Science Fair
posted by Unknown .
Hi, my question is are part 1,2, and 3 different ways you can do the project?
There are three parts. Each part should take less than 1 hour.
In Part 1, you will stare at a colored object for various amounts of time, then measure how long it takes for the afterimage to disappear each time. You will then graph the data as Cone stimulation (how long you stared at the colored object) vs. Afterimage persistence (how long before the afterimage disappears). Things to think about: Is there a minimum conestimulation time required to produce an afterimage? Do longer conestimulation times always cause longer afterimage times, or does the effect level out past a certain time?
In Part 2, you will test whether or not afterimages made by three different colors disappear at the same rate (this measures cone cell recovery).
In Part 3, you will test which color produces an afterimage in the least amount of time (this measures the rate of cone cell fatigue).
Part 1: Duration, Shape, and Color of an Afterimage
Look at Figure 1, below. Have your helper get ready to time you for exactly 30 seconds. You should say "start" when you begin looking at the object, and the helper can say "stop" when 30 seconds have elapsed.
Stare at the red circle for 30 seconds. Try not to blink. When 30 seconds are up, look at the white space in the square to the right. Describe the size, shape, and color of the afterimage in your lab notebook. Note: It is important to view this on a bright monitor with clear colors, or if you printed it out, that the color is vivid.
Turn off any lights near your computer or the printedout image. Stare at the red circle for 30 seconds again, but this time, record how long the afterimage is visible in your lab notebook. Have your helper use the stopwatch to keep track of how long you are able to see the afterimage. You might want to say "start" as soon as you begin looking at the white space and keep saying "I still see it" repeatedly until it disappears, then say "it's gone" so your helper can stop the stopwatch and you can note the time. Why does the afterimage disappear?
Repeat step 3 two more times, for a total of three trials, and record all data in a data table in your lab notebook, like the one below. Note: Give your eyes a minute or so to rest between every trial.
Figure 1. This is the first afterimage test for this science fair project. View the red circle on the left for 30 seconds, and then note the afterimage when you look in the white space to the right.
Now let's see how changing the amount of time you look at the red circle ("cone stimulation" time) changes the time that the afterimage is visible ("afterimage persistence"). How do you think the length of time the afterimage persists will vary?
Repeat steps 34 four more times, changing the amount of time you look at the red circle each time. Look at the red circle for 5, 10, 20, and then 60 seconds before you look at the white area (you already completed the 30second trial in steps 34).
Record how long the afterimage persists after each time in your data table.
Afterimage Persistence (seconds)
Cone Stimulation
(seconds) Red Circle
Trial 1 Red Circle
Trial 2 Red Circle
Trial 3 Red Circle
Average
5
10
20
30
60
Calculate the averages and insert that data in the last column.
Graph the data. Put the number of seconds you looked at the object on the xaxis and the average time the afterimage persisted on the yaxis. Call the xaxis Cone Stimulation and the yaxis Afterimage Persistence, or choose your own axis names. Include the units (seconds) on the graph.
What was the maximum amount of time that the afterimage persisted?
If you stare at the object for longer periods of time, beyond 30 seconds (say 60, 90, and 120 seconds) does the persistence time of the afterimage also keep increasing? Explain your results in terms of the level of fatigue of the cone cells.
Part 2: Determining Cone Cell Recovery Rates
Figure 2. Use this threecolored circle to compare cone cell fatigue and recovery times.
Turn off any lights near your computer or printedout image. Stare at the threecolored circle in Figure 2 for 30 seconds and then look at the white space to the right. Using the same method as in Part 1, have your helper time how long you see the afterimage and record the data in your lab notebook.
Also describe the colors of the afterimage in your lab notebook. In your descriptions, call the three sectors Left, Right, and Bottom. This avoids confusion about the colors.
Use colored pencils or a computer graphics program to draw the afterimage.
Repeat Part 2 steps 13 two more times, for a total of three trials, recording your data each time. And don't forget to give your eyes a break between each trial.
How do afterimage persistence times compare for the blue, red, and green regions? Do the three sectors disappear at the same rate, or at different rates?
Part 3: Determining Cone Cell Fatigue Rate
Look at the threecolored circle in Figure 2 very briefly, for 2 or 3 seconds, then look at the white space. Record what you see or don't see in your lab notebook.
Repeat Part 3 step 1 with different times (1, 2, 3, 4 seconds) to determine the minimum time you need to form an afterimage.
Did the afterimage include all three segments? Or did only one of the colors make an afterimage? If so, how would you interpret this in terms of which cone cell fatigued the fastest?
Record your observations in your lab notebook
Respond to this Question
Similar Questions

science
What part of science is genomics part of? 
physics
A 9.3 kg firework is launched straight up and at its maximum height 45 m it explodes into three parts. Part A (0.5 kg) moves straight down and lands 0.29 seconds after the explosion. Part B (1 kg) moves horizontally to the right and … 
physics
A 9.3 kg firework is launched straight up and at its maximum height 45 m it explodes into three parts. Part A (0.5 kg) moves straight down and lands 0.29 seconds after the explosion. Part B (1 kg) moves horizontally to the right and … 
physics
A 9.3 kg firework is launched straight up and at its maximum height 45 m it explodes into three parts. Part A (0.5 kg) moves straight down and lands 0.29 seconds after the explosion. Part B (1 kg) moves horizontally to the right and … 
math
(a) You have of an hour to take a threeparts exam. You use of an hour for the first part and of an hour for the second part. How much time do you have left to finish the last part of the test? 
Chemistry
Part 1: Each molecule of NO2, nitrogen dioxide, consists of 1 atom of N and 2 atoms of O. If you have 0.155 g. of NO2, how many molecules of NO2 do you have ? 
Reiny!!!! math help
We understand how to do the questions now and we are really glad n thankful, but the graphing portion of it is confusing. Continuation of the function. The teacher wants us to plot the points from the different parts of the questions … 
Maths
Divide Rs 116 among 4 parts such that 5 added to first part 4 subtracted from the second part 3 mutltiplied by third part and fourth part divided by 2 are all equal 
Combination
In a question paper there are two parts A and B . Part A contains 6 questions and part B contains 7 questions . in how many ways a student can select 4 questions in part A of which 2 questions are compulsory and 5 questions in part … 
Quantitative, stastics and business
A company has three machines A, B and C which all produce the same two parts, X and Y. of all the parts produced, machine A produces 60%, machine B produces 30%, and machine C produces the rest. 40% of the parts made by machine A are …