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If we really understand gravity

  1. Nov 17, 2005 #1
    then why don't we have some "anti-gravity" device by now...?! No one has ever given me a clear definition of gravity. Yeah it's a force.. that makes things stick to it... what about intricacies?! What's the true properties of gravity? If we really understood it, we'd be able to get off this planet without using combustable rocket propulsion, and why is every attempt at it laughed at, skorned, and debunked? How will this ever achieve any advancements in physics or technology?
     
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  3. Nov 17, 2005 #2

    Pengwuino

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    Well for one, I don't think physicists understand gravity as much as other things. Two... why do you think there is an anti-gravity? Just because we understand something doesn't mean we can do whatever we want with it.
     
  4. Nov 17, 2005 #3

    matthyaouw

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    We understand pretty well how volcanoes work. That doesn't mean we can stop them from doing their thing.

    Because they don't work.
     
  5. Nov 17, 2005 #4

    Pengwuino

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    Yah I mean... if it is laughed at and debunked... that means theres a fatal flaw in the theory. If a theory makes sense and theres no inconsistencies or incorrect math, by definition it can't be debunked at the time!
     
  6. Nov 17, 2005 #5
    No one ever said that we fully understand gravity.
     
  7. Nov 17, 2005 #6

    Ivan Seeking

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    We have a theory that works extremely well - General Relativity - and it doesn't yield any easy way to do what you say. In fact it may true that anti-gravity cannot exist. If we ever find a Theory of Everything, then we should know for sure exactly what is and what is not possible.

    Most people who pursue anti-gravity "research", and I use that term as loosely as possible here, are not physicists at all. What is laughed at, scorned, and debunked is for the most part a bunch of people who are way out of their league and who have no idea what they're talking about. Now if someone actually demonstrated an anti-gravity device, scientists would be rushing to see it no matter who did it. But that's not what happens. Instead we find people with little to no scientific training who are either making things up, selling conspiracy theories, and/or whether or not they know it, promoting complete nonsense.

    Would you want credible and highly trained scientists who have spent between ten and fifty years refining their skills, to pretent that a bunch of half baked amateurs are doing something, when they're really just talking nonsense and gibberish?
     
    Last edited: Nov 17, 2005
  8. Nov 17, 2005 #7

    As far as I know, we do not understand why gravity does what it does, (As in tht cause of it) however we understand, or belive we understand, what its effects are.
     
  9. Nov 17, 2005 #8

    Ivan Seeking

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    Curved spacetime according to the stress energy tensor is what acts as the force of gravity, but I think it's fair to say that we don't know what spacetime is.
     
  10. Nov 17, 2005 #9
    Lets see
    Here the maths
    A Quantum Mechanical Approach to the Existence of Negative Mass and Its Utilization in the Construction of Gravitationally Neutralized Bodies

    http://au.geocities.com/psyberplasmic/ccX-3-a2.html

    Here the practical application

    CA 726,958 - Method for benefication of & Devices employing gravitational isotopes -1966 followed by "Method for producing Gravitationally-Anomalous materials - 1973 (

    http://ether.sciences.free.fr/patents/TTBrown/CA726958 and method 1973.pdf
     
  11. Nov 18, 2005 #10

    Pengwuino

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    Hmm a geocities website eh....

    Ivan, have at it :)
     
  12. Nov 18, 2005 #11
    It's nice to hear that everyone admits we don't know what gravity truly is :) This gives me some more motivation to work towards understanding it, and eventually rocketless/combustionless flight. I have a deep appreciation for science and scientists.. and i find it disturbing when others are bashed for making attempts at the unknown... it's like calling someone stupid for asking a question. In fact it is exactly like volcanoes... we know what volcanoes are doing.. but we don't understand them... give us another couple hundred years of research (wish i could live that long to see it) and i think we'd all be surprised at the ways we could maipulate mother nature. Well anyway... I'm going to spend my adult life searching for an answer to flight without rockets. Laugh if you want... but if you have all the answers to gravity, then people like me will stop our attempts in seeking them out.
     
  13. Nov 18, 2005 #12

    Pengwuino

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    You do realize there are already probes out in space that do not use chemical rockets....

    Also, heres an analogy that really fits the situation...

    I'll assume your a guy for this analogy. What if someone walked up to you and said "you're a girl because I remember you wearing a pink shirt one day. I am right, do not dismiss me as wrong because I am right". Now... lets say you actually never wore pink in your life. What can you judge about this person? Well, 1) he/she used incorrect logic in determining the factual basis of something (since what you wear is not an indicator of sex), 2) he/she was wrong in their evidence (since you never wore pink in your life) and 3) that person knows nothing about your dna or "whats in your pants".

    This is what happens to people who are laughed at. They will make illogical assumptions such as the person I just made the analogy about did. They will also have inaccurate/wrong data about what they are saying, just like the person did. Of course, last but not least, they do not know hte ultimate truth themselves but will assume they do.

    If you cannot see how one would laugh at them... well then i don't know what to say.

    You're idea that there is a such thing as anti-gravity is as stupid as our idea that there is no such thing as anti-gravity.... the only difference is that the greatest minds and numberous experiments have shown that the no-anti-gravity side is probably right. There very well may not be a way to achieve anti-gravity and to make the assumption that such a thing exists is to make a very bad scientific mistake. It's possible... but quite improbable.
     
  14. Nov 18, 2005 #13
    i don't think any of the ideas are stupid... i dunno if there is actual anti-gravity, persay... but i'd like to find a way to get out of earths atmosphere through gravity modification after truly understanding what gravity is. Also to make an assumption that something does not exist, is highly improbable... and false... with time things change. I never assume i know the ultimate truth.. i am the first to admit that neither I or anyone else does... but everyone i come accross always implies that they do. I don't ever laugh at anyone's ideas or assumptions... i have been in the same place before, so i understand how it feels. In fact, everytime someone laughs... it gives me more motivation to do what i am trying to do. So in the end... whether i figure it out or not, i get the last laugh. The worst scientific mistake is to think you know everything, and to never make an assumption about what may exist. I'll take bad over worse.
     
    Last edited: Nov 18, 2005
  15. Nov 18, 2005 #14

    Pengwuino

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    That's omniscience. We may very well be at the same mercy in 500 years that we are today. Who knows. But really, when you say "I don't think any of the ideas are stupid", you need to realize that the backbone of science is that theories must have mathematical backing in order to be real. These ideas proposed normally involve completely incorrect math or ideas that defy the current physical laws (which all have mathematical backing) we know of. That is why they are normally called stupid.
     
  16. Nov 18, 2005 #15
    It may be omniscience, i just like to look forward and dream. The current physical laws are not complete... to call someone stupid based on something( a belief) that isn't complete(blind faith)... is extremely ignorant and irresponsible.
     
    Last edited: Nov 18, 2005
  17. Nov 18, 2005 #16

    Pengwuino

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    Actually its science because most people who are laughed at don't call it a belief, they call it a theory. People can go off and believe whatever they want to believe but once you start proposing real scientific ideas and theories, you better have some logic and mathematical reasoning to back it up.
     
  18. Nov 18, 2005 #17
    I think I've done a good job of that... no one here admits they know what gravity is.
     
  19. Nov 18, 2005 #18

    ZapperZ

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    I'm just glad that this isn't in the Physics forum or I would have been seriously pissed! :)

    DEFINE what you mean by "know".

    I will put it to you that what you accept as something that YOU know has less certainty than what physicists describe gravity with. Think about it - we can use gravity and predict the constellation, send spacecraft to planets, predict motion of celestial bodies, etc. We have qualitative AND quantitative predictions that agree with observations. Compare that with what you can predict of the things that you "know"?

    You and every one need to keep in mind what physicists mean when they say "oh, we don't know about so-and-so". These are the same people who would say that there is a small, but non-zero probability that if I throw a broken vase onto a floor, it can reassemble itself. The high standards that we have to finally be able to say "yes, we know about so-and-so" is why many keep saying we don't know ENOUGH about gravity. But please, don't mistaken it by assuming that we DON'T KNOW about gravity. This is not only wrong, it's hysterically funny and contradicts what we have done and can do.

    And no one seems to notice of what exactly is meant by "anti-gravity" here. For example, is a repulsive force considered as an "anti-force"? If it is, then someone needs to do a lot of explaining. We have repulsive force in EM interaction, yet, I see no one calling that as an "anti-EM" force. Do we have an "anti-EM" concept? Sure we do. EM forces are mediated by photons. We have anti-photons. They are the same as the photons themselves.

    So, are these "anti-force" defined strictly as the anti-particle carriers, such as anti-gravitons? Or are we simply talking about a "repulsive" gravity, something that is already contained in GR?

    When you don't have ample knowledge of what we already formulated, and then start making all these statements and "accusation", then you can't help but make a series of ambiguities. When this occurs, there's more uncertainty in your question, then there is in the issue that the question asked.

    We understand gravity ENOUGH to make it work. It may not have the same degree of certainty as some areas of physics, but it has more than enough to hold its own.

    Zz.
     
  20. Nov 18, 2005 #19
    First off... thank you very much for the post! very informative for the reader, straight to the point, and not rude :) a good neutral stance. I thought about posting this in the physics area.... And that's exactly why i posted it here :P
    I agree... i never said that gravity is not understood... it's just not TOTALLY understood... if it was, it'd seem quite easy to say, "hey okay, then we can do this to manipulate it, and we can do this for propulsion." or modification. I don't necessarily mean "anti"... i just mean understanding gravity at such a minute nature, that it would become clear what is needed to have a repelling force large enough to have flight without rockets. I know the many marvelous things phycisists do/have done :) I'm not knocking them... I'm just knocking the "know it all" position some take. It's alright sometimes to just admit that not everything is known... Einstein wasn't Jesus... so he shouldn't be viewed as a religion (i have resect for him too! but i just see this often as well) In fact many of the things Einstein said, he later wishes he woudn't have, because he realized the implications he was having on people.. they were believing every theory or idea as absolute. I think the current understanding of gravity is justttt fine for calculating etc... but wouldn't it be great to get down to the nitty gritty and start doing amazing things?
     
  21. Nov 18, 2005 #20
    I mean it's all good to know how much X volume of water will weigh... and how it will re-act when a rock is thrown into it... but once you figure out it is made up of oxygen and hydrogen atoms.. everything changes.
     
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