# I don't think so

### What's a 1989 Suzuki GS500E that isn't running worth?

5 AnswersMotorcycles5 years ago### Why does Dark Energy have to exist?

Newton's laws of motion were found to be incomplete because they didn't give the right answers for objects in strong gravitational fields, and for objects moving quickly (such as the planet Mercury). Einstein developed more refined equations in his theory of relativity to correct for these effects.

Now we have discovered that galaxies far away appear to not be slowing down the way we expect according to how we believe gravity works. So to explain this, physicists invent 'Dark Energy'.

But couldn't it simply be that we don't understand exactly how gravity works at very long distances and very low levels? What if gravity is quantized, and the math doesn't work the way we expect at galactic distances? Resulting in the inverse square law not being strictly accurate at very long distances?

How much would our current understanding of the inverse square law of gravity need to be adjusted to explain what we're observing without invoking a completely unknown 'Dark Energy'? Is it a tiny correction, or a large one?

4 AnswersPhysics8 years ago### How much more energy does it take to orbit an object vs. just lifting it?

How much energy does it take to lift a 1000kg mass to 100km altitude (straight up), vs putting that same mass into orbit around the Earth at 100km?

What about at 400km altitude?

2 AnswersPhysics8 years ago