Paper Towel Absorbancy

My sister finished her science fair project today. She did the classic "Which paper towel brand best absorbs water?" experiment.

There were a number of things she did wrong.

Her procedure was basically have a square (27 cm x 27 cm) of each of the three brands and put each one into a liter of water. Then she kept it in for some amount of time, I'm not sure the exact amount, and removed it, looking at the new level of water to figure out how much was absorbed. Lather, rinse, repeat so you did each brand thrice.

My first issue is technically she should've had a control experiment where she had a liter of water and stared at it for the same amount of time to ensure that evaporation was insignificant. I do, however, acknowledge that this is probably okay to skip for a middle school science fair.

The next issue, which is significantly more major, is the container she used measured in increments of 50 mL, and the absorbency was always less than 150 mL. She should've used a more precise measuring device. Personally, I think the best way to measure how much it absorbed would be to take the weight of the dry paper towel and then wet paper towel, but we don't have any scales precise enough for that.

The third issue is dripping water from the paper towels. Should the water that's pulled out but not fully absorbed count towards the absorbency? It seems far more logical to allow the paper towel to drip off back into the container for, say 15 seconds, before taking your measurements. This way, only what the paper towel is actually holding onto counts.

The fourth and most important issue is no one should do this experiment anymore unless they're working for a paper towel company and want to make claims of superior absorbency.

Making a Pig Fly

There are two major methods of making a pig fly.

The first is messing with genetics. This is very complex.

You take a bunch of genes out of a pig and put them into a bacteria, and you get a nice strand of DNA with all the pig stuff you want in the bacteria. Then you extract it from the bacteria and put it into a standard housefly population. Allow reproduction.

Some individuals should retain the pig DNA. You now have pig flies.

The second method is much more fun.

Take two pieces of wood and fashion them into wings. Use a method of your choice to attach these wings to the pig's back.

Next, secure rockets. The bigger, the better. Point them away from the pig's head and attach as appropriate.

Give the pig a running start for best results, then have the rockets go off. Make sure there's some upward thrust, but then the wings should take care of the rest.

If all goes well, the pig should now be flying.