AboutDan Fink Expertise Though my experience is mostly in the fields of electricity, magnetism, and physics, I have a broad science background. My career is in the field of alternative power sources -- solar, wind, water and battery power. But any questions about electricity, magnetism, energy conservation, power generation, electric motors, and even general physics are very welcome--especially from kids. They ask the best questions of all! I pride myself in answering science questions accurately, with ideas for SAFE, easy experiments that kids can perform by themselves--and that let them prove the answers to their own satisfaction. I think science should be fun, and available to everyone, regardless of age.
Experience I have volunteered in our local public schools for 5 years. I currently make presentations at our schools about electricity and magnetism, with a focus on solar, wind, water and other alternative power sources. I try to demonstrate at our schools how easy it is to make electricity, with simple devices using spinning magnets and coils of wire--powered by wind, water, bicycles, gerbils...etc. And of course solar panels! I am the webmaster of Otherpower.com, an alternative energy website. I have lived 10 miles from the nearest power pole for 11 years--I make all my own electricity from scratch with sun, wind and water.
Expert: Dan Fink Date: 1/8/2008 Subject: help por favor!!!!
Question hi uhh mr dan. i just had a question. im doing a science fair project. i mean the topics not THAT great but its on the behavior of hot and cold fluids. im on the introduction for it and it tells me to put background info about it. what kinds of things do u think i should put 4 this project?? please help me!!!
Answer Hola Lauren.
It's a pretty good topic actually....lots of places you can go with your experiments.
What happens to liquids when they get cold or hot?
They freeze and turn solid when cold, and evaporate and turn to gas when hot. Some liquids get more and more like a gel (their viscosity changes) as they get cold (but water does not do that, though it changes in density). Example would be vegetable oil---it's a messy goo with high viscosity when temperatures get low, and is a very volatile, thin, low viscosity and flammable liquid when it gets hot.
Here's a good one for you to look up (and a project idea)-- at what temperature is water the most dense?
Most other liquids get more dense (and therefore sink) as they get colder. But not water--ice floats in water. And lakes have water at the bottom that's warmer than the nearly frozen water on top just below the ice, during winter. Why?
See what I'm getting at? Pick your favorite liquid, do your research at the library or online or both, and you've got an excellent project. I suggest water because it has such strange properties compared to other liquids. The reason?
(hint) -- REALLY strong hydrogen-oxygen atomic bonds from multiple directions.
Feel free to ask again for more specific advice on your project. I hope these hints at least get you started.
DAN
PS -- what if water had the same properties when hot or cold as veggie oil did? Ouch....we'd all be dead.
