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Thursday, October 15, 2009
Saturday, October 3, 2009
Hypoglycemia And Thrush'
SOLAR TIME, TIME LEGAL. - I -
Trying to understand time.
in the previous release for the sundial azimuthal quadrant had highlighted the phenomenon of the time displayed by the clock "mechanical" and that shown by the sundial for the time differed from the picture in about 20 minutes and This lack of agreement was interpreted by people as a defect in construction or design of the sundial, forgetting the fact that our watch is who in any case we would be lying on the hour. No matter
the way on how you look, but the Sun that governs our lives since the beginning of time. It is the Sun which tells us when to leave and when to return. It's the Sun that inspires and feeds, not all cultures in vain they worship Him, either endian or just bronze ... and the Sun with whom you try to set the hours and day length.
try to be brief and explicit in a very confusing topic and wide, trying to clear our concern for the cause of the discrepancy between solar time and clock time "mechanic." Although today most of our watches are electronic, we will define as "mechanical" all man-made clocks and whose hours regularly pass every day.
The establishment of "time", has proven to be an astronomical task quite difficult and this is evidenced by the existence in the "times" following
Sidereal Time.
Time.
True Solar Time, or Time.
mean solar time.
Civil Time.
Astronomical Clock.
Standard Time (Official Time).
Universal Time (UTC), among others. Before proceeding
remember a little regard to geographical and celestial coordinates.
relying on the figure below, in the geographic coordinate system we have the north pole "N" and the south pole "S" through which passes the axis of rotation of the Earth and the plane perpendicular to this axis that cuts into two equal parts the globe is the Earth Ecuador. Any plane parallel to Ecuador determines a geographical parallel to Ecuador as a distance on a meridian plane determines North and South latitude parallel.
Prolonging the world axis passing through the pole "N" and "S" in the sky determines the North and South Celestial Poles or Boreal and Austral (P and P ') and is the imaginary axis on which the stars rotate with the apparent movement from east to west. The projection of the Earth Ecuador in Ecuador determines the blue sky.
The extension of the flat southern or meridian lines in the sky determines the hour circle.
the same way that the Earth is measured the latitude of a place on a meridian, the sky is measured in the "decline" (d) to a celestial body on its Circle Time and is the angular distance separating it from Ecuador Celeste. The decline is positive (+), Northern Lights or and minus (-), South Austral otherwise.
Corresponding to the longitude, the sky is called Right Ascension (RA) to the angle formed by the Circle Time the star with the hour circle of vernal point or point Aries, which is taken into the sky as the origin of right ascensions. The right ascensions (RA) is measured from west to east as the sun moves throughout the year, ie, contrary to the apparent motion of stars in the sky and is given in time. The point of origin, or Aries vernal point is the point of intersection between Ecuador and the Ecliptic Celeste. This point indicates the Spring Equinox falls 21 March. At this intersection, the Sun moves across the sky in their annual travel passes from the southern hemisphere to northern hemisphere. In conclusion, on the celestial sphere Circle Time that passes through the Vernal Point is equivalent the prime meridian or Greenwich geographic.
On the other hand, if an observer "A" on Earth is the sun, culminating in its meridian, to the observer "B" at the very moment the sun is not on the meridian, but shifted to the east. There should be a time "H" for the sun to fill the new position "S" (Circle Time) on the meridian of the observer "B", see figure below.
Returning to the measurement of time, cases of interest are the Legal Time and True Solar Time, with the True Solar Time True Local Time, which is unique to where you are measuring. This time is defined by the position of the sun in the sky with respect to the meridian of the place and mark the noon just as the sun is on the meridian. True Solar Time is precisely the time indicated by sundials.
legal time is the time taken by the government of a country to set the time in all its national territory and refers to a particular meridian as a reference point for setting the clocks on its territory, in turn, this reference meridian is referred to an international time zones, which in the case of Venezuela the government adopted corresponding to -4:30 UTC (Coordinated Universal Time). Which means that the Legal Time in Venezuela is behind in 4 hours 30 minutes with respect to Universal Time taken on the meridian "LOST" or Greenwich. In short, the legal time is the time indicated by clocks "mechanism", as our clock bracelet.
If the reference meridian have a sundial at noon the watch should be given the same time that the clock of the Sun To the extent that the sundial is relocated to the east or west of this meridian reference , the hours reported by both clocks start to differ, fast or slow the sundial with respect to the wristwatch, the discrepancy being equal to the angular difference between the meridian on the location of the sundial and the meridian of reference taken to "hours", ie its hour angle. Remember that you can give the location of the Sun or any celestial body in hours with respect to a meridian is taken as reference.
To clarify: if the reference meridian for a country is -60 ° (longitude W 60) and the sundial is on the meridian -70 °, the time difference between them is the angular difference between the meridian sundial and the reference meridian, hence -70 ° - (-60 °) = -10 °. We know by definition that 15 ° is 1 hour and therefore 1 ° are 4 minutes from half time, the time difference between both clocks is -10 ° x 4 minutes = -40 minutes, (the hour angle between the sundial and the reference meridian is -40 minutes). That is, the sundial would be 40 minutes late with respect to the wristwatch, so that when the clock mechanical indicates 12 pm, the sundial on the meridian -70 ° accuse 11:20 AM.
up lines I wrote that "should give equal time if the sundial was on the reference meridian", what happens is that they usually do not agree on a certain number of minutes and this is where the complication begins.
The problem started when astronomers try to set the duration of 24 hours a day on accurate with reference to the Sun By measuring the time when a star passes the meridian twice in the place of observation and do the same with Sol, put in comments clear that "solar day" is different from "day Sidereal ", that the difference between the two days is not constant throughout the year, declining in a few months and increasing in others.
Viewed from Earth, the Sun has two simultaneous movements in the sky, the most obvious is that provided for the nights and days and goes from east to west, the other movement is slower and goes from east to west similar to that done during the moon phase changes. This last movement of the Sun is what allows us to see new stars and constellations each month, is that we change the starry nights of spring by winter and is also responsible for all four seasons.
The Sun's path in sky is called ecliptic, and through the constellations of the zodiac, provided the Sun a year to complete a cycle on this path.
The movement of the sun that determines the days and nights due to the rotation of the Earth on its axis, viewed from space above the north pole is done in a counterclockwise direction, as reflected in the sky as Sun's apparent motion that allows us to see the sunrise and sunset to the west.
On the other hand, the movement of the sun determines the seasons, going from west to east along the year is due to the shifting of the Earth around the Sun, seen from space above the north pole is it anti-clockwise, but since the Earth is reflected in the sky as a translation from east to west. As the rotation axis is tilted with respect to the orbital plane, the Sun's apparent annual movement across the sky is not made on the celestial Ecuador, but in a path inclined with respect to the equator, known as the ecliptic.
Earth's orbit is an ellipse where the Sun occupies one focus, resulting from this is that the distance between two bodies varies as the Earth orbits the Sun With the change of distance, force gravitational changes as well and to maintain the dynamic equilibrium and the earth does not end up clashing with the Sun, the travel speed is variable, so that being near the Sun the Earth moves faster than when you are away. Johannes Kepler from the observations of the motion of the planets, particularly Mars had noticed that the planets move with greater speed during the approach to the Sun that during his departure, less of this behavior his second law, which postulates that areas swept by a planet in equal times are equal.
SOLAR TIME, TIME LEGAL. - I -
Sundial Clock Mechanical vs
Sundial Clock Mechanical vs
Trying to understand time.
in the previous release for the sundial azimuthal quadrant had highlighted the phenomenon of the time displayed by the clock "mechanical" and that shown by the sundial for the time differed from the picture in about 20 minutes and This lack of agreement was interpreted by people as a defect in construction or design of the sundial, forgetting the fact that our watch is who in any case we would be lying on the hour. No matter
the way on how you look, but the Sun that governs our lives since the beginning of time. It is the Sun which tells us when to leave and when to return. It's the Sun that inspires and feeds, not all cultures in vain they worship Him, either endian or just bronze ... and the Sun with whom you try to set the hours and day length.
try to be brief and explicit in a very confusing topic and wide, trying to clear our concern for the cause of the discrepancy between solar time and clock time "mechanic." Although today most of our watches are electronic, we will define as "mechanical" all man-made clocks and whose hours regularly pass every day.
The establishment of "time", has proven to be an astronomical task quite difficult and this is evidenced by the existence in the "times" following
Sidereal Time.
Time.
True Solar Time, or Time.
mean solar time.
Civil Time.
Astronomical Clock.
Standard Time (Official Time).
Universal Time (UTC), among others. Before proceeding
remember a little regard to geographical and celestial coordinates.
relying on the figure below, in the geographic coordinate system we have the north pole "N" and the south pole "S" through which passes the axis of rotation of the Earth and the plane perpendicular to this axis that cuts into two equal parts the globe is the Earth Ecuador. Any plane parallel to Ecuador determines a geographical parallel to Ecuador as a distance on a meridian plane determines North and South latitude parallel.
The line crossing the surface of the sphere representing the Earth and connects the poles "N" and "S" is the southern or meridian line and the distance between two lines measures in the southern Ecuador gives the difference in length between the two meridians. The length of a geographical point is determined by the angular distance between the level of Ecuador reference meridian of Greenwich or Prime Meridian and the Meridian passing through the location of the point. The length is East (E) or west (W) at this Meridian, if not referenced "E" or "W" to the plans are positive west south and east are counted negative.
Prolonging the world axis passing through the pole "N" and "S" in the sky determines the North and South Celestial Poles or Boreal and Austral (P and P ') and is the imaginary axis on which the stars rotate with the apparent movement from east to west. The projection of the Earth Ecuador in Ecuador determines the blue sky.
The extension of the flat southern or meridian lines in the sky determines the hour circle.
the same way that the Earth is measured the latitude of a place on a meridian, the sky is measured in the "decline" (d) to a celestial body on its Circle Time and is the angular distance separating it from Ecuador Celeste. The decline is positive (+), Northern Lights or and minus (-), South Austral otherwise.
Corresponding to the longitude, the sky is called Right Ascension (RA) to the angle formed by the Circle Time the star with the hour circle of vernal point or point Aries, which is taken into the sky as the origin of right ascensions. The right ascensions (RA) is measured from west to east as the sun moves throughout the year, ie, contrary to the apparent motion of stars in the sky and is given in time. The point of origin, or Aries vernal point is the point of intersection between Ecuador and the Ecliptic Celeste. This point indicates the Spring Equinox falls 21 March. At this intersection, the Sun moves across the sky in their annual travel passes from the southern hemisphere to northern hemisphere. In conclusion, on the celestial sphere Circle Time that passes through the Vernal Point is equivalent the prime meridian or Greenwich geographic.
On the other hand, if an observer "A" on Earth is the sun, culminating in its meridian, to the observer "B" at the very moment the sun is not on the meridian, but shifted to the east. There should be a time "H" for the sun to fill the new position "S" (Circle Time) on the meridian of the observer "B", see figure below.
In this way we can set the time difference between observer A and observer "B", ie has to distance in time (hours, minutes and / or seconds) is the observer "A" observer "B". The Earth takes 24 hours to complete a full 360 degrees so that each hour represents an angular displacement of 15 degrees. In fact, by convention, the globe has been divided into 24 time zones from Greenwich, are counted towards this positive and negative if taken in a westerly direction. In the case of Venezuela, the reference time zone to set the time in the country is in the UTC -4:30, indicating that we are 4 hours and 30 minutes late with respect to the time taken in Greenwich or seeing another Thus, while the sun at noon on the Greenwich meridian must spend 4 hours and 30 minutes for the sun is just above our reference meridian and indicating that it is noon. This UTC -4:30 time zone corresponds to the length -67.50 °, which is the same as the meridian +292.5 °.
Returning to the measurement of time, cases of interest are the Legal Time and True Solar Time, with the True Solar Time True Local Time, which is unique to where you are measuring. This time is defined by the position of the sun in the sky with respect to the meridian of the place and mark the noon just as the sun is on the meridian. True Solar Time is precisely the time indicated by sundials.
legal time is the time taken by the government of a country to set the time in all its national territory and refers to a particular meridian as a reference point for setting the clocks on its territory, in turn, this reference meridian is referred to an international time zones, which in the case of Venezuela the government adopted corresponding to -4:30 UTC (Coordinated Universal Time). Which means that the Legal Time in Venezuela is behind in 4 hours 30 minutes with respect to Universal Time taken on the meridian "LOST" or Greenwich. In short, the legal time is the time indicated by clocks "mechanism", as our clock bracelet.
If the reference meridian have a sundial at noon the watch should be given the same time that the clock of the Sun To the extent that the sundial is relocated to the east or west of this meridian reference , the hours reported by both clocks start to differ, fast or slow the sundial with respect to the wristwatch, the discrepancy being equal to the angular difference between the meridian on the location of the sundial and the meridian of reference taken to "hours", ie its hour angle. Remember that you can give the location of the Sun or any celestial body in hours with respect to a meridian is taken as reference.
To clarify: if the reference meridian for a country is -60 ° (longitude W 60) and the sundial is on the meridian -70 °, the time difference between them is the angular difference between the meridian sundial and the reference meridian, hence -70 ° - (-60 °) = -10 °. We know by definition that 15 ° is 1 hour and therefore 1 ° are 4 minutes from half time, the time difference between both clocks is -10 ° x 4 minutes = -40 minutes, (the hour angle between the sundial and the reference meridian is -40 minutes). That is, the sundial would be 40 minutes late with respect to the wristwatch, so that when the clock mechanical indicates 12 pm, the sundial on the meridian -70 ° accuse 11:20 AM.
up lines I wrote that "should give equal time if the sundial was on the reference meridian", what happens is that they usually do not agree on a certain number of minutes and this is where the complication begins.
The problem started when astronomers try to set the duration of 24 hours a day on accurate with reference to the Sun By measuring the time when a star passes the meridian twice in the place of observation and do the same with Sol, put in comments clear that "solar day" is different from "day Sidereal ", that the difference between the two days is not constant throughout the year, declining in a few months and increasing in others.
Viewed from Earth, the Sun has two simultaneous movements in the sky, the most obvious is that provided for the nights and days and goes from east to west, the other movement is slower and goes from east to west similar to that done during the moon phase changes. This last movement of the Sun is what allows us to see new stars and constellations each month, is that we change the starry nights of spring by winter and is also responsible for all four seasons.
The Sun's path in sky is called ecliptic, and through the constellations of the zodiac, provided the Sun a year to complete a cycle on this path.
The movement of the sun that determines the days and nights due to the rotation of the Earth on its axis, viewed from space above the north pole is done in a counterclockwise direction, as reflected in the sky as Sun's apparent motion that allows us to see the sunrise and sunset to the west.
On the other hand, the movement of the sun determines the seasons, going from west to east along the year is due to the shifting of the Earth around the Sun, seen from space above the north pole is it anti-clockwise, but since the Earth is reflected in the sky as a translation from east to west. As the rotation axis is tilted with respect to the orbital plane, the Sun's apparent annual movement across the sky is not made on the celestial Ecuador, but in a path inclined with respect to the equator, known as the ecliptic.
Earth's orbit is an ellipse where the Sun occupies one focus, resulting from this is that the distance between two bodies varies as the Earth orbits the Sun With the change of distance, force gravitational changes as well and to maintain the dynamic equilibrium and the earth does not end up clashing with the Sun, the travel speed is variable, so that being near the Sun the Earth moves faster than when you are away. Johannes Kepler from the observations of the motion of the planets, particularly Mars had noticed that the planets move with greater speed during the approach to the Sun that during his departure, less of this behavior his second law, which postulates that areas swept by a planet in equal times are equal.
FIGURE 1
The drawing above (figure 1) allows us to visualize the second law of Kepler. Earth when it is near perihelion moves quickly and after a while "T" is changed from P1 to P2 sweeping the area A1 of the graph. When close to apohelio (aphelion) moves slowly from P3 to P4 and sweeping the area A2 for the same time "T". For areas A1 and A2 are equal to require the speed of the Earth at aphelion is lower than at perihelion.
Taking the earth as our frame of reference and considering fixed, describing the Earth orbits around the Sun is projected on the sky so that it is the Sun who apparently moves around the Earth in an elliptical orbit.
The Sun's position can be referred to the axis connecting the peak with the perigee, line "B" B1 "in Figure 2, or referred to the line" Aries-Libra "(A-Li) corresponding to the line of intersection between the plane of the ecliptic Ecuador and blue.
FIGURE 2 is called "anomaly" of the Sun the angle between the axis of the apses and the sun as shown in Figure 2.
The "length" of the Sun is the angle formed by it with respect to the line of the equinoxes "A-Li", if we take the point position of the Sun "S2" in Figure 2, the Sun's longitude is defined by the angle "AT-S2" measured or ever taken in the direction of motion of the Sun is preferred to use the "length" of the sun instead of the "anomaly" for measurements and take the origin of celestial coordinates is the vernal point.
The "length" of the Sun is not commensurate with the time due to irregular motion and is referred to as the orbital speed change daily traffic is reflected in the Sun for the reason sky where the Sun is not true serves as an indicator of the time because it is an element of variable speed clocks reproducible.
To avoid this drawback, measurements do a lot of true solar day length and its average value is obtained (compared with the sidereal time), so we have a fictitious Sun moving at constant speed on the ecliptic and it takes just as Sun to cover it completely true, with the same fictitious with the real sun at perigee and apogee. Based on the perigee
simultaneously, the true Sun is ahead of the fictitious due to the higher initial velocity with which the sun starts true, so that in the way of "B" to "A" to "S2" (Figure 2) real Sun will advance to the sun fictional, tying two suns at the peak, but as the real sun is slower at the apogee, the fictional Sun anticipates this, so that during the journey "B1" to "S3" true Sun is late with respect to the dummy.
The difference between the length of the Sun real and fictional Sun's longitude is called "Equation of the Centre."
FIGURE 3
Without the tilt of the ecliptic with respect to Ecuador Celeste, the fictional Sun would move at constant speed on Ecuador would serve well to establish the "Mean Time" (because the length "L" covered by the fictitious sun would equal right ascension "AR"), but taking into account the slope (Figure 3) the length "L" of the Sun dummy that is measured in the plane of the ecliptic only match with ascension "AR" which is measured at the Equator on the equinoxes (about Aries "A" Libra "Li") and the Solstice (Cancer "Ca" and Capricorn "Cp"), ie at 90 °, the 180 º to 270 º and 360 º (0 º). Considering that our sun moves fictitious constant speed along the ecliptic, means without a rigorous mathematical proof that the Right Ascension and therefore the Sun's hour angle remains unchanged fictional time proportion basis, so that in the interval "Aries-Cancer, the fictional Sun is ahead of his ascension, behind Ascension in the area "Cancer-Libra, on the way ahead" Libra-Capricorn "and again behind his ascension on the tour" Capricorn-Aries. " Under these conditions, the fictional Sun does not serve us to measure the time since his ascension has variable speed. Recall that the ascension of a celestial body is the equivalent of and longitude is the vernal equinox origin. The hour circle time or measured by the Ascension.
FIGURE 4
return to this point again to try to clarify it, because it is crucial for the solution of the problem, but from a more analytical and less intuitive. Figure 4 shows the spherical triangle "A-SF-BA" which is the vernal point or origin of the coordinates, point "A" point "Sf" dummy representing the sun and the "B" is the projection of "Sf" perpendicular to Ecuador (Circle Time PB), so that the dihedral angle "AOB" formed by the planes "AOPA" and "BOPB" is the right ascension (RA) from the Sun dummy, the angle "AO-Sf" is the length (L) of the fictional Sun and the dihedral angle formed by the planes "AOBA" and "AO-SF-A" is the inclination of the ecliptic (E). A fundamental relationship for spherical triangles is that states:
Tg (AR) = Tg (L) xCos (E)
From this formula we can easily deduce that if the angle (E) formed by the planes of the ecliptic and the plane equator is zero, the angle swept by "Sf" equals the right ascension (RA), but if the tilt angle "E" is different from zero, the angle "L" swept "Sf" is different from right ascension "AR", but we can deduce from this fundamental relationship, which for angles 0 º, 90 º, 180 º and 270 º angles "L" and "AR" are equal. This demonstrates the trigonometry that if "L" is constantly changing, the angle "AR" does not, falling behind or ahead of the angle "L". For
jump this drawback turns the plane of the ecliptic around the axis formed by the Aries point "A" and point of Libra "Li" as indicated by the arrow in Figure 5 to match the equatorial plane, so the fictional Sun Ecuador is killed on the spot taking the place of "B" so that the angle "AR" is equal to angle "L".
FIGURE 5
fictional Sun shot on Ecuador is called "mean sun" and forms a spherical isosceles triangle with the Sun Aries fictitious point "A", so that the length " L "swept Sun dummy is equal to the angle swept in Ecuador by the mean sun and is equal to the right ascension "AR" of the mean sun, so you get an imaginary sun crosses the Ecuador at a constant speed at which the angle the mean sun time grows proportionally to time (Figure 6) and now have a Sun that allows us to adjust mechanical watches. The average Sun and Sun agree fictional Aries point A and point pound "Li."
FIGURE 6 days is called "Solar Middle double pass to the reference meridian and fixed the mean sun mean noon is the source of half time.
FIGURE 7
already been mentioned that the difference between the length of fictional and Sol Sol true length is called "Equation of Center" and the angular difference between the two Suns is due to the difference velocity of each other.
To facilitate the following analysis, killed the real sun on Ecuador (see Figure 7) and recalling that the mean sun is the sun fictional Ecuador.La killed in the Equation of Center (EC) we can write it like this:
EC = "AO" mean sun "-" AO "Sol real shot
Reduction to be known as Ecuador (RE), the length difference between the real sun and the true ascension of the Sun (point "C" in Figure 7) and we can formulate as follows:
RE = "AO" Sol real shot "-" AOC "
This angular difference between the length of Sol Ascension real and stems from the inclination of the ecliptic with respect to Ecuador.
Both deviations are added to form what is known as the Equation of Time (ET), so that:
ET = EC + ET
RE = ("AO" mean sun "-" A- true sun down ") + (AO-Sol real shot "-" AOC ")
ET =" AO "mean sun" - "AOC"
Recall that the angle measured in Ecuador "AO" mean sun "is the ascension of the mean sun and the trajectory "AOC" is the true ascension of the sun. We must also remember that the hour angles of celestial bodies are measured under the same right ascension.
As we have already seen, the real sun is early or late with respect to the mean sun and the difference between the mean sun Ascension and Ascension of the Sun truly is the "Equation of Time." In short, the equation of time is the correction to add to the true solar time (HSV) to the mean solar time (HSM).
ET = HSM - HSV
As the instruments of observation and measurement have improved over time, is to become clear that the vernal point is not fixed with respect to the stars (precession) nor what is the semi-major axis (line of apses) of Earth's orbit, so that tables are published each year with the equation of time every day of every month and these are available online.
However, because it functions both deviations of cyclical the sum of them vanishes certain angle covered, so that by that time the hour angle (Ascension) the real Sun and the Sun half agree with what the sundial and the mechanical clock show the same time. This is repeated four times throughout the year in the months April, June, September and December.
In the next release will conclude the study by comparing the time shown by the sundial Azimuthal and the mechanical clock in three different days. The calculations necessary to enable us to verify this difference observed according to the Equation of Time and the difference between the meridians, plus you will notice that the time difference is not constant throughout days.
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