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Putting Time In Perspective

Java Calculator

Instructions
Sample entry and result

Scale = 4.5e9  or 4500000000 (a current estimate for the age of the Earth - 4.5 billion years)
# of years ago = 1.2e5 or 120000 (a current estimate for the appearance of modern humans - 120,000 years)
Calculated result = The event appears on December 31 at 11:45:58 pm

The Calculator Sun's Java plug-in is needed to view this page

 

 

 

 

 

 

Instructions
Sample entry and result

Enter the scale and the # of years ago your event took place in the spaces provided above. Click in one of the spaces to start data entry there.  Be certain to enter only whole numbers WITHOUT commas or other separators. (Scientific notation is accepted.)  When you have entered data in both spaces, click the CALCULATE button.  You may calculate as many sets of numbers as you like.

If you compare, you may find that the results obtained from this page are sometimes 1 second off those calculated manually, or with the Excel workbook.   I suspect that this is the result of a known problem with the precision of Java floating point calculations.  Sun's Java programmers may make these calculations more precise in the future.  At that point, the discrepancy should disappear.

The calculator is ready to use when the data entry prompts and the CALCULATE button appear above.  If you do not see the prompts and button, and you want to use the calculator, you'll need to download and install a JAVA enabled web browser.  If your browser is JAVA capable, you need to make certain that its JAVA capabilities are not disabled.

If you're curious to know happens when you click the calculator's Calculate button, click here.  After you've read and/or printed the page that will appear here, click your browser's Back button to return to this page.


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copyright 1998-2004 classroomtools.com. All Rights Reserved.
original web posting: Wednesday, September 9, 1998
last modified: Tuesday, March 16, 2004