visible light - How do I see things of the bright room, being in the dark room?

Visible light emitted or reflected from the objects around us provides information about the world.

If I sit in a dark room, and see the bright room outside, I am able to see all the objects of that bright room. In other words, it mean light emitted or reflected from those objects of the bright room are entering into the dark room. Shouldn't that make my room bright? But, my room is dark and I am able to see those objects of bright room, both are contrary?

Edit: If we consider another situation like the one in the picture below, lets assume that we move as far from the street light, that even in the presence of street light the place remains as dark as it was before. I believe even then we can see the street light, won't we?

If we agree that we still can see the lamp, it mean that we are able to see the lamp, without the ray from lamp hitting our eye? Won't it be contrary? Edit: Lets consider a laser beam in the dark room (in the picture room is not totally dark, but assume a dark room). Look the laser in the same angle as shown in the picture, as laser remains narrow over long distance, I hope we can assume light is not spreading in other directions. But I hope we can see it even though light is not spreading and reaching me, how is it possible?

Answer

There exists coherent light and incoherent light

The laser is an example of coherent light, i.e. it can be described by a wave with a known amplitude and phase .

Amplitude is connected with the power that the beam distributes. In lasers this is very concentrated . Amplitude is also connected with the number of photons in the beam .

The street lamp is an example of incoherent light: individual atomic excitations emit photons incoherently so there exists no wave whose phases are known.

You also completely ignore diffusion of light. Diffusion of light is what gives us twilight when the sun goes down . Photons from the light hit on air atoms and change directions, no longer pointing at the source, as infinitesimal reflections.

Now in your last entry, the laser, the reason that one can see the green light is because of diffusion of the laser light in the air of the room. A small part of its photons hit the molecules of air and reach not only our eyes, but the whole surrounding ambiance, reflecting also from the walls etc. If the laser were in vacuum you would not see the beam unless you crossed it ( careful of your eye, though that would be the least of your worries if you were in vacuum :) )

Diffusion also accounts for the light in a dark room next to a lit room even if the source does not shine into the room . Light diffuses in the air enters the dark room hits the walls and furniture and "lights dimly" the dark. If the street lamp were in vacuum the light would illuminate only in the direct optical rays from the source and shadows would be sharp and black.

The further away one is from a light source the smaller the intensity of the beam, which in direct optical ray falls as 1/r^2. For diffusion it is more complicated because each rescatter from the molecules becomes a source and each reflection of light also becomes a source, still intensity falls rapidy with distance, that is why the dark room is mainly dark and the laser green line is clearly defined: the scatterings are few and mainly next to the beam, and do not markedly reduce the intensity of the laser beam.