# How can light travel in every direction? Conclusions?

Light is emitted from a star in the form of photons, the number of photons emitted (intensity) is dependant on the energy of the source (star). The photons have wave-partical duality and no mass, and travel at the speed of light. Eventually they are shot out so far from the source they thin out making very distant stars hard/impossible to see.

Conclusion light travels in every direction to a finite distance, where after this distance defined by the initial energy source it fails to reach some parts of space in an increasingly wide area with too few photons to fill the gaps. The photon will go on forever until absorbed.

Space now has to be a physical invisible body for photons to travel in a wave form. Space exists, thats spooky.

Lastly thanks to everyone who took the time to take part in this question, excellent replies especially from mgleeson, Polo, andy muso, Bob P, mias_bur, frothuk, PRyder 20, Rick B, bw 022, ray c, Colin G and lastly Dimblond for correcting my spelling!

Relevance

"Conclusion light travels in every direction to a finite distance"

"The photon will go on forever until absorbed"

The second comment seems to preclude the first, but I understand what you are trying to ask: Once you get far enough from a star eventually you won't see any of its photons.

Unfortunately photon emission from a star follows a continuous probability distribution because every direction is equally probable from another. And since photons travel infinitely through space until absorbed, there is no point in space that you can say will NEVER see a photon from that star. You may be so far away that the light will not be continuous (i.e. one photon arrives every x seconds), but probability theory states that you can never say never.

Photon duality is just the electric and the magnetic waves, electromagnetic radiation. The human eye cannot detect only one photon, so what

"Conclusion light travels in every direction to a finite distance, where after this distance defined by the initial energy source it fails to reach some parts of space in an increasingly wide area with too few photons to fill the gaps. The photon will go on forever until absorbed."

means is that yes you can see a star but as the photons continue in a straight line from the star the get farther apart.

Let's say that Star A has a surface area of 100 sq. feet (small i know) but if 1x10^8 photons are emitted from each sq. foot (I know thats dim) Once those photons get the set distance to where if an imaginary sphere was place around Star A to where it would have a surface area of 200 sq. feet, there would only be 5x10^7 photons emitted from each square foot (half as many) so for each increment away from Star A you get that is how much dimmer it is. The distance for a ten times larger sphere would mean that it would be ten times dimmer. If you still do not understand e-mail me.

• Shahid
Lv 7

When astronauts visited the Moon the left few supper reflective mirror-pieces, the shape somewhat like that of a prism, those mirror are for the purpose of reflecting a laser bean back to its starting point. The device is used to constantly measure and monitor the accurate distance between the Earth and the Moon. Now it is not always that a laser beam emanated from any of the observatories round the globe hit the reflector head on. It is difficult to pinpoint the laser gun right at the to p of them, and therefore sometimes a laser beam is only partially reflected, returning only few photon back to earth, sometimes only a few as five or even just one. The reading of the time taken by a photo to and from in between to bodies, however, always yield accurate results, thanks to highly photosensitive apparatus used.

This is true that space, the great voids of vacuum filling in where there is no matter, is not exactly empty but seething with activity of strange particles that scientists now can prove that they exists. They cannot however tell what they are and where they come from. They say that they come from the future dimension, or from some other dimension into physical reality of our world.

Light would travel endlessly in form of electromagnetic radiation, a bipolar waveform with its field at right angle to each other. It is natural quality that photons posses, i.e. to be in motion with universally constant speed. It is not known exactly what photons are and how much energy is there that they are made of, we cannot see photons until they hit a photosensitive surface that in our case is the retina at the back of our eye. Therefore, light is in fact invisible, to us - no one would ever notice even if the entire light of the sun were turned into a beam and passed right under one’s nose.

• simsjk
Lv 5

Yawn.. this old subject.

Light cannot travel in every direction.. It can only travel in straight lines.

You see things because there are enough photons to focus on the back of your eye. The thing you see is the image.

One photon is not an image. A lot of photons is not an image.

So eyes cannot measure photons. Actually we can only measure lightness. Dark is only a lack of phtotons.

Physical bodies do not travel at the speed of light.. Including photons. This why they have the accompanying EM radiation explanation.

Very simply EM radiation needs a medium in which to travel.. Space is thyat medium. So what is out there we don't see??

Therein lies the answer.. We don't see it..

• Anonymous