How does the sun's diameter cmpare with the distance between the earth and the sun?

Question

How does the sun's diameter cmpare with the distance between the earth and the sun?

Answer 1

The sun's diameter is about 1.392E+9 meters. However, that figure is for an optical depth of 2/3, which is where the photosphere is defined to be.

The distance between the Earth and the sun is, on the average, about 1 astronomical unit, or 1.496E+11 meters, which is 107.5 times greater than the solar diameter. The average angular diameter of the sun, as seen from Earth, is 0.5331 degrees.

The radius of a population 1 main sequence star, having an elemental composition similar to our sun's, is equal to about

R = Rsun (M / Msun)^0.72

Rsun = 6.96E+8 meters

Msun = 1.99E+30 kilograms

A planet with the same substellar temperature that Earth has would be located a distance, r, from the star, such that

r = (1 AU) (M/Msun)^2

The period, P, of that planet would be about

P = (365.25 days) (M/Msun)^2.5

The angular diameter, D, of the star, as seen from the planet, would be about

D = 2 Arctan{ 0.0046524 (M/Msun)^(-1.28) }

Under ordinary circumstances, only stars with mass in the range of 0.8<M/Msun<1.42 should be considered eligible to have a habitable planet. Stars having more than 1.42 times the sun's mass will evolve off the main sequence in less time than 3 billion years from "Zero Age Main Sequence" (ZAMS), which wouldn't give life enough time to arise. Stars having less than 0.8 solar masses would probably cause a tidal slowing of the habitable planet's rotation, which would make the planet like Venus.

Answer 2

Solar diameter at the equator is

1,392,530km

The distance from sun to earth is

149,597,900km

Simple division will tell you how many times larger the distance from earth to sun is than the distance around the sun.  Without doing the math and just eyeballing those numbers, I can tell it's a bit more than 100x.