Editing 2981: Slingshots

{{comic
| number    = 2981
| date      = September 4, 2024
| title     = Slingshots
| image     = slingshots_2x.png
| imagesize = 397x420px
| noexpand  = true
| titletext = In my reboot, Dennis the Menace was just trying to send Mr. Wilson a nice comet, but accidentally wiped out his dinosaur garden.
}}

==Explanation==
The {{w|Slingshot|slingshot}} (in this comic, styled "Regular Slingshot") is primarily refering to the hand-held device used for accelerating small projectiles, such as stones or steel balls. The "forked stick and elastic" contraption (known as a catapult, in the UK) acts by a pull-back-and-release action, and has become associated with youthful recklessness (or an outright tendency towards vandalism), but is also the basis of manufactured sport/hunting devices as well as all of the more organic child-made contraptions.

The '''gravitational''' slingshot, or {{w|gravity assist}}, is not a device but a term used to describe how gravity can significantly alter the path of an object in space, such as a spacecraft or an asteroid.  A gravitational slingshot generally involves a small object passing by a much more massive object, which turns the smaller object's trajectory, trading momentum and kinetic energy between the two bodies.  The smaller object can undergo a large change in velocity, "paid for" (in the sense of conserving the momentum and energy of the system) with a negligible change in the velocity of the more massive body.

This comic humorously compares the two, in tabular format.

{| class="wikitable"
|-
!
! Regular slingshot
! Gravitational slingshot
|-
! Used for hunting
| ✓
| X
|-
! Used for sport shooting
| ✓
| X
|-
! Used for spacecraft propulsion
| X
| ✓
|-
! Large online enthusiast community
| ✓
| ✓
|-
! May have caused dinosaur extinction
| Probably not
| Maybe
|-
! Used by Dennis the Menace to terrorize Mr. Wilson
| ✓
| Not yet, but I'm pitching a reboot
|}

The first four categories accurately reflect reality. As a hunting tool (and as an offensive weapon), recent designs have been claimed to propel a projectile with [https://www.uslawshield.com/tactical-slingshots-mere-toy/ more force than .22 and .38 caliber pistols]. Consequently, several communities have prohibited the possession of such slingshots, which may be called "wrist rockets". The state of Massachusetts, where cartoonist Randall resides, is one of those communities. Gravitational slingshots would be inefficient and cause overkill for such purposes, as well as being difficult to achieve sufficient accuracy and specificity.

Conversely, gravitational slingshots are a useful way to change the velocity of a spacecraft without having to use large amounts of fuel, whereas building a regular slingshot capable of propelling a spacecraft is likely to be impractical - not to mention the destructive/fatal consequences, to vehicle and cargo, of near-instantaneous acceleration to useful speeds, such as the Mach 33 required for an object at sea level to escape Earth's gravity, especially when there's an atmosphere present.

Both types of slingshot excite interest among many people who may form online communities to discuss them, but for quite different reasons, and the size of overlap between these communities is uncertain.

The fifth category ventures into the absurd, at least with respect to "regular" slingshots, which did not exist (as far as we know) at the time of the {{w|Cretaceous–Paleogene_extinction_event|Cretaceous-Tertiary extinction event}}. (Humans, which invented them, did not exist at that time. Use of slingshots would therefore require some other contemporaneous intelligent species to have invented them, or some kind of {{w|A_Sound_of_Thunder|time}} {{w|A_Gun_for_Dinosaur|travel}}.) However, it is likely that the event resulted from the impact of a space-rock that was perturbed into an Earth-crossing orbit by a planet such as Jupiter, given at least a minor gravitational slingshot on its way to eventually crashing into the Earth.

The sixth category references the long-running comic and cartoon character {{w|Dennis_the_Menace_(U.S._comics)|Dennis the Menace (USA)}}, in which the titular character unintentionally harasses neighbor Mr. Wilson with (regular) slingshots and other devices and behaviors. In Randall's projected reboot of the franchise, which is elaborated on in the title text, Dennis trades his regular slingshot for a gravitational slingshot. By miscalibrating his ammunition, or the force of his slingshot, he turns a demonstration ("a nice comet") into a destructive event (the loss of Wilson's dinosaur garden). The reference is to the relative size and velocity of the space objects responsible for, respectively, comets and "meteors" <em>versus</em> asteroid impacts.

This comic is probably inspired by the recently released movie {{w|Slingshot_(2024_film)|Slingshot}}.

This is very similar to [[2844: Black Holes vs Regular Holes]].

==Transcript==
:[A table grid with two columns and six rows.]
:[Two column labels placed above the respective columns, six row labels to the left of the respective rows.  Each table cell contains a tick for "Yes", a cross for "No", or a note.]

::[Column 1:] Regular slingshot
::[Column 2:] Gravitational slingshot

:[Row 1:] Used for hunting
::[Tick]
::[Cross]
:[Row 2:] Used for sport shooting
::[Tick]
::[Cross]
:[Row 3:] Used for spacecraft propulsion
::[Cross]
::[Tick]
:[Row 4:] Large online enthusiast community
::[Tick]
::[Tick]
:[Row 5:] May have caused dinosaur extinction
::Probably not
::Maybe
:[Row 6:] Used by Dennis the Menace to terrorize Mr. Wilson
::[Tick]
::Not yet, but I'm pitching a reboot

==Trivia==
An other form of {{w|Sling (weapon)|stone flinging hand-held weapon}} had existed since ancient times, and has been used for personal defense and for hunting game such as squirrels, birds and {{w|Goliath|Philistines}} through skillful use of its mechanical advantage and rotation. It is essentially a mimimalist hand-held form of {{w|trebuchet}} (using the the thrower's arm as a much more versatile main beam, taken back to mechanical extremes in some proposed {{w|SpinLaunch|kinetic energy space-launch}} ideas), compared to the version that is more of a cut-back {{w|crossbow}}-like 'catapult' (as well as partially duplicating the mechanics of a {{w|ballista}}), but had necessitated the easy availability of an elastic cord before it could become the common form of slingshot/catapult that then became the signature toy/tool/weapon of both Dennis Mitchell (the American version) and his British namesake (see below).

The 'gravitational slingshot' can be perhaps more likened to the ancient 'stone slinger', by dint of using a radial redirection to build up energy for the object being slung and released, and is also very dependent upon the exact timing of the 'release' (insofar as one can ever be released from any gravitational field). Although as it also makes key use of exchanging potential and kinetic energies there are also elements by which the elasticated thrower does also share some conceptual similarity to the gravitational assist. It is not recorded<!-- anywhere that I've looked! --> which particular form of slingshot became the primary inspiration for this particular spacecraft manoeuvre terminology.

The "Dennis the Menace" that the [[Randall]] refers to, familiar to those in the US, is not to be confused with the ''other'' long-running comic and cartoon character from the UK, also called {{w|Dennis the Menace and Gnasher|Dennis the Menace}}, who has a surprisingly similar premise and identical date of creation but is more willfully disruptive and capable of far more 'cartoonish' behaviour (which might well include planetary-scale fork-stick slingshots/catapults). {{w|Mark Hamill}} is a fan of the British character (possibly from his time filming the original Star Wars films in the local studios), and also has some experience with (fictional) disruption of planets by {{w|Death Star|constructed weapons}}.

{{comic discussion}}

[[Category: Charts]]
[[Category: Space]]
[[Category: Dinosaurs]]
[[Category: Fiction]]