cbeast
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Let's talk governance, lipstick, and pigs.
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September 25, 2012, 02:21:41 AM |
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Now I'm wondering about fake silver.
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Any significantly advanced cryptocurrency is indistinguishable from Ponzi Tulips.
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kokojie
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September 25, 2012, 02:24:22 AM |
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Man this gives me a lot of anxiety because I plan to buy back some bullion in the near future. How the hell can I unsure, without wasting a lot of money, that what I buy will be real? Buy an ultrasound machine like the ones that dealers have, that's the only way to be sure. Otherwise, you can never be sure.
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btc: 15sFnThw58hiGHYXyUAasgfauifTEB1ZF6
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conspirosphere.tk
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Bitcoin is antisemitic
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September 25, 2012, 08:21:31 AM |
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Inaba
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September 25, 2012, 02:02:42 PM |
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If you're searching these lines for a point, you've probably missed it. There was never anything there in the first place.
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allthingsluxury
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September 25, 2012, 05:04:03 PM |
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Now I'm wondering about fake silver. Someone actually attempted to sell me a fake silver morgan. Luckily I check all coins before I purchase. The coin was incredibly realistic. It was scary, especially since silver was only around $15.00 an oz. I wondered how is this remotely cost effective?? Then I did a bit of research and you could actually buy the fake coins for roughly $1.50 a coin, so yah it was actually incredibly profitable for the original scammer.
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Gold & Silver Financial News: Silver Liberation Army, Gold & Silver News, Geopolitical & Financial News, Jim Rickards Blog, Marc Faber Blog, Jim Rogers Blog, Peter Schiff Blog, David Morgan Blog, James Turk Blog, Eric Sprott Blog, Gerald Celente Blog
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allthingsluxury
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September 25, 2012, 11:45:07 PM |
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Haha wow, the lengths people will go to make a dishonest buck. Sad.
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Gold & Silver Financial News: Silver Liberation Army, Gold & Silver News, Geopolitical & Financial News, Jim Rickards Blog, Marc Faber Blog, Jim Rogers Blog, Peter Schiff Blog, David Morgan Blog, James Turk Blog, Eric Sprott Blog, Gerald Celente Blog
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cypherdoc
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September 26, 2012, 12:54:16 AM |
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so i have access to an US that i'd like to use to scan my gold coins for integrity. i was wondering if any of you guys know the velocity settings. i captured this image off the Goldmoney video but see 2 different velocity settings that are quite far apart. what do they mean and which one is the appropriate one? ![](https://ip.bitcointalk.org/?u=https%3A%2F%2Fi.imgur.com%2Ff5uUG.jpg&t=665&c=CdoTXPrwDUUelw)
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kjj
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September 26, 2012, 04:03:51 AM |
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so i have access to an US that i'd like to use to scan my gold coins for integrity. i was wondering if any of you guys know the velocity settings. i captured this image off the Goldmoney video but see 2 different velocity settings that are quite far apart. what do they mean and which one is the appropriate one? ![](https://ip.bitcointalk.org/?u=https%3A%2F%2Fi.imgur.com%2Ff5uUG.jpg&t=665&c=CdoTXPrwDUUelw) The screen shows Velocity L and Velocity S. If I had to guess, I'd say Velocity L and Velocity SAlso, my understanding of waves in general suggests that one or more of those isn't a setting, but a measured parameter.
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17Np17BSrpnHCZ2pgtiMNnhjnsWJ2TMqq8 I routinely ignore posters with paid advertising in their sigs. You should too.
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Dusty
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September 26, 2012, 06:53:03 AM |
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Sound wave velocity in tungsten is almost the double that of the gold, I don't know which kind of equipment is needed to measure them, but the difference is so relevant that I suppose it should be quite easy to spot.
Also, if suddendly a relevant percentage of gold held by bullions would be found false I suppose that would spike the gold price by quite a lot, since the real gold in circulation would be less that what was thought.
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mintymark
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September 26, 2012, 11:07:16 AM |
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So I'd like to ask the OP what it was that made him suspicious enough to risk cutting open a perfectly good bar? How did he know because I am not sure I would have been sure enough?
Next I would like to say that I am pretty sure that it would be quite a simple matter to measure the difference between filled and solid gold bars based on resistivity which would be a simple measurement to make in practice.
There are two key principles here - use a 4 terminal measuring device I would suggest that wooden or plastic block with contacts on the side and ends, could be used where the wooden block has an indentaion to match the exact size of gold bar. The principle of a 4 terminal resistance is that 2 terminals are used to inject a test current and 2 terminals used to read the voltage generated by this current. This cuts out completely voltage generated by poor contacts or leads.
Its not necessary to use a particularly large current - modern amplifiers are capable of accurately measuring very small offset voltages, and you are measuring a true differential voltage here that makes it a lot easier.
The last 'trick' which would add a little to the cost of what I have so far described a very simple cheap instrument, would be if it did in fact turn out to be too difficult to measure the offset voltage accurately due to offset noise in the amplifier. In this case you instead use an alternating current to perform the measurement and a synchronous decode to accurately measure the offset voltage. Such a decoder will reject all other frequencies including DC so that you only have the signal you want. I dont think this would be required, but it could be.
I can see that provided that you were happy to have an instrument that effectively only measured one size of gold bar, it would be very easy to devlop such an instrument. How could it be made more general purpose (to cater for many different sizes?). Not sure. To compare the same sized gold bar, its essential to have the contacts in the same place.
Indeed perhaps the hardest part (really) is that if I did this you'd have to loan me a few genuine bars to calibrate it! (As well as the fake!)
If there IS anyone who wants such an instrument I do actually have relevant experience to develop such a thing and am looking for work right now. Please PM me. It wont be cheap for a 1-off instrument, but it WILL work (I'd do a better feasibility study first. and it could save you a small fortune!! ) It would also be pretty interesting in that I have never heard of such an instrument but am pretty sure I could make one.
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barbarousrelic
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September 27, 2012, 03:12:01 PM |
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Drop the coins on a table and listen to the ringing sound. Tungsten should sound different. Also, I am 90% certain you can't press tungsten the way that gold coins are minted. It's very brittle and hard. So the fine details on these coins are probably going to look different than on real minted coins. I would also like to hear from anyone who has seen these coins in person. I have my doubts.
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Do not waste your time debating whether Bitcoin can work. It does work.
"Early adopters will profit" is not a sufficient condition to classify something as a pyramid or Ponzi scheme. If it was, Apple and Microsoft stock are Ponzi schemes.
There is no such thing as "market manipulation." There is only buying and selling.
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jojo69
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diamond-handed zealot
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September 30, 2012, 11:43:23 AM |
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uhhhh, skin effect? So I'd like to ask the OP what it was that made him suspicious enough to risk cutting open a perfectly good bar? How did he know because I am not sure I would have been sure enough?
Next I would like to say that I am pretty sure that it would be quite a simple matter to measure the difference between filled and solid gold bars based on resistivity which would be a simple measurement to make in practice.
There are two key principles here - use a 4 terminal measuring device I would suggest that wooden or plastic block with contacts on the side and ends, could be used where the wooden block has an indentaion to match the exact size of gold bar. The principle of a 4 terminal resistance is that 2 terminals are used to inject a test current and 2 terminals used to read the voltage generated by this current. This cuts out completely voltage generated by poor contacts or leads.
Its not necessary to use a particularly large current - modern amplifiers are capable of accurately measuring very small offset voltages, and you are measuring a true differential voltage here that makes it a lot easier.
The last 'trick' which would add a little to the cost of what I have so far described a very simple cheap instrument, would be if it did in fact turn out to be too difficult to measure the offset voltage accurately due to offset noise in the amplifier. In this case you instead use an alternating current to perform the measurement and a synchronous decode to accurately measure the offset voltage. Such a decoder will reject all other frequencies including DC so that you only have the signal you want. I dont think this would be required, but it could be.
I can see that provided that you were happy to have an instrument that effectively only measured one size of gold bar, it would be very easy to devlop such an instrument. How could it be made more general purpose (to cater for many different sizes?). Not sure. To compare the same sized gold bar, its essential to have the contacts in the same place.
Indeed perhaps the hardest part (really) is that if I did this you'd have to loan me a few genuine bars to calibrate it! (As well as the fake!)
If there IS anyone who wants such an instrument I do actually have relevant experience to develop such a thing and am looking for work right now. Please PM me. It wont be cheap for a 1-off instrument, but it WILL work (I'd do a better feasibility study first. and it could save you a small fortune!! ) It would also be pretty interesting in that I have never heard of such an instrument but am pretty sure I could make one.
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This is not some pseudoeconomic post-modern Libertarian cult, it's an un-led, crowd-sourced mega startup organized around mutual self-interest where problems, whether of the theoretical or purely practical variety, are treated as temporary and, ultimately, solvable. Censorship of e-gold was easy. Censorship of Bitcoin will be… entertaining.
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Meni Rosenfeld
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September 30, 2012, 11:59:59 AM |
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uhhhh, skin effect?
That's only for AC of sufficiently high frequency, DC measurement should be fine.
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jojo69
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diamond-handed zealot
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October 03, 2012, 01:14:42 AM |
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uhhhh, skin effect?
That's only for AC of sufficiently high frequency, DC measurement should be fine. I guess you are right...but good grief, how much current are we talking to saturate a bar?
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This is not some pseudoeconomic post-modern Libertarian cult, it's an un-led, crowd-sourced mega startup organized around mutual self-interest where problems, whether of the theoretical or purely practical variety, are treated as temporary and, ultimately, solvable. Censorship of e-gold was easy. Censorship of Bitcoin will be… entertaining.
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Meni Rosenfeld
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October 03, 2012, 06:06:47 AM |
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uhhhh, skin effect?
That's only for AC of sufficiently high frequency, DC measurement should be fine. I guess you are right...but good grief, how much current are we talking to saturate a bar? IANAE but you don't "saturate" a bar. You apply a known voltage V and measure the current I, the resistance is R=V/I, you compare this against the resistance of a good gold bar (measured or calculated). You can do it with low current if you can measure things accurately enough.
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MrTeal
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October 03, 2012, 07:32:52 AM |
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uhhhh, skin effect?
That's only for AC of sufficiently high frequency, DC measurement should be fine. I guess you are right...but good grief, how much current are we talking to saturate a bar? IANAE but you don't "saturate" a bar. You apply a known voltage V and measure the current I, the resistance is R=V/I, you compare this against the resistance of a good gold bar (measured or calculated). You can do it with low current if you can measure things accurately enough. Make a couple assumptions here, but from Wikipedia an average size of a Good Delivery gold bar is 250mmx70mmx35mm. The resistivity of gold is 22.14nOhm*m. (22.14nOhm*m)*(.25m)/((0.07m)*(0.035m)) = 2259nOhm = 2.26uOhm If you had a bar of the same dimensions that was tungsten covered with a 5mm layer of gold, the bar would have an end to end resistance of 3.44uOhm. Something like this micrometer should be able to measure the difference reasonably well.
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mintymark
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October 03, 2012, 09:44:53 AM |
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Using low frequency AC and a 4 terminal resistance would work well, but there is an even better way to do this.
Use transformer with an airgap. (Operating around 50/60 Hz. Negligible skin effect at 50Hz.) A sheet of conducting metal inserted in the gap acts as shorted "turn" in the secondary of the transformer. The energy lost is detectable in the primary and is proprtional to the thickness of the metal and inversly so to its resistivity. So I believe that you could calibrate such an instrument in millimetres of gold and, well if it was actually mainly tungsten, then the reading would show as having a thickness of about one-fifth that observed in fact.
Certain assumptions need to be made about resistive and magnetic losses in the the core, the size of the airgap, the flux that does not go through the coin etc, but such an instrument could be made. It has to be designed correctly in short. And if it had an airgap 1cm by 1cm by 1cm this would allow its use on coins (there is a whole factory making fake tungsten gold coins in china, and has been for ten years so we have not seen the end of this!!) as well as 10oz bars. This seems to me much better than we previously discussed since it allows a measurement to be made without spiky contacts on your expensive polished gold bar, and it allows you to make a measurement even if you have not got a genuine bar to test against. You need a set of calipers and this instrument: thats all. In fact you can probably do it by eye anyway!! If your gold bar is 5mm thick and the instrument shows its thickness as 1mm, its tungsten!!
The most difficult part of the prototype is finding a suitable transformer type core that I can either hacksaw an airgap in. It needs to be laminated for low eddy-current loss at 50Hz.
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