PhET-Simulations-for-Biology/C2/Color-Vision/English

Visual Cue	Narration
Slide Number 1 Title Slide	Welcome to this tutorial on Color Vision, an interactive PhET simulation.
Slide Number 2 Learning Objectives We will demonstrate, Color Vision PhET simulation	In this tutorial, we will demonstrate, Color Vision, an interactive PhET simulation.
Slide Number 3 System Requirements Ubuntu Linux OS version 16.04 Java version 1.8.0 Firefox Web Browser version 60.0.2	Here I am using, Ubuntu Linux OS version 16.04 Java version 1.8.0 Firefox Web Browser version 60.0.2
Slide Number 4 Pre-requisites	Learners should be familiar with high school physics and biology.
Slide Number 5 Learning Goals White light Colours from visible spectrum Light and filters of different colours of visible spectrum Red, green and blue light, separately or in combination	Using this simulation, we will look at colour vision when the human eye sees: White light Light of different colours from the visible spectrum Light and filters of different colours of the visible spectrum Red, green and blue light, separately or in combination
	Please refer to the additional material provided with this tutorial. Let us begin.
Slide Number 6 Visible Light [[Image:]] Electromagnetic spectrum, 380 -760 nm, visible light. VIBGYOR Lowest wavelength (highest frequency) appears violet Highest wavelength (lowest frequency) appears red All colours --> white light	Visible Light A portion of the electromagnetic spectrum is detected by human eye as visible light. This portion extends from 380 to 760 nanometers'. The colours of the visible spectrum can be remembered as VIBGYOR. Violet-indigo-blue-green-yellow-orange-red The lowest wavelength (highest frequency) appears violet. The highest wavelength (lowest frequency) appears red. Combining all the colours gives white light.
Slide Number 7 Link for PhET simulation http://phet.colorado.edu	Use the given link to download the simulation. http://phet.colourado.edu
Point to the file in Downloads folder.	I have already downloaded the Color Vision simulation to my Downloads folder.
Right click on color-vision_en.html file. Select Open With Firefox Web Browser option. Point to the browser address.	To open the simulation, right click on the color-vision_en.html file. Select the Open With Firefox Web Browser option. The file opens in the browser.
Cursor on the interface.	This is the interface for the Color Vision simulation.
	Now we will explore the interface.
Point to two screens in the interface.	The interface has two screens Single Bulb RGB Bulbs
Click on Single Bulb screen.	Click on Single Bulb screen.
In the Single Bulb screen, point to the person facing the right. Point to two small images below the neck.	In the Single Bulb screen, you can see a person facing the right. Just below the neck are two small images.
Point to the first highlighted image. Point to the person’s face.	The first one is highlighted. It allows you to see the person’s face.
Click on the second image. Point to the highlighted image and the cross-section of the person’s brain. Show the optic nerves extending from the eyes into different parts of the brain.	Click on the second image. On being highlighted, it shows the cross-section of the person’s brain. Observe the optic nerves extending from the eyes into different parts of the brain.
Slide Number 8 Color Vision [[Image:]] Cone receptors of retina Trichromatic colour vision (S ~B, M~G, L~R)	Color Vision, Cone cells are photoreceptors in the retina that are sensitive to a range of wavelengths. The leaf absorbs all wavelengths of visible light except green light. Green light of 520 nanometers wavelength is reflected and reaches the eye. Here, it activates the M or gamma type cones. The visual information is sent from cones to retinal ganglia via the optic nerve. The two optic nerves meet and cross over each other at the optic chiasma. Now called optic tracts, they enter and synapse in the thalamus. They then continue to the primary visual cortex in the occipital lobe in the back of the brain.
	Let us return to the simulation.
Point to the ellipses above the person’s head.	Observe the ellipses above the person’s head. They will be filled with the colour that the person sees.
Point to the Play/Pause button at the bottom and the Step button next to it. Point to the Reset button.	Note the Play/Pause button at the bottom and the Step button next to it. The Reset button will take us back to the start.
Point to the torch or flashlight in front of the person’s eyes. Point to the red button on the flashlight.	Observe the torch or flashlight in front of the person’s eyes. The red button on the flashlight will switch it off and on.
Click on the first bulb above the flashlight. Show white light. Click on the red button of the flashlight.	Click on the first bulb above the flashlight. This is white light. Click on the red button of the flashlight.
Point to the first highlighted image below the flashlight. Point to the beam of light.	The first image below the flashlight is highlighted by default. This will show the light as a beam.
Click on the second image below the flashlight. Show the photons.	Click on the second image below the flashlight. This will show the light in the form of photons.
Click on the Pause button. Point to the Step button that is now active.	Click on the Pause button. Observe that the Step button is active.
Click on the Step button.	Click on the Step button to see the photons move in a stepwise manner.
Click on the first beam image below the flashlight.	Click on the first image to return to the beam from the flashlight.
Point to the white ellipses above the person’s head.	Observe the white ellipses above the person’s head. This means that the person sees white light coming out of the flashlight.
Click on the second bulb above the flashlight. Point to the slider Bulb Color.	Click on the second bulb above the flashlight. Observe the slider Bulb Color containing all colours of the visible spectrum.
Drag the Bulb Color slider from end to end. Point to the colour on which the handle is placed and the colour of the light from the flashlight. Point to the ellipses above the person’s head. Drag the Bulb Color slider to red at the right end.	Drag the Bulb Color slider from end to end. The colour on which the handle is placed indicates the colour of the light from the flashlight. Observe that the ellipses above the person’s head fill with the same colour. 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.
Point to the toggle switch in front of the person. Point to the connection between the toggle switch and the Filter Color slider. Point to the Filter Color slider.	Note that there is a toggle switch in front of the person. It is connected to the Filter Color slider. Observe that the Filter Color slider also contains the colours of the visible spectrum.
Click on the toggle switch. Point to the filter in the path of the beam from the flashlight.	Click on the toggle switch. Observe that a filter appears in the path of the beam from the flashlight.
Drag the Filter Color slider from end to end. Point to the colour on which the handle is placed and the filter. Drag Filter Color slider to red at the right end.	Drag the Filter Color slider from end to end. The colour on which the handle is placed indicates the colour of the filter.
Point to the red filter and the red beam. Point to the red ellipses above the person’s head.	Note the filter is red and transmits a red beam. The person also sees red light.
Drag the Bulb Color slider to violet. Point to the violet light beam from the flashlight. Point to the absence of any beam from the filter to the person’s eyes. Point to the empty ellipses above the person’s head.	Drag the Bulb Color slider to violet. Violet light comes out from the flashlight. But with red as the Filter Color, no light is transmitted to the person. The person does not see any light.
Drag the Filter Color slider to violet at the left end. Point to the violet filter and violet light transmitted to the person. Point to the violet ellipses above the person’s head.	Drag the Filter Color slider to violet at the left end. Note the filter becomes violet and violet light is transmitted to the person. The person now sees violet light.
Drag the Bulb Color slider to red at the right end. Point to the violet filter and the red light beam. Point to the violet filter and the absence of the red light from the filter. Point to the empty ellipses above the person’s head.	Drag the Bulb Color slider to red at the right end. Observe how the filter remains violet but the light beam is now red. But the violet filter does not transmit the red light. The person sees no light.
Drag both sliders to different colours to see whether light is transmitted to the person.	Drag both sliders to different colours to see whether light is transmitted to the person.
Point to both sliders.	Observe how light is only transmitted when both sliders are set at the same or nearly same colour. The filter subtracts all wavelengths and only transmits the wavelength of its own colour. Transmission is weaker for wavelengths very close to and maximum for the filter’s colour.
Slide Number 9 Assignment White light from flashlight Observe light transmission from filter	As an assignment, Choose white light to come from the flashlight and observe the transmission of light from the filter.
Click on the RGB Bulbs screen at the bottom of the interface.	Now, let us click on the RGB Bulbs screen at the bottom of the interface.
Show the person facing the right. Click on the second image which allows you to see the cross-section of the person’s brain.	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.
Point to the Play/Pause, Step and Reset buttons at the bottom of the interface.	The Play/Pause, Step and Reset buttons are all seen at the bottom of the interface.
Show 3 sliders and three flashlights on the screen. All sliders are set at the minimum levels. Point to the red slider, then the green one and then the blue slider.	Three sliders and three flashlights are seen on the screen. All sliders are set at the minimum levels. The uppermost one is a red slider, the second green and the lowermost one is a blue slider.
Drag the red slider to the maximum level. Show red photons coming out of the flashlight next to the red slider. Show the photons reaching the person’s eye. Point to the red ellipses above the person’s head.	Drag the red slider to the maximum level. Note how red photons come out of the flashlight next to the red slider. The photons reach the person’s eye and the person sees red light.
Drag the green slider to the maximum level. Show red and green photons coming out of the flashlights next to the red and green sliders. Point to the yellow ellipses above the person’s head.	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. Red and green add to give yellow. The cones sensitive to red and green light are activated so that the person sees yellow.
Click the Pause button.	Click the Pause button.
Drag the blue slider to the maximum level.	Drag the blue slider to the maximum level.
Click on Play button. Point to the three beams and the white ellipses above the person’s head.	Click on Play button. Observe how all three colours mix so that the person sees white.
	Let us summarize.
Slide Number 10 Summary We have demonstrated, Color Vision PhET simulation	In this tutorial, we have demonstrated how to use the Color Vision PhET simulation.
Slide Number 11 Summary White light Light of different colours from visible spectrum Light and filters for different colours of visible spectrum Red, green and blue light, separately or in combination	Using this simulation, we looked at colour vision when the human eye sees: White light Light of different colours from the visible spectrum Light and filters for different colours of the visible spectrum Red, green and blue light, separately or in combination
Slide Number 12 Assignment [[Image:]] RGB? Color wheel Colors for schemes: complementary, analogous, triadic, rectangle	As an assignment, Adjust the red, blue and green sliders to get these 6 colours. Which RGB combination would you pick to design these schemes? Look for an image of the colour wheel on the Internet. Pick colour combinations for the following schemes.
Slide Number 13 About the Spoken Tutorial Project Watch the video available at http://spoken-tutorial.org/ What_is_a_Spoken_Tutorial It summarizes the Spoken Tutorial project If you do not have good bandwidth, you can download and watch it	The video at the following link summarizes the Spoken Tutorial project. Please download and watch it.
Slide Number 14 Spoken Tutorial workshops	The Spoken Tutorial Project team conducts workshops using spoken tutorials and gives certificates on passing online tests. For more details, please write to us.
Slide Number 15 Forum for specific questions: Do you have questions in THIS Spoken Tutorial? Please visit this site Choose the minute and second where you have the question Explain your question briefly Someone from our team will answer them	Please post your timed queries in this forum.
Slide Number 16 Acknowledgement	This project is partially funded by Pandit Madan Mohan Malaviya National Mission on Teachers and Teaching.
Slide Number 17 Acknowledgement	Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India. More information on this mission is available at this link.
	This is Vidhya Iyer from IIT Bombay, signing off. Thank you for joining.

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