Radioactive Dating: Take Your Programming Skills Nuclear *
Difficulty  
Time Required  Short (25 days) 
Prerequisites  Familiarity with a programming language and basic programming algorithms 
Material Availability  Readily available 
Safety  No issues 
Abstract
Have you ever wondered how it's possible to so accurately date ancient artifacts? Geologists, paleontologists, archeologists, and anthropologists use a statistical process like radioactive isotope decay to date objects through a method called radioactive dating (also known as radiometric dating). To learn more about that method, check out the geology science project How Old Is That Rock? Roll the Dice & Use Radiometric Dating to Find Out. In that particular Project Idea, radioactive decay of isotopes is modeled by rolling dice. While that procedure is a great way to grasp the concept, it would certainly be a timeconsuming and tedious process in the real world, even with samples of only 100 dice, which could scarcely be called a "large number." Furthermore, how many trials of rolling up to 100 dice over and over again—while accurately keeping track of the results—would you be willing to do by hand? The most motivated student will only get to a pretty small number of trials. Why not get the help of a computer to do this repetitious work for you?A computer program can help you create a simulation of what would happen in real life. In this Abbreviated Project Idea, you will simulate the decay of radioactive isotopes. To get started, do you know how to program a random event like rolling a die or a decaying isotope? The tool you will use for this is called a pseudorandom number generator, which creates almostrandom numbers on a computer. This will set you on the path to generating a radioactive decay curve on your computer. At the end of this Abbreviated Project Idea, you'll find some suggestions on how you can incorporate this information into a computer science project.
As you roll a standard sixsided die, you know each number from 1–6 has an equal chance, or probability, to land on top; but you cannot predict which exact number it will be on your roll. This type of process is called a random process. So how can you generate a sample of random numbers by using a perfectly logical machine like a computer? Most programming languages have a random number generator. This is a function that will provide you with an almostrandom (or pseudorandom) number. Check out the references provided in the Bibliography section to get a feel for the difference between true randomness and computergenerated randomness, as well as some information about how computers generate these numbers. To test whether or not these pseudorandom numbers can help generate the outcome of rolling dice or predict how isotopes decay, start by looking up the random number generator function for your choice of programming language and read trough its specifications. As an example, in Microsoft® Excel® (a spreadsheet program), RAND() generates a random real number between 0 and 1. The RAND() function in Excel clearly is not going to do the job. You might be lucky; the programming language of your choice might be able to provide a random integer between 1 and 6—exactly what you would get from rolling one die. If not, do you know how to translate a random real number between 0 and 1 to a random integer between 1 and 6?
The algorithm below will guide you to the formula.
 First, transform the random real number between 0 and 1 to a random real number between 1 and 7. You can do this by multiplying the generated number by 6 and adding 1, as shown in the formula below:
Formula 1:
Can you verify this result in a random real number between 1 and 7?
 Then, round this number down to its nearest integer. In Excel, the function INT will do this for you. You can program this functionality yourself, or look up the function for rounding in your choice of programming language. Formula 2, below, lists the final formula for Excel.
Formula 2:
Can you verify this result is a random integer number between 1 and 6?
Now you only have to execute this formula 100 times, and store the numbers, to generate a sample of numbers you might get by rolling 100 dice.
The geology science project How Old Is That Rock? Roll the Dice & Use Radiometric Dating to Find Out can help you translate the result of rolling 100 dice to the decay of 100 isotopes and explains how to add a time component and how to generate a decay curve.
Start by generating a decay curve for an isotope that decays with a chance of 1/6 in 1 time unit.
Here are some suggestions to expand your exploration:
 Investigate how the decay curve changes when you use a larger number of initial isotopes to generate your decay curve.
 Investigate how the decay curve changes as the decay probability of your isotope changes. What does it look like for a shortlived isotope (an isotope with a higher probability of decaying in 1 time unit) or a longlived isotope (an isotope with a lower probability of decaying in 1 time unit)?
 Some isotopes have several decay paths; they decay with a specific probability to one daughter isotope, and with a different probability to a different daughter isotope. As an advanced challenge, can you change the model to accommodate for these decay patterns? Can you graph a decay curve and make predictions using these decays?
 Some isotopes have a decay chain; they decay with a specific probability to a first daughter isotope, which in turn is unstable and decays with a specific probability into a final (stable) isotope. As another advanced challenge, can you change the model to accommodate for this decay pattern? Can you graph a decay curve for these decays?
Share your story with Science Buddies!
Yes, I Did This Project! Please log in (or create a free account) to let us know how things went.Credits
Sabine De Brabandere, PhD, Science Buddies
Cite This Page
General citation information is provided here. Be sure to check the formatting, including capitalization, for the method you are using and update your citation, as needed.MLA Style
APA Style
Last edit date: 20181203
Bibliography
 Random.org. (n.d.). Introduction to Randomness and Random Numbers. Retrieved April 22, 2013, from http://www.random.org/randomness/
 HowStuffWorks. (n.d.). How can a totally logical machine like a computer generate a random number? Retrieved April 21, 2013, from http://computer.howstuffworks.com/question697.htm
News Feed on This Topic
Share your story with Science Buddies!
Yes, I Did This Project! Please log in (or create a free account) to let us know how things went.Ask an Expert
The Ask an Expert Forum is intended to be a place where students can go to find answers to science questions that they have been unable to find using other resources. If you have specific questions about your science fair project or science fair, our team of volunteer scientists can help. Our Experts won't do the work for you, but they will make suggestions, offer guidance, and help you troubleshoot.Ask an Expert
Related Links
If you like this project, you might enjoy exploring these related careers:
Computer Programmer
Computers are essential tools in the modern world, handling everything from traffic control, car welding, movie animation, shipping, aircraft design, and social networking to book publishing, business management, music mixing, health care, agriculture, and online shopping. Computer programmers are the people who write the instructions that tell computers what to do. Read moreGeoscientist
Just as a doctor uses tools and techniques, like Xrays and stethoscopes, to look inside the human body, geoscientists explore deep inside a much bigger patient—planet Earth. Geoscientists seek to better understand our planet, and to discover natural resources, like water, minerals, and petroleum oil, which are used in everything from shoes, fabrics, roads, roofs, and lotions to fertilizers, food packaging, ink, and CD's. The work of geoscientists affects everyone and everything. Read moreStatistician
Statisticians use the power of math and probability theory to answer questions that affect the lives of millions of people. They tell educators which teaching method works best, tell policymakers what levels of pesticides are acceptable in fresh fruit, tell doctors which treatment works best, and tell builders which type of paint is the most durable. They are employed in virtually every type of industry imaginable, from engineering, manufacturing, and medicine to animal science, food production, transportation, and education. Everybody needs a statistician! Read moreNews Feed on This Topic
Looking for more science fun?
Try one of our science activities for quick, anytime science explorations. The perfect thing to liven up a rainy day, school vacation, or moment of boredom.
Find an ActivityExplore Our Science Videos
Slow Motion Craters  STEM Activity

DIY Toy Sailboat

Why Won't it Mix? Discover the Brazil Nut Effect
