A slight ray of hope

Ok, I have found UV meters on a Chinese website. And my mom has friends who will be going back to China this school holiday, so they can pick it up for me! I really hope that it will work. I hope that they can all get their air tickets, receive the meter promptly and at the right place, the customs wouldn't block it and that when it finally gets to me it is not broken or problematic. I know this sound very paranoid, but I had been unlucky in the past...
And my back-up plan - the paper pieces, I've also got a better idea. I will use newspaper pieces. This gives two advantage - I can buy multiple copies cheaply and that the newpaper paper would change colour most easily (since they print so much of them everyday, and newspapers lose their value the very next day so there is no point printing them too expensively). I put out a paper for a test, the paper didn't fade in ink though, it just got very yellowish. But that's an indicator of exposure to UV nonetheless.

Frustration over Equipment

Well, as I wrote in my last entry, I'm going to do the UV experiment. Although I said that I CAN use the paper pieces, I still hope that I can get some sort of equipment so that the experiment would be easier and quicker. I think a spectrophotometer can help me out here. But they are generally like $500 plus, so not very realistic... Another option would be the domestic UV detectors that tell you the UV level so you can put on your sunscreen and stuff. They are cheaper and can give me the UV degree in a number (instead of the UV sensitive bead that can only change colour). The problem with these is that I did not find any in Sydney via internet. I found it in England, Europe, USA and China!!! (but I don't want to wait for it to be shipped here and shipping also costs) I just don't get why we don't have any in Australia - since we are perhaps the most sun-burnt country in the world. It's just frustrating.

First Blog Submission

Experiment Idea
The experiment will be investigating whether the thickness of glass will affect the amount of ultraviolet radiation passing through it. From my research, glass does block part of the UV in the sunlight and thickness is a factor. Glass of same composition but different thickness will be set up under the sun with a UV detector underneath it to record the differences. Glass should be obtained easily and since the experiment does not require much, the cost should not be high. And the glass will be a dome or a box shape to ensure the complete covering of the tested object – to prevent the changing angle of sunlight throughout the day making a difference on the results. If a UV detector cannot be found in shops (which, I think, will happen; because I cannot recall seeing any UV detectors in shops), I will put pieces of colored paper under each glass shade to test UV radiation. Also from my research, UV radiation stimulates certain chemical reaction in dyes that makes them fade or change color. Thus, the piece of paper that receives the least radiation will retain most of its color and a conclusion can be made. I can borrow the shades of color books in paint shops to further compare the colors of the paper pieces if the difference is hard to be distinguished.

But if using the paper pieces, the experiment time will be a lot longer than if I had a detector; I will use multiple samples all at one time to save time running the experiment. This experiment is easily controlled and should not be too hard to conduct.

Variables
Independent – thickness of glass shading the paper pieces

Dependent – the amount of fading in each piece of paper

Controlled:
- The glass quality, i.e. composition, chemicals, coatings etc.
- The capacity of the glass box/domes – just to be fair
- The time the papers are exposed to sunlight
- The place the papers are placed – has to have similar sun exposure
- The type of papers
- The color of the papers – certain shades of color (such as black) absorb more energy from sun, so difference in color might alter the results
- The area of the papers

Changes again...

I decided that the thermal experiment is too hard to make accurate and the new idea is in the next post - which is the one I'm sending in to Ms. Zhang.

New idea

Sorry to the people who actually read my posts, hopefully more than just me - I just changed my experiment idea again, hope it has not become too boring for you. I changed the nail rusting one because again, it is not that practical. There is only around 30% difference in density between iron and rust, so it might be hard to measure any changes. And that it takes a long time for a nail to corrode completely (just the surface rust makes too small a difference). So I decided not to do it. (Crying face...)

So my new favourite idea is that I would measure the change rate of temperature in different liquids - i.e. their specific heat capacity. It is practical enough, can be done in my kitchen with some bowls, a heat source and a thermometer. My only concern is that it is too basic and simple and not the standard expected in year 10 assessments. So I'll ask Ms. Zhang on Monday - which I hope I will remember because she's not at school Tuesday, Wednsday and Thursday. Crossed fingers that this idea is okay - I would hate to have to think up another one.

Another idea

Well, I tested the elasticity experiment today and it didn't go well - apparently the vibration of the rulers is too slow for a 400 Hz tester. It just could not pick up the vibration! (But I tried yelling at the apparatus and that worked extremely well. But human tests require 30 something people, and it's such as hassle to get people to agree to do it, sign the permission forms and not turning up).

So the new idea is that I would test the rate iron rusts in different PH solutions. I can use vinegar for acid and dishwash for base - and use water to water them down to different PH. I'll buy a new pack of nails, so that they are the same (a controlled variable) and put them in solutions of the same volume in closed similar containers (to prevent water from evaporating). And, I found out that rust is less dense than iron, so I would just measure how much the water rises up in the container (that's why they have to be the same shape and size) - the mass of the things in the containers don't change. Seems pretty nice. But I still have to find the difference in densities - if they are just 1 gram apart in a cubic metre then my experiment can't work!

It's so hard.......

The first blog marking is due next Thursday, and I still don't have a clear idea of what I am going to do. I think I am going to avoid the plant experiments and look to something involving physics - plants involve a lot more uncertainties and they also take a longer time to experiment with (so that I would have less time to repeat the experiement and thus less chance of an accurate result). But I just don't know what to do!

And this SRP has such harsh marking conditions - do this you'll get a zero, do that you'll get a zero. I'm just so scared that I'm going to do something wrong; I really wish to do well in Science - or my friends will never forgive me for changing school (may sound strange, but true).

I think I'll stick with the ruler vibration one. It's easy to do and the the equipments are easy to set up - I have the pitch measurer and rulers already have markings on them. Or I can even expand it into plastic rulers, wood rulers and metal rulers! Yes! That's a terrific idea! (I just asked Mum and Dad and they think it's good too). Coming to think about it, my friend in Year 11 also did something with sound frequencies. ^-^

Now I can stop worrying and I can finally go study for my History inclass essay tomorrow.