# What is gravity really? **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [August 2, 2008, 10:55pm UTC](https://boards.straightdope.com/t/what-is-gravity-really/458642 "2008-08-02T22:55:29Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![rwjefferson](https://avatars.discourse-cdn.com/v4/letter/r/a6a055/32.png) [@rwjefferson](https://boards.straightdope.com/u/rwjefferson)\ **Post date:** [August 3, 2008, 6:35pm UTC](https://boards.straightdope.com/t/what-is-gravity-really/458642/21 "2008-08-03T18:35:42Z")
[QUOTE=KGS] There is no such thing as gravity. The Earth just sucks. [/QUOTE] Don’t forget that energy also blows. Peace rwj ---
**Author:** ![Half\_Man\_Half\_Wit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/half_man_half_wit/32/21766_2.png) [@Half\_Man\_Half\_Wit](https://boards.straightdope.com/u/Half_Man_Half_Wit)\ **Post date:** [August 3, 2008, 6:42pm UTC](https://boards.straightdope.com/t/what-is-gravity-really/458642/22 "2008-08-03T18:42:02Z")
[QUOTE=rwjefferson] I will agree that the answer, ‘gravity is acceleration of space and time’ is so easily shown and obvious and mundane that it is pointless to deny. [/QUOTE] So why do you keep asking a question whose answer you consider to be ‘easily shown and obvious’? And how, exactly, is ‘gravity is acceleration of space and time’ easily shown? ---
**Author:** ![rwjefferson](https://avatars.discourse-cdn.com/v4/letter/r/a6a055/32.png) [@rwjefferson](https://boards.straightdope.com/u/rwjefferson)\ **Post date:** [August 3, 2008, 7:07pm UTC](https://boards.straightdope.com/t/what-is-gravity-really/458642/23 "2008-08-03T19:07:27Z")
[QUOTE=Half Man Half Wit] …., it can be described astonishingly well using the mathematical concept of curvature,… [/quote] This is called [relative equivalence.](http://en.wikipedia.org/wiki/Equivalence_principle) Relative equivalence is not the same as reality. Please forgive, but there are too many questions at least by half and half again and again. [QUOTE=Half Man Half Wit] …What happens to that space-time, does it just kinda pile up in the centre? [/quote] What happens to mass when it is swallowed by a black hole? Does it just kinda pile up in the centre? I would predict that it simply changes dimension. Please feel to ask another question. Peace rwj ---
**Author:** ![rwjefferson](https://avatars.discourse-cdn.com/v4/letter/r/a6a055/32.png) [@rwjefferson](https://boards.straightdope.com/u/rwjefferson)\ **Post date:** [August 3, 2008, 7:16pm UTC](https://boards.straightdope.com/t/what-is-gravity-really/458642/24 "2008-08-03T19:16:48Z")
[QUOTE=Q.E.D.] _sigh_ One more time, with feeling. Repeat after me: **We. Don’t. Know.** What part of that concept is so difficult for you to grasp? [/QUOTE] I understand You do not know. Your lack of understanding does not negate my observations. Peace rwj ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [August 3, 2008, 7:25pm UTC](https://boards.straightdope.com/t/what-is-gravity-really/458642/25 "2008-08-03T19:25:15Z")
[QUOTE=rwjefferson] Your lack of understanding does not negate my observations. [/QUOTE] What observations? That the effects of gravity and acceleration are indistinguishable from one another? Sorry, pal, but a patent clerk beat you to that way back in the early 1900s. However, that their effects are identical does not mean they are the same thing. ---
**Author:** ![Gfactor](https://avatars.discourse-cdn.com/v4/letter/g/9de053/32.png) [@Gfactor](https://boards.straightdope.com/u/Gfactor)\ **Post date:** [August 3, 2008, 7:26pm UTC](https://boards.straightdope.com/t/what-is-gravity-really/458642/26 "2008-08-03T19:26:40Z")
[QUOTE=rwjefferson] How many times must a question be restated before it qualifies as a General Question? [/Quote] Once, but it has to be a question that’s likely to have a factual answer. You seem more interested in a debate. And by the way, complaints and questions about moderator actions go in the Pit or About This Message Board. > [@](#): > > What is gravity really? > I am certainly glad Newton and Einstein did not feel the question to be pointless. > What is gravity really? > That is the simple question I wish better answered. > Really. You can get questions answered in other forums besides General Questions. For example, I’d have moved a question about the meaning of life to Great Debates. > [@](#): > > What is gravity really? > Please support your response with observation as evidence. I don’t know. Do you? If you do, then why are you asking? **Gfactor** General Questions Moderator ---
**Author:** ![rwjefferson](https://avatars.discourse-cdn.com/v4/letter/r/a6a055/32.png) [@rwjefferson](https://boards.straightdope.com/u/rwjefferson)\ **Post date:** [August 3, 2008, 7:44pm UTC](https://boards.straightdope.com/t/what-is-gravity-really/458642/27 "2008-08-03T19:44:26Z")
[QUOTE=Half Man Half Wit] So why do you keep asking a question whose answer you consider to be ‘easily shown and obvious’? And how, exactly, is ‘gravity is acceleration of space and time’ easily shown? [/QUOTE] Please forgive. When I find an easily demonstrated observation to be denied and banned and censored and called pointless, I tend toward wonder and question. Only dogma censors and hides, truth answers for itself. As relative mass increases, [acceleration as G increases as time slows.](http://en.wikipedia.org/wiki/Gravitational_time_dilation) Peace rwj ---
**Author:** ![Don\_t\_fight\_the\_hypothetical](https://avatars.discourse-cdn.com/v4/letter/d/59ef9b/32.png) [@Don\_t\_fight\_the\_hypothetical](https://boards.straightdope.com/u/Don_t_fight_the_hypothetical)\ **Post date:** [August 3, 2008, 7:49pm UTC](https://boards.straightdope.com/t/what-is-gravity-really/458642/28 "2008-08-03T19:49:09Z")
You know what else is pointless and is not truth/fact? A couple of links connected cryptically. I suspect you choose not to explain yourself with actual words of your own because they could too easily be shown to be nonsense. But I would love for you to take a whack at it. ETA: On second thought I challenge you to post your “observation” with no math formulas or links. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [August 3, 2008, 7:52pm UTC](https://boards.straightdope.com/t/what-is-gravity-really/458642/29 "2008-08-03T19:52:42Z")
[QUOTE=Don’t fight the hypothetical] But I would love for you to take a whack at it. [/QUOTE] Yes, this please. A complete detailing of this “easily demonstrated” observation entirely in your own words without resort to links or copy-and-pastes. Surely this should be trivial for something so true and obvious. I’ll wait. ---
**Author:** ![Marley23](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@Marley23](https://boards.straightdope.com/u/Marley23)\ **Post date:** [August 3, 2008, 7:57pm UTC](https://boards.straightdope.com/t/what-is-gravity-really/458642/30 "2008-08-03T19:57:16Z")
**rwjefferson** , I don’t know what you’re trying to say on this board or on the other one - although it looks like you violated their policy on copy and pasting material and were not “censored” for asking questions. (I will not get into an argument about this.) You asked what gravity is. People keep telling you we don’t know. We can predict what it will do, but “what it is” is apparently not answerable at this point. You keep insisting it’s a simple question and that that answer is somehow unacceptable, but that doesn’t change anything. Do you have some kind of further question? If not I see no point in continuing this thread. ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [August 3, 2008, 8:11pm UTC](https://boards.straightdope.com/t/what-is-gravity-really/458642/31 "2008-08-03T20:11:00Z")
[QUOTE=rwjefferson] Please forgive. When I find an easily demonstrated observation to be denied and banned and censored and called pointless, I tend toward wonder and question. [/QUOTE] Then the question you should be asking about why something so obvious and easily demonstrated (which has yet to be done by you), yet is being denied, getting you banned, censored, and such, should be: **“Why am I alone in this thinking?”.** The factual answer according to main-stream science is “We don’t know.” Anything else you want to talk about beyond that, should go into Great Debates, where you are free to express your ideas on equal ground with the board’s other members. Really. [QUOTE=rwjefferson] Only dogma censors and hides, truth answers for itself. [/QUOTE] That is, unless the truth is unintuitive to human understanding. ---
**Author:** ![rwjefferson](https://avatars.discourse-cdn.com/v4/letter/r/a6a055/32.png) [@rwjefferson](https://boards.straightdope.com/u/rwjefferson)\ **Post date:** [August 3, 2008, 8:11pm UTC](https://boards.straightdope.com/t/what-is-gravity-really/458642/32 "2008-08-03T20:11:02Z")
[QUOTE=Q.E.D.] What observations? That the effects of gravity and acceleration are indistinguishable from one another? Sorry, pal, but a patent clerk beat you to that way back in the early 1900s. However, that their effects are identical does not mean they are the same thing. [/QUOTE] My observation is that relative equivalency fails to predict [observed (real) acceleration.](http://www.space.com/scienceastronomy/080229-spacecraft-anomaly.html) Dark space monkeys are often invoked to explain these failures. Relative equivalence is not the same as reality. That their effects are not identical seems as a clue for me. Peace rwj ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [August 3, 2008, 8:20pm UTC](https://boards.straightdope.com/t/what-is-gravity-really/458642/33 "2008-08-03T20:20:46Z")
[QUOTE=rwjefferson] That their effects are not identical seems as a clue for me. [/QUOTE] It’s a clue that something is lacking from our understanding. We don’t know what that something is, and neither do you. ---
**Author:** ![Apocalypso](https://avatars.discourse-cdn.com/v4/letter/a/f19dbf/32.png) [@Apocalypso](https://boards.straightdope.com/u/Apocalypso)\ **Post date:** [August 4, 2008, 2:08am UTC](https://boards.straightdope.com/t/what-is-gravity-really/458642/34 "2008-08-04T02:08:26Z")
Scott Adams was talking about questioning things in one of his books (might’ve been _the Dilbert Future_). Often there are simple attempts to explain complicated scientific concepts, and people accept those explanations as the truth. They’re just “placeholder” explanations made up to explain things we don’t fully understand. One of the examples mentioned was gravity. It can not be seen or weighed or touched. All scientific explanations (the bowling ball on a bed) are just simple attempts to visualize a complex process. You could come up with a different explanation that fits all the known observations of gravity. For example, the universe and everything in it is constantly expanding at a rate which keeps the size of everything the same relative to everything else. The effect is that we’re standing on a ball which is constantly expanding and pushing on us. If we jump up, the ball rushes up to meet us and it appears as though we are falling back down. There were some other cool examples too (time is your consciousness moving from an endless series of frozen universes, all slightly different). ---
**Author:** ![nd\_n8](https://avatars.discourse-cdn.com/v4/letter/n/439d5e/32.png) [@nd\_n8](https://boards.straightdope.com/u/nd_n8)\ **Post date:** [August 4, 2008, 2:43am UTC](https://boards.straightdope.com/t/what-is-gravity-really/458642/35 "2008-08-04T02:43:42Z")
[QUOTE=rwjefferson] Dark space monkeys are often invoked to explain these failures. [/QUOTE] I’ll have one of what he’s having, with extra ice and two slices of lime please. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [August 4, 2008, 3:09am UTC](https://boards.straightdope.com/t/what-is-gravity-really/458642/36 "2008-08-04T03:09:51Z")
[QUOTE=nd\_n8] I’ll have one of what he’s having, with extra ice and two slices of lime please. [/QUOTE] Not me; I’ll stick with Jameson 12 Year Old, neat. That other stuff seems to interfere with the _Pars triangularis_ of _Broca’s region_. Stranger ---
**Author:** ![Don\_t\_fight\_the\_hypothetical](https://avatars.discourse-cdn.com/v4/letter/d/59ef9b/32.png) [@Don\_t\_fight\_the\_hypothetical](https://boards.straightdope.com/u/Don_t_fight_the_hypothetical)\ **Post date:** [August 4, 2008, 3:18am UTC](https://boards.straightdope.com/t/what-is-gravity-really/458642/37 "2008-08-04T03:18:31Z")
[QUOTE=nd\_n8] I’ll have one of what he’s having, with extra ice and two slices of lime please. [/QUOTE] I’m pretty sure you have to be born with it. ---
**Author:** ![Yumblie](https://avatars.discourse-cdn.com/v4/letter/y/76d3ee/32.png) [@Yumblie](https://boards.straightdope.com/u/Yumblie)\ **Post date:** [August 4, 2008, 4:21am UTC](https://boards.straightdope.com/t/what-is-gravity-really/458642/38 "2008-08-04T04:21:27Z")
[QUOTE=rwjefferson] My observation is that relative equivalency fails to predict [observed (real) acceleration.](http://www.space.com/scienceastronomy/080229-spacecraft-anomaly.html) Dark space monkeys are often invoked to explain these failures. Relative equivalence is not the same as reality. That their effects are not identical seems as a clue for me. Peace rwj [/QUOTE] The equivalence principle merely states that in an accelerating frame, one would not be able to conclude whether the acceleration was due to movement or gravity. Like a lot of physics principles, this only works in the hypothetical perfect lab. In reality, you’d be able to tell the difference due to small tidal effects, which occur in gravitational fields but not while merely accelerating. So gravity and acceleration are not exactly the same thing, but are similar enough ideas to use as a theoretical framework. As for the Pioneer anomaly, I’m not convinced that physics needs to be rewritten to explain it, as it could very well be an instrument failure. It’s an interesting problem though. ---
**Author:** ![Half\_Man\_Half\_Wit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/half_man_half_wit/32/21766_2.png) [@Half\_Man\_Half\_Wit](https://boards.straightdope.com/u/Half_Man_Half_Wit)\ **Post date:** [August 4, 2008, 9:15am UTC](https://boards.straightdope.com/t/what-is-gravity-really/458642/39 "2008-08-04T09:15:23Z")
[QUOTE=Yumblie] As for the Pioneer anomaly, I’m not convinced that physics needs to be rewritten to explain it, as it could very well be an instrument failure. It’s an interesting problem though. [/QUOTE] Interestingly enough, though, one proposed explanation for the Pioneer anomaly, the flyby-anomalies exhibited by a couple of probes (Galileo, NEAR, Cassini and Rosetta), and even dark matter (or more correctly, the galaxy rotation problem) involves a modification of the principle of equivalence – essentially, the proposition is that inertia is caused by [Unruh radiation](http://en.wikipedia.org/wiki/Unruh_radiation) , which is (black-body) radiation experienced by an accelerated observer (leading to a theory like Milgrom’s MOND, only modifying inertial mass instead of acceleration). Thus, inertial mass becomes dependent on the acceleration of an object, which can be made to fit observations regarding irregular accelerations like those exhibited by some probes during flyby-manoeuvres – essentially, if the inertial mass reduces for low accelerations, conservation of angular momentum demands a sudden jump in speed for an object doing an orbital flyby. The paper can be found [here](http://arxiv.org/PS_cache/arxiv/pdf/0712/0712.3022v1.pdf), if anyone’s interested. Now I’m wondering if it’s some jumbled-up version of that idea that caused the OP’s insights… ---
**Author:** ![rwjefferson](https://avatars.discourse-cdn.com/v4/letter/r/a6a055/32.png) [@rwjefferson](https://boards.straightdope.com/u/rwjefferson)\ **Post date:** [August 9, 2008, 12:13am UTC](https://boards.straightdope.com/t/what-is-gravity-really/458642/40 "2008-08-09T00:13:02Z")
**Mundane Pointless Stuff I Must Share** Please forgive. I was simply expecting to share a little levity and observation with other seekers of Master Cecil and truth over dogma. I confess I am always amazed by hostility released as dogma pricked. Even in the most unexpected places. Silly me. All material presented is either my own (with humble gratitude to Newton and Einstein and Al gebra and All) or appropriately linked or quoted. Thank you for all compliments. [QUOTE=Don’t fight the hypothetical] I challenge you to post your “observation” with no math formulas or links. [/QUOTE] The flow of space and time carries me weightless towards center of mass. Yet I feel force of 1 G by gravity and inertia. The electromagnetic force of me and chair and earth as matter easily holds the mass of me against the current of spacetime through earth. Yet even still, I do not feel the flow of space or time toward sun or galaxy center or even greatest attractor. How simple still are your needs? Please consider just so a story even for college professors and other children. Consider the breed of space monkeys called by sum as gravitons. Though infinitesimal by size, they are infinite by number. Some claim them even as space itself. Yet please rest assured that the flight of these pesky monkeys is always straight and true and constant… unless, of course, spacetime bananas are involved. It is observed and shown that spacetime bananas are found in one of two equal and opposite flavors: mass and energy. Like moths to a flame, these pesky space monkeys curve toward increasing flavor of mass even as they flee in verse from increasing flavor and pressure of energy. Monkeys that accelerate space and time and satellites appear dark only to those unfamiliar with natural habits. Peace rwj [Previous page](https://boards.straightdope.com/t/what-is-gravity-really/458642.md?page=1) [Next page](https://boards.straightdope.com/t/what-is-gravity-really/458642.md?page=3)