AntiBubbles: Science Fair '08-'09

[Michael]

Hey again guys,

I spoke to my Science Teacher once more yesterday. He said, I'm definitely off to a good start but that he wants be to test "Antibubbles," in general. For example. forming them and testing density? temp? etc.

I didn't want to turn him down But, traditionally, I make my project have one variable (dependant & independant, control) to test- in addition, that's what i've been told in the passed to do!

Which would make the "better idea?"

All opinions are appreciated =]

-Michael

[ChrisG]

Hi Michael,
From your post, I am having a difficult time understanding the difference between what your teacher wants you to do and what you would prefer to do. Could you clarify the difference, please?
There's nothing fundamentally wrong with testing multiple variables. It just becomes a different sort of experiment.
In my experience, if someone like your teacher is suggesting a change to your experiment, it is worth understanding exactly why they are making that suggestion. Even if their suggestion is not on the mark, it sometimes indicates that there is some sort of misunderstanding or minor flaw that needs to be corrected.
Looking forward to hearing more.
Chris

[Michael]

Heya Chris,

What my teacher meant was, instead of testing just the velocity of antibubbles in different densities of liquids (ONE specific topic) to investigate Antibubbles, in general meaning: the velocities, how their formed, why they form, etc.

Hope the clarifies a bit. We have today and Wednesday off for a Jewish Holiday.

Michael

[phi-unit]

Hi Michael,

Just as Chris mentioned there is nothing wrong with testing multiple variables. The benefit being that you would have a much more comprehensive project and discussion. However in each instance you will have to be careful to change only one independent variable at a time or else your dependent variable will not follow a simple one cause one effect relationship. There's nothing wrong with varying temperature and density at the same time but that would require checking a tremendous number of combinations of temperature and density to determine the trends you are seeing and possibly any synergistic effects.This would become more complicated.

There is no really "better idea" as you long as you do your experiment in a scientific manner. If you want your project to be more comprehensive you could with your teacher's suggestion or if you don't want do that you could opt for your alternative. Also, why and how antibubbles form are important questions to address but I'm not sure on you plan to address them from the experimental standpoint. Just as a rough example, experimentally, you could see how temperature affects rate of antibubble formation, but explaining how antibubbles form would require theoretical argument driven by observations. This question won't be as simple as changing a variable and noting the result.

Hope this helps and good luck! You've chosen a very cool topic to research.
Feel free to post any further question you may have.

[Gizzmo46]

Michael,

Your teachers suggestion to test antibubbles in general does not necessarily change the experiment but rather gives you more of a focus. Your literature research which you are performing will provide much of the basic insight into the formation and behavior of antibubbles. This will give you a basis for your tests. Previously we had discussed measuring the velocity and size of the antibubbles through liquids of different densities. It seems as though your teacher wants you to focus more on the antibubble formation itself. Think of it like this ... what is your best educated (from the literature) guess for the conditions (temperature, liquid type, density, etc.) to form the most ideal antibubbles? (Here you will have to define "ideal." aka. large size?) No hold all variables constant and vary one parameter ... say temperature ... when you find the ideal temperature ... then vary the next parameter ... and so on until you determine experimentally the best conditions for the formation of antibubbles. There will be a number of variables but as long as you only vary one at a time and keep track of everything very carefully then you will be able to optimize the conditions to produce the best antibubbles. It is good to have an educated guess as to a starting point, as the parameters will not have to be changed much to show that you have the best possible scenario.

Good luck!

Heidi

[Michael]

Hi Guys,

Sorry I haven't been very up-to-date here. In the passed month or so, I put together and researched a lot of antibubbles. This passed week, I also got the chance to make some- it turned to be very cool!

What I have decided to do, is to research and understand how the antibubble forms, then to add different substances to the water to make it more dense. From there, I will measure the velocity (speed) of the antibubbles, and compare if it is slower/faster from the Water Antibubbles. I was thinking of adding alcohol and glycogen to each to make it less/more dense.

Any suggestions would be appreciated.

In other news , I am now also trying to develop a procedure to follow for the experiment. I will try and post that once it is developed to show how I am conducting the project a little bit better.

Thanks,
Michael

[Gizzmo46]

Michael,

Alcohol and glycogen sound like great starting points! Just remember, if you try them and they don't work out you can try something else. There are plenty of substances around but I think they are great to start with! (I really don't know what will work best but, of course, that is what you will soon be able to tell me.) Developing a procedure to follow is a very good idea. You want to make sure to keep everything constant except the item you are varying.
Sounds like things are going great! Keep it up!
Heidi

[Michael]

[quote="Gizzmo46"]Michael,

Alcohol and glycogen sound like great starting points! Just remember, if you try them and they don't work out you can try something else. There are plenty of substances around but I think they are great to start with! (I really don't know what will work best but, of course, that is what you will soon be able to tell me.) Developing a procedure to follow is a very good idea. You want to make sure to keep everything constant except the item you are varying.
Sounds like things are going great! Keep it up!
Heidi[/quote]

Hey again!!

Thanks for the responses These passed few weeks, in lab, I have been performing, really, "segment A" of my experiment, which is to "master" forming the antibubbles.

Though, through reading my introduction report & my procedure outline, one of my teachers pointed something out,and I just wanted to see if you could comment/help on it :

My teacher said, that, both Glycogen and Alcohol are both monosaccharides. She suggested, that in order to sort of "balance" the project out a bit, it would be a good idea to chose a monosaccharide (glycogen, alcohol, etc. -- the alcohol I would chose would be ethanol) and a disaccharide (sucrose?).

Well, once again, thanks for the great support!! So far, it's a ton of fun !!

-Michael

[Craig_Bridge]

My limited and dated experience with anti-bubbles in alkyds is that viscosity, surface tension, temperature, pressure, and other physical factors including any mixing processes has more to do with the formation and behavior of the anti-bubbles than any chemical structure.

I haven't looked up the properties of sucrose and glycogen solutions but I doubt there would be enough of a difference in their behaviors with respect to the factors I mentioned from my alkyd experiences. The viscosity of pure ethanol and a pure water (and any mixture thereof) won't change much until you get close to the freezing point. This is significantly different behavior in terms of viscosity than what will happen with either sucrose or glycogen.

Unless you are looking at some specific use of anti-bubbles where the chemical structure matters to the end result (e.g. some chemical reaction is happening), I'm thinking that first looking at liquids (including different solution concentrations of the same substance) with significantly different viscosities would allow you to better understand what affects anti-bubble behaviors.

[MFagan]

I don't know if you got this answered thoroughly or not, but with regards to measuring velocity:

Basically velocity is the change in displacement over time, so if you can measure the displacement in two images taken a known time apart, you can measure the velocity. In your case, the easiest way is to use a video camera. Modern video cameras capture images at a rate of 30 frames per second. This gives us the change in time. Now we just need displacement. You'll need to mount a ruler or scale in the image. Since you're trying to measure something inside a liquid, you will probably have to mount the ruler inside the vessel to combat the effects of diffraction. Above all, make sure that it is clearly visible to the camera. Go ahead and perform your experiment, taping each trial. Now, take the videos and put them into an editing software which allows you to view the video frame by frame. Using the ruler, measure the displacement in sequential frames. Dividing the distance by the time (1/30 of a second or 0.033) will give you the speed in distance/second (either meters or centimeters per second, depending on how you measured the distance).

One thing to keep in mind is that a bubble rising to the surface from depth is not moving at a constant velocity, rather, it is accelerating. The measurements of velocity made over two sequential frames will give you the average velocity over that time interval. In order to find acceleration, you need to look at change in velocity over time, by comparing the velocity across several different frames. A spreadsheet or mathematics program may come in very handy for this step.

Hope this helps you with your investigation and good luck.
Michael