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How do scientists know our universe is flat?

Answer 1

The observable universe is spherical.

We can only see so far from Earth because light travels at a fixed speed and in straight lines; light from some parts of the universe may not have reached us yet because the universe is simply too young. Nevertheless, the part of the universe we can prove exists is the part we can observe.

#s = d/t#

#s = speed# #d = distance# #t = time#

As #t# is limited by the age of the universe, and #s# is limited to exactly the speed of light (which is given the notation of "#c#"), we can only see a certain distance from earth at any moment.

Although we can only speculate about what lies beyond it, the universe is expanding and we will never be able to know for sure whether it is "flat" as scientists have suggested.

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Answer 2

Clara Avalos

Scientists determine that our universe is flat based on observations of the cosmic microwave background radiation, which is the afterglow of the Big Bang. This radiation provides evidence for the geometry of the universe, indicating that it is flat rather than curved or positively curved like a sphere.

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.