What Do You Call the Quantity When You Multiply Light Flux by Detector Area?

  • Thread starter Thread starter Mu naught
  • Start date Start date
AI Thread Summary
Multiplying light flux by the area of a detector yields a quantity measured in watts, which is technically considered power. However, the discussion seeks the correct term for this quantity, distinguishing it from luminosity, which refers to the total energy emitted by an object. The conversation suggests that the term "radiant flux" may be more appropriate, as it describes the energy per unit area per second detected. This highlights the difference between total emitted energy and the energy received by a specific detector area. The focus remains on accurately defining the measurement related to light detection.
Mu naught
Messages
208
Reaction score
2
If you take the Flux of a light source and multiple by the area of your detector you are left with a quantity in units of only watts.

Now this is technically "power", but what is the correct term for this quantity?
 
Astronomy news on Phys.org
Mu naught said:
If you take the Flux of a light source and multiple by the area of your detector you are left with a quantity in units of only watts.

Now this is technically "power", but what is the correct term for this quantity?

Are you talking about luminosity?

Luminosity is a function of the amount of light output (brightness or flux) per given unit of surface area multiplied by the total surface area.L= b*((d^2)*pi*4)

L=luminosity (watts)
b=brightness or flux ("watts/meters^2")
d=diameter of star (meters)
((d^2)*pi*4)=surface area (meters^2)

It's basically the surface area (m^2) of the sphere multiplied by the brightness per unit of area. Which finds the total output (commonly shown in the form of watts.).
 
Last edited:
No, because luminosity describes the total amount of energy emitted by an object.

I'm talking about multiplying the apparent brightness of an object by the area of a detector to get the total amount of energy per second falling on that detector. I believe there is a certain term for this that is not "power" but I don't know what that term is.
 
I think you're talking about "radiant flux" if you are talking about the amount per surface area unit per second observed by a detector.
 

Thread 'How feasible is home radio astronomy?'

Is a homemade radio telescope realistic? There seems to be a confluence of multiple technologies that makes the situation better than when I was a wee lad: software-defined radio (SDR), the easy availability of satellite dishes, surveillance drives, and fast CPUs. Let's take a step back - it is trivial to see the sun in radio. An old analog TV, a set of "rabbit ears" antenna, and you're good to go. Point the antenna at the sun (i.e. the ears are perpendicular to it) and there is...
View full post »

Thread 'Our Beautiful Universe - Photos and Videos'

This thread is dedicated to the beauty and awesomeness of our Universe. If you feel like it, please share video clips and photos (or nice animations) of space and objects in space in this thread. Your posts, clips and photos may by all means include scientific information; that does not make it less beautiful to me (n.b. the posts must of course comply with the PF guidelines, i.e. regarding science, only mainstream science is allowed, fringe/pseudoscience is not allowed). n.b. I start this...
View full post »

Similar threads

I Motional EMF in Faraday disc, co-rotating magnet axial mean flux
Replies
5
Views
169
I Is there a list of root-power quantities? Or a rule of thumb?
Replies
14
Views
2K
I What is the correct way to calculate the area of the sky in square degrees?
Replies
11
Views
4K
I Question regarding the use of Electric flux and Field Lines
Replies
25
Views
2K
Heat Transfer Through a Two Material System due to a Light Source
Replies
10
Views
3K
A Understanding MASERs and their properties
Replies
1
Views
2K
I What do you need to establish that spin is conserved?
Replies
3
Views
1K
Calculating flux density of radio telescope
Replies
28
Views
3K
Electric flux through ends of an imaginary cylinder
Replies
7
Views
2K
B Electric Flux - confused about integrating over a tilted area
Replies
8
Views
2K

Hot Threads

Recent Insights

Back
Top