Search All of the Math Forum:
Views expressed in these public forums are not endorsed by
NCTM or The Math Forum.


Posts:
822
Registered:
9/1/10


Re: If you bring together the entire world population and split the people into groups of 365 people, 1% of the people can be placed into groups composed of entirely unique birthdays.
Posted:
Jan 26, 2013 3:44 PM


On Jan 26, 8:07 am, karl <oud...@nononet.com> wrote: > Am 26.01.2013 12:56, schrieb Musatov:> Bringing together any possible group of 366 people guarantees with > > 100% certainty two people will share the same birthday. > > wrong. You have, including the 29th February, 366 different dates for a birthday.
No, I just prove the existence of the false calculation of a distributive cycle of an extra day and the entire existence of the 400 day Devonian period per research The fish of the Devonian Period experienced rather short days. We know that the Devonian year had 400 days, making each day only 22 hours long.(72 kb) This just goes to show that nothing is constant on Earth, not even the length of a day! Just as continents move and change direction, the speed at which our planet rotates also changes over time.
How is this possible? It is really the fault of the Moon, our celestial companion. Since it formed 4.2 billion years ago (4.2 Ga), the Moon has driven the tides on our planet. The Moon?s gravitational pull attracts great masses of water toward it while in orbit around us. As the Earth turns eastward, the tides move westward, and this phenomenon imperceptibly slows the rotation of our planet by 0.0016 seconds per century!
Our planet was therefore turning faster in the past, such that each year consisted of more, but shorter, days. Though the features of the Earth may change, the laws of physics are constant. In a binary system like the Earth and Moon, if one of the two companions loses momentum, the other must gain momentum. Over time, as Earth?s rotation slows, the orbital velocity of the Moon increases, forcing it to gradually recede away from us. Using lasers, we have confirmed this movement and found it to be 3.8 centimetres per year. This may seem too small to make a real difference, but when added up over hundreds of millions of years, we can calculate that the Moon is now twice as far from Earth as it was during Devonian time. As a consequence, Devonian tides were up to seven times larger than today?s tides.
These physics calculations have been verified by paleontological discoveries. One line of evidence comes from corals. Corals, both living and fossilized, are animals that live inside little cups of calcium carbonate (calcite; CaCo3) that they themselves secrete. The coral ?skeleton? grows because the animals deposit calcite every day they are alive. The activity temporarily stops at night because the animals live symbiotically with singlecelled algae that need light to function. The daily layers are visible under a microscope, making it possible to count days, somewhat like counting tree rings to determine the passage of years.
Species that live in temperate waters are subjected to seasonal variations in temperature, so winter growth is slower and the marks farther apart. Years are therefore easily distinguished among the series of growth lines. A modern coral would show us years consisting of 365 lines.
Coral fossils living 400 million years ago (400 Ma) in the Early Devonian display years of 400 lines, and thus 400 days, proving that the Earth did indeed turn faster at that time. For corals that lived during the Upper Carboniferous (300 Ma), there are approximately 380 lines each year. The fossil record thus clearly demonstrates that Earth?s rotation has gradually slowed over time, and that it is still slowing down today.http://www.miguasha.ca/migen/a_devonian_day.php
On Sat, Jan 26, 2013 at 8:50 AM, Brian Gordon <briang@panix.com> wrote: In article <360bc6637c174f139677 bce6bef397a7@r10g2000pbd.googlegroups.com> you write: >Bringing together any possible group of 366 people guarantees with >100% certainty two people will share the same birthday.
Close, but no cigar. You forgot about February 29, so it takes 367 for certainty :)
 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++  Brian Gordon >briang@panix.com< brian dot gordon at cox dot net  + brianggordon@hotmail.com Bass: Lexington "Main Street Harmonizers" chorus + 
 Martin Musatov
Tel: (818) 4304586 Email: marty.musatov@gmail.com


Date

Subject

Author

1/26/13



1/26/13


karl

1/26/13




