There are stars and galaxies and whatever space objects everywhere we look weither it’s up, down, left or right. Yet, scientists say that the universe is flat? How?
In: Physics
What scientists mean by that is that the universe has a flat geometry. If you draw a triangle on a piece of paper, it’ll have angles that add to 180° and the same is true of the universe when we measure as large a triangle as we can. If you draw a triangle on the surface of a globe or a saddle or a donut, by contrast, that isn’t the case. The angles add up to a different number.
Obviously, a piece of paper is 2D and clearly flat; the surface of a sphere is 2D and clearly curved. That’s where the terms comes from. Scientists and mathematicians working on 3D (or higher) geometry still use “flat” and “curved” even though it’s harder to imagine.
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