Fool's Gold

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Korrente
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Fool's Gold

Postby Korrente » Mon Mar 14, 2011 6:35 pm UTC

I hope you guys don't think I'm dumb for asking this, but I present to you a situation:

Due to unforeseen electromagnetic interference, you have been transported back to the year 1865 and through a series of events end up robbing a train carrying an evil but not too smart businessman's boxcar full of unmarked gold bars. He finds out about you and kidnaps your family or girlfriend or dog or something and says that if you don't return every ounce of his gold within a month (he understands that it'll take a while to move all that metal around), he'll have them killed.
Now, you've gone through a lot of trouble to pull off this heist and you really need some spending money since you're probably stuck in the past (and a savings account, 'cause that time machine is gonna cost a lot to build in a few hundred years). So being a century and a half smarter than him, you decide to trick him into thinking you've returned the gold.

So here's the challenge: How, using your knowledge and period tech, do you trick him into giving up the hostage while keeping as much of the gold as possible for yourself?
Bonus: Change the year to 2011. Now what do?


I figured the easiest way would be to pour about 80-90% lead into a mold and then coat it with enough gold to make the end weight close and to pass a not-too thorough examination (and then run far away and disappear before he decides to cut one open). How about some way to make the fake bars pure enough to pass a test of that period but impure enough to keep a large percentage of it? Also I have no idea how to do something like that today.

Moose Hole
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Re: Fool's Gold

Postby Moose Hole » Mon Mar 14, 2011 6:43 pm UTC

Make a bomb that goes off when you shake it out of a hollowed-out gold bar. Give it to him to test. Stand back.

Bonus: Wait, did you steal a bunch of gold bars lately?

Meem1029
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Re: Fool's Gold

Postby Meem1029 » Tue Mar 15, 2011 5:17 pm UTC

Break into his lair and steal back the hostages that he has taken from you. Bonus points if you incapacitate him and put him in jail (if he's evil and not intelligent, getting the courts on your side shouldn't be a problem, especially since you happen to have a large amount of gold.). That way he cannot take any more hostages.

Or you can always take the lethal route with him to avoid having to bribe the courts. Make sure to dispose of the body well though. People might be suspicious if a guys body shows up dead, all his gold is missing, and there's a random person who has a lot of gold. Or you can dispose of him and take his place to avoid having to steal the gold in the first place.
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gorcee
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Re: Fool's Gold

Postby gorcee » Tue Mar 15, 2011 7:37 pm UTC

It's 1865.

Take your gold, and flee to the deep south. When you get there, spread rumors about how he was a Confederate traitor and stole your gold bars when you gave them to him for safekeeping before Sherman came rolling through your (now burned and devastated) town in the next state over.

When he comes after you, he'll meet a lynching mob.

Seraph
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Re: Fool's Gold

Postby Seraph » Tue Mar 15, 2011 10:50 pm UTC

Korrente wrote:I figured the easiest way would be to pour about 80-90% lead into a mold and then coat it with enough gold to make the end weight close and to pass a not-too thorough examination (and then run far away and disappear before he decides to cut one open). How about some way to make the fake bars pure enough to pass a test of that period but impure enough to keep a large percentage of it? Also I have no idea how to do something like that today.

Lead (11.3g/cc) is a lot less dense then Gold (19.3g/cc). As such even a fairly weak check will reveal the lead bars as fake. I'd expect that someone who was used to handling gold bars (say someone who ships them by the train car full) could tell just by picking them up. I know I can tell the difference between zirconia(5.7g/cc) and alumina (3.4g/cc), which are about the same difference percentage wise.

That said, Uranium and Tungsten are the only things I can think of that are close to golds density and aren't horribly toxic, expensive, or rare. If forced to it takes only simple equipment to do a density measurement on a bar of gold so you'll need to figure how to match golds density to pass "a test of that period".

EDIT:
I'd probably invent dynamite (beat Nobel by two years) and a mercury fulminate based hot wire blasting cap. After I start making money I'd return the gold (or pay him off with some of my profits).
Last edited by Seraph on Tue Mar 15, 2011 11:48 pm UTC, edited 1 time in total.

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Antimony-120
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Re: Fool's Gold

Postby Antimony-120 » Tue Mar 15, 2011 11:07 pm UTC

"Here's you gold back, gimme my loved ones. Also, could I borrow that pen and paper? Dear U.S. Patent office, I've had an idea for a heavier-than-air flying device, sketched within..."

Unfortunatly in the spirit of the thing I don't think this is going to have some magical interesting solution. Most forgeries are possible using the technology of the time will be known at the time. If we allow the traveller to take back some technology capable of fooling them, why bother hijacking the train in the first place? They have an interesting bit of chemical wizardry at their disposal!

This isn't to say that someone from present day couldn't do a lot with the tech of the time, but most of the things they could amaze people with would be things that were NEW, or unknown, not ways to fool people into thinking they did something else.
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Carnildo
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Re: Fool's Gold

Postby Carnildo » Wed Mar 16, 2011 7:10 am UTC

Seraph wrote:
Korrente wrote:I figured the easiest way would be to pour about 80-90% lead into a mold and then coat it with enough gold to make the end weight close and to pass a not-too thorough examination (and then run far away and disappear before he decides to cut one open). How about some way to make the fake bars pure enough to pass a test of that period but impure enough to keep a large percentage of it? Also I have no idea how to do something like that today.

Lead (11.3g/cc) is a lot less dense then Gold (19.3g/cc). As such even a fairly weak check will reveal the lead bars as fake. I'd expect that someone who was used to handling gold bars (say someone who ships them by the train car full) could tell just by picking them up. I know I can tell the difference between zirconia(5.7g/cc) and alumina (3.4g/cc), which are about the same difference percentage wise.

That said, Uranium and Tungsten are the only things I can think of that are close to golds density and aren't horribly toxic, expensive, or rare. If forced to it takes only simple equipment to do a density measurement on a bar of gold so you'll need to figure how to match golds density to pass "a test of that period".

Gold-plated tungsten is a near-perfect density match for solid gold, but there's no way to match gold's color, ductility, or hardness. The traditional "quick test" for gold in 1865 was to bite it: pure gold dents easily, while alloys and plated base metals don't.

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jaap
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Re: Fool's Gold

Postby jaap » Wed Mar 16, 2011 7:28 am UTC

Carnildo wrote:Gold-plated tungsten is a near-perfect density match for solid gold, but there's no way to match gold's color, ductility, or hardness. The traditional "quick test" for gold in 1865 was to bite it: pure gold dents easily, while alloys and plated base metals don't.
According to the (researchers of the) tv programme QI, it was the other way around. The bite test was to check that a coin wasn't lead, so if it dented it was a false coin, if it didn't dent (and was heavy) it was probably gold.

p1t1o
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Re: Fool's Gold

Postby p1t1o » Wed Mar 16, 2011 9:34 am UTC

I also watched that episode of QI and it does seem to ring true.

For reference:
Mohs Hardness values:
Gold - 2.5 to 3
Lead - 1.5
Teeth - roughly 5

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Antimony-120
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Re: Fool's Gold

Postby Antimony-120 » Wed Mar 16, 2011 3:16 pm UTC

p1t1o wrote:I also watched that episode of QI and it does seem to ring true.

For reference:
Mohs Hardness values:
Gold - 2.5 to 3
Lead - 1.5
Teeth - roughly 5


It probably runs both ways, it's not like humans are only capable of sensing two consistencies "bitable" and "not-bitable". If it was too soft, it was lead, if it was too hard, it was an alloy.
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Carnildo
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Re: Fool's Gold

Postby Carnildo » Thu Mar 17, 2011 2:56 am UTC

p1t1o wrote:I also watched that episode of QI and it does seem to ring true.

For reference:
Mohs Hardness values:
Gold - 2.5 to 3
Lead - 1.5
Teeth - roughly 5

The bite test is an indentation hardness test, where Mohs hardness is a scratch hardness test. Unfortunately, I can't find indentation hardness numbers for gold and lead on a consistent scale: I can find Vickers hardness numbers for gold, and Brinell numbers for lead, and it's not possible to convert between the two.

mercutio_stencil
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Re: Fool's Gold

Postby mercutio_stencil » Thu Mar 17, 2011 7:25 am UTC

I think the solution to this problem lies with the boxcar full of gold bars; can I just pay someone to rescue the hostages? A gold bar is a lot of money after all, and if you have a trail car full, you can afford to give away a few.

Korrente
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Re: Fool's Gold

Postby Korrente » Thu Mar 17, 2011 7:37 am UTC

Antimony-120 wrote:"Here's you gold back, gimme my loved ones. Also, could I borrow that pen and paper? Dear U.S. Patent office, I've had an idea for a heavier-than-air flying device, sketched within..."

Unfortunatly in the spirit of the thing I don't think this is going to have some magical interesting solution.


That is exactly what I'd do, actually. And I didn't really expect anything amazing to come up but I wanted to see what people thought of. Some of the answers gave me a laugh anyway. But in all seriousness we need to think about things like this more often, it might be useful if you find yourself in this situation :wink:



mercutio_stencil wrote:I think the solution to this problem lies with the boxcar full of gold bars; can I just pay someone to rescue the hostages? A gold bar is a lot of money after all, and if you have a trail car full, you can afford to give away a few.


We're scientists, it can't be that simple.

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Re: Fool's Gold

Postby firechicago » Thu Mar 17, 2011 7:51 am UTC

Korrente wrote:
mercutio_stencil wrote:I think the solution to this problem lies with the boxcar full of gold bars; can I just pay someone to rescue the hostages? A gold bar is a lot of money after all, and if you have a trail car full, you can afford to give away a few.


We're scientists, it can't be that simple.

Oh but it can, just so long as we call it "social engineering" and pretend like we made it up.

Moose Hole
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Re: Fool's Gold

Postby Moose Hole » Thu Mar 17, 2011 1:31 pm UTC

1) Insulate the boxcar's wheels.
2) Hide a huge battery, made using the materials of the time, in the middle of the gold bar stack, making sure all gold bars are touching.
3) Drill a hole through the bottom of the boxcar and run a wire into the ground connected to one end of the battery.
4) Park the boxcar next to a puddle.
5) Tell the evil guy to go grab a gold bar and test it.
6) Profit.

Headshrinker
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Re: Fool's Gold

Postby Headshrinker » Thu Mar 17, 2011 5:36 pm UTC

If he had one hostage killing that hostage would leave him with no control over you and a further profit of zero. Therefore he can't kill that hostage but that hostage is worthless,
If he kills the second to last he would have one hostage who he can't kill and would have no control over you.
Works backwards from there. He has no control.
However if he keeps the hostages he has to pay for their food and keeping, If he kills them he risks the law comming after him.
The only logical thing for him to do would be to release his hostages,
If we explain this to him I'm sure he will understand.

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Re: Fool's Gold

Postby Tass » Thu Mar 17, 2011 7:41 pm UTC

Headshrinker wrote:If he had one hostage killing that hostage would leave him with no control over you and a further profit of zero. Therefore he can't kill that hostage but that hostage is worthless,
If he kills the second to last he would have one hostage who he can't kill and would have no control over you.
Works backwards from there. He has no control.
However if he keeps the hostages he has to pay for their food and keeping, If he kills them he risks the law comming after him.
The only logical thing for him to do would be to release his hostages,
If we explain this to him I'm sure he will understand.


Except that this reasoning relies on him being rational, which humans rarely are. We fear that he might kill the hostage out of spite, and thus strangely his strategy works.

Moose Hole
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Re: Fool's Gold

Postby Moose Hole » Thu Mar 17, 2011 7:56 pm UTC

Tass wrote:
Headshrinker wrote:If he had one hostage killing that hostage would leave him with no control over you and a further profit of zero. Therefore he can't kill that hostage but that hostage is worthless,
If he kills the second to last he would have one hostage who he can't kill and would have no control over you.
Works backwards from there. He has no control.
However if he keeps the hostages he has to pay for their food and keeping, If he kills them he risks the law comming after him.
The only logical thing for him to do would be to release his hostages,
If we explain this to him I'm sure he will understand.


Except that this reasoning relies on him being rational, which humans rarely are. We fear that he might kill the hostage out of spite, and thus strangely his strategy works.
Assume a perfectly logical evil but not too smart businessman.

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Re: Fool's Gold

Postby Antimony-120 » Thu Mar 17, 2011 8:37 pm UTC

Moose Hole wrote:Assume a perfectly logical evil but not too smart businessman.


First we assume the gold bars are spherical...
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idobox
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Re: Fool's Gold

Postby idobox » Mon Mar 21, 2011 1:42 pm UTC

Carnildo wrote:Gold-plated tungsten is a near-perfect density match for solid gold, but there's no way to match gold's color, ductility, or hardness. The traditional "quick test" for gold in 1865 was to bite it: pure gold dents easily, while alloys and plated base metals don't.


After checking on wikipedia, tungsten is slightly heavier than gold. My best guess, make a tungsten bar, coat it with a little layer of anything to match the density of gold, and then coat that in a thick layer of gold (at least 1 or 2 mm).
Anyone knows if tungsten and gold have a significant difference in X-ray trnasparency?
Also, the bar might sound different when shocked, due to the inhomogenous medium, and ultrasound scanning of the bar would probably reveal the trick.
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Moose Hole
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Re: Fool's Gold

Postby Moose Hole » Mon Mar 21, 2011 1:52 pm UTC

idobox wrote:
Carnildo wrote:Gold-plated tungsten is a near-perfect density match for solid gold, but there's no way to match gold's color, ductility, or hardness. The traditional "quick test" for gold in 1865 was to bite it: pure gold dents easily, while alloys and plated base metals don't.


After checking on wikipedia, tungsten is slightly heavier than gold. My best guess, make a tungsten bar, coat it with a little layer of anything to match the density of gold, and then coat that in a thick layer of gold (at least 1 or 2 mm).
Anyone knows if tungsten and gold have a significant difference in X-ray trnasparency?
Also, the bar might sound different when shocked, due to the inhomogenous medium, and ultrasound scanning of the bar would probably reveal the trick.
They didn't have ultrasound technology until the 1940s. Before, that, they'd bite womens' bellies to figure out if they're pregnant.

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idobox
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Re: Fool's Gold

Postby idobox » Mon Mar 21, 2011 3:39 pm UTC

The x-ray and ultrasound parts were for the bonus.
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ikrase
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Re: Fool's Gold

Postby ikrase » Thu Mar 24, 2011 5:54 am UTC

Grind tungsten to an impalpable powder and mix a few percent of in in with the gold. Have it out of places likely to be cut, and none at the surface.
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idobox
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Re: Fool's Gold

Postby idobox » Thu Mar 24, 2011 10:19 am UTC

This might still not pass a modern ultrasound test. Does anyone have experience with ultrasound for testing metal parts?
Light is deflected by water, and turning it into a cloud of small particles mixed with air, while changing the signature, still gives a visible one. It might be the same for ultrasound and powdered tungsten in gold.
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ikrase
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Re: Fool's Gold

Postby ikrase » Fri Mar 25, 2011 7:10 am UTC

I meant for 1865.

Social Engineering is likely to be very important. Trick the guy into cutting open the one gold bar that is not adulterated. Mess with the ones at the middle of the train car but not the top or bottom. Tungsten powder would not affect a simple wheigign.
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