Elephants with spiderlegs - Revision history

Apm: Category:Surprising facts

2026-03-29T20:41:42Z

← Older revision		Revision as of 22:41, 29 March 2026
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	* [https://en.wikipedia.org/wiki/File:Dali_Elephants.jpg "The Elephants" by Salvador Dali]		* [https://en.wikipedia.org/wiki/File:Dali_Elephants.jpg "The Elephants" by Salvador Dali]
	* Originally posted here on twitter: [https://twitter.com/mechadense/status/1424965538330128388]		* Originally posted here on twitter: [https://twitter.com/mechadense/status/1424965538330128388]

			[[Category:Surprising facts]]

Apm: cleanup

2021-08-24T06:48:24Z

cleanup

← Older revision		Revision as of 08:48, 24 August 2021
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	But if structures are hollowed out, as it is possible under low enough gravity, speeds can be scaled up along with the size.		But if structures are hollowed out, as it is possible under low enough gravity, speeds can be scaled up along with the size.

	{{todo\|How does this go together with the scale invariant [[unsupported rotating ring speed limit]]??}}		{{todo\|How does this go together with the scale invariant [[unsupported rotating ring speed limit]]? Infinitesimally thin surfaces in the limit maybe?? To investigate.}}

	== Conclusion ==		== Conclusion ==

	Machines shaped like		Machines shaped like Salvador Dalì's Elephants might actually work and exist in the future on asteroids. <br>
	Salvador Dalì's Elephants		Heck, space-probes could probably do this in the foreseeable future (written 2021).
	~~Might~~ actually work and exist in the future on asteroids.
	Heck space-probes could probably do this in the foreseeable future.

	== Related ==		== Related ==

Apm: /* Math in more detail & making it work even better by "making the elephants hollow" */ added some elaborations

2021-08-24T06:44:29Z

Math in more detail & making it work even better by "making the elephants hollow": added some elaborations

← Older revision		Revision as of 08:44, 24 August 2021
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	we get		we get
	𝜎 = F/A ∝ L^0		𝜎 = F/A ∝ L^0

			Good! works for all scales :)
			But speeds stay constants so frequencies drop.
			Not so good. Can we do something about it? Yes ...

	hollowing stuff out		hollowing stuff out
	(as is possible in low gravity)		(as is possible in low gravity)
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	changes		changes
	𝜎 = ∝ L^-1		𝜎 = ∝ L^-1
	so we can do		so we can do what we wanted (increase speeds along with size)
	v ∝ L^1		v ∝ L^1
	and be back at		and be back at
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	When scaling to larger sizes forces from accelerations do NOT scale faster than the strength of the material. Given speeds are kept constant! <br>		When scaling to larger sizes forces from accelerations do NOT scale faster than the strength of the material. Given speeds are kept constant! <br>
	But if structures are hollowed out, as it is possible under low enough gravity, speeds can be scaled up along with the size.		But if structures are hollowed out, as it is possible under low enough gravity, speeds can be scaled up along with the size.

			{{todo\|How does this go together with the scale invariant [[unsupported rotating ring speed limit]]??}}

	== Conclusion ==		== Conclusion ==

Apm: /* Math in more detail & making it work even better by "making the elephants hollow" */ added spaces (that where left out due to twitter char limit)

2021-08-24T06:35:38Z

Math in more detail & making it work even better by "making the elephants hollow": added spaces (that where left out due to twitter char limit)

← Older revision		Revision as of 08:35, 24 August 2021
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	F_inertial = m ω^2 r = m v^2 / r		F_inertial = m ω^2 r = m v^2 / r
	with		with
	~~m∝L~~^3		m ∝ L^3
	and assuming		and assuming
	★ ~~v∝L~~^0		★ v ∝ L^0
	★ ~~r∝L~~^1		★ r ∝ L^1
	we get		we get
	F_inertial ∝L^2		F_inertial ∝ L^2
	with		with
	A ∝L^2		A ∝ L^2
	we get		we get
	𝜎 = F/A ∝ L^0		𝜎 = F/A ∝ L^0
	hollowing stuff out		hollowing stuff out
	(as is possible in low gravity)		(as is possible in low gravity)
	changes		changes
	~~m∝L~~^2		m ∝ L^2
	changes		changes
	𝜎 = ∝ L^-1		𝜎 = ∝ L^-1
	so we can do		so we can do
	~~v∝L~~^1		v ∝ L^1
	and be back at		and be back at
	~~𝜎∝L~~^0		𝜎 ∝ L^0
	again		again

Apm: /* Making it work by by reducing gravity */

2021-08-24T06:34:36Z

Making it work by by reducing gravity

← Older revision		Revision as of 08:34, 24 August 2021
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	Pros:		Pros:
	* no propellant needed		* no continuously depleting propellant needed
	* more control than jumping		* more control than jumping

Apm: /* In fiction and art */ cleanup

2021-08-24T06:33:37Z

In fiction and art: cleanup

← Older revision		Revision as of 08:33, 24 August 2021
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	In "star wars", "war of the worlds", and Salvador Dali's pictures <br>		In "star wars", "war of the worlds", and Salvador Dali's pictures <br>
	it's ~~lileky~~ just an artistic choice to make it look alien/surreal by making it look like something that cannot be found by a long stretch		it's likely just an artistic choice to make it look alien/surreal by making it look like something <br>
	(pun intended) in our world. The artists ~~proobably~~ have not thought deeply about the physics involved.		that cannot be found by a long stretch (pun intended) in our world. <br>
			The artists probably have not thought deeply about the physics involved.

	== Making it work by by reducing gravity ==		== Making it work by by reducing gravity ==

Apm: added link to page Scaling law

2021-08-24T06:32:26Z

added link to page Scaling law

← Older revision		Revision as of 08:32, 24 August 2021
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	Might actually work and exist in the future on asteroids.		Might actually work and exist in the future on asteroids.
	Heck space-probes could probably do this in the foreseeable future.		Heck space-probes could probably do this in the foreseeable future.

			== Related ==

			* [[Scaling law]]

	== External links ==		== External links ==

Apm: basic page

2021-08-21T16:27:38Z

basic page

New page

== In fiction and art ==

In "star wars", "war of the worlds", and Salvador Dali's pictures 
it's lileky just an artistic choice to make it look alien/surreal by making it look like something that cannot be found by a long stretch
(pun intended) in our world. The artists proobably have not thought deeply about the physics involved.

== Making it work by by reducing gravity ==

Despite clearly not working here down on Earth with our crushing gravity 
interestingly this "gargantuan spiderelephant anatomy" might actually practically work 
on low but not too low gravity celestial bodies like e.g. big asteroids where the k in 
» F_grav ∝ k * L^3 « 
is sufficiently small. 

Pros:
* no propellant needed
* more control than jumping

=== Math in more detail & making it work even better by "making the elephants hollow" ===

F_inertial = m ω^2 r = m v^2 / r
with
m∝L^3
and assuming
★ v∝L^0
★ r∝L^1
we get
F_inertial ∝L^2
with
A ∝L^2
we get
𝜎 = F/A ∝ L^0
hollowing stuff out
(as is possible in low gravity)
changes
m∝L^2
changes
𝜎 = ∝ L^-1
so we can do
v∝L^1
and be back at
𝜎∝L^0
again

In words: 
When scaling to larger sizes forces from accelerations do NOT scale faster than the strength of the material. Given speeds are kept constant! 
But if structures are hollowed out, as it is possible under low enough gravity, speeds can be scaled up along with the size.

== Conclusion ==

Machines shaped like
Salvador Dalì's Elephants
Might actually work and exist in the future on asteroids.
Heck space-probes could probably do this in the foreseeable future.

== External links ==

* [https://en.wikipedia.org/wiki/File:Dali_Elephants.jpg "The Elephants" by Salvador Dali]
* Originally posted here on twitter: [https://twitter.com/mechadense/status/1424965538330128388]