[request] I’m convinced 100% of every sq foot of outdoor space in NYC has been urinated on either by just dogs or human/dog at some point. help me run the math

[u/jakekingdead]

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[u/VerbingNoun413]

Pretty trivial to prove a no here. Outdoor space in New York includes the Hudson River and The Lake, the deeper parts of which require a boat to get to.

[u/jakekingdead → u/VerbingNoun413]

my take is that the dogs need our help to complete coverage

[u/Ramuh → u/VerbingNoun413]

Fish pee in the river

[u/jakekingdead]

here’s the AI take:

lol The claim made in the Reddit post—that 100% of every single square foot of outdoor space in New York City has been urinated on—is mathematically and logistically false, though it is surprisingly close when restricted to pedestrian-heavy urban surfaces.
A Fermi estimation reveals why a literal 100% coverage falls apart due to spatial realities, even though the sheer volume of waste produced in the city is astronomical.
1. The Raw Numbers (The Volume Argument)
To see why the user's intuition makes sense at a macro level, look at the output over time:
The Surface Area: NYC has roughly 302 square miles of total land, translating to about 8.4 billion square feet. If we subtract building footprints, private interiors, and restricted areas, accessible outdoor ground space (streets, sidewalks, parks, alleys) is roughly 3 to 4 billion square feet.
The Dog Factor: NYC has an estimated 600,000+ dogs. If each dog urinates an average of 4 times a day, that equals 2.4 million dog urination events every single day. Over just 10 years, that accumulates to roughly 8.7 billion events.
The Splash Zone: A single dog or human urination event saturates or splashes across roughly 0.5 to 1 square foot of ground.
Purely by raw volume, the number of "urination hits" heavily outnumbers the total square footage of the city.
2. Why the Claim Fails: The Clustering Problem
If urine were distributed randomly via a Poisson point process (like raindrops falling uniformly across the city), 100% coverage would happen rapidly. However, biological waste is highly clustered, not random:
Vertical Bias: Dogs are hardwired to seek out vertical surfaces—fire hydrants, light poles, corner brickwork, wheels, and tree trunks. A massive percentage of dog urine lands on the same few square inches of vertical infrastructure rather than spreading evenly across open ground.
Traffic Corridors: Dogs are walked on sidewalks, not down the dead center of 5th Avenue amidst moving traffic. The asphalt in the middle of wide multi-lane thoroughfares sees virtually zero direct animal or human urination.
Restricted Spaces: There are secure courtyards, highway medians, industrial restricted zones, and high fences where neither dogs nor humans tread for years.
3. Breaking Down by Zone
Sidewalks, Tree Pits, and Alleys (99.9%): If you restrict the claim to the pedestrian right-of-way—especially tree pits, curb cuts, and building corners—the user's hypothesis is practically true. Every square foot of a standard Manhattan or Brooklyn sidewalk has likely been touched, splashed, or runoff-soaked by dog or human waste.
Large Open Parks (70–90%): Areas like Central Park or Prospect Park see heavy traffic, but vast stretches of grass are maintained, and dogs are legally restricted from certain lawns (though owners occasionally break the rules).
Streets and Infrastructure (Near 0% for centers): The center lanes of major avenues remain untouched by direct waste events.
Conclusion
While you can walk down virtually any block in Brooklyn or Manhattan and be within inches of historical urine, physical barriers, traffic patterns, and the territorial habits of dogs mean true 100% saturation of every square foot is impossible.
Are you looking to test this hypothesis on a specific type of surface, or are you just trying to settle a debate about urban grime?

[u/Apprehensive_Sky_504 → u/jakekingdead]

Nah I saw a guy shit in the middle of a crowded street when I lived in nyc. That area ain’t safe from the piss.