Why is the big bang a theory and not a fact

Amajor difference radio waves, visible light, and gamma rays is the of the photons, which results in different photon frequencies and wavelengths

Does the distance travelled by an oscillating mass between times t=0 and t2 equal the displacement of the particle over the same time period if t2> t/2? hint: consider a sine wave starting at t1=0, then consider a closing wave starting at t1=0, for your explanation.

What ions are formed when hcl dissolves in water?