Observations

Alrighty. I've just conducted my marvy (georgia Slang) experiment. I did it 4 times to ensure reliability. so here are some pics of the set up:

So the results for the four trials were pretty similar. The intensity was really high at the 10cm interval but once it hit the 20-30cm intervals it dropped drastically. I've been trying to make my table for hours though. I think the excel equivalent for mac, graphs just won't let me insert a line of best fit. It's pretty frustrating...

Method, Variables, aim, hypo etc.....

Ms. Zhang if you are reading this, please know this is not blog 2, blog 2 is further down. I have changed my project since blog two and i put up the method of my new experiment for it.
Hypothesis

My hypothesis stated that the closer the light source, the stronger the light intensity.

Aim

To investigate whether distance effects the intensity of light from a light source.

Risky Assessment
Identify Light bulb
Assess If the light bulb is touched, it may burn the skin.
If the lamp was dropped, the bulb could break
Control Avoid touching the bulb at all times
Dispose Switch off the bulb when the experiment is over to allow it to cool down


Materials
Dick Smith Lux meter
A music stand
Sticky tape
Measuring Tape (at least 2 metres)
lamp with a lightbulb (lightbulb needs to be exposed)
Darkened Room (at least 1 by 2 metres in area)
A pen
A notebook
A computer
Excel(windows) program/Graphs (mac) program

Method
Setting up the equipment
1. An area of 1 by 2 metres was cleared up to conduct the experiment
2. A lamp, with an exposed bulb was connected to a power point and placed on one side of the area.
3. Books were placed under the lamp so the light bulb was 70cm from the ground
4. A music stand was set up directly opposite the lamp
5. The sensor was taped- to prevent movement- onto the bulb at an elevation of 70cm.
6. Measuring tape was positioned directly above the lamp and then taped down with sticky tape.
7. The sensor was positioned horizontally opposite to the light bulb at an interval of 10cm.
8. The lightbulb was then turned on.
9. After the light meter was turned on
10. A measurement was read from behind the stand.
11. Observations were recorded into the log book
12. The stand was pulled back another ten centimetres
13. Steps ten to twelve was repeated until a distance of 2 metres was reached
14. Steps ten to fourteen was repeated another three times to ensure reliability
The average luminosity for each distance was calculated


Controlled Variables
wattage of the lightbulb, the height at which the lamp stood, the height of the music stand, the length of the tape, the darkness of the room and the allocation of the lux meter

The independent variable was the distance between the light source and the sensor and the dependent variable will be the light intensity from the light source.

LUX LUX LUX

One essential equipment i needed to use to conduct my experiment was the lux meter. A Lux meter is used to measure the light intensity of a certain object.

Equipment

Yes. Yes. Yes. I've got all of my equipment. Now all I need to do is the experiment : D

SAD but OK news

I know it's so close the hand in due date for the srp, but i was forced to change my topic because after weeks of research i couldn't find the products that i needed and the unpredictable weather forced me to cancel the experiment and find another one. I was really upset as i wasted so much time on researching this srp on spf.
I have to move on though and my current project is to determine whether light intensity changes with distance. I have all the equipment and have already trialled the experiment. My only dilemma: my teacher hasn't approved it. I've been sick all week and I haven't been able to ask her. SO monday morning i'll ask. If it's ok, then i'll post my method and everything up asap.

FLAWS

1) the chemicals in sunscreen may affect the photo sensitivity of the photo paper
2) the chemicals in sunscreen may affect the development process of the photo paper
3) the photo paper may not be sensitive to the UV spectrum
4) the photo paper sensitivity to visible light may swamp the UV spectrum exposure
URGGGGGHHHH!

Science Climograph

Hey
Here's Miss Zhangs Climate Graph Thingo...

PLEASE FIXER MY DILEMMA

Okay. I'm in a sitch. Seriously. It's been raining. It's all grey and the only fixer around is 2% sodium thiosulfate and now I feel...depressed. I seriously thinking of changing this. Seriously. by the end of tomorrow even.

Second Blog Submission

Aim
To determine whether there is a difference in the protection against UV rays by sunscreens of different SPFs 15+, 30+ and 40+.

Hypothesis
There won't be a significant difference with the protection given by sunscreens with higher SPF to those with lower.

Equipment
-3 sunscreens of the same brand but different SPFs
-1 timer
-9 pieces of photo paper
-9 clear plastic folders
-1 bottle of photogenic fixer (sodium thiosfulate)
-1 A4 sized plastic rectangular container
-1 knife
-1 working computer and scanner

Risk Assessment...


Method
1. Cut the photo paper vertically into 3 equal sheets of paper and label the sunprint paper from 1 to 3 to indicate the SPFs
2. Squeeze a small amount (size of a 50 cent coin) of sunscreen with SPF 15+ on the centre of the glossy side of the phot paper and spread the sunscreen equally around the paper
3. Repeat steps 1-2 with SPF 15+ and 45+ on the remaining 2 sunprint paper
4. Place the 3 sheets of paper carefully into the plastic folders and leave it outside in a sunny area
5. Start the timer for 5 minutes
6. Place 200mls of Photogenic fixer into the Rectangular container in a dimly lit room
7. Bring the folder back into after 5 minutes
8. Place the photo paper glossy side down for 3 seconds in the photogenic fixer and then rinse immediately with cold water
9. Lay it to dry for fifteen minutes
10. Scan the three solutions onto the computer
11. Analyse each one by determining the blue pixel value to get an average darkness for each sunscreen and time interval and compare the data
12. Repeat steps 1-16 twice leaving the folder outside for 10 minutes the first repeat, and 20 minutes for the second repeat


This experiment will be repeated once again to ensure it's reliability
This is a very rough example of how the table may look like...

WHoops! photo turned out ridiculously small! {click} to enlarge it

APPROVAL!!

Yes! Miss Zhang Approved this today! I'm really happy, now I just need to get on with it. Before I leave, just some things that may pose as a problem. The weather. Yes, the lovely transition from autumn to winter. Luckily the week will be sunny, but I'll have to continuously look at the weather to plan when I can actually conduct the experiment-it has to be on a reasonably sunny day!

SPF Sunscreen

So I've researched some things on the sunscreen vs sunscreen under make up. I decided to tweek the experiment a bit and do something similar to it. I want to test the difference of the SPFs in sunblocks and I also wanted to see if a more expensive sunblock was more effective than a cheaper one.

I found I could test this by using 4 different spf sunscreens, 4 different brand sunscreens, photo paper, clear plastic folders and a photographic fixer. My mother's friend is a photographer and he may be able to help me get the photographic fixer. (Hopefully lend it to me if he has one!) After cutting the photo paper in equal squares and label 1, 2, 3 and 4 to make note of which sunscreen is which. I will measure a certain amount of sunscreen and spread each type on 4 separate photo papers. Then I'll carefully place them into the clear plastic folders, then place them out on the driveway for five minutes. After the five minutes is up, I'll take the results to a dimly-lit room (so I don't affect the results). The papers will be carefully removed and, lay it glossy side down in the photographic fixer. The results, hopefully will indicate, which one sunblocks are more effective and price worthy. The sunblock which allowed the least least amount of sun penetration will turn white, and the most will turn dark.

IMPOSSIBLE

So I'm still finding it hard to retrieve my fixer. I went to ted's and their fixer is only like 2% Sodium Thiosulfate. This equates to two words: NOT GOOD. Plus the cloudy days aren't making me feel any better. I have to find this fixer soon if not, I'll never be able to conduct my experiment!

WHere can I get my FIXER?

Hi Hi!
So I am looking for something called a Photogenic fixer that is made up of Sodium Thiosulfate, which will help indicate how much sun has penetrated the sunscreen. If I can't find this I always have an alternative way of buying a sunprint kit which I believe may have the fixer included.