Here's why:
* Scientific understanding: We have a very well-established scientific understanding of the Earth's rotation and its relationship to the Sun.
* Past observations: We have observed the sun rising every day for millennia.
* No evidence to suggest otherwise: There is no known reason to believe that the Earth's rotation or the Sun's position would suddenly change drastically.
However, it's important to note that:
* Predictions are not guaranteed: While extremely likely, it's theoretically possible for an unforeseen event to disrupt the Earth's rotation or the Sun's position.
* The term "fact" is often reserved for things that are definitively proven: While the sun rising tomorrow is extremely likely, it's not a scientifically proven fact in the same way that the Earth is round is a fact.
Therefore, while it's a very confident prediction, calling it a "fact" would be technically inaccurate.