Time of atomic clocks runs slower at sea level than at 40,000 feet because gravity slows the time effect. GPS makes allowances for this or it would be way off. If you orbited a black hole where you still could generate escape velocity, the effect on time is magnified by years.

For future and past time to exist simultaneously you would have to be going at 99% the speed of light. Heading away from Earth you would eventually be in the same 'time frame' as Beethoven. Going toward Earth would put you in the time frame of the future. Notice it is not a time machine that lets you meet Beethoven.

Relationships in physics can not reliably explain itself in a language of nouns and verbs. Thats why geometry and math are better tools. We can approximate understanding with words however.

The Hadron collider has not found dark matter either. Dark matter interacts with us less than neutrinos except it has gravity!?!.