If you could build a ladder tall enough

If you could build a ladder tall enough

Author
Discussion

superlightr

12,899 posts

269 months

Friday 11th December 2015
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tuffer said:
OP here, glad to see this thread is going strong and has not dissolved into the vitriol and abuse that most threads seem to do nowadays. All very interesting reading and helping with my research. I am planning on starting to build my ladder in the new and should be completed just before Donald Trump comes to power in the USA. I can then begin my escape.

I have one other question, does anyone know what the depreciation will look like over a 3 year PCP on the base materials and should I have maybe waited for the Spyder version as I believe these will be more limited numbers?
I will hold the ladder for you- health and safety and all that.....

Dont know about the Spyder version but make sure its painted White -

CrutyRammers

13,735 posts

204 months

Friday 11th December 2015
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RizzoTheRat said:
In theory either a tower or a rope would work if you had strong enough materials and it didn't get blown down by high winds. The critical bit is the geostationary orbit though.
Good post.
Going back to the OP, the bit about geostationary orbits all depends on if you want to stay in orbit, or are happy clinging to the ladder. If it were just "climb into space" as per the op, then a ladder up to 200 miles or whatever will be fine. But if you let go, you'd fall straight back to earth. If you wanted to be able to let go and stay in orbit, then you would indeed need to go up to geostationary heights. wink

Nimby

4,888 posts

156 months

Friday 11th December 2015
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RizzoTheRat said:
...
  • If you throw a ball forwards from your geostationary tower it will ... end up in a higher orbit...
  • If you throw a ball backwards from your tower it will fall in to a lower orbit...
The ball will go into an elliptical orbit with one radius still at the top of the tower, and the other radius higher or lower respectively.
Either way, you might even be able to catch it when it returns.




Edited by Nimby on Friday 11th December 17:24

V8LM

5,255 posts

215 months

Friday 11th December 2015
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You might have to wait a long time to catch the ball though for the orbits of the ball and ladder to coincide at the same time.

glazbagun

14,451 posts

203 months

Saturday 12th December 2015
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V8LM said:
You might have to wait a long time to catch the ball though for the orbits of the ball and ladder to coincide at the same time.
This is such a great idea. Never mind fighting ISIL or propping up the banks, the world needs to get on with this now!

Dr Jekyll

23,820 posts

267 months

Saturday 12th December 2015
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Nimby said:
RizzoTheRat said:
...
  • If you throw a ball forwards from your geostationary tower it will ... end up in a higher orbit...
  • If you throw a ball backwards from your tower it will fall in to a lower orbit...
The ball will go into an elliptical orbit with one radius still at the top of the tower, and the other radius higher or lower respectively.
Either way, you might even be able to catch it when it returns.
But suppose your team mate is in front of you, but on a lower tower, how do you pass the ball? Do we have to modify the offside rule to cover this?

V8LM

5,255 posts

215 months

Saturday 12th December 2015
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Dr Jekyll said:
Nimby said:
RizzoTheRat said:
...
  • If you throw a ball forwards from your geostationary tower it will ... end up in a higher orbit...
  • If you throw a ball backwards from your tower it will fall in to a lower orbit...
The ball will go into an elliptical orbit with one radius still at the top of the tower, and the other radius higher or lower respectively.
Either way, you might even be able to catch it when it returns.
But suppose your team mate is in front of you, but on a lower tower, how do you pass the ball? Do we have to modify the offside rule to cover this?
The maths of this is interesting. Easier to throw it backwards so its orbit decays enough for the other chap to catch it almost a day later.

Easier still to ask him to climb down his ladder and climb up to you.

Nimby

4,888 posts

156 months

Saturday 12th December 2015
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Dr Jekyll said:
But suppose your team mate is in front of you, but on a lower tower, how do you pass the ball? Do we have to modify the offside rule to cover this?
https://en.wikipedia.org/wiki/Transfer_orbit

"In space, no-one can hear the ref's whistle"

RizzoTheRat

25,949 posts

198 months

Monday 14th December 2015
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Nimby said:
RizzoTheRat said:
...
  • If you throw a ball forwards from your geostationary tower it will ... end up in a higher orbit...
  • If you throw a ball backwards from your tower it will fall in to a lower orbit...
The ball will go into an elliptical orbit with one radius still at the top of the tower, and the other radius higher or lower respectively.
Either way, you might even be able to catch it when it returns.
Good point, I didn't explain it well. If you throw it forwards its periapsis (lowest point) will remain at the same height as the tower, but you'll raise it's apoapsis, which will be the other side of the planet. However it's orbital period (the time it takes to do one orbit) will now be longer, due to the longer path it's taking despite it's higher speed, so when it next reaches periapsis you'll have already passed that point, however as suggested your team mate on another tower behind you could be in the right place to catch it.




Edited by Nimby on Friday 11th December 17:24

otolith

58,722 posts

210 months

Monday 14th December 2015
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RizzoTheRat said:
If you throw a ball and fire a bullet horizontally from the same height they'll both hit the ground at the same time because they fall at the same acceleration, but the bullet will have travelled further obviously.
Approximately, unless in a vacuum.

tuffer

Original Poster:

8,875 posts

273 months

Monday 14th December 2015
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otolith said:
RizzoTheRat said:
If you throw a ball and fire a bullet horizontally from the same height they'll both hit the ground at the same time because they fall at the same acceleration, but the bullet will have travelled further obviously.
Approximately, unless in a vacuum.
https://www.youtube.com/watch?v=E43-CfukEgs

otolith

58,722 posts

210 months

Monday 14th December 2015
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tuffer said:
otolith said:
RizzoTheRat said:
If you throw a ball and fire a bullet horizontally from the same height they'll both hit the ground at the same time because they fall at the same acceleration, but the bullet will have travelled further obviously.
Approximately, unless in a vacuum.
https://www.youtube.com/watch?v=E43-CfukEgs
Nicely demonstrated, though of course the effect would be far less pronounced with a ball and a bullet than a ball and a feather.

Halmyre

11,502 posts

145 months

Monday 14th December 2015
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glazbagun said:
This is such a great idea. Never mind fighting ISIL or propping up the banks, the world needs to get on with this now!
I think it was Carl Sagan who said you could have a one-man game of rounders (well, he called it baseball but YKWIM) on the Martian moon Phobos. You throw the ball, pick up your bat and wait for the ball to come round, bat it away and then pick up your catcher's mitt and wait for it to come round again. Not sure why the ball isn't heading into Martian orbit orbit at this point, but still...