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Bmpbmp1975

Question about merging supermassive black holes

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Posted (edited)

Trying to understand this article. Are they stating if 2 supermassive black holes merge and are they claiming that they see 2 supermassive blackholes merging

https://www.google.ca/amp/s/www.forbes.com/sites/startswithabang/2020/03/03/the-most-energetic-event-in-the-universe-hasnt-been-discovered-yet/amp/

thank you 

Edited by Bmpbmp1975
Fixed link

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Second paragraph:

 

“But there's another class of event that definitely exists in the Universe that can output even more energy in a shorter amount of time: the merger of two supermassive black holes. Although we've never seen such an event...

 

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Posted (edited)
16 minutes ago, swansont said:

Second paragraph:

 

“But there's another class of event that definitely exists in the Universe that can output even more energy in a shorter amount of time: the merger of two supermassive black holes. Although we've never seen such an event...

 

I saw that but I am not sure if they meant haven’t seen it yet. I am trying to determine if they are aware of one happening or if they are looking to see if they can find one 

 

also is this something that never happened before or is it something that has happened and never been detected

Edited by Bmpbmp1975

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31 minutes ago, Bmpbmp1975 said:

I saw that but I am not sure if they meant haven’t seen it yet. I am trying to determine if they are aware of one happening or if they are looking to see if they can find one 

also is this something that never happened before or is it something that has happened and never been detected

It is fairly safe to say that if they are aware of one having happened, then it is because they have seen/detected it.

Whether it has happened before is something we cannot know unless we detect it.

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Posted (edited)
26 minutes ago, taeto said:

It is fairly safe to say that if they are aware of one having happened, then it is because they have seen/detected it.

Whether it has happened before is something we cannot know unless we detect it.

Ok your comments seem contradicting or I am not sure if I am understanding 

Also how do they know one will happen in the next decade

they also say it will be more powerful than the power of all the stars in the universe?

Edited by Bmpbmp1975

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Posted (edited)
1 hour ago, Bmpbmp1975 said:

Ok your comments seem contradicting or I am not sure if I am understanding 

A scientific theory may state that some event can happen and predict the outcome of such an event. In this case theories state that super massive black holes can collide and that it will be energetic. We've never seen such an event according to the article. By "see" I mean detected; visible light, gamma rays, gravitation or other.
So the theories states that an event is possible. Universe is large and have many galaxies so it may be likely that there are collisions happening ot have happened and left observable traces. And when we detect such an event we will know that it happened. 

1 hour ago, Bmpbmp1975 said:

I saw that but I am not sure if they meant haven’t seen it yet. I am trying to determine if they are aware of one happening or if they are looking to see if they can find one 

also is this something that never happened before or is it something that has happened and never been detected

Scientist can't be aware of a merger of two supermassive black holes happening unless it is detected. Probably one can make predictions about future events if we observe merging galaxies or observe galaxies predicted to merge in the future. Note that galaxy mergers take time so a predicted event may occur far into the future. 

 

Disclaimer due to other threads I've read: note that supermassive black hole mergers in remote galaxies are not a threat to us. 

Edited by Ghideon
clarified. Edit after comment from Strange

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7 minutes ago, Ghideon said:

A scientific theory may state that some event can happen and predict the outcome of such an event. In this case theories state that super massive black holes can collide and that it will be energetic. We've never seen such an event according to the article. By "see" I mean detected; visible light, gamma rays, gravitation or other.
So the theories states that an event is possible. Universe is large and have many galaxies so it may be likely that there are collisions happening ot have happened and left observable traces. And when we detect such an event we will know that it happened. 

Scientist can't be aware of a merger of two supermassive black holes happening unless it is detected. Probably one can make predictions about future events if we observe merging galaxies or observe galaxies predicted to merge in the future. Note that galaxy mergers take time so a predicted event may occur far into the future. 

 

Disclaimer due to other threads I've read: note that supermassive black hole mergers in remote galaxies are not a threat to us. 

I think I get it

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1 hour ago, Bmpbmp1975 said:

I saw that but I am not sure if they meant haven’t seen it yet. I am trying to determine if they are aware of one happening or if they are looking to see if they can find one 

They have not seen one yet. (They have seen mergers of stellar mass black holes.) As it says, the current detectors (LIGO and VIRGO) would not be able to detect such a merger (because the frequency of the signal is too low).

They have seen pairs of supermassive black holes that will probably merge at some time in the future.

Quote

also is this something that never happened before or is it something that has happened and never been detected

It has almost certainly happened before. One theory about how supermassive black holes become supermassive is by merging.

 

9 minutes ago, Ghideon said:

Disclaimer due to other threads I've read: note that supermassive black hole mergers in remote galaxies are not a threat to us. 

Nearly all of the energy of such an event would be released as gravitational waves. These interact only weakly with matter so you would have to be really, really close to notice any effect at all. 

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Posted (edited)
37 minutes ago, Strange said:

They have not seen one yet. (They have seen mergers of stellar mass black holes.) As it says, the current detectors (LIGO and VIRGO) would not be able to detect such a merger (because the frequency of the signal is too low).

They have seen pairs of supermassive black holes that will probably merge at some time in the future.

It has almost certainly happened before. One theory about how supermassive black holes become supermassive is by merging.

 

Ok before anything sometime is the future define what’s exactly. Cause the article mentions they will see it within the decade I also think they said 5 years?

 

 

Edited by Bmpbmp1975

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6 minutes ago, Bmpbmp1975 said:

Ok before anything sometime is the future define what’s exactly. Cause the article mentions they will see it within the decade I also think they said 5 years?

They think that, using a new technique based on measuring the frequency of pulsars, they should be able to detect such mergers within 10 years:

Quote

The first supermassive black holes that are inspiraling, according to our best modern estimates, should be detectable this decade by advanced pulsar timing arrays such as NANOGrav, the European Pulsar Timing Array and the Parkes Pulsar Timing Array.

That is when they should have the capability to detect such mergers. But they are not absolutely certain they happen:

Quote

The detection of a supermassive black hole merger would offer new insights into how massive galaxies and black holes evolve, Mingarelli says. A lack of any such a sighting within the 10-year timeframe, on the other hand, would necessitate a rethink of whether and how supermassive black holes merge, she says.

https://www.simonsfoundation.org/2017/11/13/gravitational-waves-supermassive-black-hole-merger/

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also if it will be as powerful as they say with it not cause mass devistation. For billions and billions of light years in the vicinity? Concidering it will be more powerful that the power of every star in the universe?

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Posted (edited)
45 minutes ago, Strange said:

Nearly all of the energy of such an event would be released as gravitational waves. These interact only weakly with matter so you would have to be really, really close to notice any effect at all. 

Good catch. I was thinking of future merger of Milky Way and Andromeda. But any possible danger from that galaxy merger, far into the future, will likely not be from SMBH merger.
I edited my post to reflect this. 

 

Edited by Ghideon

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18 minutes ago, Bmpbmp1975 said:

also if it will be as powerful as they say with it not cause mass devistation. For billions and billions of light years in the vicinity? Concidering it will be more powerful that the power of every star in the universe?

No. And stop twisting every thread to fit your delusions. Have you spoken to your doctor yet?

In the case of the black hole mergers detected so far, which are black holes around 20 to 30 times the mass of the Sun, even if they were as close to us as the Sun is it would only cause the Earth the stretch by about 1 metre, which is about the same as happens everyday due to the moon. (They would also be only about 100km across and so not visible without a really good telescope.)

I will try and get some rough figures for the merger of supermassive black holes...

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1 minute ago, Strange said:

No. And stop twisting every thread to fit your delusions. Have you spoken to your doctor yet?

In the case of the black hole mergers detected so far, which are black holes around 20 to 30 times the mass of the Sun, even if they were as close to us as the Sun is it would only cause the Earth the stretch by about 1 metre, which is about the same as happens everyday due to the moon. (They would also be only about 100km across and so not visible without a really good telescope.)

I will try and get some rough figures for the merger of supermassive black holes...

I was not twisting anything I was asking because of the amount of power unleashed 

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I can't be bothered to work it out in detail, and I probably can't easily find all the information, but because supermassive black hole mergers happen much more slowly the actual power (rather than energy) is only something like 100 times greater than for typical black hole mergers. So, even if it happened at the distance of the nearest black hole, the effect on the Earth would be minute (about half a millimetre change in the diameter of the Earth). As it would actually happen thousands or millions of light years away, the effect would be completely unnoticeable. Which is why we need incredibly sensitive measurement techniques to detect it.

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2 hours ago, Bmpbmp1975 said:

Also how do they know one will happen in the next decade

He didn’t say that. He said the technology to detect such an event will come online in the next decade.

Please, please, please quote the relevant section of text so we don’t have to search for what you are talking about. Perhaps the act will force you to (re)read the text and you will improve your comprehension of what was said.

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I still don’t get how our universe contains possible 1 googol of stars and this type of merger would be more powerful than all the energy of those stars together but still only become gravitational waves?

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6 minutes ago, Bmpbmp1975 said:

I still don’t get how our universe contains possible 1 googol of stars and this type of merger would be more powerful than all the energy of those stars together but still only become gravitational waves?

Who says it would be more powerful than all those stars together?

 

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Posted (edited)
8 minutes ago, Strange said:

Who says it would be more powerful than all those stars together?

 

It the original article there was a mention made it would be more powerful

When we detected our first black hole-black hole merger, there was a brief time period lasting under 200 milliseconds where that merger produced more energy than all the stars in the Universe combined. If we can find a supermassive black hole merger where the smaller mass is more than 500 million solar masses, not only will it emit more energy than all the stars in the Universe for about a week, 

Edited by Bmpbmp1975

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Posted (edited)
Quote

When we detected our first black hole-black hole merger, there was a brief time period lasting under 200 milliseconds where that merger produced more energy than all the stars in the Universe combined. If we can find a supermassive black hole merger where the smaller mass is more than 500 million solar masses, not only will it emit more energy than all the stars in the Universe for about a week, but it will become the most energetic event since the Big Bang, emitting more than ~10^55 J over that time interval.

Source:https://www.forbes.com/sites/startswithabang/2020/03/03/the-most-energetic-event-in-the-universe-hasnt-been-discovered-yet/amp/

A suggestion: the above quote may be more helpful than the following post:

16 minutes ago, Bmpbmp1975 said:

It the original article there was a mention made it would be more powerful

 

Edited by Ghideon

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27 minutes ago, Bmpbmp1975 said:

It the original article there was a mention made it would be more powerful

When we detected our first black hole-black hole merger, there was a brief time period lasting under 200 milliseconds where that merger produced more energy than all the stars in the Universe combined. If we can find a supermassive black hole merger where the smaller mass is more than 500 million solar masses, not only will it emit more energy than all the stars in the Universe for about a week, 

Note that it is a large amount of energy released over a very short time.

It is a bit like comparing a lightning flash, which releases a large amount of energy (about a billion joules) in a very short time (around 1 millisecond). This is equivalent to 1 trillion 1W LED bulbs shining for the same amount of time. Or one of those bulbs shining for 32 years.

His estimate is, I think, based on about 10% of the mass of the black hole being converted to gravitational waves (which is roughly what we have seen so far); say 50 million solar masses. So that is massive amount of energy being released over a very short time (a few hours). 

But stars burn very slowly, and only convert a tiny fraction of their mass to energy. So it takes billions and billions of starts to release the same amount of energy. The difference is that the stars can keep releasing that tiny trickle of energy for billions of years.

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4 hours ago, Bmpbmp1975 said:

I still don’t get how our universe contains possible 1 googol of stars and this type of merger would be more powerful than all the energy of those stars together but still only become gravitational waves?

Do you understand the difference between energy and power that Strange has highlighted?

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I suggest that if you don’t understand such basic physics, then understanding more advanced topics is not possible. 

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