Editing 1720: Horses

{{comic
| number    = 1720
| date      = August 15, 2016
| title     = Horses
| image     = horses.png
| titletext = This car has 240% of a horse's decision-making ability and produces only 30% as much poop.
}}

==Explanation==
{{incomplete|Is White Hat clearly either a sales man or just owner of a nice new car? Maybe this cannot be determined, until Randall makes a transcript... but until then discuss in the comments.}}
[https://techcrunch.com/2016/08/10/are-consumers-automakers-and-insurers-really-ready-for-self-driving-cars/ The programming] of {{w|self-driving cars}} has been in the news lately, as engineers and philosophers debate what rules the cars should follow in dangerous situations (for instance, what to do when forced to choose between hitting a pedestrian or swerving into oncoming traffic). [[Randall]], in the form of [[Ponytail]], suggests one approach for solving this problem: to think of the car as behaving like a horse, using its own intelligence and ignoring dangerous commands in the interests of self-preservation.

The comic begins with Ponytail claiming that in the old days, riding a horse or driving a horse drawn vehicle while drunk was less dangerous than {{w|drunk driving}} today. Given the higher speed and the denser traffic today this might seem plausible.  On the other hand, modern cars have seat belts, airbags, and other features designed to save lives when crashes do occur; horses and horse-drawn vehicles lacked these safety features. But if you do fall asleep the horse will not suddenly walk into another oncoming horse, and may actually just stop walking while you sleep.

Ponytail expands the argument by stating the horse itself will be acting in the interest of its own self-preservation. She finally states that in a comparison of the ability of self-driving cars, we should forget humans, and instead it should be the ability of horses that should be the benchmark that the self-driving cars should be judged against.

This segues into a scene with [[White Hat]], bragging to Cueball and Megan about the features of a car (either to sell the car or simply boast; it's unclear whether White Hat is acting as a salesman) by comparing the features to those of horses. Car engines are traditionally measured in {{w|horsepower}}, which (roughly) compares the power output of the engine to that of a horse. White Hat goes a step further, claiming he can measure the car's onboard computer's driving abilities in the equivalent number of "horses", comparing the car's ability to mitigate for a drunk driver and/or avoid obstacles to that of a horse. (White Hat has been [http://www.explainxkcd.com/wiki/images/9/9f/lorenz_-_sale_2.png depicted as a salesman] before in [[1350: Lorenz]] and similarly earlier in [[260: The Glass Necklace]]).

The title text features more comparisons of the car to horses. Apparently the car has 240% of a horse's decision-making ability while producing only 30% as much poop. So even with 3.5 horse-intelligence it may only have 2.4 times the decision-making ability (assuming it's the same car). A cars "poop" would be its exhaust, which is usually not found on the road in the form of solid waste but could still nonetheless be measured, as it contains mass.  While no source is stated for the 30% ratio, the point that cars are less polluting than horses is surprisingly valid when regarding waste left in the street. Before the invention of the automobile, city streets were commonly filled with horse manure. Of course the amount of pollution created by the cars of the worlds makes them much more toxic both for humans breathing the exhaust fumes and on the larger scale with the climate. (Then again, if there where a horse for each horsepower in all the cars, then that would also be a problem with the release of methane gas etc.)

Note that riding a horse while drunk is in fact still dangerous and illegal in many places (for example, {{w|Licensing Act 1872|the UK and Ireland}}). A badly-driven horse can throw off its owner, trample passersby, fall on bad surfaces, and destroy any wagon or carriage it's pulling. A self-driving car should be able to understand road rules, which a horse will not - which is presumably why the cars in the comic and the title text are both specified as being more intelligent than a horse.

In [[887: Future Timeline]] dogs driving cars are mentioned. Self-driving cars is a [[:Category:Self-driving cars|recurring topic]] on xkcd. In [[1461: Payloads]] spacecraft mass is measured in horses.

==Transcript==
:[Ponytail walks right with Cueball.]
:Ponytail: Drunk driving was less of a problem before cars. If you got on your horse drunk and fell asleep, it could just walk home.

:[Zoom in on Ponytail's torso; she holds up a palm to proffer an idea.]
:Ponytail: And if you tried to ride into a tree, the horse could be like "No." 
:Ponytail: Forget human drivers – ''that's'' the benchmark we should be judging self-driving cars against.

:[The front end of a car, with the bottom of the windshield and the right side mirror just inside the panel is parked before White Hat. He is holding his hand, palm up, out to the left to indicate his car as he brags about it to Megan and Cueball standing in front of him admiring the car. At the top left of the panel a small frame with a caption is placed over the panels frame:]
:Soon:
:White Hat: This baby has 200 horses under the hood and 3.5 in the computer.
:Megan and Cueball: Ooooh!

{{comic discussion}}

[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring White Hat]]
[[Category:Comics featuring Megan]]
[[Category:Animals]]
[[Category:Self-driving cars]]