Gravity has arrived

[swansont]

Thank you.

Would this be a little? or a lot?

 

Depends on the reactants and products. You often take the oxygen a from the air and carbon from a solid and produce CO₂ which will mean the number of moles of gas has not changed. But if you produce CO, the number of moles increases, and so does the volume. And there are other possible products.

 

If, instead of igniting some solid, you combust hydrogen gas with oxygen you might get your desired result, because the product is water. So if you had the right mix and were able to condense the vapor back down to liquid, the gas volume would disappear.

[TOAWNIF]

Depends on the reactants and products. You often take the oxygen a from the air and carbon from a solid and produce CO₂ which will mean the number of moles of gas has not changed. But if you produce CO, the number of moles increases, and so does the volume. And there are other possible products.

 

If, instead of igniting some solid, you combust hydrogen gas with oxygen you might get your desired result, because the product is water. So if you had the right mix and were able to condense the vapor back down to liquid, the gas volume would disappear.

 

Ta much!

[insane_alien]

still have a pressure of about 4kPa above vacuum after condensation.

[TOAWNIF]

I am a stupid and ignorant being. While your contributions are acceptable and I am sure, worthy, they don't really help me. I actually understood magnetism once and I still retain, I think, a reasonable memory of my understanding of atmospheric pressure. What I have never been able to understand is gravity. Whilst I'm sure the technicalities are astoundingly convincing for the highly educated I think they are mostly incomprehensible to the rest of us. I would appreciate a simple explanation of the hows, whys and wherefores of gravity. If its not too much to ask.

[swansont]

Physics doesn't dabble all that much in the hows, whys and wherefores. It explains how things behave, but not how the underlying effect actually works.

 

Newtonian gravity was an observation that masses attract in an inverse-square relationship with the distance, and it's a useful thing to know that nature behaves that way.

 

Einstein took it to the next level; there are some phenomena that Newtonian gravity doesn't adequately explain. Mass and energy actually yield space that is not "flat," i.e. not Cartesian. Motion in curved space explains the effect we call gravity.

[TOAWNIF]

Physics doesn't dabble all that much in the hows, whys and wherefores. It explains how things behave, but not how the underlying effect actually works.

 

Newtonian gravity was an observation that masses attract in an inverse-square relationship with the distance, and it's a useful thing to know that nature behaves that way.

 

Einstein took it to the next level; there are some phenomena that Newtonian gravity doesn't adequately explain. Mass and energy actually yield space that is not "flat," i.e. not Cartesian. Motion in curved space explains the effect we call gravity.

 

Here is a part of my problem. You say this is an observation but I have never observed it except between magnetic objects or objects falling to earth under the influence of atmospheric pressure. For instance buildings don't attract each other, nor do cars (unless I'm driving one)or planets, in any way that can't be more easily understood in terms of magnetism or, 'as I like to think of it' the space equivalent of atmospheric pressure namely Solar wind or pressure. if as I suggested in my original post, magnetism accounts for ferrous matter and atmosphere for non ferrous matter then gravity looks after the rest surely?

[insane_alien]

gravity is not pressure dependant seeing as its gravity that keeps the atmosphere which causes pressure. buildings DO attract each other it just that gravity is a feeble force and you don't normally notice it. just think that it take a mass as big as the earth to provide only 9.81 N/kg of gravitaional field strength.

[Klaynos]

Here is a part of my problem. You say this is an observation but I have never observed it except between magnetic objects or objects falling to earth under the influence of atmospheric pressure. For instance buildings don't attract each other, nor do cars (unless I'm driving one)or planets, in any way that can't be more easily understood in terms of magnetism or, 'as I like to think of it' the space equivalent of atmospheric pressure namely Solar wind or pressure. if as I suggested in my original post, magnetism accounts for ferrous matter and atmosphere for non ferrous matter then gravity looks after the rest surely?

 

You have never observed anything without some outside influence, the trick is working out how big the outside influence is and removing it from your measurements.

 

Buildings, cars etc, DO attract each other just because your detectors are not good enough, and there are other retarding forces does not mean it is not there....

 

The magnetic filed of the earth is tiny at any significant distance from it compared to gravity. We can model the orbit of the Earth extreamly well using Newtonian gravity, show me the same way you could do that using magnetism, or do the same with a satellite around the Earth.

[TOAWNIF]

You have never observed anything without some outside influence, the trick is working out how big the outside influence is and removing it from your measurements.

 

Buildings, cars etc, DO attract each other just because your detectors are not good enough, and there are other retarding forces does not mean it is not there....

 

The magnetic filed of the earth is tiny at any significant distance from it compared to gravity. We can model the orbit of the Earth extreamly well using Newtonian gravity, show me the same way you could do that using magnetism, or do the same with a satellite around the Earth.

 

1. Can you tell me what detectors you use please?

 

2. Isn't the moon a satellite? I am content with the theory that the moon relies on magnetic forces. And can explain it simply.

 

PS I worked with measuring instruments for a quarter of a century so I shall understand some of what you might say in this regard.

[MM]

Physics doesn't dabble all that much in the hows, whys and wherefores. It explains how things behave, but not how the underlying effect actually works.

 

Newtonian gravity was an observation that masses attract in an inverse-square relationship with the distance, and it's a useful thing to know that nature behaves that way.

 

Einstein took it to the next level; there are some phenomena that Newtonian gravity doesn't adequately explain. Mass and energy actually yield space that is not "flat," i.e. not Cartesian. Motion in curved space explains the effect we call gravity.

 

Hope you can clarify this for me for when you write that mass yield space I imagine that it requires information (stored in space?). So when I add all information in space from a mass of a gravitational field I want a finite value.

[Spyman]

You say this is an observation but I have never observed it except between magnetic objects or objects falling to earth under the influence of atmospheric pressure.

You say you understand atmospheric pressure, so can you explain why the atmosphere don't expand out in space, there is no container preventing that and the vacuum in space has a very low pressure ?

[TOAWNIF]

You say you understand atmospheric pressure, so can you explain why the atmosphere don't expand out in space, there is no container preventing that and the vacuum in space has a very low pressure ?

 

When rockets etc leave our atmosphere the need to do so at a certain angle and within a range of speeds. When they return they heat up to the point of burning up. These effects only occur at the junction between atmosphere and space demonstrating the existence of something different in that place. Sci-Fi nicely provides a name for this, The Chrono-sphere. This in turn is borrowed from mythology Chronos the god who eats planets. I prefer to think of it as a balloon! This happily satisfies me at night that our air will not be shooting off into space by morning.

[insane_alien]

When rockets etc leave our atmosphere the need to do so at a certain angle and within a range of speeds. When they return they heat up to the point of burning up. These effects only occur at the junction between atmosphere and space demonstrating the existence of something different in that place. Sci-Fi nicely provides a name for this, The Chrono-sphere. This in turn is borrowed from mythology Chronos the god who eats planets. I prefer to think of it as a balloon! This happily satisfies me at night that our air will not be shooting off into space by morning.

 

OK, you don't understand atmospheric mechanics. First, rockets can leave the atmosphere at any angle or speed they want, as long as they have sufficient fuel. not all things that leave the atmosphere burn up on rentry as they may not have the necessary velocity (spaceship one is an example of this as it did not develop a plasma)

 

it does not occur at a "junction between atmosphere and space" as there isn't one. there has been lots of debate as to what qualifies as space since the atmosphere does not suddenly stop at some arbitrary altitude. It looses pressure and density in an inversely exponential manner up until about 50km then it deviates a bit depending on the time of day, temperature, solar wind and various other parameters. even what we term as space (>80 km at the moment) is still within earths atmosphere even the ISS at ~300 km is still experienceing atmospheric drag. this is because of gravity. pressure does not cause gravity. if pressure caused gravity(i'm going to assume some kind of negative buoancy effect) i would experience more than a thousand g's if i submerged myself in water. since i float in water and have regularly swam under water(i even did so 20 minutes ago) and have not been horribly mashed to a pulp i can only conclude that you are wrong and mainstream science is correct on modeling the atmosphere and gravity.

[TOAWNIF]

OK, you don't understand atmospheric mechanics. First, rockets can leave the atmosphere at any angle or speed they want, as long as they have sufficient fuel. not all things that leave the atmosphere burn up on rentry as they may not have the necessary velocity (spaceship one is an example of this as it did not develop a plasma)

Quickly. I got my info from scientists years ago so paint me dumb for believing scientists eh!

I'll read the rest later and get back.

[TOAWNIF]

it does not occur at a "junction between atmosphere and space" as there isn't one. there has been lots of debate as to what qualifies as space since the atmosphere does not suddenly stop at some arbitrary altitude. It looses pressure and density in an inversely exponential manner up until about 50km then it deviates a bit depending on the time of day, temperature, solar wind and various other parameters. even what we term as space (>80 km at the moment) is still within earths atmosphere even the ISS at ~300 km is still experienceing atmospheric drag. this is because of gravity. pressure does not cause gravity. if pressure caused gravity(i'm going to assume some kind of negative buoancy effect) i would experience more than a thousand g's if i submerged myself in water. since i float in water and have regularly swam under water(i even did so 20 minutes ago) and have not been horribly mashed to a pulp i can only conclude that you are wrong and mainstream science is correct on modeling the atmosphere and gravity.

It has been my observation that while scientific evidence could one day be infallible, human interpretation is not.

So also my interpretation of what you say now. As I read it your argument goes that a balloon skin could not possibly be 30 kilometres thick and there must be gravity because you can swim. Is that right? Or is my interpretation fallible?

[Spyman]

When rockets etc leave our atmosphere the need to do so at a certain angle and within a range of speeds. When they return they heat up to the point of burning up. These effects only occur at the junction between atmosphere and space demonstrating the existence of something different in that place. Sci-Fi nicely provides a name for this, The Chrono-sphere. This in turn is borrowed from mythology Chronos the god who eats planets. I prefer to think of it as a balloon! This happily satisfies me at night that our air will not be shooting off into space by morning.

Hopefully you don't get nightmares from the thought that NASA might accidentally punctuate our balloon...

[TOAWNIF]

Hopefully you don't get nightmares from the thought that NASA might accidentally punctuate our balloon...

I do actually, since scientists told me there was a hole in it at the south pole. Scientists eh?

[swansont]

When rockets etc leave our atmosphere the need to do so at a certain angle and within a range of speeds. When they return they heat up to the point of burning up.

 

The angle is critical in the return to the earth, not the escape from it. The speed requirement is there because of gravity and the capabilities of rockets

[TOAWNIF]

Hopefully you don't get nightmares from the thought that NASA might accidentally punctuate our balloon...

 

"Sorry!! I 'thought' you,, said; (Puncture) <our> B'a'l'oo'n!";)

 

Ha! Ha!

[TOAWNIF]

Captains Kirk and Picard taught me all I need to know about where it is and what it does but, I am still no nearer understanding it.

[Spyman]

"Sorry!! I 'thought' you,, said; (Puncture) <our> B'a'l'oo'n!";)

 

Ha! Ha!

Actually I meant puncture but English is not my first language.

And leave my grammar alone please or you might offend my spell-check.

LOL - And now you have offended mine...

 

What I have never been able to understand is gravity. /snip/ I would appreciate a simple explanation of the hows, whys and wherefores of gravity. If its not too much to ask.

The strong have the opportunity to protect the weak.

The rich have the opportunity to help the poor.

The knowledgeable have the opportunity to inform the ignorant.

The ignorant have the opportunity to mock around.

 

So do you really want to learn or just mock around ?

 

I got my info from scientists years ago so paint me dumb for believing scientists eh!

Captains Kirk and Picard taught me all I need to know about where it is and what it does but, I am still no nearer understanding it.

With those kind of teachers it's no wonder about that...

 

Which color do you want to have ?

[TOAWNIF]

Actually I meant puncture but English is not my first language.

LOL - And now you have offended mine...

The strong have the opportunity to protect the weak.

The rich have the opportunity to help the poor.

The knowledgeable have the opportunity to inform the ignorant.

The ignorant have the opportunity to mock around.

So do you really want to learn or just mock around ?

With those kind of teachers it's no wonder about that...

Which color do you want to have ?

I appologise if my need to know has outstripped your ability to explain.

English isn't my first language either.

[insane_alien]

the hole your talking about isn't really a hole.

 

There is the ozone 'layer' which is a relatively narrow range of altitudes where the pressure is suitable for ozone production and stability. the hole(i'm assuming this is the 'hole' your talking about) is an area in the layer where there is less concentration of ozone, there is still ozone there, just not as much as everywhere else.

[TOAWNIF]

the hole your talking about isn't really a hole.

 

There is the ozone 'layer' which is a relatively narrow range of altitudes where the pressure is suitable for ozone production and stability. the hole(i'm assuming this is the 'hole' your talking about) is an area in the layer where there is less concentration of ozone, there is still ozone there, just not as much as everywhere else.

 

Hooray. See, it is possible to explain things simply. Now please have a go at Gravity.

[insane_alien]

okay, gravity isn't so simple, we don't know WHY it acts the way it does. or even how it acts, we just know that it does. now, i'm going to use the rubber sheet analogy but it should only be taken as an analogy since it is flawed but its close enough for a beginner.

 

say you have an infinite, frictionless rubber sheet(space-time) and a bowling ball and a golf ball(a planet and a rock). now the rubber sheet is taught and will deform slightly if you put a mass on it. (just imagine that the balls are pulled down it doesn't matter by what force but it acts on the mass, bigger mass = bigger downward force)

 

so you place your bowling ball on the rubber sheet it deforms a bit and its kinda steep near the ball but gradually gets less and less steep as you get further away. so, you could place the golf ball ANYWHERE on the sheet and it would start sliding towards the bowling ball (cos its going down hill). Or you could put some velocity on the golf ball when its near the bowling ball and it would have an orbit.

 

This is, very basically, how we think gravity works. to get it right you need a couple more dimensions and some other stuff that i don't know about since i don't study physics. It does actually get quite complicated when you try to put in the third spatial dimension, frame dragging, speed of propagation and all that jazz.