I created this to establish a baseline of the Globe/Heliocentric model for discussions.
When Flat Earthers make assertions that disagree with this model they are being dishonest.
You don't win an argument when you create a strawman of the Model -- you LIE.
You can get the current axial tilt from timeanddate.com
And in "meme" form for sharing (minus the big Refraction Discussion)
When Flat Earthers make assertions that disagree with this model they are being dishonest.
- Earth is roughly an oblate spheroid described in the WGS-84 Reference Model having:
ellipsoidal flattening (f) = 1/298.257223560
equatorial radius (a) = 6378137 m
polar radius (b) = a - a f - Earth distance from the Sun varies from
147095000 km at Perihelion and
152100000 km at Aphelion - Earth mass is 5.97237×10²⁴ kg giving a surface acceleration of 9.807 m/s²
- Earth rotates once per 23h 56m 4.100s (sidereal day, 23.934472 hr)
Over a year, the average solar noon-to-noon time is 24h (synodic day) - Earth obits the Sun every 365.25635535 days, and makes 365.25635535 (+1) sidereal rotations
- Moon radius is approximately 1740 km and the distance from Earth varies from 356,500 km at perigee and 406,700 km at apogee
- Sun radius is 696,342 km (±65 km) with a mass of 1.9885×10³⁰ kg (330,000x Earth)
- Earth's Obliquity (axial tilt relative to the ecliptic, or orbital, plane) varies slightly over time, as of 2019-01-01 it is ~23.4368°
- Since Gravity is proportional to mass and is a mutual attraction of ALL mass it does not "emanate" from the center of anything but rather we can treat rigid objects as a single mass in the simple case.
From this principle, "down" *MEANS* closer to the center of the Earth.
Someone on the other side of the Earth is not "upside down".
Level is an equipotential of gravity. - Refraction exists, and is pretty well understood, but accurately measuring the atmosphere over tens or hundreds of miles is not feasible. Under common field conditions, for shorter distances you can approximate the effect of refraction by assuming an Earth Radius of 15% larger than normal. This is a very simplistic assumption but is a good approximate when nothing else can be known.
The problem for most long-range optical observations is that refraction can create a duct through which you can see substantial distances right over land or (more commonly) water. I'm sorry but this is just a FACT. The good news is that such views are usually highly distorted so we can identify when this is happening. However, the more common failure is harder to detect and that is cases of substantial looming which can cause distant objects to appear somewhat higher than normal. The setting sun is very commonly raised by about 34 arc minutes [see usno.navy.mil], meaning the sun has actually fully set when you see the lower limb reach your horizon. Flat Earthers need to either scientifically PROVE that this is false or stop lying about it. An easy way to observe this effect is to use a equatorial tracking mount with reasonably high-power optics (and a proper solar filter) follows the sun from about 2 hours before sunset. The tracking will be very accurate at first (and all day) and it will get slightly ahead of the Sun near sunset as the refraction increases and raises the Sun's apparent position. Measuring this shift is one way to measure the Refraction along that line-of-sight.
The best way to avoid the worst variations of Refraction is to get up higher.
Walter Bislin's Refraction Simulation
You don't win an argument when you create a strawman of the Model -- you LIE.
You can get the current axial tilt from timeanddate.com
And in "meme" form for sharing (minus the big Refraction Discussion)