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

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Discussion Overview

The discussion centers around the terminology used to describe the quantity obtained by multiplying light flux by the area of a detector. Participants explore the implications of this operation in the context of physics, particularly focusing on concepts related to power and luminosity.

Discussion Character

  • Conceptual clarification, Debate/contested

Main Points Raised

  • One participant states that multiplying the flux of a light source by the area of a detector results in a quantity measured in watts, which is technically "power".
  • Another participant suggests that this quantity might be referred to as "luminosity", providing a formula that relates brightness, surface area, and total output in watts.
  • A different participant counters that luminosity refers to the total energy emitted by an object, not the quantity in question, and emphasizes that they are discussing the energy per second falling on a detector.
  • Another participant proposes the term "radiant flux" as a possible descriptor for the quantity observed by a detector.

Areas of Agreement / Disagreement

Participants express differing views on the correct terminology, with no consensus reached regarding whether the term should be "luminosity", "radiant flux", or another term. The discussion remains unresolved.

Contextual Notes

There are assumptions regarding the definitions of luminosity and radiant flux that are not fully explored, and the discussion does not clarify the distinctions between these terms in detail.

Mu naught
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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?
 
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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.
 

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