Environment & Energy

muriel_volestrangler

(105,866 posts)

38. And the point is you have to expend energy to bring asteroids to earth

Wed May 4, 2016, 03:11 PM

May 2016

They are not a way to obtain the energy to desalinate seawater, or clean up pollution.

Once anything is 'falling toward Earth', ie on an elliptical orbit that intersects with Earth's, it will have a velocity relative to Earth. You then have to change that velocity to get it to be captured by Earth's gravitational field - which takes more energy. And once you've got something in an orbit around Earth, you still don't get energy from it. You've expended a lot of energy to get it there.

It's not a solution to sustainability - it's just expanding the volume you are permanently altering. Perhaps there will one day be something we need to get this way, but it will require energy, and is not a solution to man-made environmental change on Earth.

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Sustainability is destroying the Earth [View all] GliderGuider May 2016 OP

Practice birth control. haikugal May 2016 #1

Birth control will keep children from dying unnecessarily GliderGuider May 2016 #2

No, my heart goes out to them but at the same time I have no special knowledge or access and haikugal May 2016 #4

Eventually, we will have to go off-planet for our resources. immoderate May 2016 #3

Good luck with that! nt GliderGuider May 2016 #5

Well, I'm not going myself... immoderate May 2016 #7

So where ya gonna go? GliderGuider May 2016 #8

We may very well get extinguished. I (for instance) have no descendants. immoderate May 2016 #9

Why, then, suggest a project requiring orders of magnitude more energy than our current lifestyle? muriel_volestrangler May 2016 #13

The OP suggests that our current lifestyle, and ordinary remedies are unsustainable. immoderate May 2016 #15

Are you saying that you don't understand what's so hard about space travel? muriel_volestrangler May 2016 #16

I'm suggesting we have not yet reached the epitome of technology. immoderate May 2016 #17

A moment ago you wanted to expend energy in bringing water and raw materials from off earth muriel_volestrangler May 2016 #18

If you think natural resources can't be exhausted, you're covered. immoderate May 2016 #21

No, you're making even less sense as you go along, not more muriel_volestrangler May 2016 #22

So let's start simple. immoderate May 2016 #25

You can't just take energy from something in a different orbit muriel_volestrangler May 2016 #28

The sun has gravity. The asteroids are "above" the earth. immoderate May 2016 #29

No, mechanics doesn't work like that muriel_volestrangler May 2016 #30

This is not about climate change. immoderate May 2016 #32

I've already assumed the rocket is solar or nuclear powered muriel_volestrangler May 2016 #33

Well, asteroids, if nothing else, have "mass to burn." immoderate May 2016 #37

And the point is you have to expend energy to bring asteroids to earth muriel_volestrangler May 2016 #38

You have to aim it 'just right.' immoderate May 2016 #40

It's a reversible process. If you think of what you'd have to do to leave an earth orbit muriel_volestrangler May 2016 #41

Yes, relatively little effort... immoderate May 2016 #42

OK, I think you've finally conceded that mining asteroids is an energy sink muriel_volestrangler May 2016 #43

Thanks for including me in your pigeon hole. immoderate May 2016 #44

'equal and opposite' refers to forces, not energy muriel_volestrangler May 2016 #45

Microwave projectors in space? A bit "third way," doncha think? immoderate May 2016 #46

I think I heard them suggested on a TV documentary about 35 years ago muriel_volestrangler May 2016 #47

IMO, it was a scheme for corporations to retain control over solar energy. immoderate May 2016 #48

Whereas your scheme for towing and mining asteroids would be done by a cooperative muriel_volestrangler May 2016 #49

Don't confuse corporatism with entrepreneurism. immoderate May 2016 #50

There are consumer benefits in energy. muriel_volestrangler May 2016 #51

What is the benefit to consumers of paying for transmission from space? immoderate May 2016 #52

The benefit is that it's a way to get the energy we need muriel_volestrangler May 2016 #53

Why should I pay a utility company to beam down microwaves to maintain EMF on a grid, immoderate May 2016 #55

If someone gives you a solar panel for free, then go for it muriel_volestrangler May 2016 #56

Ordinary remedies are unsustainable, and extraordinary remedies are unachievable. GliderGuider May 2016 #31

OK. So the world will collapse in 30 years, then the population will double in 80? immoderate May 2016 #34

Who has claimed here the population will double in 80 years? NickB79 May 2016 #35

Population increase depends on a functional civilization. GliderGuider May 2016 #36

I had surmised that the earth would not tolerate that number of humans. immoderate May 2016 #39

That can't possibly work Binkie The Clown May 2016 #10

Dyson Sphere? Ring World? Lots of ways. immoderate May 2016 #11

Lots of ways in fantasy land! Binkie The Clown May 2016 #12

So will the population double in 80 years? immoderate May 2016 #14

That's certainly what I see happening. GliderGuider May 2016 #19

Oh, a Dyson sphere doesn't preclude extinction. immoderate May 2016 #20

This message was self-deleted by its author immoderate May 2016 #26

In a word: "Yes" that is exactly what I expect will happen. n/t Binkie The Clown May 2016 #24

I think it will level off. immoderate May 2016 #27

Malthus where is thy sting? pscot May 2016 #23

I'm not sure how the word harm is defined The2ndWheel May 2016 #6

Excellent post.... AuntPatsy May 2016 #54