All sorts of things - The largest prime number. Pi number records.

 ─── All sorts of stuff ───

     ENIAC - the first electronic compu-
ter.  Abbreviate of the Electronic Numeric
Integrator And Computer. Went in to operate
February 15, 1946. Today placed in the Mu-
seum of Pennsylvania University. Contains
15,000 electronics lamps, 10,000 condensa-
tes and 70,000 resistors. Room used 140
m.sq.  Speed ​​is 5,000 op/sec. Weight about
15 tons.

     (ETSIK - the first electronic computer
ter. The abbreviation is revealed as: Elect-
ronal Digital Integrator And Computer.
Entered work on the fifteenth of February 1946
year.  Today it is in the Museum at
University of Pennsylvania.   Contains
15,000 vacuum tubes, 10,000 condenser
ditch and 70,000 resistors. Occupies a room
with an area of 140 square meters. Speed -
5000 operations per second. Weight approximately 15
tons - transl. editor-in-chief)

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     Peeling an apple must be every one of
tried to cut us off as long as possible
new strip of peel. American Katie Wyfler
took this entertainment seriously, chose
grabbed a particularly large apple, armed herself
with a sharp knife and cut off a continuous line of
that length is 52 m 54 cm. The result is entered in
"Guinness Book of Records".

   "Science and Life" 7/1990

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     The largest prime number.

     As you know, prime numbers are
which are divisible without remainder only into
one and itself, for example, 2, 3, 5,
7, 11, 13...

     The search for prime numbers began in III
century BC, when Euclid proved that they
the clutter must be infinite. But a number
prime numbers known to mathematicians
slowly until computers appeared that could
quickly check the divisibility of huge numbers.
Thus, the largest prime number known
new in 1952, contained 157 digits, and in
1985 - 65,050. Now the American group
many mathematicians, using a powerful computer,
surpassed the 1985 record and received pro-
that number consisting of 65,087 digits. For
it took more than a year of work,
had to check 350,000 candidates for
honorary rank, dividing each of these numbers
for several billion known simple ones.

     The search for such numbers is interesting not only
from a theoretical point of view. It allows
improve calculation methods, test
vat computers. In addition, the theory of simple
number of numbers is used in cryptography -
for developing ciphers.

   New Scientist, No. 1682, 1989

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          More precisely, even more precisely

     The Bible says that by command
King Solomon was made round copper
a vessel with a diameter of 10 cubits,and the circle
in 30. Therefore, pi (ratio
circumference to its diameter) with the then
the accuracy of measurements was taken equal to three.
     Ancient Egyptian surveyors and architects
Thors believed that the circumference was greater
its diameter is 3.16 times. Ancient Romans
were mistaken in the other direction: they believed
pi equals 3.12. However, for technology
at that time such accuracy was quite
sufficient.  In the 16th century, the number pi was
already calculated with an accuracy of 35 characters
after the comma.  For almost a hundred years the record is accurate
ity remained with the English mathematician
W. Shanks, who for twenty years handed-
I outputted pi with 707 decimal places.
     When did the first computers appear?
more and more decimal places of pi
has become a kind of sport for programmers
comrades and operators.  It was found that
Shanks made a calculation error [by 536 digits]
ke].  Already in 1962 the number was obtained
pi with 100,000 digits, reached in 1973
millionth milestone.
     Latest achievements in this area
Japanese mathematicians Yoshiaki Tamu achieved
ra and Yasumasa Kanada. Last year they
calculated in 7.2 hours of computer time
number pi with 2,097,152 [2^21] signs after-
le comma. Then, using the faster one
computer, received 4,194,304 in 2.9 hours
[ 2^22 ] digits, and in 6.8 hours - 8,388,608
[2^23] characters. If the plans of mathematicians are not
will fall apart by the time they leaveprint this-
th numbers they will have number pi s
16,277,216 [2^24] signs.
     What is the purpose of such research if
even for the most accurate engineering calculations
Is it enough to have 5-6 decimal places?
Firstly, this is a good test of the possibility
features of modern computers. Secondly, mathematics
ticks are wondering if there is infinitely
a long “tail” of some order,
for example, does it appear somewhere in his
given a natural sequence of numbers
(123456...).

   Scientific American N2, 1983

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         Pi number records

     For the most accurate calculations, it is sufficient
but there are at most 10-15 digits of the number
pi after the decimal point. But for a long time already mathematicians
compete in computing more and more new
signs of this infinite fraction.
     Earlier this year, a supercomputer
installed in one of the research
NASA centers, in 28 hours of work issued
pi with 29,360,128 decimal places
that one.  For this purpose, a new
program.  The author of the program believes that
will soon receive 60 million with her help
decimal places.
     Using our own algorithm,
a group of Japanese mathematicians hopes to enrich
to get Americans by getting 33 to begin with
million, and then a hundred million characters.
Although such accuracy has nopractical meaning, calculating pi with everything
a large number of decimal places
le comma can serve as a kind of
testing the capabilities of modern
COMPUTER.

   Science News, v. 129, No. 6, 1986

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     As is known, the old unit of power
"horsepower" (735.5 watts in conventional
units) is actually significantly
greater than the value that the average lo-
a shad is capable of developing some
for a long time. And yet, when the horse creates
does it give that much power? This question is answered
says one of the authors of the magazine "American Sa-
yentist": one horsepower
develops a horse weighing 750 kilograms,
jumping over an obstacle wide
and a height of 183 centimeters.

          "Science and Life" 12/1987



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