Barry Posted October 16, 2005 Posted October 16, 2005 Hi there, Im having a bit of a debate with my friends. Ice - is it the hardest thing know to man? I reckon it is.
RoyLennigan Posted October 16, 2005 Posted October 16, 2005 Hi there, Im having a bit of a debate with my friends. Ice - is it the hardest thing know to man? I reckon it is. what? no, why would you think this? diamond is the hardest known naturally occuring mineral. but there are several artificial materials that are harder. at colder temperatures, these materials are relatively harder than normally.
RyanJ Posted October 16, 2005 Posted October 16, 2005 what? no, why would you think this? diamond is the hardest known naturally occuring mineral. but there are several artificial materials that are harder. at colder temperatures, these materials are relatively harder than normally. I'd have to agree with RoyLennigan on this one. Ice cna be scratched by diamond and therefor is not as hard as diamond. You coudl say the ide is extremly compressed but then you coud still do the same for the diamond and we'r back in the original position - Ice is not as hard as diamond infact you can scratch it with your fingernail! Cheers, Ryan Jones
Dr.Reiniger Posted October 16, 2005 Posted October 16, 2005 Ice, in the extreme low temperate is the hardest thing known to man as it is in a state whereby no atoms are moving.
Mokele Posted October 16, 2005 Posted October 16, 2005 If you hit ice with a hammer, the ice breaks and the hammer is undamaged. Mystery solved.
RyanJ Posted October 16, 2005 Posted October 16, 2005 If you hit ice with a hammer, the ice breaks and the hammer is undamaged. Mystery solved. But then again if you hit a diamond with a hammer it too will shatter and the hammer will remain undamaged. I'm not saying that Ice is harder I'm just saying the same thign woudl happen for a diamond Cheers, Ryan Jones
Anjruu Posted October 16, 2005 Posted October 16, 2005 "Ice, in the extreme low temperate is the hardest thing known to man as it is in a state whereby no atoms are moving." Thats unfair. Its like saying, "Oh, at extremly high temperatures, diamond is a liquid, so it is softer than ice." If you are goning to drop ice down to near absolute zero temperaters, than you need to do the same thing for the diamond, and if that were the case, I think that the diamond would win. Furthermore, you can crush ice with your teeth! Try crushing a diamond with your teeth. But be sure you have severe painkillers and and a damn fine dentists on hand. You need a hella more accleration, thus force, to break a diamond, and a normal hammer would not remain unharmed. To break diamonds you need special hammers.
RyanJ Posted October 16, 2005 Posted October 16, 2005 You need a hella more accleration' date=' thus force, to break a diamond, and a normal hammer would not remain unharmed. To break diamonds you need special hammers.[/quote'] I beg to differ. I've broken a small industral diamond with a normal hammer and there was no damage at all to the hammer. I can say I hit it quite hard but there mas nothing much lest of the diamond, it was turned to powder... Diamonds are easy to break if you hit them with somehting... Cheers, Ryan Jones
sanjaygeorge Posted October 16, 2005 Posted October 16, 2005 Water only under certain conditions is harder. if u take diamond and water at a normal condition. then diamond will win. when anyone challenge of hardness of something they do so with normal room condition as a standard.
swansont Posted October 16, 2005 Posted October 16, 2005 If you hit ice with a hammer, the ice breaks and the hammer is undamaged. Mystery solved. Hitting it with a hammer is more a measure of brittleness, not hardness. Brittleness is often inversely correlated with hardness. Scratch the ice with the diamond and vice-versa. That will tell you which is harder - the one that doesn't get scratched. edit: fixed sign error
swansont Posted October 16, 2005 Posted October 16, 2005 Ice, in the extreme low temperate is the hardest thing known to man as it is in a state whereby no atoms are moving. No, there is no achievable state where atomic motion ceases.
RyanJ Posted October 16, 2005 Posted October 16, 2005 No, there is no achievable state where atomic motion ceases. Good point, a big no-no. What is it called? Absolute Zero? Nothing can reach or excede it correct? Cheers, Ryan Jones
swansont Posted October 16, 2005 Posted October 16, 2005 According to this link the hardness of ice at -70 C is 6, which is about the same as quartz. However, it's unclear if that refers to the average ice you find out in nature, or ice made from demineralized water, which is harder because it has no impurities to weaken the bonds.
MattC Posted October 16, 2005 Posted October 16, 2005 Just to clarify - hardness is a specific property which is indeed measured (at least, in one way) by scratching things. However, this method is not always a good way of testing something. Ice, for example, at normal temperatures (say, in your freezer, or outside when it's very cold, whatever ...) will turn into a liquid under pressure. When you scratch it, you are actually melting it - ice is much harder than your finger nails, but your nails do not turn into liquid until a very high temperature, whereas ice will become water at low temperatures provided there is enough pressure on it. Most of you know this, but for those who don't, this is due to a unique (somewhat unique) property of water - when it is liquid, it is more dense than it is as a solid. Most other materials, under pressure, solidify. Water (ice) will melt under pressure - this is how an ice-skater slides across the ice when skating. The ice melts under the concentrated pressure of the blades of the ice skates. So, to measure the hardness of ice, you have to test it against something else at a temperature at which, under the pressure conditions of the test (whatever they may be - it depends upon how hard the two materials are grated against eachother), the ice will not melt. If it is cold enough, it will not become a liquid at that pressure. Apply enough pressure and ice will become water, at any temperature. That said, I suspect diamond is harder, but I don't really know the hardness of ice offhand. It's pretty hard, though!
RyanJ Posted October 16, 2005 Posted October 16, 2005 Just to clarify - hardness is a specific property which is indeed measured (at least' date=' in one way) by scratching things. However, this method is not always a good way of testing something. Ice, for example, at normal temperatures (say, in your freezer, or outside when it's very cold, whatever ...) will turn into a liquid under pressure. When you scratch it, you are actually melting it - ice is much harder than your finger nails, but your nails do not turn into liquid until a very high temperature, whereas ice will become water at low temperatures provided there is enough pressure on it. Most of you know this, but for those who don't, this is due to a unique (somewhat unique) property of water - when it is liquid, it is [b']more dense[/b] than it is as a solid. Most other materials, under pressure, solidify. Water (ice) will melt under pressure - this is how an ice-skater slides across the ice when skating. The ice melts under the concentrated pressure of the blades of the ice skates. So, to measure the hardness of ice, you have to test it against something else at a temperature at which, under the pressure conditions of the test (whatever they may be - it depends upon how hard the two materials are grated against eachother), the ice will not melt. If it is cold enough, it will not become a liquid at that pressure. Apply enough pressure and ice will become water, at any temperature. That said, I suspect diamond is harder, but I don't really know the hardness of ice offhand. It's pretty hard, though! This came up in the Cassini-Huygens proble launch to Titan: First off, relatively pure ice at -180C doesn't flow. It's HARD. At -70C ice is as hard as quartz rock (6-7 on the mohs scale), and it gets even harder. So glaciers wouldn't flow very easily, if at all. And thats about the hard as ice can possible get. Cheers, Ryan Jones
RyanJ Posted October 17, 2005 Posted October 17, 2005 I can agree that ice is indeed harder than diamond. It just is' date=' it's like, dead hard. I was pondering this while feeding my taratula, AndyBell, some Alpen this morning while watching the Bear/Human heavyweight boxing match of [/quote'] Ice is not as hard as diamond, no-where near... even if you put the stuff in space or at high preassure then it will still be scratched by a diamond... There is one big test... cool water down to near absolute zero and a diamond too then see if it will scratch the ice... yes it will scratch the ice. If water was hearder then why isn't water used (At really low temperatures) instead of diamonds in industry? Ice is not harder than a diamond, to have a fair test you'd need both at the same temperature, preassure, etc. In such a case then the results would be the same as ice at room temperature, the ice would be scratched by the diamond and thus the diamond if harder, there is no escaping this conclusion... Cheers, Ryan Jones
swansont Posted October 17, 2005 Posted October 17, 2005 If water was hearder then why isn't water used (At really low temperatures) instead of diamonds in industry? There would be engineering difficulties in keeping the ice that cold that I imagine would swamp any advantages you might have.
CanadaAotS Posted October 17, 2005 Posted October 17, 2005 I beg to differ. I've broken a small industral diamond with a normal hammer and there was no damage at all to the hammer. I can say I hit it quite hard but there mas nothing much lest of the diamond' date=' it was turned to powder... Diamonds are easy to break if you hit them with somehting... Cheers, Ryan Jones[/quote'] So what your saying is you destroyed a diamond??? Why would you do that? lol
RyanJ Posted October 17, 2005 Posted October 17, 2005 So what your saying is you destroyed a diamond???Why would you do that? lol Because I had one spare - like I said it was an industreal one anyway so it was practually worthless.... YT2095 - is there any better cause? Cheers, Ryan Jones
YT2095 Posted October 17, 2005 Posted October 17, 2005 YT2095 - is there any better cause? Cheers' date=' Ryan Jones[/quote'] I can`t think of one
Locrian Posted October 17, 2005 Posted October 17, 2005 what? no, why would you think this? diamond is the hardest known naturally occuring mineral. but there are several artificial materials that are harder. Which ones are you thinking of?
Conceptual Posted October 18, 2005 Posted October 18, 2005 When water freezes to form ice, it expands. This anomoly is due to the hydrogen bonding optimizing or minimizing potential. Irregardless, this expansion makes ice less hard than if it was a normal contracting solid. At cold enough temps, all solid materials will contract. Both water and diamond start as tetrahedral atomic arrangements. Theoretically, maximum density packing would be better served by changing to a hexagonal style packing arrangment. This is where water may have the advantage; hexagonal carbon is no longer diamond.
RyanJ Posted October 18, 2005 Posted October 18, 2005 Which ones are you thinking of? Maybe Boron Nitride or one of the carbides? Cheers, Ryan Jones
CanadaAotS Posted October 18, 2005 Posted October 18, 2005 practically worthless? well that makes me feel better lol
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