-
----------------------- # 1979 - Circles and spheres in astronomy .
-
- A sphere has the minimum surface area of any geometric shape.
-
- If a spherical object spins its midsection bulges. As planets “circle” the Sun they travel in ellipses. This lack of perfect circles messed up the ancients for decades. They came up with epi-circles to keep orbits circular and still match their observations. Finally the ellipse was used to get the math to match their observations.
-
- Gravity must create the most perfect spheres in Neutron stars. These 12 mile diameter stars have the density equivalent to an entire freight train crushed down to the size of the period at the end of this sentence. That 12 mile sphere must be perfectly shaped?.
-
- Can that circle of perfection be beat? There is a star the size of Vega that rotates so slowly it has a 100 day spin. The equatorial diameter is just 2 miles longer than its polar diameter. Interesting? How could they possibly know that?
-
- We watch the Sun and the Moon rise in the east and set in the west. The same happens with all he stars in the night sky. You can certainly convince yourself that the Earth is the center of things and everything else rotates around us.
-
- How did anyone ever figure out that we were not in the center? Actually someone did in 230 B.C. The Sun was the center and we were rotating around it. In 230 B.C. Aristarchus in ancient Greece came up with this theory. At the time he was contradicting Aristotle who said the Earth was the center. Aristotle’s incorrect theory remained the authority for centuries.
-
- It was not until Galileo in 1610 using the first telescope discovered the phases of the planet Venus. Like what causes the phases of the Moon, phases that occur on Venus must be because it is orbiting closer to the Sun than Earth’s orbit. If Venus and Earth were both orbiting the Sun then that must be the center of the Solar System.
-
- Astronomers were able to prove this theory again using parallax with the stars.. They calculated the diameter of Earth’s orbit to be 186,000,000 miles. By measuring the position of a nearby star, then, measuring it again 6 months later, the stars apparent position would shift compared to the distant background stars. This trigonometry used in 1838 was proof again that the Earth was orbiting the Sun, the center of the Solar System.
-
- Friedrich Bessel used this same parallax method to estimate the distance to the star 61Cygni.
-
- In our modern era the Earth’s orbit around the Sun could be detected due to the tilt of incoming starlight. Just as driving your car in the rain. The rain appears to hit the windshield at an angle , a “ tilt”. English astronomer, James Bradley, did this measurement in 1725. The tilt is created by the finite speed of light versus the Earth’s motion around the Sun.
-
- The Earth is a 5.97*10^24 kilogram rock circling the Sun at 29,800 meters per second while spinning at 464 meters per second. In other words the Earth is a 7,926 mile diameter ball traveling 66,660 miles per hour while spinning 1,038 miles per hour.
-
- Is the Earth a perfect sphere? The Moon looks like a perfect sphere. Or, a perfect circle since we only see one side. Actually the Moon differs from a perfect sphere by only 1.24 miles. The Sun is a more perfect sphere being only 6 miles out of being perfectly round. That is out of a 864,337 mile width. If the Sun were a basketball the two diameters, polar and equatorial, would differ only ½ the width of a human hair.
-
- The real miracle in all of this is that you are here trying to figure this stuff out. Stay tuned, an announcement will be made shortly.
-
-------------------------------- -------------------------------------------------------------------
(1) An index of recent reviews available.
-----------------------------------------------------------------------------------------------
RSVP, with comments, suggestions and corrections. An index of all reviews is available. Some reviews are at: -------------------- http://jdetrick.blogspot.com
,or: email request for copies to: ------- jamesdetrick@comcast.net
or: ---- https://plus.google.com/u/0/ ,or, “Jim Detrick” ------- www.facebook.com,
------ www.twitter.com or cell: 707-536-3272 ------ Monday, December 11, 2017
No comments:
Post a Comment