Luminosity

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Jun 1, 2020
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More luminous, perhaps, than that race was the 1967 movie Robbery (Bullitt was in 1968):

From Wiki (Bullitt)
"Bullitt was director Yates's first American film. He was hired after McQueen saw his 1967 UK feature Robbery, with its extended car chase. Joe Levine, whose Embassy Pictures had distributed Robbery, did not much like the film, but Alan Trustman, who saw the picture the very week he was writing the Bullitt chase scenes, insisted that McQueen, Relyea, and D'Antoni (none of whom had ever heard of Yates) see Robbery and consider Yates as director for Bullitt."
 

Catastrophe

The devil is in the detail
Luminosity

Have we finished with the maximum value? Has someone mentioned:

Quote
Although quasars appear faint when viewed from Earth, they are visible from extreme distances, being the most luminous objects in the known universe. The brightest quasar in the sky is 3C 273 in the constellation of Virgo.

Quasar - Wikipedia
https://en.wikipedia.org › wiki › Quasar


Quote

Cat :)
 
Hi Cat!
If I understand correctly, now we have just ended with this speech!
The maximum must be found in quasar whereas the minimum must be found in Black Holes. I really can't believe that two objects to different are instead so close to each other.
 
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Jun 1, 2020
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Hi Cat!
If I understand correctly, now we have just ended with this speech!
The maximum must be found in quasar whereas the minimum must be found in Black Holes. I really can't believe that two objects to different are instead so close to each other.
I enjoy irony and that's a good one! Quasars are bright due to their central BH (SMBH), and yet there is no greater darkness - both observed from the outside.

Luminosity is also a function of flux density, which is determined by temperature. Thus the hottest spots have the highest flux density, and if they are large, will necessarily have the greatest luminosity.
 
I enjoy irony and that's a good one! Quasars are bright due to their central BH (SMBH), and yet there is no greater darkness - both observed from the outside.
Well, this is something true, I can't say the opposite, but I was talking about the central point of a Black Hole more than the BH itself (of course, it was what I meant to tell the truth)
 
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I am going to be frank here, I didn't even realize that I had mistakenly done a cool alliteration.

P.S.: Did I alliterate in this post too?
And then there is me who has never realized it, but I'm not alone. I barely know what is an allitteration :tearsofjoy:
(I know what is an allitteration to tell the truth, it's just a repetition of the same sound in a sentence, at least three times if I'm not mistaken)
 

Catastrophe

The devil is in the detail
Luminosity

OP asked:
"Is there a limit to luminosity?
Put simply, is there a limit to how bright light sources can get, like stars, or anything else in the universe? "

Have we completely answered his question?

Cat :)
 
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Have we completely answered his question?
Maybe the question itself makes no-sense. Today, thinking about it, I remembered the good old days when I went to middle schools. My teacher, she wasn't an astronomer though, told us about an explosion, a clash between two stars, this explosion gave a temperature very high (we are now talking about some milion/bilion kelvin degrees. She said "it seem to be possible to define the minimum temperature possible in the Universe, but the highest one can't be found".
But not only that! Now that I'm thinking about it, I just "discovered" that not even the lowest one can be found cause we always have to take into account that the minimum temperature can't be zero, it's impossible, so a fraction of a kelvin. A fraction of a kelvin degree can't be calculate as well as we can't calculate the highest one, so, the question is now solved. As we can't find a minimum ( at least we can say it tent to zero never touching that temperature) and a maximum in temperature, we can't find anything like that in luminosity (not even BH can have "zero luminosity", for this reason the limit is that, but we can't basically reach it).
Tell me what you think about it please, I'm not so sure whether we can compare luminosity to temperature in this speech.
 
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Catastrophe

The devil is in the detail
Here is IG's reference. Does this settle it?

Eddington luminosity
From Wikipedia, the free encyclopedia

The Eddington luminosity, also referred to as the Eddington limit, is the maximum luminosity a body (such as a star) can achieve when there is balance between the force of radiation acting outward and the gravitational force acting inward. The state of balance is called hydrostatic equilibrium. When a star exceeds the Eddington luminosity, it will initiate a very intense radiation-driven stellar wind from its outer layers. Since most massive stars have luminosities far below the Eddington luminosity, their winds are mostly driven by the less intense line absorption.[1] The Eddington limit is invoked to explain the observed luminosity of accreting black holes such as quasars.

Cat :)
 
Jul 27, 2021
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Correct. We use flashlight to describe a larger version probably about 4-6 inches across. A torch (for us) is a smaller thing probably using AAA batteries (do you have AA AAA etc?).

Strange for us, because we also use the word torch to describe a larger flaming source of light. Hence the expression (do you have same?) "carry a torch for someone"? - probably meaning carry this to light their path, try to get "in" with them i.e., become friendly.

Has anyone produced a US/UK English dictionary
'Has anyone produced a US/UK English dictionary'

Webster and Oxford are doing. Both indicate differences between US/UK. Moreover, they consider and give examples of hundred of thousand over the World dialects (including not native speakers).
 
I have come to agree with him. And, anyway, does it matter if some new quasar, or whatever, suddenly exceeds the previous limit?
Hi Cat!
Thank you for sharing this. I would have posted something more on it here but only now I remember that I have said everything in the post #42 even though that seem to be more a philosophical speech than a scientific one.
 
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