Is science too much about assumptions?

[Soleron]

pauluzzz1981 said:

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i  agree with this. Mathemetical equations are only equal because they use some element that is a theory, like dark matter or 9 dimensions or wormholes. I dont understand it so my opinion is based on that. For the people who can understand it. For instance,is carbon dating a fact? And there is also a theory that lightspeed is slowing down at a certain point?

Dark matter - Lots of evidence, but not 100%
9 dimensions - no evidence, mathematically sound
wormholes - no evidence, mathematically sound
carbon dating - Overwhelming evidence

Could you clarify about the light slowing down?