2007-02-27 06:10:21 · 6 answers · asked by shlyhndrsn8 1 in Science & Mathematics ➔ Other - Science
becuase of a property of water called surface tension, water will take on a particular shape and size when broken down. It's like an outer skin on the outside of the water holding it together. you can see it if you look closely at a small drop of water, you'll see it's rounded. the water is held in place by this outer layer.
water alone isn't good enough to get the dirt off our hands and head. the droplets are too big, because of the surface tension. instead of getting under the dirt to pry it out, the water bounces right off. thats where soap and shampoo come into play. they break down the water's surface tension to make the droplets smaller. making it easier for them to get under and around the dirt to get it out. the water becomes wetter.
shine and bounce is a great bonus.
if you float a paper clip in a cup of water and then drop soap in the water, you'll see the paperclip sink as the surface tension breaks.
2007-02-27 08:46:57 · answer #1 · answered by vcas30 3 · 0⤊ 0⤋
There is no real scientific reason...its simply a hygeine reason...the oils in your hair are good for it as long as they are rinsed every once ina while...the thing is they smell and the longer you leave if the more they will smell lol so you use shampoo to clean out the oils which is actually bad for you hair...then use conditioner to try and simulate what should be there naturally...
2007-02-27 14:35:56 · answer #2 · answered by Sean C 2 · 1⤊ 0⤋
People do not need to use shampoo, but the oil from our hair will build up and make the hair look really nasty, how does the shampoo help? It cuts down the oil from the hair to make it shiny, fluffy, and clean looking
2007-02-27 14:20:54 · answer #3 · answered by Cow Girl 2 · 1⤊ 0⤋
I don't believe there is a scientific reason, not even a medical reason. If you have hair below your shoulders then maybe a hygiene reason but as far as I know there is nothing that will be detrimental to you or anyone else if your hair is 'dirty'. The hair follicle produces it's own oils etc. Headlice will live in very clean hair or very dirty hair - they are not fussy.
2007-02-27 14:20:36 · answer #4 · answered by Anonymous · 1⤊ 1⤋
you dont. the scalp produces natural oils that are actually really good for both the health of your scalp and the shine of your hair.
however, if you use any kind of hair products, the chemicals in them counter act the benefit of the oils, so it is a good idea to wash out those chemicals.
its still a good idea to go a day without shampooing every once in a while... it makes your scalp and hair healthier
2007-02-27 14:16:43 · answer #5 · answered by lostatlimbo 2 · 1⤊ 1⤋
to clean your hair so you don't get lice crabs
2007-02-27 14:14:11 · answer #6 · answered by Macgyver with Crosby 4 · 1⤊ 1⤋