Kotlorz Chorynskowice

RADIO MEASUREMENT OF THE EARTH by Eratosthenes

As was done last year in many schools in Spain an experiment that many years ago and had made great Eratosthenes, but this from Alexandria.

This experiment was performed by 4th year students of the College Base on 23 March. 4 pupils began that than from 9.30 am (approximately) until 12 am (time it went down to the patio students 4 ESO B) were taking measurements every 10 minutes of which was the shadow of the gnomon of our disposal, until 2 in the afternoon, it took us to this:

-gnomon and clock

-bolígrafo y metro

-papel

Unfortunately at times we lacked an essential element as the clouds have often kept the sun in the shadow of the gnomon out.

But that has not been a problem since, as we knew the rest of the points we were easy to calculate the rest. Students in 4 ESO B finished the experiment environment at 2 noon.

The steps we were:

First glue the paper on the floor with zeal to not fly later paste the gnomon so that its shadow was over the paper in order to take action on it.

With all the brands we did we realized that we went a sort of arch, but these measures were not served as an afternoon get together the two groups and what we did was draw an arc longer using a compass

Once all these steps we were ready to end this experiment:

• We choose a school among those who had done this experiment and decided to take the IES River of the grains found in Jaén, and it was that that it had almost equal measures than ours.

  
  

But to calculate all needed to know some information like the distance between the two schools (310 km) and latitude found in our school (41.04 º) and another school (52.25 º). Once we knew that we got down to work.

When we started we realized we had not done properly, because the angle of our school did not match that should be as far as we began to think and gave us realized that by some estimates it could take so here did the following:

x = 180 ° - 90 ° + 41.04 ° = 48.96 °

With this information and whether we could continue the experiment .

a = 180-a1-(180-a2) = a2-a1

So knowing this:

52.25 ° -48.96 ° = 3.29 °

And thanks to this last fact we are down to do the last two steps

360-360

3.29-d

d = 39392.09 km

and last but not least

39392.09 km / 2Л = 6269.44 km (radius of the earth according to our calculations)

The radius of the earth is actually 6378, so we conclude that our calculations have not been as erroneous as failures that may have been committed are measurement errors.

With this video we can understand more easily the work done:

http://www.youtube.com/watch?v=EPT574BveWA