Wonder World Of Science: Where Does Sand Come From? (1989)

thank you [Music] thank you [Music] I wonder I wonder what do you wonder wonder cat I wonder where does sand come from where does sand come from well if you're curious enough you can find out have you ever looked really closely at Sand you mean with my magnifying glass that's right what does sand look like now like like little stones or rocks yes it does grains of sand are really tiny pieces of rock well that's what the sand grains are on this beach in fact most grains of sand are this sand is brown because it came from rocks that were that color in some places sand is more black because it came from rock that was black and sand will be more white if it comes from white rocks or tiny bits of seashells but whatever its color and whatever it's made of all grains of sand are about the same size I can see that with my magnifying glass [Music] I can see that the grains of sand are solid like rocks are but you get a lot of them together and they sort of act like water C you can pour them but the grains don't always stay together you fill up a pail you empty it out and the sand all spreads apart I see what you can do about that if you wet this sand the grains stick together [Music] you can build things with wet sand pretty nice Castle it looks like it has walls made of Rock but I can see they're just a lot of grains of sand stuck together we can speed up what happens when the sun dries the sand the grains of sand just fall apart wow Hey look somebody made me out of sand that's a very nice sand sculpture it looks a lot like you well I don't have to worry about that sand drying up and falling apart the waves are going to wash me away before that ever happens well I'm disappointed about the sand sculpture of you being washed away no see I was curious about sand like you said I ought to be I found out a lot of things about sand but I didn't find out where sand comes from I found out where it goes to some of it gets washed off the beach by the waves but look there that's the hole someone dug to get the sand to make that sculpture of you watch what happens as the waves roll over it hey the waves are moving sand into it not out of it and there are the footprints of the person who made the sand sculpture the water is filling them with sand too so maybe the waves just move the sand around yes that's what the waves do on this beach they move the sand around every time they roll over it waves even move the sand that's under the water every time they come in those little ripples in the sand are made by the waves every time the waves come onto the beach they move the ripples of sand a little slowly the little ripples of sand are moved out of the water and onto the beach here a beach takes a long time to make it takes a lot of waves and a lot of sand well I guess the answer to my question is that all the sand at least on this beach comes out of the water the waves wash it up on the beach [Music] but I wonder what do you wonder wonder cat I wonder how does the sand that the waves wash up on the beach get into the water in the first place remember what the sand looked like when you looked at it through your magnifying glass I think I remember but I'll look at it again anyway just to be sure yes I did remember sand grains look like little pieces of rock and where do you suppose little pieces of rock come from little pieces of rock must come from bigger pieces of rock maybe big rocks yes good thinking but how do little pieces of rock break off of bigger rocks and get into the water well if you're I know curious enough I can find out well there are some big rocks let's go look at them they're hard I don't think I could break pieces off of them very easily but hey there are a lot of rocks down there they're not as small as grains of sand are but they're a lot smaller than the rock they came from I wonder how they got there maybe some of the pieces came off the rock here where it's cracked and look there's a plant growing in another crack in the rock it looks like little pieces of the rock have broken off there too did they come off of that rock good observation yes there are many reasons why rocks break apart one reason is those plants growing in the cracks as the plants grow and get bigger they make the cracks bigger and that can break pieces off of the rock too quick turn away from the beach okay why sand is blowing over this way from the beach you don't want it to get in your eyes hey it's blowing against these rocks hmm these rocks are smooth these rocks are smooth too if sand blows on them a lot out here it does then maybe the blowing sand wears off little bits of the rock the way sandpaper wears off little bits of wood I guess sandpaper is just paper with sand stuck on it grains of sand when you rub sandpaper on wood the wood gets smooth it gets smooth because rubbing with the Sandpaper rubs off little bits of the wood yes and sand blowing against the Rocks wears off little bits of the rocks sand helps to make more sand waves have sand in them too when water with sand in it washes over these rocks that wears off little bits from them too for these rocks to get smooth their rough Parts have to wear away sand in the air and in the water doesn't and sand keeps wearing away the Rocks year after year the pieces of rock that break off the big rocks here get washed into the ocean and then when they're in the water they keep being moved around all the time because the water keeps moving water makes the pieces of rocks bump into each other this makes tiny pieces break off and so these rocks get worn away too these tiny pieces of rock in the water keep breaking into smaller and smaller pieces until they have become grains of sand rocks near the ocean and far away from it wear away slowly turn into sand and then a lot of that sand goes into the oceans then some of it comes up on beaches where the waves wash it up under the shore wind and water keep moving the sand beaches are always changing wind can pile sand into hills called sand dunes or big waves and storms can wash away beaches instead of building them up but for now sand makes this beach a very nice one sorry for those grains of sand once they were big rocks and now look at them you need a magnifying glass to see them well don't feel too sorry for grains of sand because they can turn back into rocks again they can yes this is a kind of rock called sandstone oh I can see it's made of tiny grains of sand all stuck together Sandstone isn't as hard as some other kinds of Rock it's easy to break off the tiny grains of sand and to change the rock into any shape you want hey that's me a Sandstone statue of me and there goes some of the sand that came off the sandstone well now I know where sand on this beach comes from most of it comes from rocks that get worn away and a little teeny tiny part of it comes from a Sandstone statue of me right here on this Sandy Beach that came out of the ocean thank you foreign