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Author Topic: Is there zero zero gravity?  (Read 16001 times)

Offline Hadrian

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Is there zero zero gravity?
« on: 14/12/2009 11:41:18 »
No zero gravity anymore?

In another topic the a discussion about zero gravity has emerged
http://www.thenakedscientists.com/forum/index.php?topic=27298.0;topicseen

If I am reading right zero gravity is not possible.

So basically talking about zero gravity is a waist of time as it is nonexistent in our universe.   Yet it’s a term we hear a lot. 

Where did it come from?

and what would be a better term to use?
« Last Edit: 14/12/2009 19:32:40 by Hadrian »


 

Offline JP

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Re: Is there zero zero gravity?
« Reply #1 on: 14/12/2009 17:50:07 »
Zero gravity is a useful approximation in many cases.  It all depends on how accurate your measurements are.  Even if you're on the earth's surface, if you're measuring forces that are much stronger than gravity, you can often neglect it in the problem at hand. 

In that case, negligible gravity might be a better term, indicating that it can be neglected in your computations.
 

Offline Mr. Scientist

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Re: Is there zero zero gravity?
« Reply #2 on: 14/12/2009 18:03:19 »
You can say there is a zero-gravity in the center of the earth, because all vector lines which describe the force cancel out.
 

Offline Mr. Scientist

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Offline rosy

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Re: Is there zero zero gravity?
« Reply #4 on: 14/12/2009 18:41:54 »
Well, at any rate if the earth were infact perfectly spherical and there were no gravity due to the sun or moon it would... I think in reality this doesn't quite stand up to the realities of the shape of our planet.
 

Offline Hadrian

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Re: Is there zero zero gravity?
« Reply #5 on: 14/12/2009 18:52:37 »
Does anyone know who coined the phrase?
 

Offline Mr. Scientist

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Re: Is there zero zero gravity?
« Reply #6 on: 14/12/2009 18:59:25 »
I have a sneaky suspicion it may have been Newton.
 

Offline Hadrian

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Re: Is there zero zero gravity?
« Reply #7 on: 14/12/2009 19:00:57 »
Ah the old head banger himself… LOL
 

Offline Hadrian

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Re: Is there zero zero gravity?
« Reply #8 on: 14/12/2009 19:01:23 »
Isn’t it fantastic we can be so passionate about something as fundamental as gravity.   
 
DID gravity = 0 exist anywhere inside our universe at any time?
 

Offline Mr. Scientist

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Re: Is there zero zero gravity?
« Reply #9 on: 14/12/2009 19:04:49 »
I'd be very reserved about the ''we'' part around here. Bored chemist the other day tried to excuse the very nature of gravitational acceleration and the presence of mass as not being the same things because they use different units.

Geezer also seems to think that gravity doesn't need to use any work, neglecting the fact also that matter and gravity are actually the same thing. So passionate we might all be, but whether or not certain members here are even sure on what they are saying is quite troublesome.
« Last Edit: 14/12/2009 19:15:49 by Mr. Scientist »
 

Offline Hadrian

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Re: Is there zero zero gravity?
« Reply #10 on: 14/12/2009 19:18:26 »
Perhaps gravity (of the moon) affects people in different ways around here….. LOL
 

Offline Mr. Scientist

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Re: Is there zero zero gravity?
« Reply #11 on: 14/12/2009 19:29:00 »
It's more a lack of them being bothered to understand the concepts they speak about. I'm not overly concerned about new conjectures and suggestions, but if it goes against physics that we understand with quite a great degree of certainty, then there is no reason why they spout it off as a true maintsream statement - it annoys me at best.

I just wish that people like Geezer (and obviously bored chemist whose not a scientist or a physics student) would not argue necesserily with the points of physics which are really actually very basic. It doesn't take too long to learn some of these things. The length to understand gravity on the basic level is actually very easy if one has a certain ineterest in learning that subject.

Einstinean is greately more difficult to understand, but i've been learning on it for years now and i just wish that the given posters exampled would accept what i say as being gospal, because i know for sure they wouldn't understand the math - even i fail to understand all the mathematical conjectures today which involve relativity, but i know quite a bit about it; there is no such thing as a stupid question - but if you are provided the mainstream answer, you should just accept it, instead of trying to flout it with impunity based on the fact you don't really like the character you are communicating with. I know this be the case especially in Geezers behalf. Sad thing is, i actually don't have any problems with either of them personally apart from their ignorance.
« Last Edit: 14/12/2009 19:39:09 by Mr. Scientist »
 

Offline Ron Hughes

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Is there zero zero gravity?
« Reply #12 on: 14/12/2009 19:38:09 »
No where in the Universe is there a place where zero gravity exists.Just as there is no place where electromagnetic radiation does not exist.
« Last Edit: 14/12/2009 19:39:51 by Ron Hughes »
 

Offline Mr. Scientist

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Is there zero zero gravity?
« Reply #13 on: 14/12/2009 19:41:03 »
No where in the Universe is there a place where zero gravity exists.Just as there is no place where electromagnetic radiation does not exist.

Read the link.
 

Offline Mr. Scientist

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Offline Hadrian

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Is there zero zero gravity?
« Reply #15 on: 14/12/2009 19:51:47 »
It's more a lack of them being bothered to understand the concepts they speak about. I'm not overly concerned about new conjectures and suggestions, but if it goes against physics that we understand with quite a great degree of certainty, then there is no reason why they spout it off as a true maintsream statement - it annoys me at best.

I just wish that people like Geezer (and obviously bored chemist whose not a scientist or a physics student) would not argue necesserily with the points of physics which are really actually very basic. It doesn't take too long to learn some of these things. The length to understand gravity on the basic level is actually very easy if one has a certain ineterest in learning that subject.

Einstinean is greately more difficult to understand, but i've been learning on it for years now and i just wish that the given posters exampled would accept what i say as being gospal, because i know for sure they wouldn't understand the math - even i fail to understand all the mathematical conjectures today which involve relativity, but i know quite a bit about it; there is no such thing as a stupid question - but if you are provided the mainstream answer, you should just accept it, instead of trying to flout it with impunity based on the fact you don't really like the character you are communicating with. I know this be the case especially in Geezers behalf. Sad thing is, i actually don't have any problems with either of them personally apart from their ignorance.

I would not begin to claim to be even in the same planet as people who have devoted their life to study these matters.  So I am always out of league around here.  So forgive my naivety I am just fascinated by these subjects.

I seams to me that gravity is a key to understanding the big questions of how our universe came into existence and how it continues evolve.  Yet it is full of mysteries and subject to many weird and wonderful (and I meant that in best way) theories. 

You have spoken many times about gravity being the same as matter.  How dose this work with the concepts around “anti gravity” and “dark matter” etc.   
 

Offline Bored chemist

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Is there zero zero gravity?
« Reply #16 on: 14/12/2009 20:00:47 »
I'd be very reserved about the ''we'' part around here. Bored chemist the other day tried to excuse the very nature of gravitational acceleration and the presence of mass as not being the same things because they use different units.

Geezer also seems to think that gravity doesn't need to use any work, neglecting the fact also that matter and gravity are actually the same thing. So passionate we might all be, but whether or not certain members here are even sure on what they are saying is quite troublesome.
An interesting pair of flat out lies.
I said that mass and gravity are not the same thing because one is a force and the other is that on which the force acts.
I pointed out that they have different units and, therefore cannot be the same thing.
You ignored this and ploughed your own furrow.
Your most recent post on the matter ended with this  total giberish.
"Force IS a vector quantity, so having the information of two vectors form a vertical point of saturation. Are you telling me that we cannot associate two vectors which are perpendicular together and not define each other using calculus?"
 

Offline Mr. Scientist

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Is there zero zero gravity?
« Reply #17 on: 14/12/2009 20:10:41 »
Matter and gravity are the same thing because you cannot have one without the other. Force of gravity on something gives them their weight, and as i have tried to explain to you, units cannot be used as the units we use for matter can be converted into the units that matter exerts gravitational forces on. Hence i said - the work in which the forces derive from.

Hence also how 1N is relatively the same as one apple, and 1kg on the earths surface is a thumbrule for the conjecture it is the same relatively-speaking to the gravitational acceleration g on the surface of the earth.

You and him have been wrong all this time. It's not about how i explain it - you just flat out won't listen - you fail to understand.
 

Offline lightarrow

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Is there zero zero gravity?
« Reply #18 on: 14/12/2009 20:13:48 »
Isn’t it fantastic we can be so passionate about something as fundamental as gravity.   
 
DID gravity = 0 exist anywhere inside our universe at any time?
Exactly zero it's very difficult not to say impossible, but you can easily achieve quasi-zero gravity: inside a free-falling lift; you don't have to consider which planet or sun is near you, the lift authomatically accelerates the exact amount it's required to canceal gravity inside of it.
 

Offline Bored chemist

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Is there zero zero gravity?
« Reply #19 on: 14/12/2009 20:48:41 »
"Matter and gravity are the same thing because you cannot have one without the other."
In the same way that a predator and prey are the same thing.
Meanwhile, back in the real world...
 

Offline JP

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Is there zero zero gravity?
« Reply #20 on: 14/12/2009 22:29:10 »
Exactly zero it's very difficult not to say impossible, but you can easily achieve quasi-zero gravity: inside a free-falling lift; you don't have to consider which planet or sun is near you, the lift authomatically accelerates the exact amount it's required to canceal gravity inside of it.

You can, however, detect that you're accelerating.  

In another interesting note, modern quantum theories generally work in the framework of field theories.  I'm not an expert, but they assume that forces arise from fields that are permeating all space and time.  These fields have quantum-level fluctuations, so in a sense, you never have "zero" field anywhere (or in other words, the lowest energy level of the field is non-zero).  If gravity has a similar description (and that's a big open question in physics), then you would expect it to have a minute non-zero energy value everywhere. 
 

Offline Ron Hughes

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Is there zero zero gravity?
« Reply #21 on: 15/12/2009 17:22:45 »
Key phrase Mr Scientist, ( no force is exerted by the shell on objects inside the shell ) but gravitational forces outside the shell do exert forces on objects inside the shell.
 

Offline Geezer

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Is there zero zero gravity?
« Reply #22 on: 15/12/2009 20:39:23 »
It's more a lack of them being bothered to understand the concepts they speak about. I'm not overly concerned about new conjectures and suggestions, but if it goes against physics that we understand with quite a great degree of certainty, then there is no reason why they spout it off as a true maintsream statement - it annoys me at best.

I just wish that people like Geezer (and obviously bored chemist whose not a scientist or a physics student) would not argue necesserily with the points of physics which are really actually very basic. It doesn't take too long to learn some of these things. The length to understand gravity on the basic level is actually very easy if one has a certain ineterest in learning that subject.

Einstinean is greately more difficult to understand, but i've been learning on it for years now and i just wish that the given posters exampled would accept what i say as being gospal, because i know for sure they wouldn't understand the math - even i fail to understand all the mathematical conjectures today which involve relativity, but i know quite a bit about it; there is no such thing as a stupid question - but if you are provided the mainstream answer, you should just accept it, instead of trying to flout it with impunity based on the fact you don't really like the character you are communicating with. I know this be the case especially in Geezers behalf. Sad thing is, i actually don't have any problems with either of them personally apart from their ignorance.

Mr Scientist,

If you persist in making personal attacks on other forum members I will have no choice but to ban you. Bored Chemist and I have patiently tried to fill in obvious gaps in your education. If you don't like that, I suggest you move to another forum.

Geezer - Moderator
« Last Edit: 15/12/2009 20:56:50 by Geezer »
 

Offline Geezer

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Is there zero zero gravity?
« Reply #23 on: 15/12/2009 20:56:05 »
but you can easily achieve quasi-zero gravity: inside a free-falling lift; you don't have to consider which planet or sun is near you, the lift authomatically accelerates the exact amount it's required to canceal gravity inside of it.

Em, I don't think so. Gravity is not cancelled. Weight is.
 

Offline LeeE

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Is there zero zero gravity?
« Reply #24 on: 15/12/2009 23:20:26 »
At no point in the universe is gravity zero.  Gravitational equipotential can occur where non-zero values are balanced, but at no point does it ever reach zero.  For example, the Lagrangian points around the Earth are in gravitational equipotential relative to us, but our entire solar system, and indeed our entire galaxy exists within the gravitational field of the local super cluster, which is not balanced and is not in equipotential in our region of space.
 

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Is there zero zero gravity?
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