How can i calculate the brightness of moon's light at night on the earth?

In summary, you can measure the brightness of moonlight by measuring the temperature increase and time it took.
  • #1
rony01
2
0
hello Forum

i am a novice physics learner. actually i want to calculate or construct an equation through which i can measure the maximum brightness of moon's light on our planet.

can anyone give me any idea from where to start?
 
Science news on Phys.org
  • #2
well there is an experiment to measure the energy output of the sun , And this might work on a full moon . Set out a glass of water and see if the light from the moon heats up the glass of water , and measure the temperature increase , and measure the time it took and then you can get the energy per second it was putting out over that cross-sectional area . Now i feel stupid for writing this because i don't know if it will work, I don't know if there is enough light coming off the sun . Maybe you could do something with a solar cell.
 
  • #3
welcome to pf!

hello rony01! welcome to pf! :smile:

for an equation, you can assume that the full moon is a light bulb which radiates a certain percentage (the "albedo" of Moon-rock) of the light from the sun falling on it …

and assume it radiates equally over a 2π solid angle (ie only on one side!) …

then use the angular diameter of the Moon as seen from the Earth :wink:
 
  • #4
Just to be clear, you are asking about the *brightness*, as opposed to the irradiance?
 
  • #5
First you need a photo receptor. For dim sources i suggest a photo resistor from a night light removed and connected to a resistance meter. The resistance will be a function of the light on it. If you are able to get measurable changes by directing the photo resistor on the moon then you need to calibrate it. I suggest a candle placed 1 foot from the photo resistor. ( one candle power ) in a dark room. Add more candles to get a curve. This is all a little sloppy but it should work and get you started. If you are in a city it may be hard to find moonlight without other light sources interfering.
 
  • #6
i think it would be easier to calculate in that to measure the unit LUMEN in which i must require the periphery and the radiation angle. for the radiation angle it will be easily calculated with stick perpendicular to Earth and then using F = Iv × 2π × (1 - cos(A/2)), this law might be easier.but thanks for the comments!
 
  • #7
Great. What did you get?
 

1. What factors affect the brightness of the moon's light on Earth at night?

The main factors that affect the brightness of the moon's light on Earth at night are the phase of the moon, the distance between the moon and Earth, and atmospheric conditions.

2. How can I calculate the distance between the moon and Earth?

The distance between the moon and Earth can be calculated using the formula D = 1/2 * (2 * pi * R * (1 - cos(theta))), where D is the distance, R is the radius of the Earth, and theta is the angular diameter of the moon. The angular diameter can be found using a telescope or by using the formula theta = 2 * arctan(d / 2D), where d is the diameter of the moon and D is the distance between the moon and Earth.

3. How does the phase of the moon affect its brightness on Earth?

The phase of the moon plays a significant role in its brightness on Earth. A full moon appears brightest because the entire side facing Earth is illuminated by the sun. On the other hand, a new moon appears dim because the side facing Earth is not illuminated at all.

4. Does the Earth's atmosphere affect the brightness of the moon's light at night?

Yes, the Earth's atmosphere can affect the brightness of the moon's light at night. The atmosphere acts as a filter, scattering and absorbing some of the light from the moon. This is why the moon appears dimmer when it is closer to the horizon compared to when it is higher in the sky.

5. Can I use a formula to calculate the brightness of the moon's light on Earth at night?

Yes, there is a formula that can be used to calculate the brightness of the moon's light on Earth at night. It is known as the Moonlight Illuminance Formula and it takes into account the phase of the moon, the distance between the moon and Earth, and atmospheric conditions. However, the formula is quite complex and it is easier to use online calculators or apps to determine the brightness of the moon's light at specific locations and times.

Similar threads

Replies
3
Views
910
  • Optics
Replies
4
Views
1K
Replies
1
Views
984
Replies
7
Views
844
  • Introductory Physics Homework Help
Replies
18
Views
1K
  • Sci-Fi Writing and World Building
Replies
17
Views
2K
Replies
40
Views
14K
  • Special and General Relativity
2
Replies
58
Views
3K
  • Astronomy and Astrophysics
Replies
33
Views
3K
Back
Top