Volume of average human brain to that of the Earth

Don't know how to calculate the area of your garden or circumference of a pond? Ask your question here.
Forum rules
Dear convert-me.com forum visitors,

Our forum has been available for many years. In September 2014 we decided to switch it to read-only mode. Month after month we saw less posts with questions and answers from real people and more spam posts. We were spending more and more resources cleaning the spam until there were less them 1 legitimate message per 100 spam posts. Then we decided it's time to stop.

All the posts in the forum will be available and searchable. We understand there are a lot of useful information and we aren't going to remove anything. As for the new questions, you can always ask them on convert-me.com FaceBook page

Thank you for being with us and sorry for any inconveniences this could caused.

Volume of average human brain to that of the Earth

Postby bholderness » Sat Apr 17, 2004 12:17 am

Hi, I'm doing a design project about space and thought it would be interesting to find out what fraction of the total volume of the earth an average human brain is. I have both figures in cubic meters:
human brain: .0013 cubic meter
earth: 1, 097, 509, 500, 000, 000, 000, 000 cubic meters

due to the gigantic disparity between the two numbers I am unsure how to convert this into a fraction that would make sense to non math people as to the magnitude of it.

Please let me know if you have any ideas. Thanks a lot!
bholderness
 

Re: Volume of average human brain to that of the Earth

Postby Knight » Sat Apr 17, 2004 5:06 am

bholderness wrote:Hi, I'm doing a design project about space and thought it would be interesting to find out what fraction of the total volume of the earth an average human brain is. I have both figures in cubic meters:
human brain: .0013 cubic meter
earth: 1, 097, 509, 500, 000, 000, 000, 000 cubic meters

due to the gigantic disparity between the two numbers I am unsure how to convert this into a fraction that would make sense to non math people as to the magnitude of it.

Please let me know if you have any ideas. Thanks a lot!

It was for reasons like this that Archimedes invented a notation for expressing large numbers.

In Archimedes' The Sand Reckoner, addressed to Gelon, King of Syracuse, he attempted to count the number of grains of sand required to fill the entire universe. Assuming that one poppy-head would not contain more than 10,000 grains of sand, and that its diameter is not less than 1/40th of a finger's breadth, and assuming that the sphere of the fixed stars, which was to Archimedes the boundary of the universe, was less than 107 times the sphere exactly containing the orbit of the sun as a great circle, he found that the number of grains of sand required to fill the universe turns out to be less than 10 raised to the 63rd power.

In modern notation, this would be written as 1x10^63, or 1.0e63.

Using that notation:
0.0013 m³ = 1.3e-3 (1.3 with the decimal point moved 3 spaces to the left)
1,097,509,500,000,000,000,000 m³ = 1.0975095e+21 (1.0975095 with the decimal point moved 21 spaces to the right)

Now, we can divide these really large numbers:

1.3e-3
-------------------- = 1.184e-24
1.0975095e+21

Now to convert this to a percentage: 1.184e-24 / 100 = 1.184e-26

So, the average brain is 1.184e-26 (or 0.000,000,000,000,000,000,000,000,0184) percent of the size of the earth.

By way of comparison, the total number of atoms in your body is about 1.0e+28. The total number of particles in the universe has been variously estimated at numbers from 1.0e+72 up to 1.0e+87. If the universe were packed solid with neutrons, there would still be only 1.0e+128 particles.
Knight
Expert
 
Posts: 309
Joined: Tue Jan 13, 2004 9:43 pm
Location: Los Alamos, NM

Describe

Postby Guest » Sat Jun 03, 2006 3:21 am

bholderness wrote:Hi, I'm doing a design project about space and thought it would be interesting to find out what fraction of the total volume of the earth an average human brain is.


You sure "about" is the best way to describe it?
Guest
 


More info

  • List of all units you can convert online
  • Metric conversion
  • Convert pounds to gallons
  • Convert grams to cups
  • Grams to milliliters
  • Imperial vs US Customary
  • History of measurement
  • Return to Calculating things



    Our Privacy Policy       Cooking Measures Converter       Metric conversions