Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Kenneth Silva on 15/10/2011 12:30:05

Title: Why do sunbeams appear to spread out?
Post by: Kenneth Silva on 15/10/2011 12:30:05

Kenneth Silva  asked the Naked Scientists:
   
Distance of sun from Earth.

I was out, walking my dog this morning, just as the sun came up. There was a thin cloud cover, but the sun's rays were coming through. I noticed that the light rays came in a fanned pattern. If I trace the rays back to a point of origination, I determine that the sun is maybe a mile up in the sky.

Either they've been lying to us all these years as to how far away the sun is, or something else is going on here.

Why are the light rays fanned out? Shouldn't they be more parallel if the sun is 93,000,000 miles away?

Thanks.
Ken Silva
Phoenix, AZ
USA

What do you think?

Title: Why do sunbeams appear to spread out?
Post by: Soul Surfer on 15/10/2011 15:41:40

It is a perspective effect the rays are straight parallel lines but they appear to converge in the same way that railway tracks appear to converge as they recede into the distance.

Title: Why do sunbeams appear to spread out?
Post by: Geezer on 15/10/2011 16:21:59

I think the light has to be coming from a nearby bright spot caused by different densities in the cloud to observe that effect. The "rays" look as if they are emanating from the sun, but they are really emanating from an image of the sun projected onto something in the Earth's atmosphere.

Title: Why do sunbeams appear to spread out?
Post by: Bored chemist on 15/10/2011 16:47:38

Is this what you mean?
http://en.wikipedia.org/wiki/Crepuscular_rays

Title: None
Post by: Bruce Ing on 12/12/2016 08:28:37

It's optical illusion.

Light rays are coming toward you as they come down.

https://www.google.ca/url?sa=t&source=web&rct=j&url=https://en.m.wikipedia.org/wiki/Crepuscular_rays&ved=0ahUKEwjX55Cine7QAhVBSyYKHURcDSEQFghoMBE&usg=AFQjCNHeoB8P4zYGIYdLYu9C_mcVXAN-kg&sig2=jIK0hw2Ig4VF6u3NQjmoRA