# The mass of a supermassive black hole **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [March 12, 2017, 12:55pm UTC](https://boards.straightdope.com/t/the-mass-of-a-supermassive-black-hole/781994 "2017-03-12T12:55:37Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\ **Post date:** [March 12, 2017, 12:55pm UTC](https://boards.straightdope.com/t/the-mass-of-a-supermassive-black-hole/781994/1 "2017-03-12T12:55:37Z")
This is mind boggling. Link to gif: [The mass of a supermassive black hole - GIF on Imgur](http://m.imgur.com/gallery/MUg63B0) ---
**Author:** ![QuickSilver](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quicksilver/32/7832_2.png) [@QuickSilver](https://boards.straightdope.com/u/QuickSilver)\ **Post date:** [March 12, 2017, 2:28pm UTC](https://boards.straightdope.com/t/the-mass-of-a-supermassive-black-hole/781994/2 "2017-03-12T14:28:35Z")
[Needs more cowbell.](https://www.youtube.com/watch?v=pta-gf6JaHQ) ---
**Author:** ![Hey\_Hey\_Paula](https://avatars.discourse-cdn.com/v4/letter/h/85e7bf/32.png) [@Hey\_Hey\_Paula](https://boards.straightdope.com/u/Hey_Hey_Paula)\ **Post date:** [March 13, 2017, 3:40am UTC](https://boards.straightdope.com/t/the-mass-of-a-supermassive-black-hole/781994/3 "2017-03-13T03:40:49Z")
> [@QuickSilver](#): > > [Needs more cowbell.](https://www.youtube.com/watch?v=pta-gf6JaHQ) That song is exactly the first thing i thought of when reading the thread title. Now it’s stuck in my head, thanks a lot. ---
**Author:** ![Weisshund](https://avatars.discourse-cdn.com/v4/letter/w/ba8739/32.png) [@Weisshund](https://boards.straightdope.com/u/Weisshund)\ **Post date:** [March 13, 2017, 7:54am UTC](https://boards.straightdope.com/t/the-mass-of-a-supermassive-black-hole/781994/4 "2017-03-13T07:54:39Z")
i watched the linked youtube video as well If a black hole stopped time, would it not then be undetectable? invisible so to speak? ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [March 13, 2017, 9:45pm UTC](https://boards.straightdope.com/t/the-mass-of-a-supermassive-black-hole/781994/5 "2017-03-13T21:45:30Z")
> [@Weisshund](#): > > If a black hole stopped time, would it not then be undetectable? > invisible so to speak? No, because “stopping time” is the extrapolation of the Schwarzchild solution at the event horizon; anywhere short of the event horizon, the gravitational effects of the black hole on everything around it and the effects of infalling matter (X-ray emissions, a visible accretion disk, etc.) would be plainly visible, as indeed it appears that they are. The more intriguing question is if time tends to zero at the EH from the standpoint of a distant observer, how can anything cross the EH and how can black holes grow or come into existence in the first place? As an object approaches the EH, we would see it apparently going slower and slower and emitting fewer and fewer photons which would be increasingly red-shifted. At the EH it would no longer be visible and would presumably be frozen in time forever. So how can anything ever fall in? The answer that the object falls in just fine in the finite proper time of the object’s own reference frame seems dismissive in light of what we would be expected to actually observe in theory, and the fact that we seem to empirically observe the effects of actual infalling matter around presumed black holes. We had a bit of a discussion about that [in this thread](http://boards.straightdope.com/sdmb/showthread.php?t=807193). It really becomes a question of how one wants to interpret the math and cast it in conceptual terms. One of the more intriguing conceptual interpretations is the one that I cited [in this post](http://boards.straightdope.com/sdmb/showpost.php?p=19704058&postcount=22), where the object’s transition across the EH is presumed to involve an infinite trajectory in both time directions in Schwarzchild coordinate time. It’s no more bizarre than the strange things that (mathematically) are predicted to happen to coordinate time inside a black hole. According to this interpretation, as the object approaches the singularity inside the black hole, it is returning from an infinitely distant future – but that remarkable fact is of no use to us because the event horizon forever cuts it off from any possible observation. ---
**Author:** ![Gatopescado](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gatopescado/32/5711_2.png) [@Gatopescado](https://boards.straightdope.com/u/Gatopescado)\ **Post date:** [March 14, 2017, 4:05am UTC](https://boards.straightdope.com/t/the-mass-of-a-supermassive-black-hole/781994/6 "2017-03-14T04:05:59Z")
Hey, man. I’m married, so… ---
**Author:** ![Ike\_Witt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ike_witt/32/283_2.png) [@Ike\_Witt](https://boards.straightdope.com/u/Ike_Witt)\ **Post date:** [March 14, 2017, 4:37am UTC](https://boards.straightdope.com/t/the-mass-of-a-supermassive-black-hole/781994/7 "2017-03-14T04:37:47Z")
How many suns was that in the link in the OP? I lost count kind of early on.