0:04 [Music]
0:06 how do we humans perceive the things
0:10 around us we have five senses that help
0:12 us to interact with the world around us
0:16 these are sight hearing taste smell and
0:20 touch eyes help us to see things years
0:23 help us to hear sounds we smell with our
0:25 nose taste with our tongue and a sense
0:28 of touch is provided by our skin of
0:32 course all senses are important but the
0:35 sense of sight is the most important
0:38 here is an interesting fact we perceive
0:41 almost 80% of the world around us by
0:47 using our sense of sight we see objects
0:49 around us with our eyes but then why
0:51 don't our eyes see these objects in the
0:54 dark the answer to this question is
0:57 light we are able to see the objects
0:59 around us because of the light coming
1:02 from these objects the light from these
1:05 objects travels in space and reaches our
1:08 eyes when it's dark or during night time
1:11 as there is no light we are unable to
1:14 see these objects clearly some objects
1:16 can generate their own light
1:19 for instance the Sun the fluorescent
1:21 bulbs burning candles can generate their
1:24 own light the objects which generate
1:26 their own light are called the luminous
1:29 objects almost all of the objects that
1:31 we come across cannot generate their own
1:35 light the table a chair wall paper a few
1:39 of such examples such objects are called
1:42 as non luminous objects but I just told
1:44 you that we see objects around us
1:46 because of the light coming from them
1:49 and if objects like these cannot
1:51 generate light then how come we're able
1:54 to see them we are able to see them
1:57 because of the reflection of light these
2:00 objects reflect the light to our eyes
2:03 what light are they reflecting where is
2:06 the light coming from this light is
2:07 nothing but the light coming from the
2:10 luminous objects so how can we summarize
2:13 this for you're able to see Nalu
2:15 objects because they reflect the light
2:18 of the luminous objects falling on these
2:22 surfaces let me repeat the light coming
2:24 from the luminous objects falls on the
2:26 non luminous objects non luminous
2:29 objects then reflect this light and this
2:31 reflected light travels towards our eyes
2:36 and that's why we see the objects in the
2:38 daytime we are able to see blue skies
2:40 the white clouds and the green grass
2:42 because the light from the Sun is
2:45 getting reflected by them and traveling
2:48 towards our eyes at night we are able to
2:50 see the moon because it is reflecting
2:53 the light from the Sun note that moon is
2:55 non luminous and it cannot generate its
2:59 own light as I said earlier most of the
3:01 objects that we come across in our daily
3:05 life are non luminous we only see them
3:08 because they reflect the light step
3:10 inside a dark room light up a torch and
3:13 point it at the distant wall look
3:15 carefully at the path of the light
3:18 coming from the torch you will see tiny
3:21 dust particles in the air what does the
3:21 reason for this
3:24 why are you able to see these particles
3:27 you are able to see the dust particles
3:29 because the light from the torch is
3:31 getting reflected from their surfaces
3:35 and travelling towards our eyes we also
3:37 see the same thing in a very dimly lit
3:40 room where the only source of light is a
3:42 small amount of sunlight coming from the
3:45 window in this video we saw that the
3:47 reflection of light plays an important
3:50 role it's because of the reflection of
3:52 light that we are able to see most of
3:56 the objects in the next video we will
3:58 talk about the laws of reflection of light
3:58 light [Music]
