What causes stars to twinkle?
A) It is intrinsic to the starstheir brightness varies as they expand and contract.
B) variations in the absorption of the atmosphere
C) variable absorption by interstellar gas along the line of sight to the star
D) bending of light rays by turbulent layers in the atmosphere
E) the inability of the human eye to see faint objects
Question 2
The red hydrogen alpha line carries more energy per photon than the blue-green hydrogen beta line does.
Indicate whether the statement is true or false
Rooting depth varies across a broad geographical gradient
All objects in the image are distant galaxies – not stars
Internal structures of main sequence stars, convection zones with arrowed cycles and radiative zones
Planets and Their Stars
Brain activity varies by culture
The answer to “What is the proper role of children in an economy?” varies by social class, ...