a kind of "poor man's atomic clock". A proper one, used by scientists is a Caesium Atomic Clock.

Caesium oscillates 770631192.9 times per second, and when properly divided, provides the most accurate timepiece known to man, with a regularity of about a second per some sixty years.

Caesium clocks were used to confirm Lorentz's "slowing clock" hypothesis, later used by Einstein.

I find this a terribly interesting point. Let us say, at a given temperature, atoms in matter are oscillating at their natural frequencies. Hence, they are dissipating energy, since they are actually moving. The energy that they dissipate is precisely heat, the origin of the temperature. You do not call it "perpetual motion" but just energy that is originated and lost by the same ultimate origin???

...they dissipate is precisely heat, the origin of the temperature...

No. What you describe here, is not continuous and stable heat circulation of whatever sort, which can never exist - It is against the second TD law. This is simply some heat-transfer from one localised point (lower entropy) to another (higher entropy).

To enable the oscillation, environmental surrounding heat is considered "imported energy" into the system. Should you drive the system to absolute zero (Kelvin), molecule oscillation will stop. Not perpetual. You'll need additional (imported) energy from outside the system, to enable the movement.

Perpetual motion is the natural state of all things, in my way of thinking, at least. We have been trying to completely stop something, anything for many years and have not achieved success. It has been very frustrating to see billions of dollars go down the drain in cryogenic research in quest of that magic moment when some tiny object is so cold that all activity ceases. We had been working at this for years when someone came up with the startling idea of denying the existence of perpetual motion as a remedy to the problem. Of course Albert Einstein had recently become frustrated with his attempts to explain gravity and had comically suggested that gravity is an illusion. He went on to explain that the universe and everything in it is expanding at a rate of 1 G and that it has been doing so since the dawn of time. Eventually we will exceed the speed of light and everything will simply vanish. I think that was on his third glass of brandy.

...the natural state of all things...

In the sense of mental being?

Now, who on earth, could argue with that?

Having the imagination faster than c, I wouldn't mind having a shot of what you're having...

Firstly my apologies to all for not reading the posts correctly.

Secondly as Sabo said it is very interesting that man has spent vast sums of money,time and energy trying to reduce the kinetic energy of a single atom to zero by cooling to absolute zero. Then on the other hand man has also spent vast sums of money,time and energy trying to invent a machine which will continually output kinetic energy but requires no input energy.

Thirdly, I'm very glad that people have the curiosity to ask and be interested in these types of questions but feel a little dissapointed that the laws of our universe (as far as we know) give us a very definite answer to the perpetual motion question. I believe talking about questions and theorising possibilies is far more fun than reaching the end point of our question.

...very definite answer to the perpetual motion...

Until the eighteenth century it was very seriously considered as possible. As a consequence, it was duely questioned, researched, tested, then theorised.

It's not that we don't want to have it. It's that nothing in nature seem to act untaxed. It's nature, not us.

...very glad that people have the curiosity...

Right, this is what we somehow do here, and I admit to love it. No wonder, being retired and all that ...

I believe talking about questions and theorising possibilities is far more fun than reaching the end point of our question.

I agree. But I also sometimes share the frustration that many here have experienced when someone unveils their perpetual motion machine in CR4. (The current thread is an exception to the rule. The "rule" is a machine, often a generator-motor combination -- or something that logically reduces to that -- in which a small amount of energy goes in to "get it started" and then a much larger amount comes out in a continuous stream.) It can be hard, at times, to tell the difference between those who are simply unaware and those who are aware, but true frauds.

Then there are those who are simply asking reasonable questions, as is the original poster here: resonant systems, like the famous narrows bridge, seem to have an energy all out of proportion to the input energy. Tuning forks seem to put out so much sound, for so long, given just a slight tap. Foucault pendulums in museums seem to swing forever.

You can imagine someone experimenting with a pendulum. Theorizing that air resistance damps the motion, he could put the pendulum in a vacuum. It would swing much longer. But it eventually stops. So then he improves the pivot, and it swings longer. He improves the pivot again, and it swings even longer -- tantalizingly close to seeming to want to swing forever.

The experimenter might say "I've gone from .9 efficient, to .99 to .999; clearly I can get to .999 repeating. But .999 repeating is mathematically equal to 1... not close... but equal. So there you have it, my pendulum, with just a little more refinement, will swing forever."

And there are those blasted atoms. It certainly appears that their electrons just spin, and spin, and spin. And there are people telling us that there are 11 dimensions -- who knows what might be happening in the ones we can't see?

I collect rocks and have never seen a piece of Quartz so much as twitch . My conclusion is that the chance of harnessing energy from vibrating atoms is Zero. We still struggle to harness wave power.

...never seen a piece of Quartz so much as twitch...

But you have probably seen a piezo-spark lighter or a piezo tweeter. These, what can you do, need some imported energy to twitch: a mechanical bang for the lighter, and AC current for the tweeter. Otherwise, no twitching.

What so hard to explain?

Ones a student asked me: "How is it possible to transfer heat from the cold air outside the house into it by a heat pump? I cannot understand this completely!"

It is still not so easy to "regular mind". From existing installation (applications) we know is is possible so in XIX Century was impossible.

But it happened years ago and it is not a perpetuum mobile. Must we be carefully to reject all strange ideas?

Natural frequency (energy) that reaches amplitude, high enough, becomes so destructive.

Remember Jericho?

I have read the various entries bellow and some have made valid points while others have just made light of the question.

So here is my two penny worth.

You ask about the natural frequency of matter. This is its ability to vibrate either on its own (internal vibration of the atoms) or it ability when forced to resonate when stimulated by an external forced applied to it. Tuning fork tapped and held by its handle. The second is a purely mechanical effect whose frequency is determined by its dimensions. The smaller the higher the note the bigger the lower. The same as used with guitar when fingering the strings.

Perpetual motion describes a situation where a stimulus starts the process and then the motion carries on for ever after with no further intervention.

The things that go to make this unable to happen are friction, either direct as in a bearing, or as in air resistance, water resistance. Then there is gravity, this want to resist all movement. Heat from the work done also robs energy from the system.

Some of these can be over come by better materials, an applied vacuum, you could relocate to outer space, the moon would give better conditions. It has less gravity can be very cold, and has no atmosphere. One day in the not so distant future we may see very highly efficient nachines working there. Here on Earth all most everything is against there ever being any form of perpetual anything.

From what I understood till now, the only thing that hinders perpetual motion is the second law of thermodynamics, the fact that entropy should always increase. If we have a closed isolated system, energy will keep constant (so far energy is neither created not destroyed) hence if we have that energy placed in atomic motion (such as resonant vibrations) in the highest possible entropic state, i.e. without any kind of order or correlation, then the atoms will continue to move forever in this very same way. The only problem is that, by definition, we will not be able to take advantage of this energy for something useful...

I just noticed one or two minor errors crept in sorry.

But the reasoning is still correct. Perpetual motion describes a man made machine device call it what you will. In nature things are different because we are not trying to get work done for no cost. The whole concept of perpetual motion is that you can get something for nothing. It is a dream and a con. Losses it the system must bring anything to a halt sooner or later. Atomic structures don't obey the same rules.

The standard laws of thermo dynamics only apply at the macroscopic level.

All those who try to bring together a theory of everything are wasting their time.

I laugh at all the time and money wasted by these people who think just another couple of billion and just another billion volts and we will get there they will not because there is no where to go!!!! It is fools gold they are chasing. Spell check says all now ok.

Well, I would say this is precisely the origin of all problems: time...BrainWave meant nature is not trying to get work done for no cost. But nature is doing and doing work all the time...at its own way and pace. And so far if we consider the entire Universe, this must be an isolated system, if energy is neither created nor destroyed, then work is being done in Nature without paying extra energy for it. But entropy always increases, which points a direction which we call "time"...

We distinguish between micro and macro in space dimensions. When we refer to perpetual motion, how do we cope it with our everyday time-scale?

Like Alchemy , it's a fools errand . However creative thought may come from pursuing it. Newton was alleged to dabble in Alchemy . I'm not sure if the 99.99999999% of other people achieved much (even allowing for advance in Chemistry ). Must dash , I'm looking into trisecting an arbitrary angle.

Darn it , no bites . I have a 'tomahawk'. Following Euclid keeps me much busier though.

...In nature things are different...

Not even as a joke. The fact that we cannot replicate some natural phenomena, or understand their inner-workings, does not suggest that nature is somehow allowed to contradict it's own rules, and somehow act untaxed.

Hence, the thermodynamic first rule, declares the total amount of energy an uncounted constant, to hint that energy calculation is a zero-sum game. You take some here, it is missed somewhere else, no matter where.

The more you test it, the more you discover you cannot cheat it("you" being nature as well).

You just need to calculate an ever broadening picture, to catch the illusive buggers.

Now, I was once told (I should ask this an expert, Jorrie? Europium?) that localised phenomenon may temporarily cheat, but then again, only to be taxed later.

So, no, not even nature can cheat itself

Then there is gravity, this want to resist all movement. Heat from the work done also robs energy from the system.

Interestingly enough, many of the attempted perpetual motion machines are "gravity machines". Not one has worked yet, but they all attempt to use gravity to maintain a motion.

Pendulums, of course, would not work without gravity. In this case gravity is not resisting movement, but causing it. Probably pendulums are one of the things that have lured people into pursuing perpetual motion ideas. They can make gravity appear to be an appealing energy source (despite the fact that it is not an energy source at all).

...they all attempt to use gravity to maintain a motion...

Gravity in fact, is the greatest illusionist of all, and we admit to not fully understand it to this day.

Maintaining motion however, is it's greatest "perpetum" type of illusion, because, all other factors being the same, and enough time given, interacting gravity fields (in stellar terms it's referred to as tidal forces) will eventually slow, gravity driven motion.

...gravity is not resisting movement, but causing it. Probably pendulums are one of the things that have lured people...

You said it, not I.

Any gravity driven motion, is merely using a higher potential energy and transfers it to a lower potential, thus increasing entropy, and eventually loosing some momentum.

Nothing in nature managing to escape interaction totally. Not even exotic particles, such as neutrinos, said to be transparent to other particle potential fields. Even these interact, in some given circumstances. The fly through earth, but sometimes trapped in Japan, for research.

As a boy visiting the desert i was sure that i found perpetual motion.

The sand dunes seems to forever have sand available to slide down the slope.

It was only later that i realised that the dune was wind driven and actually was rolling over the terrain.

Yes, I can tell you. No, natural frequencies of oscillation is not considered to be perpetual motion. It is quite often harnessed and amplified.

Urban legend has it that a guy was sitting on the toilet after a heavy night out . He vomited , and created a spectacular syphon effect . With the foresight to connect his floor to the sewage pipe he may have been able to create perpetual motion.

Oh , sorry . I thought it said ' is natural motion frequency perpetual '.

...able to create perpetual motion...

Circular Bio-Feedback that is.

No perpetuals allowed here

It seems to me that nature demonstrates perpetual motion in many ways. Take the propagation of a wave of light for example. Light waves can propagate for billions of years as a tiny quantum of energy fluctuates between the forms of an electric field and a magnetic field. Electrons orbit atomic nuclei indefinitely. And what powers gravitation? While the tidal forces of planets and moons may act to slow their orbital and/or angular momentum, it doesn't reduce the strengths of their gravitational fields. The same can be said of perminant magnets. An electric generator certainly needs a source of external power in order to generate electricity but, a lack of power doesn't demagnatize the magnets. We may not be able to build machines that can create energy from nothing but, I don't see any reason why we can't build machines that can store energy indefinitely.

...Light waves can propagate for billions of years...

Until the photon is swallowed by an atom which converts it's initial (potential) energy into whatever - Not perpetual

...Electrons orbit atomic nuclei indefinitely...

Until heated to plasma temperature and turn into what's called "particle-soup", abundance of unbound nucleons, electrons, and photons - Not perpetual

...tidal forces of planets and moons may act to slow their orbital and/or angular momentum, it doesn't reduce the strengths of their gravitational fields...

You said it, not I

...The same can be said of permanent magnets...

Until heated to completely loose their permanent field - Not perpetual

...An electric generator certainly needs a source of external power in order to generate electricity but, a lack of power doesn't demagnetize the magnets...

See the both above

...We may not be able to build machines that can create energy...

We can hardly create machines that can convert energy with high efficiency

...I don't see any reason why we can't build machines that can store energy indefinitely...

Because of the first and second thermodynamic laws

Now, if you feel a re-occurring theme here - heat - being equivalent to loosing potential energy into higher state of entropy, don't blame me for it, mother nature is very unforgiving this way.

I only tried to describe.

There is no motion in a stationary magnet! Nature always ensures every thing sums to zero. Action reaction. Perpetual motion is an artificial circumstance a man made contrivance that seeks to produce energy out of thin air. Its practitioners are fools because they never learn that deceit most often is found out and those who try to trick others will be shown the error of their ways.

SURELY NATURE OR RATHER THE EARTH RELIES ON PERPETUAL MOTION IN ORDER TO ROTATE OR IS THIS THE GRAVITATIONAL PULL YOU ALL SPEAK OF IF SO THEN GRAVITY MUST THEREFORE THEN BE CLASSIFIED LOGICALLY AS A PERPETUAL FORCE OR MOTION?

...THEN GRAVITY MUST THEREFORE THEN BE CLASSIFIED LOGICALLY AS A PERPETUAL FORCE OR MOTION...

No.

Gravity is a form of energy.

Since the total amount of energy in the universe is given (not increasing or depleting), then the availability of potential energy for any use, must be through conversion from a high potential, into doing some work, out to low potential, for any given given system.

In other words: no available potential energy = no gravity (nothing for that matter: no particles, no mass, no atoms, no matter, no nothing! got it?)

The fact that something seem eternal to your scope of human life, does not mean it's eternal in a universal scope.

No wonder: 20-something billion years, would seem eternal to a human.

Well, nothing is. Whatever was created, will eventually end. Logically. By definition. Nothing is perpetual (#3). not even motion.

The last two posts remind me of the discussions in Bhor´s time regarding that the electrons in an atom would eventually collapse into the nucleus due to energy dissipation if they were describing circular or elliptic trajectories around...The solution was to describe those electrons as stationary waves...Curiously enough, I see that Yubal pre-assumes that the Universe must have a beginning and and end..I thought that was far from being clear.