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The Universe Within 12.5 Light Years

(www.atlasoftheuniverse.com)
266 points algorithmista | 10 comments | | HN request time: 2.934s | source | bottom
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stephc_int13 ◴[] No.45145686[source]
When the Fermi Paradox was first posited, scientists and engineers seemed to believe that interstellar travel was soon to be technologically achievable, a few decades, maybe centuries for the less optimistic. Progress around space propulsion has kind of stalled since then and we should maybe question the possibility of interstellar travel as this would give an easy but unpleasant answer to the famous paradox.
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1. BobbyTables2 ◴[] No.45145814[source]
I’ve always wondered — magnetism seems kinda crazy — how are two objects not touching but exerting a force(?). Practically witchcraft…

Without electricity, how well would we understand it? Just that some mysterious rocks that stick?

Wonder if one day in the distant future we’ll discover a new force we never imagined.

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2. infradig ◴[] No.45146039[source]
How is two objects not touching but feeling a force crazy? Isn't that what gravity does but everyone's ok with that
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3. ljlolel ◴[] No.45146252[source]
Gravity is crazy
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4. praptak ◴[] No.45146734{3}[source]
And is a force only in the non relativistic model.
5. Yokolos ◴[] No.45147140[source]
A lot of science is crazy but real. Are you not awestruck by the weird ways the real world behaves? Where's your wonder?
6. lIl-IIIl ◴[] No.45147314[source]
You might find this video of Feyman talking about magnets interesting: https://www.youtube.com/watch?v=MO0r930Sn_8
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7. DonHopkins ◴[] No.45148664{3}[source]
Velcro too.
8. mannykannot ◴[] No.45149552[source]
Well, it continued to bother Newton. Here, he seems to be foreshadowing the concept of fields:

"It is inconceivable that inanimate Matter should, without the Mediation of something else, which is not material, operate upon, and affect other matter without mutual Contact... That Gravity should be innate, inherent and essential to Matter, so that one body may act upon another at a distance thro’ a Vacuum, without the Mediation of any thing else, by and through which their Action and Force may be conveyed from one to another, is to me so great an Absurdity that I believe no Man who has in philosophical Matters a competent Faculty of thinking can ever fall into it. Gravity must be caused by an Agent acting constantly according to certain laws; but whether this Agent be material or immaterial, I have left to the Consideration of my readers."

https://plato.stanford.edu/archives/win2008/entries/qm-actio...

9. BobbyTables2 ◴[] No.45152919[source]
That is interesting. Have read his books but never seen videos.

What I was trying to get at is I argue that historically we had no reason to assume magnets to exist until we discovered them. (Sure, today we can explain them in terms of the effects of electrons traveling at relativistic speeds.)

It otherwise seems a safe assumption that we cannot move into a 4th spatial dimension (even if such exists) or do many other outlandish things. I don’t think we can prove them impossible but likely just don’t know how.

But imagine if Newton had been shown an electromagnet and asked to explain it… It would have been witchcraft!

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10. lIl-IIIl ◴[] No.45164914{3}[source]
He was familiar with attraction and repulsion of bodies due to static electric charge, which he attributed to "most subtle spirit": https://link.springer.com/chapter/10.1007/978-94-009-7715-0_...