The speed of light is a problem for ‘The Science’.  If the speed of light is inconstant in space and time, the entire edifice of modern cosmology including ‘Relativity’ is destroyed.  Other posts in this substack have adumbrated the issues with the speed of light in the context of what is wrong with modern physics and cosmology.  To further understand the importance of this issue we will provide 3 posts:  a brief history of the speed of light, the ignored and wrongly vilified Sagnac experiment, and proofs and support as to why the speed of light dogma is incorrect, including personal experiments. 

Through many years of study and experimentation with the speed of light, it is clear that the ‘settled consensus’ that the speed of light is ~186.000 miles per second in a vacuum is simply wrong.  One obvious reason is that space is not a vacuum but full of material including radiation, rays, neutrinos, positrons, quantum fluctuations and other matter.  No vacuum exists within the universe.  Einsteins’ own General Relativity assumes an ether.  Light speed obviously varies by medium including in space and in the opinion of many cannot even be measured.  More here