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Comment by jb775 | Hacker News Reader

It's crazy how little we understand about gravity if you think about it. It's a perpetual energy source right in front of us, but we never really think about it, and can barely offer a basic explanation as to what powers it. It even impacts time itself[1] for christ sake. I think better understanding gravity is the solution to all human energy needs. (interesting to note I have heard stories of disappeared scientists who made advancements in gravity research years back)

[1] http://thescienceexplorer.com/universe/how-gravity-changes-t...

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> It's a perpetual energy source right in front of us

It's not. Once something has fallen down, it can't fall down again.

To draw energy from the gravitational attraction of 2 bodies, you must first separate them. That consumes energy.

On second thought, I suppose tidal energy fills the bill. Extracting that energy is really exploiting the Moon's motion, using gravity as the "conduit". Not strictly perpetual, but essentially so for our needs.

Isn’t tidal energy just harnessing some of the existing gravitational potential energy of the Moon-Earth system, which is roughly similar to any system that harnesses energy from a massive object falling due to gravity?

But again, slowing tidal currents must be drawing energy from somewhere until there is none left.

It basically draws energy from the moon orbiting earth. It could theoretically alter that orbit, but given that the moon/earth system has a lot of mass, the timescale for that to happen is extraordinarily large.

That’s exactly what it’s doing. It’s slowing down Earth’s rotation and speeding up the Moon’s orbit (i.e. moving the Moon further from the Earth).

But that "something" keeps being pulled down until it is stopped/blocked by something (e.g. the ground). Gravity is perpetual relative to the source of the gravity. It's just that our surroundings change and give the illusion of gravity changing...i.e. we don't "run low" on gravity

I don't think Maxwell's Demon is 100% solved.

Tidal energy could play into it, some underwater tides deep in the ocean are insanely strong.

You're confusing force with work. Gravity is a perpetual force, but a force doesn't generate energy.

To generate power you need gravity to move something downwards, releasing the potential energy. And when that thing hits the bottom of the shaft you've used up all the potential every that was stored in it.

> It's crazy how little we understand about gravity if you think about it.

We understand most things about it

> It's a perpetual energy source right in front of us,

No it's not. It's a good way to store energy but in no way is a source.

> and can barely offer a basic explanation as to what powers it

It's not something that has power. It's a consequence of entropy.

> It even impacts time itself

You sound surprised by this? Given relativity it would be more surprising if it didn't.

IMO you grossly overestimate the amount humans know about things.

Science is basically a stream of updated realizations that the previous "known" things were actually wrong.

and you vastly underestimate it

I underestimate it and overestimate it.

Excuse me, I'm off to build a battery out of a bank of leaf springs.

> We understand most things about it

In a classical mechanics sense - yes. But the waves were detected just couple years ago.

It's true we only recently have been able to built equipment sensitive enough to measure them.

However, they were predicted in 1916 as part of Einstein's Relativity work: https://en.wikipedia.org/wiki/Gravitational_wave

You shouldn't repeat unsubstantiated rumors like that. Can you even name these disappeared scientists or know anything at all that could be used to verify those stories?

If you dare to venture, need to follow deep rabbit holes. Look into: work of Harold Aspden (and his coworkers & previous research partners), plancks equation origins and drop offs, dewey larson physics, piesel electric effect origin and drop offs, the adams motor, ellen brown, what maxwells equation actually determines and where it selectively isn't being used

I think you are getting unwarranted downvotes. If you are someone with a dislike of information you can just ignore it... downvotes unnecessary.

I agree but honestly I'm used to it on HN. This place is a lot of smart people but also the type of people that suffer from severe cognitive dissonance and stubbornness.

They are the types that would ridicule Christopher Columbus for even considering the notion that the Earth wasn't flat...then after proven wrong go around telling people they had a strong feeling the Earth wasn't flat.

Wikipedia tells me Harold Aspden lived to 84 years old. How was he disappeared? I don't see any mention of suspicious circumstances about his death or his body never being found.

> It even impacts time itself for christ sake.

I was under the impression that this is an effect of force generally, nothing to do with gravity in specific.

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