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Posted
9 minutes ago, koti said:

Sounds like some exotic ( crackpot if you ask me) attempt at explaining the behaviour of gravity in the BH context, using physics nomenclature to fool people into believing its something worthwhile. Your vixra link is not opening which I would say is probably a good thing because its a crackpot site posing as legitimate science. 

So let me get this straight, are you saying that GR is wrong and you’re looking for alternatives?

I have made my position sufficiently clear. And you have now made your hostile attitude clear. End of conversation.

Posted
6 minutes ago, Q-reeus said:

I have made my position sufficiently clear. And you have now made your hostile attitude clear. End of conversation.

I’m sory but both of the links you gave are dead (to the SFN thread and to the vixra site) So far we only know that you disagree with GR and youre looking for alternatives in crackpot nests like vixra.org. Plus you do not decide when the conversation is over, the rules you agreed to when you joined this forum do net let you decide when the conversation is over. 

Posted

To get back to the topic of the thread ...

A nice overview of what we have learned from the first results from the EHT (including ruling out some alternative models): https://www.forbes.com/sites/startswithabang/2019/04/11/10-deep-lessons-from-our-first-image-of-a-black-holes-event-horizon/

Also touches on some of the information we should get from further observation and analysis: polarisation data telling us about magnetic fields, the cause of flares from black holes, finding more black holes with the higher resolution now available.

 

Posted

Seeing is believing.So  what is going on at the deepest part of that beast?

Something forceful enough to hold in the contents..

Just nowhere to go ,simple as that  -the force of logic?

Just like pumping up an inner tube?

Gravity is resisted there because there is nothing there for gravity to push against..Is that just Newtonian?

Or is the force of gravity zero anyway at the bottom?

 

Posted
6 minutes ago, geordief said:

Seeing is believing.So  what is going on at the deepest part of that beast?

It's a black hole!

All we can know is that it has a certain mass, size, spin and electric charge. 

Posted
15 minutes ago, koti said:

I’m sory but both of the links you gave are dead (to the SFN thread and to the vixra site) So far we only know that you disagree with GR and youre looking for alternatives in crackpot nests like vixra.org. Plus you do not decide when the conversation is over, the rules you agreed to when you joined this forum do net let you decide when the conversation is over. 

I'm a prisoner of SFN protocol? Well anyway just to clear up re broken links, they both work fine for me. Maybe try another browser. And re 'looking for alternatives in crackpot nests like vixra.org.', you misrepresent the situation. I made a comment there directed to someone who has published articles in respected astrophysical journals. Try not to tar everything with the same brush. Now, unless you wish to push this line of talk, there has been a hint to return to the main EHT topic.
 

Posted
9 minutes ago, Strange said:

Also touches on some of the information we should get from further observation and analysis: polarisation data telling us about magnetic fields, the cause of flares from black holes, finding more black holes with the higher resolution now available.

I have tried very hard to get excited about this achievement and the findings. I've seen the excitement of others and tried to attach myself to it. Sadly my feet remain planted firmly upon the planet - though, to be clear, absolutely any planet would do. Planets and satellites and asteroids and comets and meteors. Those I can get excited about. Giant black holes at the middle of galaxies are just too far above my pay grade.

Now what did excite me was the incredible technology that mediated the signals from multiple telescopes spread across the globe. That is amazing. I can't wait to see what else we can do with it. . . . . . Hopefully something to do with planets.

Posted
Just now, Intrigued said:

Now what did excite me was the incredible technology that mediated the signals from multiple telescopes spread across the globe. That is amazing. I can't wait to see what else we can do with it. . . . . . Hopefully something to do with planets.

I also find the technology behind this much more amazing than the actual results!

Posted (edited)
1 hour ago, koti said:

Sounds like some exotic ( crackpot if you ask me) attempt at explaining the behaviour of gravity in the BH context, using physics nomenclature to fool people into believing its something worthwhile. Your vixra link is not opening which I would say is probably a good thing because its a crackpot site posing as legitimate science. 

So let me get this straight, are you saying that GR is wrong and you’re looking for alternatives?

GR gravity is the overwhelmingly supported model that in recent times, has been further confirmed with the 11 GW sightings/discoveries, and this EHT image. That is the state of the nation at this time, and as I said previously, any future model should be a QGT, which in all likelyhood would encompass GR. Other purely gravity hypotheticals are novelties. 

Totally agree re any Vixra link. 

29 minutes ago, Intrigued said:

I have tried very hard to get excited about this achievement and the findings. I've seen the excitement of others and tried to attach myself to it. Sadly my feet remain planted firmly upon the planet - though, to be clear, absolutely any planet would do. Planets and satellites and asteroids and comets and meteors. Those I can get excited about. Giant black holes at the middle of galaxies are just too far above my pay grade.

Now what did excite me was the incredible technology that mediated the signals from multiple telescopes spread across the globe. That is amazing. I can't wait to see what else we can do with it. . . . . . Hopefully something to do with planets.

 

27 minutes ago, Strange said:

I also find the technology behind this much more amazing than the actual results!

Bingo!!! Not sure though which is more amazing...aLIGO and its companion detectors, or this EHT arrangement. I would envisage even great findings and dicoveries when the SKA is finished. https://en.wikipedia.org/wiki/Square_Kilometre_Array

Edited by beecee
Posted
2 minutes ago, beecee said:

GR gravity is the overwhelmingly supported model that in recent times, has been further confirmed with the 11 GW sightings/discoveries, and this EHT image. That is the state of the nation at this time, and as I said previously, any future model should be a QGT, which in all likelyhood would encompass GR.

Totally agree re any Vixra link. 

Yes, thats why asked Q-reeus what exactly he means hoping he will bring up some form of QGT. Maybe he doesn’t understand that Newtonian gravity was not rendered wrong by GR but instead was expanded uppon by it and that the same mechanism will take place when GR is expanded uppon by a broader theory encompasing quantum gravity. Most certainly whatever theory will acomplish that, will not render GR wrong.

Whoever stops riding his bicycle when he gets his drivers licence saying the bike is now broken is just silly isn’t he.

Posted
8 minutes ago, koti said:

Yes, thats why asked Q-reeus what exactly he means hoping he will bring up some form of QGT. Maybe he doesn’t understand that Newtonian gravity was not rendered wrong by GR but instead was expanded uppon by it and that the same mechanism will take place when GR is expanded uppon by a broader theory encompasing quantum gravity. Most certainly whatever theory will acomplish that, will not render GR wrong.

Whoever stops riding his bicycle when he gets his drivers licence saying the bike is now broken is just silly isn’t he.

Check out the vector gravity thread a few months ago. :P

 

47 minutes ago, geordief said:

Seeing is believing.So  what is going on at the deepest part of that beast?

Something forceful enough to hold in the contents..

Just nowhere to go ,simple as that  -the force of logic?

Just like pumping up an inner tube?

Gravity is resisted there because there is nothing there for gravity to push against..Is that just Newtonian?

Or is the force of gravity zero anyway at the bottom?

 

The above explains the process quite succulently.

Posted
40 minutes ago, koti said:

Yes, thats why asked Q-reeus what exactly he means hoping he will bring up some form of QGT. Maybe he doesn’t understand that Newtonian gravity was not rendered wrong by GR but instead was expanded uppon by it and that the same mechanism will take place when GR is expanded uppon by a broader theory encompasing quantum gravity. Most certainly whatever theory will acomplish that, will not render GR wrong.

Whoever stops riding his bicycle when he gets his drivers licence saying the bike is now broken is just silly isn’t he.

And even sillier to set up a straw man, and then knock it down, thinking that settles anything useful.

Posted (edited)
1 hour ago, Strange said:

It's a black hole!

All we can know is that it has a certain mass, size, spin and electric charge. 

No internal structure? 

39 minutes ago, beecee said:

Check out the vector gravity thread a few months ago. :P

 

The above explains the process quite succulently.

Yes I looked at one of his videos. My head hurt :)

succulently!!   :-)

Edited by geordief
Posted
29 minutes ago, Strange said:

We don't know. More importantly, we can't know.

Would there be any consequences if there was rather than there  was not?

Posted
12 minutes ago, geordief said:

Would there be any consequences if there was rather than there  was not?

Nope. All the infalling matter could be instantly turned into dancing chocolate elephants. Or collapse to a singularity. It makes no discernible difference.

The phrase "event horizon" is a technical term that means there is no causal connection between the inside and the outside. Therefore nothing on the inside can have any effect externally.

Posted
26 minutes ago, Strange said:

Nope. All the infalling matter could be instantly turned into dancing chocolate elephants. Or collapse to a singularity. It makes no discernible difference.

Are you sure? If the elephants do not dance nicely, spherically symmetrically, wouldn't that let move the event horizon also at least a bit?

So I think we at least know, or can conjecture on theoretical grounds, that a black hole is close to symmetrical.

It would be quite a discovery if we could derive that there are nicely packed chocolate elephants in a black hole! Pity enough, we won't be able to get the chocolate... Even Hawking radiation would not help. Pity.

 

Posted
17 hours ago, Bill Angel said:

That black hole at the center of Messier 87 has a mass of 6.5 billion solar masses.

One wonders if any of those 6.5 billion suns had planets which supported intelligent life.

It would be a real bummer if the astronomers of an alien society had to inform their population that in the distant future their sun and the planet that this alien society occupys are going to be sucked into their galaxy's black hole and annihilated. 

 

Extremely unlikely.   The core of galaxies tend to be Population I stars, which have lower metalicity than the Population II stars out in the disk.   In addition, you need second generation stars (stars formed from remnants of Supernovae) to form stellar systems with the type of element diversity needed.    All this takes time. Galaxy center black holes form early on during the Galaxy's formation.  This formation could even start before the first stars came to life. ( just because it is made up of 6.5 billion solar masses worth of material doesn't mean that that material was in the form of stars to start with.)   Also, during the early active part of its life, when it is gobbling up all the nearby material, collisions between the in-falling material produces a lot of energetic radiation.  Until it settles down, this radiation would be too intense to allow life to take hold in the galaxy.   Any civilizations would likely have risen long after the BH had finished growing for the most part.

Posted
17 hours ago, Bill Angel said:

That black hole at the center of Messier 87 has a mass of 6.5 billion solar masses.

One wonders if any of those 6.5 billion suns...  

Most stars we see are less than 1 solar mass, so it's an even bigger number than that, assuming the mass gobbled up was stars that belonged to the same distribution.  

10 hours ago, Q-reeus said:

There you go again - claiming certainty re validation of GR/BH's. Anyone with an ounce of caution would not use such commitment words. And btw the logical statement would have it

!

Moderator Note

When you nitpick and miss, you just come across as being a jerk ("more certainty" was the phrase, which is not the same as "claiming certainty")

 
10 hours ago, Q-reeus said:

 I tire of endless corrections. With you the cycle is endless. Time will eventually tell which theory is correct.

!

Moderator Note

The use of GR as the prevailing mainstream theory is quite correct, and in accordance with the forum rules.

You know what the staff is tiring of? All of this sniping. Knock it off.

 
Posted

I have few additional questions about the photography:

Any idea what is the approx. mass of the accretion disk relative to the black hole mass? Should I expect it to be 'paper-thin' (like Sautrn's rings) or does it have a substantial thickness? What is the density of the accretion disk near its 'middle' region - like that of water? Or more? Or less?

What do colors/shades on the photo show - radiation intensity or radiation wavelength?

 

Posted
1 hour ago, Danijel Gorupec said:

What do colors/shades on the photo show - radiation intensity or radiation wavelength?

 

The colors represent intensity. Increasing from red to white.

Posted
1 hour ago, Danijel Gorupec said:

I have few additional questions about the photography:

Any idea what is the approx. mass of the accretion disk relative to the black hole mass? Should I expect it to be 'paper-thin' (like Sautrn's rings) or does it have a substantial thickness? What is the density of the accretion disk near its 'middle' region - like that of water? Or more? Or less?

What do colors/shades on the photo show - radiation intensity or radiation wavelength?

 

Did some checking and found that Saturn's rings are around 30ft thick and the icy dust and ice particles are typically tiny, but there are some around a km in size.

Accretion disk thicknesses apparently vary somewhat, and are essentially rotating at relativistic speeds so essentially plasma.

This may help.....https://link.springer.com/article/10.12942/lrr-2013-1 

and... http://adsabs.harvard.edu/full/1987ComAp..12...67A

Posted

Thanks beecee, hopefully this weekend I find time to read in more details (both links seem interesting, yet difficult for me).

Anyway, after a quick look at the links, it seems to me that this BH observation might mean more for the theory of accretion disks than for the theory of black holes themselves.

Posted
34 minutes ago, Danijel Gorupec said:

Thanks beecee, hopefully this weekend I find time to read in more details (both links seem interesting, yet difficult for me).

Anyway, after a quick look at the links, it seems to me that this BH observation might mean more for the theory of accretion disks than for the theory of black holes themselves.

No probs. As I previously said, the information and data that will be gained as this methodology is further enhanced and improved, will be enormous and as informative and revealing in detail as the 11 gravitational wave discoveries. I propose a toast! Get yourselves a can of VB and salute old Albert and GR!!!Image result for drinking a VB photo

 

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