Which scientist used cepheid variables to measure the distance to faint "nebulas" in our sky, proving they were actually whole other galaxies?

what is the question because that is not a question.

massxgravity x heght=weightxheight= pe

4900=490xh

h=10

hi,

what occurs during a solar eclipse?

there are small tides across earth.

the moon is between earth and the sun.

p.s. im not sure if the first answer is correct because during a solar ecliphse there are spring tides and i dont know if they are the same.

myth. it was once thought that animals, including cats and dogs, could only see in black and white. however, scientists have proven this to be a myth. in all animals, including humans, the perception of colour is determined by the presence of cells in the eye called cone photoreceptors.