Golden Coin Probability Calculator

Golden Coin Probability Calculator

To view this page, you should have the most recent Java installed 32-bit JRE (Java Runtime Environment) 1.8.0_20.
This Applet will run online in your browser, but it is a hybrid you can also download, install and run it on your own machine as standalone application. It will start and run faster if you do that. It will also work safely even if you have disabled Java in your browser.

This Applet, on the surface is very simple. It calculates your odds of getting N heads in a row tossing a coin. It also works when the coin is weighted. The same math also applies to anything you repeat over and over with the same odds. For example, what are you odds of escaping nuclear war for 80 years given the odds of escaping it one year. What are your odds of avoiding an earthquake for 90 years given the odds of having an earthquake in a given year. Using the probability enformation in the HIV Safe Sex tables, It can compute your odds of getting AIDS (Acquired Immuno-Deficiency Syndrome) given what you do and how often you do it.

The Myth Of the Golden Coin

Mankind does a number of things that amount to what the people in this mythical kingdom do. Every year the people gather and toss a large golden coin. The coin is heavily weighed to come up heads. If it comes up heads all is well for yet another year. However, if it ever comes up tails, the people explode all their nuclear weapons, release all their biotoxins and nerve gases, and their secret weapons and kill everyone. You can use the Applet below to see roughtly how long this civilisation lasts given how weighted the coin is.

Under Construction

Applet failed to run. No Java 1.7 or later plug-in found.

How to Use the Applet

Mathematician talk of probabilities rather than odds. If a coin every single time came up heads without fail because it was designed to, we would say it came up heads with probablity 1. If it came up tails every single time, we would call that probability 0. If it came up heads helf the time (a true coin), we would call that propability .5. If the coin came up heads ¾, then we would call than probability .75. Let’s say you entered .75 in the box labelled probability then entered 50 which means you are interested in the odds of getting 50 heads. The Applet will calculate a graph, showing you the odds of getting heads once, twice … all the way up to 50 times. You see the plunging toward 0 as the number of trials increases. It is realitively easy to get short strings of heads with a weighted coin, but even with that advantage, the effect of even one failing toss ruins the odds.

Let’s do a nuclear power accident. Throwing heads means running the plant for a whole year without it melting down. The odds are pretty good of doing this. You can estimate them by counting the number of nuclear plants, the total number of plant-years they have operated, and the total number of meltdowns. To do the calculation for a single plant, compute the odds of a good year as (1 - probability of plant having an accident in a given year). Put that in the probability slot in the Applet. Then pick a number of trials, say 90 years (the projected lifespan of some child you care about). You can handle an accident or terrorist attack that detonates nukes, releases biowarfare, releases chemical weapons, a really nasty industrial accident, earthquake similarly.


The formula this program uses r = pt only applies when the trials are independent, i.e. knowing the outcome of one trial does not give you a way to predict the next. For example, you could not use it on cicada populations since they have a regular seventeen year pattern. You could not use it for earthquakes which have a rough cycle and aftershocks.

Java Requirements and Troubleshooting

GoldenCoin is a signed Java Applet (that can also be run as an application) to GoldenCoin Probability Calculator. You are welcome to install it on your own website. If it does not work…
  1. For this Applet hybrid to work, you must click grant/accept/always run on this site/I accept the risk to give it permission to allow variable look and feel. If you refuse to grant permission, the program may crash with an inscrutable stack dump on the console complaining about AccessController.checkPermission.
  2. In the Java Control Panel security tab, click Start ⇒ Control Panel ⇒ Programs ⇒ Java ⇒ Security, configure medium security to allow self-signed and vanilla unsigned applets to run. If medium is not available, or if Java security is blocking you from running the program, configure high security and add to the Exception Site List at the bottom of the security tab.
  3. Often problems can be fixed simply by clicking the reload button on your browser.
  4. Make sure you have both JavaScript and Java enabled in your browser.
  5. Make sure the Java in your browser is enabled in the security tab of the Java Control panel. Click Start ⇒ Control Panel ⇒ Programs ⇒ Java ⇒ Security ⇒ Enable Java Content in the browser.
  6. This signed Java Applet (that can also be run as an application) needs 32-bit or 64-bit Java 1.7 or later. For best results use the latest 1.8.0_20 Java.
  7. You also need a recent browser.
  8. It works under any operating system that supports Java e.g. W2K XP W2003 Vista W2008 W7-32 W7-64 W8-32 W8-64 W2012 Linux LinuxARM LinuxX86 LinuxX64 Ubuntu Solaris SolarisSPARC SolarisSPARC64 SolarisX86 SolarisX64 OSX
  9. You should see the Applet hybrid above looking much like this screenshot. If you don’t, the following hints should help you get it working:
  10. Optionally, you may permanently install the Canadian Mind Products code-signing certificate so you don’t have to grant each time.
  11. If the above Applet hybrid appears to freeze-up, click Alt-Esc repeatedly to check for any buried permission dialog box.
  12. If you have certificate troubles, check the installed certificates and remove or update any obsolete or suspected defective certificates. The only certificate used by this program is mindprodcert2014dsa.cer.
  13. Especially if this Applet hybrid has worked before, try clearing the browser cache and rebooting.
  14. To ensure your Java is up to date, check with Wassup. First, download it and run it as an application independent of your browser, then run it online as an Applet to add the complication of your browser.
  15. If the above Applet hybrid does not work, check the Java console for error messages.
  16. If the above Applet hybrid does not work, you might have better luck with the downloadable version available below.
  17. If you are using Mac OS X and would like an improved Look and Feel, download the QuaQua look & feel from UnZip the contained quaqua.jar and install it in ~/Library/Java/Extensions or one of the other ext dirs.
  18. Upgrade to the latest version of Internet Explorer or another browser.
  19. Click the Information bar, and then click Allow blocked content. Unfortunately, this also allows dangerous ActiveX code to run. However, you must do this in order to get access to perfectly-safe Java Applets running in a sandbox. This is part of Microsoft’s war on Java.
  20. Try upgrading to a more recent version of your browser, or try a different browser e.g. Chrome, Firefox, SeaMonkey, Opera, Safari or Avant.
  21. If you still can’t get the program working click the red HELP button below for more detail.
  22. If you can’t get the above Applet hybrid working after trying the advice above and from the red HELP button below, have bugs to report or ideas to improve the program or its documentation, please send me an email atemail Roedy Green.
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Why I wrote This Applet

When I went to UBC (University of British Columbia), I specialised in propability and statistics. There are so many astounding things you learn that the general public never hears about. One of the first things you learn is the way things that are highly improbable become inevitable if you risk them often enough. Humans tend to grossly underestimate the long term effects of repeating a risky behaviour (such as having unsafe sex or maintaining arsenals of nuclear or biological weapons or building nuclear reactors). I hope this non-emotional, mathematical approach will let people discover for themselves how risky much of mankind’s behaviour is.
1.0 2011-06-12 free Java
more infoprecisscreenshotbrowse source repository
for the current version of GoldenCoin.
Computes probability including odds or thrown heads N times in a row.
download 555K zip for GoldenCoin Java source, compiled class files, jar and documentation to run on your own machine either as an application or an Applet.

Runs on any OS that supports Java e.g. W2K XP W2003 Vista W2008 W7-32 W7-64 W8-32 W8-64 W2012 Linux LinuxARM LinuxX86 LinuxX64 Ubuntu Solaris SolarisSPARC SolarisSPARC64 SolarisX86 SolarisX64 OSX.

First install the most recent Java.

To install, extract the zip download with WinZip, (or similar unzip utility) into any directory you please, often J:\ — ticking off the use folder names option.

To check out the corresponding source from the Subversion repository, use the TortoiseSVN repo-browser to
access goldencoin source in repository with [Tortoise] Subversion client on

After you have installed the jar, you can run it as an application. Type:

java -jar J:\com\mindprod\goldencoin\goldencoin.jar

adjusting as necessary to account for where the jar file is.

download ASP PAD XML program description for the current version of GoldenCoin.

$1989.00 US donated so far. If the CMP utilities solved your problem, please donate a buck or two, or donate to one of the charities featured in the footer public service ads throughout the website and get a tax receipt.

GoldenCoin is free. Full source included. You may even include the source code, modified or unmodified in free/commercial open source/proprietary programs that you write and distribute. Non-military use only.

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