Comments on: Is the World Cup Trophy Hollow? http://blogs.smithsonianmag.com/science/2010/06/is-the-world-cup-trophy-hollow/ Ideas, innovations and discoveries from the world of science Thu, 23 May 2013 23:31:37 +0000 hourly 1 http://wordpress.org/?v=3.4 By: Menon http://blogs.smithsonianmag.com/science/2010/06/is-the-world-cup-trophy-hollow/comment-page-1/#comment-2138 Menon Thu, 24 Jun 2010 05:51:42 +0000 http://blogs.smithsonianmag.com/science/?p=4068#comment-2138 Actually I had no idea about actual weight of FIFA World Cup Trophy. Actually I had no idea about actual weight of FIFA World Cup Trophy.

]]> By: Steve Jones http://blogs.smithsonianmag.com/science/2010/06/is-the-world-cup-trophy-hollow/comment-page-1/#comment-2110 Steve Jones Thu, 17 Jun 2010 22:19:16 +0000 http://blogs.smithsonianmag.com/science/?p=4068#comment-2110 Nb. I've no idea why I typed the noun "weight" consistently in place of the verb "weigh". Nb. I’ve no idea why I typed the noun “weight” consistently in place of the verb “weigh”.

]]> By: Steve Jones http://blogs.smithsonianmag.com/science/2010/06/is-the-world-cup-trophy-hollow/comment-page-1/#comment-2109 Steve Jones Thu, 17 Jun 2010 22:17:09 +0000 http://blogs.smithsonianmag.com/science/?p=4068#comment-2109 It's easy to approximate. Construct an outline from a photo, scale it to the known height, measure the width at regular intervals (I took 5mm apart) and treat it like a lot of disks. Add them all up and it's going to be of the right order (it's not a round section of course, so it tends to overestimate the volume). I get a figure of about 3,660 cubic centimetres. 18 carat gold comes in a range of densities according to what it is alloyed with, but the average of the range is 15.55 gm/cubic centimetre, which yields a weight of 57Kg. A bit less than the professor's calculations (maybe he used the density of 24 carat gold which is 19.32 gm per cubic centimetre which would have produced about 70Kg). There's a few other adjustments that I could have made, but it is certainly impossible that it is solid gold if it only weights about 5Kg. In fact I can estimate the wall thickness (if it is roughly the same) and I make it a bit under 3mm thick. It wouldn't be sufficient for the ball at the top to be hollow, the lower part would weight considerably more than 5Kg on its own. It is conceivable that the hollow space is filled with wax or something similar to provide a bit more rigidity. In fact this would be a jolly good puzzle to give a class of kids to see if they can work out how much something like this would weight if solid. It’s easy to approximate. Construct an outline from a photo, scale it to the known height, measure the width at regular intervals (I took 5mm apart) and treat it like a lot of disks. Add them all up and it’s going to be of the right order (it’s not a round section of course, so it tends to overestimate the volume). I get a figure of about 3,660 cubic centimetres. 18 carat gold comes in a range of densities according to what it is alloyed with, but the average of the range is 15.55 gm/cubic centimetre, which yields a weight of 57Kg. A bit less than the professor’s calculations (maybe he used the density of 24 carat gold which is 19.32 gm per cubic centimetre which would have produced about 70Kg). There’s a few other adjustments that I could have made, but it is certainly impossible that it is solid gold if it only weights about 5Kg.

In fact I can estimate the wall thickness (if it is roughly the same) and I make it a bit under 3mm thick. It wouldn’t be sufficient for the ball at the top to be hollow, the lower part would weight considerably more than 5Kg on its own. It is conceivable that the hollow space is filled with wax or something similar to provide a bit more rigidity.

In fact this would be a jolly good puzzle to give a class of kids to see if they can work out how much something like this would weight if solid.

]]> By: WilliamB http://blogs.smithsonianmag.com/science/2010/06/is-the-world-cup-trophy-hollow/comment-page-1/#comment-2095 WilliamB Wed, 16 Jun 2010 01:13:11 +0000 http://blogs.smithsonianmag.com/science/?p=4068#comment-2095 Eureka! Eureka!

]]> By: colin scrowther http://blogs.smithsonianmag.com/science/2010/06/is-the-world-cup-trophy-hollow/comment-page-1/#comment-2093 colin scrowther Tue, 15 Jun 2010 15:34:06 +0000 http://blogs.smithsonianmag.com/science/?p=4068#comment-2093 why dont the scientists just ask the sculptor? why dont the scientists just ask the sculptor?

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