A team from ETH Zurich has founnd a black hole in galaxy CID-947 which has a mass of 10% of the galaxy mass instead of the usual 0.25-0.50. The galaxy is eleven billion light years away, so it must have formed in the early stage of the Universe.
Tullio

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believe me, it doesn't have a radius of 0!
how do I know that?
the bigger the BH, the bigger the Event horizon...& EH is what we see, 'cause they are (from time to time) most brilliant emanating light sources in Universe!
;)

also, it's difference when speaking to someone about BH tends to 0 radius & tends to infinite mass (if u remember limes in math)...& the actual 0 radius & infinite mass...
btw, BH with radius 0 evaporate withing miliseconds...
;)

Hmm. Then how big is our Earth? 8 billion lightyears across?
Thats how big it is if you include the gravitational field.

if that was true, we wouldn't have "rotating BH"...'cause we wouldn't have matter to rotate!

Its the electromagnetic and gravitational fields that are rotating.
Stable black holes can be completely described at any moment in time by these eleven numbers:
mass-energy M,
linear momentum P (three components),
angular momentum J (three components),
position X (three components),
electric charge Q.
https://en.wikipedia.org/wiki/Rotating_black_hole
https://en.wikipedia.org/wiki/Gravitational_energy

thermodynamics says nothing can disappear! only transform into sthg...probably pure energy or some other state of quantum energy...

I didn't say that something disappears.
The matter is converted to gravitational energy that is the potential energy associated with the gravitational field.
The law of conservation of energy still applies:)

nope, it's the matter/energy that rotates...it says like that in all observations we saw in the last 15y...check out the DATA!

of course the electromagnetic field is rotating - it rotates with the core of the Earth & with core of the Sun...but, as the magnetars & BH don't have cores (as far as we know it), so all EMF is mass/matter fixed...so rotating EMF in BH = rotating BH...
gravitational field is rotating fixed with mass/matter of object...so rotazting GF in BH = rotating BH...
is it so hard to understand?


oh, u didn't say it disappears...no, u just put " " on disappears...u have your post before & my original quote... :P
matter can't be turn ONLY into gravitational energy...as one of the properties of all matter is gravitational energy / mass of the matter...if u prove me otherwise - a Nobel is guaranteed!
;)

believe me, it doesn't have a radius of 0!
how do I know that?
the bigger the BH, the bigger the Event horizon...& EH is what we see, 'cause they are (from time to time) most brilliant emanating light sources in Universe!
;)

also, it's difference when speaking to someone about BH tends to 0 radius & tends to infinite mass (if u remember limes in math)...& the actual 0 radius & infinite mass...
btw, BH with radius 0 evaporate withing miliseconds...
;)

Hmm. Then how big is our Earth? 8 billion lightyears across?
Thats how big it is if you include the gravitational field.

u r sometimes so hard to understand...so either u r brilliant beyond us all or the other extreme...

gravitational field of Earth is not so big...or we would have a gravity on Space station... :D

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non-profit org. Play4Life in Zagreb, Croatia, EU

nope, it's the matter/energy that rotates...it says like that in all observations we saw in the last 15y...check out the DATA!

of course the electromagnetic field is rotating - it rotates with the core of the Earth & with core of the Sun...but, as the magnetars & BH don't have cores (as far as we know it), so all EMF is mass/matter fixed...so rotating EMF in BH = rotating BH...
gravitational field is rotating fixed with mass/matter of object...so rotazting GF in BH = rotating BH...
is it so hard to understand?

oh, u didn't say it disappears...no, u just put " " on disappears...u have your post before & my original quote... :P
matter can't be turn ONLY into gravitational energy...as one of the properties of all matter is gravitational energy / mass of the matter...if u prove me otherwise - a Nobel is guaranteed!
;)

There are no observations from inside the event horizon.
As for now it's all hypothesis.
I can't even prove theories and hypothesis are even worse.
No Nobel prize for me:)
The matterless BH is put forward by Kip Thorne, Leonard Susskind and Stephen Hawking among others.

u r sometimes so hard to understand...so either u r brilliant beyond us all or the other extreme...
gravitational field of Earth is not so big...or we would have a gravity on Space station... :D

Well it's not my ideas:)
The ISS are falling to Earth because of the gravitational pull from Earth but miss it all the time. There are however places between the Earth and the Sun where true zero gravity are. They are called Lagrange Points where the Suns and the Earths gravities cancel out.

When the Earth was formed the gravitational field started to spread with the speed of light. That was about 4 billion years ago so that field is now 8 billion lightyears across.

When the Earth was formed the gravitational field started to spread with the speed of light. That was about 4 billion years ago so that field is now 8 billion lightyears across.

That is one thing I have always wondered about. I always assumed that gravity propagated at the speed of light, but that has never been measured. gravity has not actually been defined properly, even though we can work with it mathematically to great accuracy. I wonder if it really does propagate at the speed of light, or is an intrinsic property of mass, moving as the mass moves. I really don't know.

Steve

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Warning, addicted to SETI crunching!
Crunching as a member of GPU Users Group.
GPUUG Website

When the Earth was formed the gravitational field started to spread with the speed of light. That was about 4 billion years ago so that field is now 8 billion lightyears across.

That is one thing I have always wondered about. I always assumed that gravity propagated at the speed of light, but that has never been measured. gravity has not actually been defined properly, even though we can work with it mathematically to great accuracy. I wonder if it really does propagate at the speed of light, or is an intrinsic property of mass, moving as the mass moves. I really don't know.
Steve

Gravity does propagate at the speed of light.
That means some odd things can happen that for instance if the sun disappered for some reason we wouldn't notice that for about 8 minutes and the Earth starts to wander out in space.
Pluto are still circling around nothing for about 4 hours.

When the Earth was formed the gravitational field started to spread with the speed of light. That was about 4 billion years ago so that field is now 8 billion lightyears across.

That is one thing I have always wondered about. I always assumed that gravity propagated at the speed of light, but that has never been measured. gravity has not actually been defined properly, even though we can work with it mathematically to great accuracy. I wonder if it really does propagate at the speed of light, or is an intrinsic property of mass, moving as the mass moves. I really don't know.

Steve

Crunch Einstein @ home and help find out about the gravitational field.

I don't believe its velocity has been measured yet. I think everyone is expecting it to be c, but it might be some other constant, or even infinite.

But we need to start measuring it from objects a long distance from us to be able to put some error bounds on the velocity.

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When the Earth was formed the gravitational field started to spread with the speed of light. That was about 4 billion years ago so that field is now 8 billion lightyears across.

That is one thing I have always wondered about. I always assumed that gravity propagated at the speed of light, but that has never been measured. gravity has not actually been defined properly, even though we can work with it mathematically to great accuracy. I wonder if it really does propagate at the speed of light, or is an intrinsic property of mass, moving as the mass moves. I really don't know.

Steve

Crunch Einstein @ home and help find out about the gravitational field.

I don't believe its velocity has been measured yet. I think everyone is expecting it to be c, but it might be some other constant, or even infinite.

But we need to start measuring it from objects a long distance from us to be able to put some error bounds on the velocity.

What is a fact is that gravity velocity cannot exceed the speed of light.

I do crunch Einstein from time to time, and as I haven't looked in on the science results for a while, have any gravity waves been detected? A detection of a wave would eliminate the possibility of an instantaneous gravity field that moves with the mass as one object.

Steve

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Warning, addicted to SETI crunching!
Crunching as a member of GPU Users Group.
GPUUG Website

I do crunch Einstein from time to time, and as I haven't looked in on the science results for a while, have any gravity waves been detected? A detection of a wave would eliminate the possibility of an instantaneous gravity field that moves with the mass as one object.

Steve

Gravitational radiation has not been directly detected, there is indirect evidence for its existence.
https://en.wikipedia.org/wiki/Gravitational_wave
Gravitational Waves are ripples in the curvature of spacetime and are different from gravitational propagation that doesn't create ripples.

That was my understanding as well. I just wondered if there had been new evidence. It does make me think that I could understand a wave caused by any huge event such as stellar explosion/collapse/combination, but how would the propagation be different, as it was a part of the mass since the mass was first formed?

Steve

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Warning, addicted to SETI crunching!
Crunching as a member of GPU Users Group.
GPUUG Website

That was my understanding as well. I just wondered if there had been new evidence. It does make me think that I could understand a wave caused by any huge event such as stellar explosion/collapse/combination, but how would the propagation be different, as it was a part of the mass since the mass was first formed?
Steve

Well consider this. Sound waves travels very fast in the ocean.
Ripples on the surface don't even if the ripples are created by sound.

Advanced LIGO, the follow up of LIGO, has been dedicated on May 19 at Hanford and should start collecting data in fall. The eLISA Pathfinder should be put in orbit by a Vega Launcher also in fall. Visit the Einstein@home site,the LIGO site, the GEO600 site and the VIRGO site for further information on gravitational waves search.
Tullio

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Advanced LIGO, the follow up of LIGO, has been dedicated on May 19 at Hanford and should start collecting data in fall. The eLISA Pathfinder should be put in orbit by a Vega Launcher also in fall. Visit the Einstein@home site,the LIGO site, the GEO600 site and the VIRGO site for further information on gravitational waves search.
Tullio

Kip Thorne's work has dealt with the prediction of gravity-wave strengths and their temporal signatures as observed on Earth. These "signatures" are of great relevance to LIGO (Laser Interferometer Gravitational Wave Observatory), a multi-institution gravity-wave experiment for which Thorne has been a leading proponent – in 1984, he cofounded the LIGO Project (the largest project ever funded by the NSF) to discern and measure any fluctuations between two or more 'static' points; such fluctuations would be evidence of gravitational waves, as calculations describe. A significant aspect of his research is developing the mathematics necessary to analyze these objects.
https://en.wikipedia.org/wiki/Kip_Thorne

The ISS are falling to Earth because of the gravitational pull from Earth but miss it all the time. There are however places between the Earth and the Sun where true zero gravity are. They are called Lagrange Points where the Suns and the Earths gravities cancel out.

of course ISS is falling to Earth - it is in a Low Earth orbit! check your facts...
BUT didn't hear that GPS were falling from the sky...how come? :P :D

also, only L4 & L5 are STABLE gravity wells...other are not STABLE!
& don't forget there r L4 & L5 for Earth & Moon also... ;)

Gravitational radiation has not been directly detected, there is indirect evidence for its existence.

Not radiation, energy! ;)

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non-profit org. Play4Life in Zagreb, Croatia, EU

of course ISS is falling to Earth - it is in a Low Earth orbit! check your facts...

I did checked my facts:) It's best described by Newton.
The orbital speed at any position in the orbit can be computed from the distance to the central body at that position, and the specific orbital energy, which is independent of position: the kinetic energy is the total energy minus the potential energy.
https://en.wikipedia.org/wiki/Escape_velocity

Gravitational radiation has not been directly detected, there is indirect evidence for its existence.

Not radiation, energy! ;)

Whats the difference?
It's energy that propagates in space and time and is called radiation.

Here is an analogy.

Electromagnetic radiation is a wave that propagates in space and time. Radiation propagation is described by Maxwell's equations and it consists of an electric and a magnetic field that oscillates at a right angle to each other and to the direction.

Electromagnetic radiation occurs in many scientific and technological fields, and has several characteristics, such as wave-particle duality of photons as an energy-carrying quantum.

Maxwell's four equations.

All objects that man put in orbit around the earth are falling but their orbital speed balances out the fall keeping the objects in orbit. Objects in low earth orbit also suffer from drag created by collisions with molecules from the atmosphere which slows them down requiring periodic boosts in orbital velocity or the object will eventually slow enough to fall to earth. Objects in very high orbits don't suffer as much from the drag but I believe they still need to make adjustments from time to time. The moon is for some reason slowly escaping from earth's gravity but it is estimated that the sun will burn out before that happens.

I seem to recall there are places where the earth's gravity fluctuates minutely causing objects in orbit to speed up or slow down.

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Bob DeWoody

My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events.

Thanks, I was being too lazy to look up and refresh my memory regarding the moon's orbit.

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Bob DeWoody

My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events.

Giant black hole in normal galaxy breaks the rules

Most black holes have little mass compared to their host galaxy, but a recently discovered black hole grew so quickly the host galaxy couldn’t keep pace.

The discovery has astronomers questioning assumptions about how galaxies develop.

http://www.futurity.org/giant-black-hole-957892/