Nancyvarkey: Created page with "{|border=1 || '''Time''' || '''Narration''' |- ||00:01 || Welcome to this tutorial on''' Color Vision, '''an '''interactive PhET simulation'''. |- || 00:08 || In this '''tut..."

2022-08-10T13:25:38Z

Created page with "{|border=1 || '''Time''' || '''Narration''' |- ||00:01 || Welcome to this tutorial on''' Color Vision, '''an '''interactive PhET simulation'''. |- || 00:08 || In this '''tut..."

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{|border=1
|| '''Time'''
|| '''Narration'''

|-
||00:01
|| Welcome to this tutorial on''' Color Vision, '''an '''interactive PhET simulation'''.

|-
|| 00:08
|| In this '''tutorial''', we will demonstrate, '''Color Vision, '''an interactive '''PhET simulation'''.

|-
|| 00:17
|| Here I am using, Ubuntu Linux Operating System version 16.04

|-
|| 00:25
|| Java version 1.8.0

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|| 00:29
|| Firefox Web Browser version 60.0.2

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|| 00:35
|| Learners should be familiar with high school physics and biology.

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|| 00:41
|| Using this simulation, we will look at colour vision when the human eye sees:

White light

|-
|| 00:50
|| Light of different colours from the visible spectrum

|-
|| 00:55
|| Light and filters of different colours of the visible spectrum

|-
|| 01:00
|| Red, green and blue light, separately or in combination

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||01:06
|| Please refer to the '''additional material''' provided with this tutorial.

Let us begin.

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|| 01:14
||Visible Light

A portion of the electromagnetic spectrum is detected by human eye as visible light.

|-
|| 01:25
|| This portion extends from 380 to 760 ''nanometers'''.

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|| 01:33
|| The colours of the visible spectrum can be remembered as '''VIBGYOR'''.

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|| 01:39
|| Violet, indigo, blue, green, yellow, orange, red

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|| 01:47
|| The lowest wavelength (highest frequency) appears violet.

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|| 01:53
|| The highest wavelength (lowest frequency) appears red.

|-
|| 01:59
|| Combining all the colours gives white light.

|-
||02:04
|| Use the given link to download the '''simulation'''.

|-
|| 02:09
|| I have already downloaded the '''Color Vision simulation''' to my '''Downloads folder'''.

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|| 02:16
|| To open the simulation, right click on the '''color-vision_en.html''' file.

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|| 02:23
|| Select the '''Open With Firefox Web Browser''' option.

The file opens in the browser.

|-
|| 02:32
|| This is the '''interface''' for the '''Color Vision simulation'''.

|-
||02:37
|| Now we will explore the '''interface'''.

|-
||02:41
|| The '''interface''' has two screens

'''Single Bulb'''

'''RGB Bulbs'''

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|| 02:49
|| Click on '''Single Bulb''' screen.

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|| 02:53
|| In the '''Single Bulb''' screen, you can see a person facing the right.

Just below the neck are two small images.

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|| 03:04
|| The first one is highlighted.

It allows you to see the person’s face.

|-
|| 03:11
|| Click on the second image.

On being highlighted, it shows the cross-section of the person’s brain.

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|| 03:20
|| Observe the '''optic''' nerves extending from the eyes into different parts of the brain.

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|| 03:28
||Color Vision,

'''Cone''' cells are photoreceptors in the '''retina''' that are sensitive to a range of wavelengths.

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|| 03:39
|| The leaf absorbs all wavelengths of visible light except green light.

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|| 03:46
|| Green light of 520 nanometers wavelength is reflected and reaches the eye.

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|| 03:54
|| Here, it activates the '''M''' or '''gamma''' type '''cones'''.

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|| 03:59
|| The visual information is sent from '''cones''' to retinal ganglia via the '''optic''' nerve.

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|| 04:07
|| The two '''optic''' nerves meet and cross over each other at the '''optic chiasma'''.

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|| 04:14
|| Now called '''optic''' tracts, they enter and '''synapse''' in the thalamus.

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|| 04:21
|| They then continue to the '''primary visual cortex''' in the '''occipital lobe''' in the back of the brain.

|-
||04:30
|| Let us return to the '''simulation'''.

|-
|| 04:34
|| Observe the ellipses above the person’s head.

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|| 04:39
|| They will be filled with the colour that the person sees.

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|| 04:44
|| Note the '''Play/Pause''' button at the bottom and the '''Step''' button next to it.

|-
|| 04:51
|| The '''Reset''' button will take us back to the start.

|-
||04:55
|| Observe the torch or flashlight in front of the person’s eyes.

|-
|| 05:01
|| The red button on the flashlight will switch it off and on.

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||05:06
|| Click on the first bulb above the flashlight.

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|| 05:11
|| This is white light.

Click on the red button of the flashlight.

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|| 05:18
|| The first image below the flashlight is highlighted by default.

|-
|| 05:24
|| This will show the light as a beam.

|-
|| 05:28
|| Click on the second image below the flashlight.

|-
|| 05:33
|| This will show the light in the form of '''photons'''.

|-
|| 05:38
|| Click on the '''Pause''' button.

Observe that the '''Step''' button is active.

|-
|| 05:45
|| Click on the '''Step''' button to see the '''photons''' move in a stepwise manner.

|-
|| 05:51
|| Click on the first image to return to the beam from the flashlight.

|-
|| 05:57
|| Observe the white ellipses above the person’s head.

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|| 06:02
|| This means that the person sees white light coming out of the flashlight.

|-
|| 06:08
|| Click on the second bulb above the flashlight.

Observe the '''slider Bulb Color''' containing all colours of the visible spectrum.

|-
|| 06:19
|| Drag the '''Bulb Color slider''' from end to end.

|-
|| 06:24
|| The colour on which the handle is placed indicates the colour of the light from the flashlight.

|-
|| 06:31
|| Observe that the ellipses above the person’s head fill with the same colour.

|-
|| 06:38
|| You can change the colour that the person sees by dragging the '''Bulb Color slider'''.

Drag the '''Bulb Color slider''' to red at the right end.

|-
|| 06:50
|| Note that there is a '''toggle switch''' in front of the person.

It is connected to the '''Filter Color slider'''.

|-
|| 06:59
|| Observe that the '''Filter Color slider''' also contains the colours of the visible spectrum.

|-
|| 07:06
|| Click on the '''toggle switch'''.

Observe that a '''filter''' appears in the path of the beam from the flashlight.

|-
|| 07:16
|| Drag the '''Filter Color slider''' from end to end.

|-
|| 07:21
|| The colour on which the handle is placed indicates the colour of the '''filter'''.

|-
|| 07:28
|| Note the '''filter''' is red and transmits a red beam.

The person also sees red light.

|-
|| 07:38
|| Drag the '''Bulb Color slider''' to violet.

Violet light comes out from the flashlight.

|-
|| 07:56
|| But with red as the '''Filter Color''', no light is transmitted to the person.

|-
|| 07:52
|| The person does not see any light.

|-
|| 07:56
|| Drag the '''Filter Color slider''' to violet at the left end.

|-
|| 08:02
|| Note the '''filter''' becomes violet and violet light is transmitted to the person.

The person now sees violet light.

|-
|| 08:13
|| Drag the '''Bulb Color slider''' to red at the right end.

|-
|| 08:19
|| Observe how the '''filter''' remains violet but the light beam is now red.

|-
|| 08:26
|| But the violet '''filter''' does not transmit the red light.

The person sees no light.

|-
|| 08:35
|| Drag both '''sliders''' to different colours to see whether light is transmitted to the person.

|-
|| 08:43
|| Observe how light is only transmitted when both '''sliders''' are set at the same or nearly same colour.

|-
|| 08:53
|| The '''filter''' subtracts all wavelengths and only transmits the wavelength of its own colour.

|-
|| 09:01
|| Transmission is weaker for wavelengths very close to and maximum for the filter’s colour.

|-
|| 09:09
|| As an assignment, Choose white light to come from the flashlight and observe the transmission of light from the filter.

|-
|| 09:22
|| Now, let us click on the '''RGB Bulbs''' screen at the bottom of the '''interface'''.

|-
|| 09:29
|| Here, too, you can see the person facing the right.

Click on the second image which allows you to see the cross-section of the person’s brain.

|-
|| 09:41
|| The '''Play/Pause''', '''Step''' and '''Reset''' buttons are all seen at the bottom of the '''interface'''.

|-
|| 09:49
|| Three '''sliders''' and three flashlights are seen on the screen.

All '''sliders''' are set at the minimum levels.

|-
|| 10:00
|| The uppermost one is a red '''slider''', the second green and the lowermost one is a blue '''slider'''.

|-
|| 10:10
|| Drag the red '''slider''' to the maximum level.

|-
|| 10:15
|| Note how red '''photons''' come out of the flashlight next to the red '''slider'''.

|-
|| 10:22
|| The '''photons''' reach the person’s eye and the person sees red light.

|-
|| 10:28
|| Drag the green '''slider''' to the maximum level.

Note how red and green '''photons''' come out of the flashlights next to the red and green '''sliders'''.

|-
|| 10:41
|| Red and green add to give yellow.

The '''cones''' sensitive to red and green light are activated so that the person sees yellow.

|-
|| 10:53
|| Click the '''Pause''' button.

|-
|| 10:56
|| Drag the blue '''slider''' to the maximum level.

|-
|| 11:00
|| Click on '''Play''' button. Observe how all three colours mix so that the person sees white light.

|-
||11:11
|| Let us summarize.

|-
|| 11:14
|| In this '''tutorial''', we have demonstrated how to use the '''Color Vision PhET simulation'''.

|-
|| 11:22
|| Using this '''simulation''', we looked at colour vision when the human eye sees:

White light

|-
|| 11:31
|| Light of different colours from the visible spectrum

|-
|| 11:35
|| Light and filters for different colours of the visible spectrum

|-
|| 11:40
|| Red, green and blue light, separately or in combination

|-
|| 11:46
|| As an '''assignment''',Adjust the red, blue and green '''sliders''' to get these 6 colours.

|-
|| 11:55
|| Which '''RGB''' combination would you pick to design these schemes?

|-
|| 12:01
|| Look for an image of the '''colour wheel''' on the '''Internet'''.

|-
|| 12:06
|| Pick colour combinations for the following schemes.

|-
||12:11
|| The video at the following link summarizes the '''Spoken Tutorial project'''.

Please download and watch it.

|-
|| 12:20
|| The '''Spoken Tutorial Project''' team conducts workshops using '''spoken tutorials''' and gives certificates on passing online tests.

For more details, please write to us.

|-
|| 12:35
|| Please post your timed queries in this forum.

|-
|| 12:40
|| This project is partially funded by '''Pandit Madan Mohan Malaviya National Mission on Teachers and Teaching'''.

|-
||12:49
|| '''Spoken Tutorial Project''' is funded by '''NMEICT, MHRD''', Government of India.

More information on this mission is available at this link.

|-
||13:03
|| This is '''Vidhya Iyer''' from '''IIT Bombay''', signing off.

Thank you for joining.
|-
|}

PhET/C2/Color-Vision/English-timed - Revision history

Nancyvarkey: Created page with "{|border=1 || '''Time''' || '''Narration''' |- ||00:01 || Welcome to this tutorial on''' Color Vision, '''an '''interactive PhET simulation'''. |- || 00:08 || In this '''tut..."