To view this page, you should have the most recent Java installed
32-bit JRE (Java Runtime Environment) 1.8.0_11.
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.
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
If, GoldenCoin, the above GoldenCoin Probability Calculator signed Java Applet (that can also be run as an application) does not work…
Often problems can be fixed simply by clicking the reload button on your browser.
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_11.
In the Java Control Panel, configure medium security to allow vanilla unsigned applets to run.
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
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:
For this Applet hybrid to work, you must click grant/accept 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.
If the above Applet hybrid appears to freeze-up, click Alt-Esc repeatedly to check for any buried permission dialog box.
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.
Especially if this Applet hybrid has worked before, try clearing the browser cache and rebooting.
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.
If the above Applet hybrid does not work, check the Java console for error messages.
If the above Applet hybrid does not work, you might have better luck with the downloadable version available below.
If you are using Mac OS X and would like an improved Look and Feel, download the QuaQua look & feel from randelshofer.ch/quaqua. UnZip the contained quaqua.jar and install it in ~/Library/Java/Extensions or one of the other ext dirs.
If you are using Microsoft Internet Explorer 7, 8 or 9, try another browser. Seriously. Microsoft has taken great pains, over and over, to screw up Java and every other multi-platform standardisation.
If you are using Microsoft Internet Explorer 7, 8 or 9, you must click to allow blocked content permission for Active X to run. This also gives permission to Java to run. 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. Don’t put up with it! Use a different browser.
If you are using Microsoft Internet Explorer 9, makes sure the Java Plug-In SSV helper add-in is installed and enabled.
If it is not, try reinstalling the Java JRE.
If you have Windows 7 64-bit
and Internet Explorer 64-bit,
in theory you can use 64-bit Java,
but I never been able to get it to work.
Try upgrading to a more recent version of your browser, or try a different browser e.g. Firefox, SeaMonkey, Safari or Avant.
If you still can’t get the program working click HELP for more detail.
If you can’t get the above Applet hybrid working after trying the advice above and from the HELP button below, have bugs to report or ideas to improve the program or its documentation, please send me an email at.
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.
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.