We know there is gravity because apples fall from trees. We can observe gravity in daily life. If we could throw an apple to the edge of the universe, we would observe it accelerating.
Adam RiessDark energy is incredibly strange, but actually it makes sense to me that it went unnoticed, because dark energy has no effect on daily life, or even inside our solar system.
Adam RiessYour chemistry high school teacher lied to you when they told you that there was such a thing as a vacuum, that you could take space and move every particle out of it.
Adam Riess