# Can you explain Massive Gravity simply? **URL:** \ **Category:** Factual Questions\ **Created:** [February 3, 2019, 6:32pm UTC](https://boards.straightdope.com/t/can-you-explain-massive-gravity-simply/828891 "2019-02-03T18:32:49Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [February 3, 2019, 6:32pm UTC](https://boards.straightdope.com/t/can-you-explain-massive-gravity-simply/828891/1 "2019-02-03T18:32:49Z")
I was reading [this Phys.org article](https://phys.org/news/2019-01-dark-alternative-theory.html) about an alternative to Dark Matter which links to this page about [Massive Gravity](https://en.wikipedia.org/wiki/Massive_gravity) which loses me pretty much immediately. Okay, I get that the central idea is that there is a force-transfer particle called a graviton which is not massless and therefore does not travel at the speed of light and that the LIGO experiments give some bounds, but after that I’m lost. I mean, if this is the case, how are we not able to test this from Earth? The article mentions that the Sun’s bubble is 50,000 AU so we’re inside it, but should we not be able to test the effects with loosely coupled star pairs, like Alpha, Beta, and Proxima Centauri where the partners are outside each others’ bubbles? Or simply passing stars? Similarly, shouldn’t the effect change with distance? Just as the problem with Mercury helped Einstein, can it not help us here? Anyway, I’m lost, so can someone enlighten me in simple terms? ---
**Author:** ![RaftPeople](https://avatars.discourse-cdn.com/v4/letter/r/6f9a4e/32.png) [@RaftPeople](https://boards.straightdope.com/u/RaftPeople)\ **Post date:** [February 3, 2019, 7:22pm UTC](https://boards.straightdope.com/t/can-you-explain-massive-gravity-simply/828891/2 "2019-02-03T19:22:05Z")
I know nothing, but I was curious and googled a bit, one of the less technical things I found was this: > **[Massive Gravity, or You Only Live Twice](http://resonaances.blogspot.com/2018/04/massive-gravity-or-you-only-live-twice.html)** > > Proving Einstein wrong is the ultimate ambition of every crackpot and physicist alike. In particular, Einstein's theory of gravitation -  th... ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [February 3, 2019, 7:50pm UTC](https://boards.straightdope.com/t/can-you-explain-massive-gravity-simply/828891/3 "2019-02-03T19:50:33Z")
If it’s anything like all the other suggested alternatives to dark matter, the answer to “how does it work?” is “It doesn’t”. ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [February 3, 2019, 8:45pm UTC](https://boards.straightdope.com/t/can-you-explain-massive-gravity-simply/828891/4 "2019-02-03T20:45:51Z")
> [@Chronos](#): > > If it’s anything like all the other suggested alternatives to dark matter, the answer to “how does it work?” is “It doesn’t”. You obviously haven’t read the article, because the answer to that question is in my OP. ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [February 3, 2019, 8:52pm UTC](https://boards.straightdope.com/t/can-you-explain-massive-gravity-simply/828891/5 "2019-02-03T20:52:17Z")
> [@RaftPeople](#): > > I know nothing, but I was curious and googled a bit, one of the less technical things I found was this: > [RÉSONAANCES: Massive Gravity, or You Only Live Twice](http://resonaances.blogspot.com/2018/04/massive-gravity-or-you-only-live-twice.html) That’s still rather beyond me. Still, I found this in the comments: > [@Anonymous](#): > > Disproving the crackpot theories led to better understanding of the correct theory. Without the crackpot theories, may be this knowledge would never be gained. Very true. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [February 3, 2019, 8:57pm UTC](https://boards.straightdope.com/t/can-you-explain-massive-gravity-simply/828891/6 "2019-02-03T20:57:59Z")
It’s too bad that the use of “massive” here means “has mass” rather than “large”. The Wikipedia article says the upper bound on the mass of a graviton is 7.7×10[sup]−23[/sup] eV/c[sup]2[/sup]. Multiply that by 1.782662×10[sup]−36[/sup] to get kg. That’s just a _wee_ bit on the tiny mass part of the scale. 🙂 (The problem with “nearly” lightspeed dark matter particles is that they will disperse rather quickly out of galaxies so their effects on galactic rotation won’t have lasted the last 14 billion years. Which is no doubt why the OP is _not_ thinking about this in terms of dark matter.) ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [February 3, 2019, 11:21pm UTC](https://boards.straightdope.com/t/can-you-explain-massive-gravity-simply/828891/7 "2019-02-03T23:21:34Z")
Note that the Wiki page does not say anything about dark matter, but rather that it doesn’t require dark energy. ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [February 4, 2019, 9:17am UTC](https://boards.straightdope.com/t/can-you-explain-massive-gravity-simply/828891/8 "2019-02-04T09:17:58Z")
> [@ftg](#): > > It’s too bad that the use of “massive” here means “has mass” rather than “large”. That’s one of the few bits I did understand! > [@](#): > > The Wikipedia article says the upper bound on the mass of a graviton is 7.7×10[sup]−23[/sup] eV/c[sup]2[/sup]. Multiply that by 1.782662×10[sup]−36[/sup] to get kg. > > That’s just a _wee_ bit on the tiny mass part of the scale. 🙂 About the same size as a serving of Modern Cuisine. 🙂 ---
**Author:** ![AskNott](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asknott/32/5790_2.png) [@AskNott](https://boards.straightdope.com/u/AskNott)\ **Post date:** [February 5, 2019, 1:40am UTC](https://boards.straightdope.com/t/can-you-explain-massive-gravity-simply/828891/9 "2019-02-05T01:40:08Z")
My quick factual answer to the question is no, I cannot.