| 1461/
While we do not use the original Babylonian calendar today,
our division of the day into 24 hours, or 24 x 60 = 1440 minutes,
and 24 x 60 x 60 = 86,400 seconds, comes from Babylonia. The
Babylonians employed a positional notation that is similar
to the modern decimal system, but their notation was sexagesimal
ie based on powers of 60 instead of 10. Remnants of this system
are still in use to this day: the circle is divided into 360
degrees, a degree into 60 minutes, and a minute into 60 seconds.
1462/ Julius Caesar had,
at the suggestion of Greek astronomers, improved the Egyptian
calendar by adding a leap day every four years at the end
of the Roman calendar (ie to February). Furthermore, one day
was eliminated from February, so that the two months named
after Julius Caesar and Augustus could have the same number
of days, 31 each.
1463/ The Julian calendar
year has a length of 365.25 days. Since the solar year is
shorter than the Julian calendar year by 0.0078 years, by
the sixteenth century, an error of nearly 13 days at the beginning
of the year had accumulated since Julius Caesar introduced
the calendar in 46 BC.
1464/ The 13 day error
between the solar year and the Julian calendar year was finally
corrected under Pope Gregory XIII by having October 15th succeed
October 4th, 1582, without interrupting the normal sequence
of the days of the week. The beginning of spring was defined
to be March 21st. According to the new leap rule, leap years
are years whose last two digits are divisible by four. To
correct for the slightly shorter length of the solar year,
3 leap years are omitted every 400 years, and to that end,
leap days are omitted in the secular years whose unit is not
divisible by 4. Accordingly, the years 1700, 1800, and 1900
were not leap years, but 2000 was one again. It will take
3333 years before the remaining errors will have grown to
a whole day.
1465/ The mechanical
geared clock was invented between 1300 and 1350.
1466/ The term 'allergy'
is derived from two Greek words which mean "altered reactivity".
That is, an allergy is an adverse reaction to a normally harmless
substance which may be a food or other environmental agent
such as dusts, pollens or chemicals.
1467/ The Sun, the closest
of all stars to the earth, is 150 million kilometres away.
This distance is known as an "Astronomical Unit"
or AU.
1468/ Other stellar distances
are so great that a 'light year' is used to measure them.
This is the distance a ray of light will travel in a year
at a speed of 300,000 km per second. Given 31 million seconds
in a year, the light year contains 63,240 AU.
1469/ In the second century
BC, the Greek astronomer Hipparchus divided the stars into
six brightness categories called 'magnitudes'. The first magnitude
stars were the brightest, while sixth was the faintest he
could see. The system, still in use today, is now placed on
an exact mathematical scale, wherein five magnitudes correspond
to a factor (ratio) of 100 in actual brightness. A first magnitude
star is thus 100 times brighter than a sixth magnitude star,
so that each magnitude unit is 2.51... times brighter than
the next one down.
1470/ The exact scaling
method led to the very brightest stars to climb to magnitudes
of zero, or even minus. The Sun, because it is so close to
us and therefore intensely bright, is minus 27th.
1471/ The Hubble Telescope
is able to discern stars that are approaching magnitude 30
on this scale. That is stars that are 4 billion times fainter
than the human eye can see alone.
1472/ As far as we currently
know, the star SGR 1900+14 in Sagittarius, carrys the strongest
magnetic field in the Universe with an astonishing 100 trillion
times Earths.
1473/ The ancient Egyptians
called Sirius the 'dog star', after their god Osirus, whose
head in pictograms resembled that of a dog. In Egypt, Sirius
shines for most of the summer, and since it is such a bright
star, the Egyptians actually believed that the additional
light from this nearby star was responsible for the summer
heat. This of course is not true. However the origin of the
phrase 'the dog days of summer' comes from this ancient belief
- the 'dog star' being the root of this common saying!
1474/ It has been calculated
that a man's sperm volume relative to his body weight is in
fact twice that found in primate species which are known to
be monogamous.
1475/ The three brightest
stars, Sirius, Canopus and Alpha Centauri are all in the Southern
Hemisphere. The Northern Hemisphere contains the next three,
Arcturus, Vega and Capella.
1476/ In a study of 79,000
pregnancies in sixteen countries around the world, 66 per
cent of the women reported that they had suffered some degree
of sickness during the early stages of their pregnancy; with
nearly a third reporting a strong aversion to animal products,
particularly meat, fish and eggs.
1477/ The reason that
just dieting without exercise seldom works for long is that
as you start to reduce the amount of food you consume, your
body recognizes this as a famine and immediately slows down
your metabolic rate. Even a minimal weight loss of a pound
(450 kg) a week will trigger this response. Hence, the moral
of the tale is to also exercise in order to boost your metabolic
rate.
1478/ Almost all of the
developments a human baby will experience in its first year
- advances in cognition, motor skills and vision - have already
taken place in a baby chimpanzee while in the uterus.
1479/ If a top violinist
is placed into an MRI scanning machine, we can see that a
much larger area of the brain - the right primary motor cortex
- is devoted to his or her left fingers when compared with
a non-violinist. Two or three times as large, in fact. Violinists
also have more connections between the two sides of the brainwhich
account for the better co-ordination they have between each
hand compared with a non-violin player.
1480/ Ancient Greek mathematician,
and general to goodness guru, Pythagoras held that there was
a precise mathematical formula for the perfect face. In order
for someone to be considered 'beautiful', the ratio of the
width of the mouth to the width of the nose should be 1.618
to 1. This figure should also hold for the ratio of the width
of the mouth to the width of the cheekbones. Measure the faces
in a magazine for yourself. It is interesting how often the
models that we hold up as 'beautiful' fit this mathematical
profile.
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facts...
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