A text book in 1945 stated that it takes 800,000 years for light to reach us from Andromeda Galaxy , BUT IT IS NORMALLY SAID IN TEXTBOOKS THAT IT TAKES 2, 500,

Question

YEARS, what DOES THIS SAY ABOUT A SCIENTIFIC FACT AND HOW KNOWLEDGE CHANGES WITH TIME . CAN SOMEONE PLEASE EXPLAIN THIS FOR ME

Answer 1

look closer at the units of the values that you are quoting from the different text books.  The 2,500 is probably light years, or maybe million light years.  

 

Glenn