Question about stars and light after a trip to the Hayden Planetarium

  • Thread starter Thread starter joeb1990
  • Start date Start date
  • Tags Tags
    Light Stars
AI Thread Summary
The discussion centers on the visibility of distant stars and the impact of light intensity on their observation. It highlights that while light travels at a constant speed, the intensity of a star's light diminishes with distance due to the inverse square law. This means that brighter stars can be seen from farther away compared to dimmer ones, as their light spreads out over a larger area. The sensitivity of observational equipment also plays a role in detecting light from distant stars. Understanding these principles clarifies why not all stars, regardless of their age or distance, are visible to us.
joeb1990
Messages
1
Reaction score
0
Ok so I was at the Hayden Planetarium and a plaque was describing a star billions of light years away that we can see because it is so much brighter. I was puzzled thinking about this. If the speed of light is constant there is no reason the intensity of it's light should affect how far away we can see it right? I mean if something is 13 billion light years away it will take 13 billion years to reach us regardless of intensity. Shouldn't we be able to see anything in this time frame as long as the light has been traveling long enough? Is it something to do with the sensitivity of the equipment? Thanks!
 
Science news on Phys.org
The light is not in one direction. Since it spreads out in all directions, the intensity in any specific direction decreases by an inverse square law with distance.
 
Thread 'A quartet of epi-illumination methods'

Thread 'A quartet of epi-illumination methods'

Well, it took almost 20 years (!!!), but I finally obtained a set of epi-phase microscope objectives (Zeiss). The principles of epi-phase contrast is nearly identical to transillumination phase contrast, but the phase ring is a 1/8 wave retarder rather than a 1/4 wave retarder (because with epi-illumination, the light passes through the ring twice). This method was popular only for a very short period of time before epi-DIC (differential interference contrast) became widely available. So...
View full post »

Thread 'Effective absorption coefficient of gold nanoparticles'

I am currently undertaking a research internship where I am modelling the heating of silicon wafers with a 515 nm femtosecond laser. In order to increase the absorption of the laser into the oxide layer on top of the wafer it was suggested we use gold nanoparticles. I was tasked with modelling the optical properties of a 5nm gold nanoparticle, in particular the absorption cross section, using COMSOL Multiphysics. My model seems to be getting correct values for the absorption coefficient and...
View full post »

Thread 'The focal length of the eye and image inversion'

After my surgery this year, gas remained in my eye for a while. The light air bubbles appeared to sink to the bottom, and I realized that the brain was processing the information to invert the up/down/left/right image transferred to the retina. I have a question about optics and ophthalmology. Does the inversion of the image transferred to the retina depend on the position of the intraocular focal point of the lens of the eye? For example, in people with farsightedness, the focal point is...
View full post »

Similar threads

B Distance of Stars / Size of the Universe calculation
Replies
6
Views
3K
B We see a quasar 13 billion light years away. What does this mean?
Replies
4
Views
2K
I Could the Universe Be Much Older Than 13.8 Billion Years?
Replies
3
Views
2K
Can Light be used to see what's in the past?
Replies
6
Views
3K
B NGC 4590, more than 1,400 stars found in various evolutionary stages
Replies
1
Views
1K
B Theories about light and time near a black hole
Replies
20
Views
2K
I Relativistic Effect of Time Dilation: What is it Called?
Replies
4
Views
1K
Stars we see are actually their past?
Replies
12
Views
2K
B Einstein thought experiment confusion: “light clock in a moving frame”
Replies
5
Views
2K
B Question About The Stars -- Can they have died before we see their light?
Replies
5
Views
2K

Hot Threads

Recent Insights

Back
Top