I found this researching the subject:
https://arxiv.org/pdf/1004.1467.pdf
BENDING OF LIGHT NEAR A STAR: THE ALTERNATIVE EXPLANATION 3.1 THE PRINCIPLE: DEVIATION DUE TO REFRACTION Refraction of light rays is a well known optics-phenomenon [27]. This provides an alternative explanation of bending of light near a star. When light ray, from space (near vacuum), enters the star’s atmosphere (medium); the light ray bends near the star due to refraction. To illustrate the bending due to refraction, consider a spherical water-droplet as shown in Figure(1.a). When light ray enters from lighter medium (air) to denser medium (water), the droplet works as prism and thus the light-ray bends due to refraction. Similarly, when light ray enters from space-vacuum (lighter medium) to star’s atmosphere (denser medium) it bends due to refraction as shown in Figure(1.b). The atmosphere extends to great heights, it becomes rarer and rarer, however; a reasonable equivalent height is shown in the figure. The amount of bending (maximum deviation) can be estimated semi-empirically (δ = 2(µ − 1) as shown in section 3.3) as follows. Consider the limiting case when the light ray enters the atmosphere touching at point A and leaves touching at point C. The incident ray touches at i = 900 & refraction angle is r at point A and vice-versa at point C as shown in Figure- 2. The angle r is thus critical angle (µ = 1 sinr ), and for maximum deviation the line AC touches the star-core at point B. From the star-geometry of Figure-2, Cosec® = R / R where R/ & R are atmospheric-radius and core-radius of the star. Thus µ = R / R = (R+h) R = 1 + h R where h is the equivalent-height of atmosphere above the star-core (estimated in the following section 3.2). For max deviation situation (Figure-2) thus,
ESTIMATION OF BENDING (DEVIATION) OF LIGHT NEAR A STAR DUE TO REFRACTION-PHENOMENON The angular deviation at entry point A (Figure(2)) is (i − r), and similar deviation of the ray occurs at exit point C. So, the total deviation (bending) δ = 2(i − r). From optics consideration and using simplification & approximation, and also noting that deviation is more for higher µ & that there is no-deviation for µ = 1; it can be shown that deviation (i − r) ≈ (µ − 1). Hence the expressions for total deviation δ are given as in Eq. 5, as in Eq. 6 (using Eqs. 5 & 3) and as in Eq. 7 (using Eqs. 6 & 4): δ = 2(µ − 1) (5) = χ (6) = 2kGM c 2R (7) The total deviation (bending of light) δ = 2kGM c 2R given by Eq. 7 is same (for fuzz factor k = 2) as that predicted by the celebrated general-relativity and found experimentally correct. The approach (physics) of the present explanation, however, is altogether different and is much simpler. The new approach is based on the commonly well-known phenomenon of refraction of light; there is, however, a fuzz-factor k to account for uncertainty such as in estimation of star’s atmospheric height & its refractive index. The authors aim to emphasize that though refraction-phenomenon approach and general-relativity approach are in agreement as far as result is concerned but the physics of both the approaches are quite different. 3.4 GRAVITATIONAL-LENSING (IN NEW LIGHT AS REFRACTION-BENDING) In perspective of refraction phenomenon discussed for bending of light, the so called gravitational-lensing [29] is in fact ‘real’ refraction-lensing of light due to refraction through atmospheric-layer of star or galaxy (note-both star & galaxy are surrounded with cloud of gases/materials, both can cause refraction-bending of light and thus lensing). In fact the word ‘lensing’ here literally means real lensing (bending of light due to refraction). But through optical-lens deviation occurs with some dispersion too, causing chromatic aberration. It is expected that here too, if the lensing is due to refraction (as said in the present paper), a little dispersion (chromatic aberration) can also occur which may possibly be found experimentally. The sky as if will look more colorful, and it is the color which will differentiate between the object & its image.
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In Asimovs End of Eternity theres a conspiracy to supress space travel to keep getting advantage of time travel
Relativity is the thing that makes no worth bothering to try to go to the stars