no, i have not finished my report, although i do wish that i miraculously had... i have finished doing my experiment and O-M-G it was horrible. instead of taking 30 minutes for every three trials (or for each test liquid per day), i ended up taking 40 minutes to one hour for each test liquid and it was a PAIN in the bum. it's over now though, just gotta do the report. what joy. T_T
anyways, the good news is that my research was somewhat accurate with whole milk producing a foam that was relatively okay in terms of volume (do not ask me what that means. you may not know, but i know exactly what i mean. ^^) and definitely did not last long.
i need to get my measurements for the test liquids into tables and i've taken heaps and heaps of photos, so i need to sift through them all. there's over 1000 photos, so that will take time. i took heaps of photos of the trials, but i totally forgot to take photos of my equipment & test liquids. my mum threw out the cartons before i remembered to take pictures, but oh well.
i also wanted to mention that the reduced cream did not work out so i've ditched that, as well as the cream because i had a mini epiphany and realised that my aim was to investigate which types of MILK produce a good foam with high volume and longevity. and cream is technically not milk. it's the fat part of the milk they remove from milk to make skim milk. so yeah.... i did do six trials of cream though, and the first three trials, i swear, almost turned to whipped cream.
i'll try get pictures up as soon as possible, although i'm more concerned about my report at the moment. however, we need to put the raw data up (i think) so i'll try get it on soon. i won't post all 1000+ photos on for obvious reasons (such as i can't be bothered & other people probably wouldn't be bothered looking through them), so i'll select a few to post.
i wanted to ask, do we need a risk assessment? it's not a sub heading, so i wasn't sure if we needed one...
i know results are going to be dodge because there is so much human error involved (much more than i expected), but thank gosh i did fifteen trials for each test liquid. some of the results were REALLY sus. oh well, let's just hope it turns out fine.
i think that's all i really have to say for now...
GOOD LUCK to everyone. & to those people who i know that have only just started doing their experiment, i wish you EXTRA GOOD LUCK. updates on my report & results soon. :)
Showing posts with label report. Show all posts
Showing posts with label report. Show all posts
Wednesday, June 9, 2010
Thursday, May 27, 2010
16: alterations
just wanted to confirm my test liquids and make some alterations to the method.
the test liquids will be (listed in order of fat content):
-skim milk (<0.15%)
-low fat milk (<1.5%)
-reduced fat milk (approx. 2.0%)
-whole milk (approx. 3.8%)
-skim evaporated milk (20%, maybe)
-evaporated milk (28%)
-cream (48%*)
*- cream contains 48% milk fat at its natural state (which i have no idea what that is), but it is basically the fat component of milk.
i'll be changing the amount milk used in each trial from one tablespoon to one and a half tablespoons or 30mL. also, instead of shaking each trial for 40 seconds, i've changed it so each trial will be shaken for 30 seconds.
the test liquids will be (listed in order of fat content):
-skim milk (<0.15%)
-low fat milk (<1.5%)
-reduced fat milk (approx. 2.0%)
-whole milk (approx. 3.8%)
-skim evaporated milk (20%, maybe)
-evaporated milk (28%)
-cream (48%*)
*- cream contains 48% milk fat at its natural state (which i have no idea what that is), but it is basically the fat component of milk.
i'll be changing the amount milk used in each trial from one tablespoon to one and a half tablespoons or 30mL. also, instead of shaking each trial for 40 seconds, i've changed it so each trial will be shaken for 30 seconds.
Tuesday, May 25, 2010
15: milk milk milk two
haven't been posting much...too much homework/ tests and procrastinating. TT"
i've been researching a bit more on foaming milk and etc. milk is commonly foamed or frothed as an addition to certain coffees and beverages.
the process used to froth milk for use in coffee is different to my method for this experiment. to froth milk, a "steam wand" forces steam into the milk and forms tiny bubbles. the milk is heated during the process and the heat can affect how well milk foams.
when you steam milk (which is what frothing milk with steam is called), the proteins in the milk is the most important element in creating the tiny bubbles of air.
*adsorb: to gather (a gas, liquid or dissolved substance) on a surface in a condensed layer [http://dictionary.reference.com/browse/adsorb]
the stability of milk foam can vary depending on the milk's fat content. at around 5% (including whole milk), foam stability is at its lowest, meaning that as the fat content increases or decreases from 5% the foam becomes more stable.
foam volume is similar to foam stability as it is at its lowest when milk contains around 5% fat (including whole milk). skim milk supposedly has the greatest potential to produce a high volume and stable foam since it contains hardly any fat. as the fat content of milk increases from around 5%, the milk's ability to produce a foam with high volume and stability also increases.
because these observations are based on steaming milk, i am not sure whether they still apply to just shaking small quantities of milk vigorously for a short period of time. in theory, whole milk is the worst choice for producing a foam with a large volume.
it is said that low fat milk takes on the most air at lower temperatures, but this also applies to whole milk and cream (although "to a lesser extent"). however, all milk, no matter of its fat content, produces the greater volume of foam at cooler temperatures (when compared to the foam production at higher temperatures). milk at room temperature also does not foam well (and it'll probably have gone off by then). therefore, cold milk (preferably straight out of the fridge) presumably gives the best foam.
[http://coffeegeek.com/guides/frothingguide/milk] <--really awesome source [http://coffeeinfo.wordpress.com/foaming-milk-without-steam/]
the coffeegeek website above also details two different types of protein found in milk that contribute to the formation of the bubbles in the foam of milk. i will probably discuss this later on, mainly for the research and to publish more posts. as most of the research from above has come mainly from the one website, i'll need to look for more sources to verify that the information i have above is accurate. :)
i also wanted to say that i've almost finished making my totally awesome test tube rack, using scrap pieces of cardboard, my chocolate crunchie box and the lid of a shoebox. just need to finish off the base.
i hope to start my experiment VERY VERY soon, since the report is due in 3 weeks (how depressing). the experiment will hopefully take no longer than a week because i'll probably need 2 weeks to analyse my results and perfect my science report.
i've been researching a bit more on foaming milk and etc. milk is commonly foamed or frothed as an addition to certain coffees and beverages.
the process used to froth milk for use in coffee is different to my method for this experiment. to froth milk, a "steam wand" forces steam into the milk and forms tiny bubbles. the milk is heated during the process and the heat can affect how well milk foams.
when you steam milk (which is what frothing milk with steam is called), the proteins in the milk is the most important element in creating the tiny bubbles of air.
When you are steaming milk you are incorporating air into the milk. Proteins are
important because they are adsorbed* by the thin film surrounding an air bubble
giving stability to the entrapped air.
*adsorb: to gather (a gas, liquid or dissolved substance) on a surface in a condensed layer [http://dictionary.reference.com/browse/adsorb]
the stability of milk foam can vary depending on the milk's fat content. at around 5% (including whole milk), foam stability is at its lowest, meaning that as the fat content increases or decreases from 5% the foam becomes more stable.
foam volume is similar to foam stability as it is at its lowest when milk contains around 5% fat (including whole milk). skim milk supposedly has the greatest potential to produce a high volume and stable foam since it contains hardly any fat. as the fat content of milk increases from around 5%, the milk's ability to produce a foam with high volume and stability also increases.
because these observations are based on steaming milk, i am not sure whether they still apply to just shaking small quantities of milk vigorously for a short period of time. in theory, whole milk is the worst choice for producing a foam with a large volume.
it is said that low fat milk takes on the most air at lower temperatures, but this also applies to whole milk and cream (although "to a lesser extent"). however, all milk, no matter of its fat content, produces the greater volume of foam at cooler temperatures (when compared to the foam production at higher temperatures). milk at room temperature also does not foam well (and it'll probably have gone off by then). therefore, cold milk (preferably straight out of the fridge) presumably gives the best foam.
[http://coffeegeek.com/guides/frothingguide/milk] <--really awesome source [http://coffeeinfo.wordpress.com/foaming-milk-without-steam/]
the coffeegeek website above also details two different types of protein found in milk that contribute to the formation of the bubbles in the foam of milk. i will probably discuss this later on, mainly for the research and to publish more posts. as most of the research from above has come mainly from the one website, i'll need to look for more sources to verify that the information i have above is accurate. :)
i also wanted to say that i've almost finished making my totally awesome test tube rack, using scrap pieces of cardboard, my chocolate crunchie box and the lid of a shoebox. just need to finish off the base.
i hope to start my experiment VERY VERY soon, since the report is due in 3 weeks (how depressing). the experiment will hopefully take no longer than a week because i'll probably need 2 weeks to analyse my results and perfect my science report.
Wednesday, May 12, 2010
14: method
aim:
to investigate which types of milk (based on their fat content) produce a good foam with high volume and longevity.
hypothesis:
more research is needed.
materials:
-safety goggles
-test tubes with rim 25mm X 150mm
-rubber stoppers without holes
-test tube rack
-measuring spoons
-300mL (approx.) of each test liquid (the different milks mentioned in the previous post)
-stopwatch
-metric ruler
-magnifying glass (optional)
-camera (optional)
method: (for one day)
1) Measure out one tablespoon of one of the test liquids.
2) Put on safety goggles.
3) Pour the measured test liquid into a test tube and insert the rubber stopper so it is tight.
4) Hold the test tube vertically and mark the starting level of the liquid (the level of the top of the liquid).
5) Have a stopwatch ready at hand. When you begin to shake the test tube, start the stopwatch immediately.
6) Shake the test tube vigorously for 40 seconds.
7) Stop shaking at the 40 second mark and reset the stopwatch.
8) Hold the test tube vertically and make marks at the surface of the liquid and at the top of the foam.
9)* Measure and tabulate the distance between the starting level and the top of the foam.
10)* Measure and tabulate the distance between the starting level and the surface of the liquid.
11) Place the test tube in a test tube rack. A magnifying glass may be used to observe the size and uniformity of the foam's bubbles. Record observations and take photos if desired.
]12) At each time increment (later explained), repeat steps 9 to 11 until the trial is over (when there is no foam or when 30 minutes has passed).
13) Repeat steps 1 to 12 two times (there will be fifteen trials in total).
14) Repeat steps 1 to 13 for each type of milk.
*- use a table similar to the one shown in the post '08: approved experiment'
NOTE: this experiment will most likely be completed over five separate days and there will be fifteen trials in total for each type of milk. that is why the method only states to repeat the experiment twice for each type of milk as the method is for a single day.
to investigate which types of milk (based on their fat content) produce a good foam with high volume and longevity.
hypothesis:
more research is needed.
materials:
-safety goggles
-test tubes with rim 25mm X 150mm
-rubber stoppers without holes
-test tube rack
-measuring spoons
-300mL (approx.) of each test liquid (the different milks mentioned in the previous post)
-stopwatch
-metric ruler
-magnifying glass (optional)
-camera (optional)
method: (for one day)
1) Measure out one tablespoon of one of the test liquids.
2) Put on safety goggles.
3) Pour the measured test liquid into a test tube and insert the rubber stopper so it is tight.
4) Hold the test tube vertically and mark the starting level of the liquid (the level of the top of the liquid).
5) Have a stopwatch ready at hand. When you begin to shake the test tube, start the stopwatch immediately.
6) Shake the test tube vigorously for 40 seconds.
7) Stop shaking at the 40 second mark and reset the stopwatch.
8) Hold the test tube vertically and make marks at the surface of the liquid and at the top of the foam.
9)* Measure and tabulate the distance between the starting level and the top of the foam.
10)* Measure and tabulate the distance between the starting level and the surface of the liquid.
11) Place the test tube in a test tube rack. A magnifying glass may be used to observe the size and uniformity of the foam's bubbles. Record observations and take photos if desired.
]12) At each time increment (later explained), repeat steps 9 to 11 until the trial is over (when there is no foam or when 30 minutes has passed).
13) Repeat steps 1 to 12 two times (there will be fifteen trials in total).
14) Repeat steps 1 to 13 for each type of milk.
*- use a table similar to the one shown in the post '08: approved experiment'
NOTE: this experiment will most likely be completed over five separate days and there will be fifteen trials in total for each type of milk. that is why the method only states to repeat the experiment twice for each type of milk as the method is for a single day.
Friday, May 7, 2010
13: milk milk milk one
i'm going to be starting some research on milk (from cows) to see if using different milks for my test liquids is a good idea.
milk is an opaque white liquid produced by the mammary glands of mammals. milk for human consumption often comes from cattle, sheep and goats. cow's milk is the most commonly consumed form of milk & is often processed into other dairy products such as cheese, cream, butter, yoghurt and ice cream. [http://en.wikipedia.org/wiki/Milk]
milk for consumption often goes through different processes before going on sale on supermarket shelves, such as pasteurisation and homogenisation.
pasteurisation is the process used to partially sterilise milk, resulting in extended shelf life. milk is heated to 72°C for at least 15 seconds and then cooled immediately. this destroys any harmful bacteria and micro-organisms.
homogenisation is a process used to prevent the cream in milk separating and rising to the surface. the process consists of passing the milk (under pressure) through very fine nozzles, allowing the fat globules to evenly disperse throughout the milk and thus creating a smooth, creamy texture and taste. [http://www.dairyaustralia.com.au/Products-and-Recipes/Dairy-Products/Milk.aspx]
milk can be separated into groups depending on what and how much of something it contains, such as fat.
regular or whole milk is milk that (usually) has nothing added or removed. it contains on average 3.8% fat and no less than 3.2%. this type of milk is both pasteurised and homogenised and has a rich creamy texture.
reduced fat milk has approximately 2% milk fat and could have added protein and calcium.
low fat milk has less than 1.5% milk fat and usually extra calcium added.
skim milk has less than 0.15% milk fat with extra milk solids added for taste. it has a more watery appearance compared to other milks and a less creamy taste.
evaporated of unsweetened condensed milk is a type of concentrated milk. the total number of milk solids is increased to 28% by the gentle evaporation of water. the milk is sterilized after being canned to eliminate harmful micro-organisms and to ensure a long shelf life. skim evaporated milk contains around 20% milk solids.
powdered milk is "an evaporated pasteurised milk concentrate, containing about 40% milk solids". it is dried to reduce the moisture content to about 3%.
[http://www.dairyaustralia.com.au/Products-and-Recipes/Dairy-Products/Milk/Types-of-Milk.aspx#]
[http://www.milk.co.uk/page.aspx?intPageID=43]
cream is the fat component of milk and contains around 48% milk fat in its natural state. it is the removed component of milk to make skim milk.
[http://www.dairyaustralia.com.au/Products-and-Recipes/Dairy-Products/Cream.aspx]
okay, i think that's enough research for now...as you can see, for all of these types of milk (& including the cream), i've mentioned the substances fat content. i'm hoping to use this to form my hypothesis. so far, i reckon that one of the thicker liquids such as evaporated milk might produce the best foam, based on the foam's volume and longevity. this still needs more research though, so i'll see. i'm not sure if i'll include the cream as a test liquid because it's not technically milk.
by the way, milk fat is "the fatty portion of milk" [http://en.wikipedia.org/wiki/Butterfat] and milk solids are "combined yield of fat and protein in the milk" [http://medical-dictionary.thefreedictionary.com/Milk+solids]. i'm hoping that knowing amount of milk solids instead of milk fat in some of the substances might not affect the order of least to most amount of fat content...i might ask ms zhang...
i'll hopefully start my experiment VERY soon, hopefully before week 6. good luck to everybody starting their experiment. :)
milk is an opaque white liquid produced by the mammary glands of mammals. milk for human consumption often comes from cattle, sheep and goats. cow's milk is the most commonly consumed form of milk & is often processed into other dairy products such as cheese, cream, butter, yoghurt and ice cream. [http://en.wikipedia.org/wiki/Milk]
milk for consumption often goes through different processes before going on sale on supermarket shelves, such as pasteurisation and homogenisation.
pasteurisation is the process used to partially sterilise milk, resulting in extended shelf life. milk is heated to 72°C for at least 15 seconds and then cooled immediately. this destroys any harmful bacteria and micro-organisms.
homogenisation is a process used to prevent the cream in milk separating and rising to the surface. the process consists of passing the milk (under pressure) through very fine nozzles, allowing the fat globules to evenly disperse throughout the milk and thus creating a smooth, creamy texture and taste. [http://www.dairyaustralia.com.au/Products-and-Recipes/Dairy-Products/Milk.aspx]
milk can be separated into groups depending on what and how much of something it contains, such as fat.
regular or whole milk is milk that (usually) has nothing added or removed. it contains on average 3.8% fat and no less than 3.2%. this type of milk is both pasteurised and homogenised and has a rich creamy texture.
reduced fat milk has approximately 2% milk fat and could have added protein and calcium.
low fat milk has less than 1.5% milk fat and usually extra calcium added.
skim milk has less than 0.15% milk fat with extra milk solids added for taste. it has a more watery appearance compared to other milks and a less creamy taste.
evaporated of unsweetened condensed milk is a type of concentrated milk. the total number of milk solids is increased to 28% by the gentle evaporation of water. the milk is sterilized after being canned to eliminate harmful micro-organisms and to ensure a long shelf life. skim evaporated milk contains around 20% milk solids.
powdered milk is "an evaporated pasteurised milk concentrate, containing about 40% milk solids". it is dried to reduce the moisture content to about 3%.
[http://www.dairyaustralia.com.au/Products-and-Recipes/Dairy-Products/Milk/Types-of-Milk.aspx#]
[http://www.milk.co.uk/page.aspx?intPageID=43]
cream is the fat component of milk and contains around 48% milk fat in its natural state. it is the removed component of milk to make skim milk.
[http://www.dairyaustralia.com.au/Products-and-Recipes/Dairy-Products/Cream.aspx]
okay, i think that's enough research for now...as you can see, for all of these types of milk (& including the cream), i've mentioned the substances fat content. i'm hoping to use this to form my hypothesis. so far, i reckon that one of the thicker liquids such as evaporated milk might produce the best foam, based on the foam's volume and longevity. this still needs more research though, so i'll see. i'm not sure if i'll include the cream as a test liquid because it's not technically milk.
by the way, milk fat is "the fatty portion of milk" [http://en.wikipedia.org/wiki/Butterfat] and milk solids are "combined yield of fat and protein in the milk" [http://medical-dictionary.thefreedictionary.com/Milk+solids]. i'm hoping that knowing amount of milk solids instead of milk fat in some of the substances might not affect the order of least to most amount of fat content...i might ask ms zhang...
i'll hopefully start my experiment VERY soon, hopefully before week 6. good luck to everybody starting their experiment. :)
Friday, April 2, 2010
08: approved experiment
so most of us got o ur marking sheet back yesterday and discovered that our experiments were approved, mine included. congrats to everyone who did get their ones approved and have fun and good luck conducting your experiments. remember, safety first!
okay, this blog is appearing much later than i wanted it to but since i'm absolutely unorganised when it comes to schoolwork, i've been pretty busy/ lazy. this should be blog 10, but i guess blog 08 will have to do. back to the experiment. (i won't be elaborating any more on the m&m's experiment since my foam one has been approved but i might still look for new ideas in case this one doesn't work out.)
"which foods produce a good foam with high volume and longevity?"
the method is as follows:
1) Measure out one tablespoon of one of the test liquids.
2) Put on safety goggles.
3) Pour the test liquid into one of the test tubes and place on the rubber stopper so it is tight.
4) Hold the test tube vertically and mark the starting level of the liquid (the level of the top of the liquid).
5) Have a stopwatch ready at hand. When you begin to shake the test tube, start the stopwatch immediately.
6) Shake the test tube vigorously for 40 seconds.
7) Stop shaking at the 40 second mark and reset the stopwatch.
8) Hold the test tube vertically and make marks at the surface of the liquid and at the top of the foam.
9) Measure and record the distance between the starting level and the top of the foam.
10) Measure and record the distance between the starting level and the surface of the liquid.
11) Place the test tube in a test tube rack. A magnifying glass may be used to observe the size and uniformity of the foam's bubbles. Record observations.
okay, this blog is appearing much later than i wanted it to but since i'm absolutely unorganised when it comes to schoolwork, i've been pretty busy/ lazy. this should be blog 10, but i guess blog 08 will have to do. back to the experiment. (i won't be elaborating any more on the m&m's experiment since my foam one has been approved but i might still look for new ideas in case this one doesn't work out.)
"which foods produce a good foam with high volume and longevity?"
the method is as follows:
1) Measure out one tablespoon of one of the test liquids.
2) Put on safety goggles.
3) Pour the test liquid into one of the test tubes and place on the rubber stopper so it is tight.
4) Hold the test tube vertically and mark the starting level of the liquid (the level of the top of the liquid).
5) Have a stopwatch ready at hand. When you begin to shake the test tube, start the stopwatch immediately.
6) Shake the test tube vigorously for 40 seconds.
7) Stop shaking at the 40 second mark and reset the stopwatch.
8) Hold the test tube vertically and make marks at the surface of the liquid and at the top of the foam.
9) Measure and record the distance between the starting level and the top of the foam.
10) Measure and record the distance between the starting level and the surface of the liquid.
11) Place the test tube in a test tube rack. A magnifying glass may be used to observe the size and uniformity of the foam's bubbles. Record observations.
12) At each time increment (later explained), repeat steps 9 and 10 until the trial is over (when there is no foam or when 30 minutes has passed).
13) Repeat steps 1 to 12 for each test liquid with the same number of trials for each test liquid.
i know this isn't the best method, so i'll be improving it later on. the results will be recorded in a table similar to this:
i would like to have at least 10 trials for each test liquid, maybe even 15. i'll do the experiment over several days that have around the same temperature so that i'll know that the results won't be affected by the temperature on the day. on the days, i'll do the same number of trials for each test liquid, so maybe one trial of each test liquid is experimented with on any one day. by doing this, at least one trial of all the test liquids will be conducted in the same conditions. oh, i remember thinking about temperature being another variable for the experiment but have since decided it would be way too hard, so yeah...
the website uses test liquids such as tap water, milk, egg and diluted washing detergent. i might add or replace some test liquids that are common in everyday life. some people suggested coke and something else that i forgot...but coke sounded like a good idea. the test liquids that i am certain on so far are:
-water
-whole milk
-nonfat milk
-diluted washing detergent
i'll think about the egg because i know that egg whites are used to make meringue which consists of a lot of air. however, i don't want to have too many test liquids but not too little either.
i was totally confused over the controlled, independent and dependent variables before, but my sister patiently explained so i think i've got the gist of it now. attempt number 2 at listing variables:
CONTROLLED
-size of the test tube/ container
-amount of each liquid
-amount of time each trial is shaken for
-the strength at which the liquids are shaken at (i.e. not different shaking strengths for the trials)
-the temperature of each liquid before shaking (most likely room temperature)
-the time periods between each recording (foam longevity measurement)
INDEPENDENT
-the type of liquid
DEPENDENT
-the amount and longevity of foam
i think that's all of it, but i'll add more/ edit it later if i remember something.
Tuesday, March 16, 2010
07: foam&jelly
for the foam experiment, the website:
http://www.sciencebuddies.org/science-fair-projects/project_ideas/FoodSci_p057.shtml?fave=no&isb=c2lkOjEsaWE6Rm9vZFNjaSxwOjEscmlkOjYxNzkzMjM&from=TSW
had some terms and background research that you're suppose to look into before starting the experiment. i'm just going to type it all here so i don't forget where i put it. :D
aqueous foam:
formed when gas bubbles get trapped in a liquid and prevent the molecules in that liquid from flowing freely
carbon dioxide:
an odourless, colourless & incombustible gas present in the atmosphere formed during respiration and by the decomposition of organic substances; CO2 is a chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom
nitrous oxide:
a colourless, non-flammable, slightly water-soluble and slightly sweet-tasting gas, N2O; sometimes produces a feeling of exhilaration when inhaled and is often used as anesthetic in surgery and dentistry; sometimes known as laughing gas
density:
amount per unit size; concentration; the spatial property of being crowded together
emulsifier:
a substance that helps an emulsion*form or helps keep an emulsion from separating;
*emulsion: a mixture of two liquids which do not normally combine well (e.g. oil & water)
lecithin:
an important emulsifier found in egg yolks, but is also found in plant and animal tissues
water-soluble:
capable of dissolving in water
i'll list the liquids & whether they're soluble or insoluble later on.
water-insoluble:
inability to dissolve in water
listing later. :D
negative control:
i'm assuming this is meant to be the variables...which i'll list later (as well) since the ones from blog 06 are probably incorrect.
positive control:
read "negative control".
off the foam experiment for a while, i've been looking at other experiments just so i still have some choices. i've found an experiment that requires making different lenses from jelly and shining light through them (they called it jelly optics). it's basically investigating how the light bends or as we learnt last year, refraction. this experiment is like the foam one in regards to its simplicity, but i was thinking that different jellies could be tested instead of using the same jelly to construct all the lenses. for the jelly, i could vary the:
-colour
-density (maybe include salt or flour or something to the jelly mixture before it sets)
-the amount of water (which is more for changing the density)
for the actual lenses, it does state that you could vary the shape, but since we learnt about light last year, we know these "shapes" as biconvex and biconcave and they've also suggested semicircular lenses. i could also vary the thickness, although i'm not sure it would make much difference. the actual size of each lens, however, would definitely affect the outcome.
their aim (is it the aim?) for the experiment is to "make some simple lenses and see how they bend light" but because i want to vary the jellies and therefore vary the lenses, i think the aim (or whatever it's called) should be (but still working on) will the density, colour (thinking about taking out this variable), thickness (now changed to size) and shape of lenses constructed from jelly affect the refraction of light being shone through it or something similar.
the variables could be as follows:
CONTROLLED
-the light source
-the amount of light the lenses are exposed to
-the angle at which the light is shone (is that even a word?) at & the position of the lenses
-maybe the amount of water in the mixture so that the experiment is more controlled
INDEPENDENT
-the lenses (size, density, shape, etc.)
DEPENDENT
-this is suppose to relate to the results but i don't know what's being tested so...yeah...i'll think harder later. :D
note to self: the website for jelly optics is
http://www.csiro.au/resources/jelly-lens-activity.html
okay, so in my next blog (which will hopefully appear soon), i'll try to write the method of the foam experiment in more detail and discuss the variables & the types of liquids & etc. imma also try to find out more about the candy (whoo! m&m's. :D) chromatography experiment & discuss the variables of that one too if i'm bothered.
http://www.sciencebuddies.org/science-fair-projects/project_ideas/FoodSci_p057.shtml?fave=no&isb=c2lkOjEsaWE6Rm9vZFNjaSxwOjEscmlkOjYxNzkzMjM&from=TSW
had some terms and background research that you're suppose to look into before starting the experiment. i'm just going to type it all here so i don't forget where i put it. :D
aqueous foam:
formed when gas bubbles get trapped in a liquid and prevent the molecules in that liquid from flowing freely
carbon dioxide:
an odourless, colourless & incombustible gas present in the atmosphere formed during respiration and by the decomposition of organic substances; CO2 is a chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom
nitrous oxide:
a colourless, non-flammable, slightly water-soluble and slightly sweet-tasting gas, N2O; sometimes produces a feeling of exhilaration when inhaled and is often used as anesthetic in surgery and dentistry; sometimes known as laughing gas
density:
amount per unit size; concentration; the spatial property of being crowded together
emulsifier:
a substance that helps an emulsion*form or helps keep an emulsion from separating;
*emulsion: a mixture of two liquids which do not normally combine well (e.g. oil & water)
lecithin:
an important emulsifier found in egg yolks, but is also found in plant and animal tissues
water-soluble:
capable of dissolving in water
i'll list the liquids & whether they're soluble or insoluble later on.
water-insoluble:
inability to dissolve in water
listing later. :D
negative control:
i'm assuming this is meant to be the variables...which i'll list later (as well) since the ones from blog 06 are probably incorrect.
positive control:
read "negative control".
off the foam experiment for a while, i've been looking at other experiments just so i still have some choices. i've found an experiment that requires making different lenses from jelly and shining light through them (they called it jelly optics). it's basically investigating how the light bends or as we learnt last year, refraction. this experiment is like the foam one in regards to its simplicity, but i was thinking that different jellies could be tested instead of using the same jelly to construct all the lenses. for the jelly, i could vary the:
-colour
-density (maybe include salt or flour or something to the jelly mixture before it sets)
-the amount of water (which is more for changing the density)
for the actual lenses, it does state that you could vary the shape, but since we learnt about light last year, we know these "shapes" as biconvex and biconcave and they've also suggested semicircular lenses. i could also vary the thickness, although i'm not sure it would make much difference. the actual size of each lens, however, would definitely affect the outcome.
their aim (is it the aim?) for the experiment is to "make some simple lenses and see how they bend light" but because i want to vary the jellies and therefore vary the lenses, i think the aim (or whatever it's called) should be (but still working on) will the density, colour (thinking about taking out this variable), thickness (now changed to size) and shape of lenses constructed from jelly affect the refraction of light being shone through it or something similar.
the variables could be as follows:
CONTROLLED
-the light source
-the amount of light the lenses are exposed to
-the angle at which the light is shone (is that even a word?) at & the position of the lenses
-maybe the amount of water in the mixture so that the experiment is more controlled
-the thickness of each lens (i've decided to keep them the same)
INDEPENDENT
-the lenses (size, density, shape, etc.)
DEPENDENT
-this is suppose to relate to the results but i don't know what's being tested so...yeah...i'll think harder later. :D
note to self: the website for jelly optics is
http://www.csiro.au/resources/jelly-lens-activity.html
okay, so in my next blog (which will hopefully appear soon), i'll try to write the method of the foam experiment in more detail and discuss the variables & the types of liquids & etc. imma also try to find out more about the candy (whoo! m&m's. :D) chromatography experiment & discuss the variables of that one too if i'm bothered.
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