Information
Sextant has a minion!
Minion the Constellation
Minion the Constellation
Sextant
Legacy Name: Sextant
The
Hydrus MontreOwner:
nervousAge: 7 years, 2 months, 2 weeks
Born: January 30th, 2017
Adopted: 3 years, 7 months, 4 weeks ago
Adopted: August 21st, 2020
Statistics
- Level: 1
- Strength: 10
- Defense: 10
- Speed: 10
- Health: 10
- HP: 10/10
- Intelligence: 101
- Books Read: 101
- Food Eaten: 0
- Job: Unemployed
Sextants for astronomical observations were devices depicting a sixth of a circle, used primarily for measuring the positions of stars.
Gravity
Newton's Law of gravity states that every mass exerts a gravitational attraction to ever mass no matter how far away. However, action at a distance is not as simple as it seems.
Einstein's general theory of relativity does not consider action at a distance in stating that Earth feels no force tugging in its orbit. The Earth instead goes around the Sun and tells us that spacetime is curved near the sun. To state it clearly:
What we perceive as gravity arises from the curvature of spacetime.
Depending on the speed and direction, planets or other objects in free fall in space can follow different orbits like circular, elliptical, unbound, or parabolic orbits. Newton's universal law allows this. But the explanation for these orbits is different now. Rather than orbiting because of a force distance as the Sun, planets orbit because they follow the straightest possible paths thus allowed by the shape of spacetime around them.
A serial mechanism for sun positioning calculation.
Spacetime
Spacetime is a four dimensional space which each direction for possible motion is length, width, depth, and time. An object's path through a four dimensional spacetime is called the worldline, and any point along this line represents an event. The event is then explained as having a specific place and time. There are three major concepts to grasp here:
1. The worldline of an object is vertical, or parallel to the time axis.
2. The worldline is moving at a constant velocity which is straight but slanted. If the line is very slanted, then the speed is much faster.
3. The worldline of an accelerating object is curved. If the speed is increasing, the worldline curves towards the horizontal. If it is decreasing, the worldline becomes vertical.
Curved spacetime can be explained using geometry as conceptualizing a two dimensional surface in visual.
There are three types of geometry of spacetime: flat geometry, spherical geometry, and saddle shaped geometry.
Definition of the zenith distance lambda of a star or other celestial object.
Relativity
Relativity is the principle that light will follow a path of the curvature of spacetime. This theory was formulated by Albert Einstein that motion follows the frame of reference that space and time are relative rather than absolute.
This is a really important theory and consists of two parts of major importance that we will examine:
1. Special relativity is the theory of the structure of spacetime. This includes both the law of physics that is the same for observers of a frame of reference relative to one another, and the speed of light in a vacuum is the same for all observers regardless of relative motion.
2. General relativity states under the equivalence principle stating that of accelerated motion and being at rest in a field of gravity are identical.
The two differ in this way because general relativity is incompatible with special relativity, since inertially moving objects cannot accelerate in respect with one or the other.
The two circles of position correspond to the observed zenith distances of the two stars and intersect at points P and P', the two possible geographic positions of the observer.
Angle relation diagram of line and plane for longitude calculation.
Black Holes
So, greater curvature of spacetime means stronger gravity. A larger mass causes greater curvature and a distance away from from it. To increase the curvature of spacetime around an object is to leave its mass alone but to then increase its density (make it smaller in size.)
To compress an object, thus increasing the curvature, to a point of transformation is to then create a black hole.
A black hole is a place where spacetime is so curved that nothing falls into it that can in turn escape. The boundary that marks the point where the object cannot come back is the event horizon, meaning the event that occur within the boundary have no influence on the observable universe that we know of.
Gravity Vs. Time
Since gravity is comes from the curvature of spacetime, in turn, gravity affects time. Applying the equivalence principle, telling us that the same results for an object at rest in a gravitational field as one accelerating through space, it then will become a matter of time running more slowly at lower altitudes than higher altitudes. This is known as the gravitational time dilation.
The stronger the gravity, then, the greater the effect of gravitational time becomes.
The sun’s bearing, Zn, will equal 360° minus Z because bearings are always measured from north through east and south. LHA will always be greater than 180° in the morning with the sun to the east, and less than 180° in the afternoon starting at 0° at noon.
CREDITS
profile template (c)helix (get it)
Bennett, J. O., Donahue, M., Schneider, N., & Voit, M. (2020). The cosmic perspective. Hoboken, NJ: Pearson Education.
Allen, J. A. (2004). Basic principles of celestial navigation. American Journal of Physics, 72(11), 1418-1424. doi:10.1119/1.1778391
Zhang, W., Xu, X., & Wu, Y. (2016). A new method of single celestial-body sun positioning based on theory of mechanisms. Chinese Journal of Aeronautics, 29(1), 248-256. doi:10.1016/j.cja.2015.12.009
bg edits and information bynervous & more information.
Newton's Law of gravity states that every mass exerts a gravitational attraction to ever mass no matter how far away. However, action at a distance is not as simple as it seems.
Einstein's general theory of relativity does not consider action at a distance in stating that Earth feels no force tugging in its orbit. The Earth instead goes around the Sun and tells us that spacetime is curved near the sun. To state it clearly:
What we perceive as gravity arises from the curvature of spacetime.
Depending on the speed and direction, planets or other objects in free fall in space can follow different orbits like circular, elliptical, unbound, or parabolic orbits. Newton's universal law allows this. But the explanation for these orbits is different now. Rather than orbiting because of a force distance as the Sun, planets orbit because they follow the straightest possible paths thus allowed by the shape of spacetime around them.
A serial mechanism for sun positioning calculation.
Spacetime is a four dimensional space which each direction for possible motion is length, width, depth, and time. An object's path through a four dimensional spacetime is called the worldline, and any point along this line represents an event. The event is then explained as having a specific place and time. There are three major concepts to grasp here:
1. The worldline of an object is vertical, or parallel to the time axis.
2. The worldline is moving at a constant velocity which is straight but slanted. If the line is very slanted, then the speed is much faster.
3. The worldline of an accelerating object is curved. If the speed is increasing, the worldline curves towards the horizontal. If it is decreasing, the worldline becomes vertical.
Curved spacetime can be explained using geometry as conceptualizing a two dimensional surface in visual.
There are three types of geometry of spacetime: flat geometry, spherical geometry, and saddle shaped geometry.
Definition of the zenith distance lambda of a star or other celestial object.
Relativity is the principle that light will follow a path of the curvature of spacetime. This theory was formulated by Albert Einstein that motion follows the frame of reference that space and time are relative rather than absolute.
This is a really important theory and consists of two parts of major importance that we will examine:
1. Special relativity is the theory of the structure of spacetime. This includes both the law of physics that is the same for observers of a frame of reference relative to one another, and the speed of light in a vacuum is the same for all observers regardless of relative motion.
2. General relativity states under the equivalence principle stating that of accelerated motion and being at rest in a field of gravity are identical.
The two differ in this way because general relativity is incompatible with special relativity, since inertially moving objects cannot accelerate in respect with one or the other.
The two circles of position correspond to the observed zenith distances of the two stars and intersect at points P and P', the two possible geographic positions of the observer.
Angle relation diagram of line and plane for longitude calculation.
So, greater curvature of spacetime means stronger gravity. A larger mass causes greater curvature and a distance away from from it. To increase the curvature of spacetime around an object is to leave its mass alone but to then increase its density (make it smaller in size.)
To compress an object, thus increasing the curvature, to a point of transformation is to then create a black hole.
A black hole is a place where spacetime is so curved that nothing falls into it that can in turn escape. The boundary that marks the point where the object cannot come back is the event horizon, meaning the event that occur within the boundary have no influence on the observable universe that we know of.
Since gravity is comes from the curvature of spacetime, in turn, gravity affects time. Applying the equivalence principle, telling us that the same results for an object at rest in a gravitational field as one accelerating through space, it then will become a matter of time running more slowly at lower altitudes than higher altitudes. This is known as the gravitational time dilation.
The stronger the gravity, then, the greater the effect of gravitational time becomes.
The sun’s bearing, Zn, will equal 360° minus Z because bearings are always measured from north through east and south. LHA will always be greater than 180° in the morning with the sun to the east, and less than 180° in the afternoon starting at 0° at noon.
CREDITS
profile template (c)
helix (get it)Bennett, J. O., Donahue, M., Schneider, N., & Voit, M. (2020). The cosmic perspective. Hoboken, NJ: Pearson Education.
Allen, J. A. (2004). Basic principles of celestial navigation. American Journal of Physics, 72(11), 1418-1424. doi:10.1119/1.1778391
Zhang, W., Xu, X., & Wu, Y. (2016). A new method of single celestial-body sun positioning based on theory of mechanisms. Chinese Journal of Aeronautics, 29(1), 248-256. doi:10.1016/j.cja.2015.12.009
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nervous & more information.Pet Treasure
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