Re: xkcd: What If? #98 - Blood Alcohol
Posted: Wed May 28, 2014 8:34 pm
Squirrels. Why’d it have to be squirrels? I hate squirrels!bystander wrote:
Blood Alcohol
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Squirrels. Why’d it have to be squirrels? I hate squirrels!bystander wrote:
Blood Alcohol
Because, IF you are what you eat, then squirrels is nuts, which fits right in with some of the nutty questions asked and answered(?) in xkcd.neufer wrote:Squirrels. Why’d it have to be squirrels? I hate squirrels!bystander wrote:
Blood Alcohol
neufer wrote:Squirrels. Why’d it have to be squirrels? I hate squirrels!
I found the starlings-collapsing-into-a-star example interesting.bystander wrote:Starlings
- I was watching this video and was wondering: How many birds there would need to be for
gravity to take over and force them into a gargantuan ball of birds? — Justin Basinger
See: A Mighty Wind.Beyond wrote:
How about methane?
http://en.wikipedia.org/wiki/Sinclair_Oil_Corporation wrote: <<At the Chicago World's Fair of 1933-1934, Sinclair Oil Corporation sponsored a dinosaur exhibit meant to point out the putative correlation between the formation of petroleum deposits and the time of dinosaurs, now a largely discredited misconception. The exhibit included a two-ton animated model of a brontosaurus. The exhibit proved so popular it inspired a promotional line of rubber brontosaurs at Sinclair stations, complete with wiggling heads and tails, and the eventual inclusion of the brontosaur logo. Later, inflatable dinosaurs were given as promotional items, and an anthropomorphic version appeared as a service-station attendant in advertisements. Some locations have a life-size model of the mascot straddling the building's entrance.
At the New York World's Fair of 1964–1965, Sinclair again sponsored a dinosaur exhibit, "Dinoland", featuring life-size replicas of nine different dinosaurs, including their signature brontosaurus. Souvenirs from the exhibit included a brochure ("Sinclair and the Exciting World of Dinosaurs") and molded plastic figurines of the dinosaurs featured. After the Fair closed, Dinoland spent a period of time as a traveling exhibit. Two of the replicas are still on display at Dinosaur Valley State Park near Glen Rose, Texas. Another, a model of a Trachodon, has been displayed at Brookfield Zoo outside Chicago, Illinois.>>
bystander wrote:
Vanishing Water
- What would happen if all the bodies of water on Earth magically disappeared? — Joanna Xu
http://en.wikipedia.org/wiki/A_Modest_Proposalbystander wrote:Cannibalism
- How long could the human race survive on only cannibalism? — Quinn Shaffer
geckzilla wrote:
Hah, it took me a few moments to understand that this picture was supposed to be the tournament bracket and not two sideways hills with snow on top.
http://en.wikipedia.org/wiki/Logistic_map wrote: <<The logistic map is a polynomial mapping (equivalently, recurrence relation) of degree 2, often cited as an archetypal example of how complex, chaotic behaviour can arise from very simple non-linear dynamical equations. The map was popularized in a seminal 1976 paper by the biologist Robert May, in part as a discrete-time demographic model analogous to the logistic equation first created by Pierre François Verhulst. Mathematically, the logistic map is written
where:
This nonlinear difference equation is intended to capture two effects.
- xn is a number between zero and one which represents the ratio of existing population to the maximum possible population at year n, and hence x0 represents the initial ratio of population to max. population (at year 0)
r is a positive number, and represents a combined rate for reproduction and starvation.
- reproduction where the population will increase at a rate proportional to the current population when the population size is small.
starvation (density-dependent mortality) where the growth rate will decrease at a rate proportional to the value obtained by taking the theoretical "carrying capacity" of the environment less the current population.>>
http://en.wikipedia.org/wiki/Logistic_function wrote: A logistic function or logistic curve is a common special case of the more general sigmoid function, with equation:
It was named in 1844-1845 by Pierre François Verhulst, who studied it in relation to population growth. The initial stage of growth is approximately exponential; then, as saturation begins, the growth slows, and at maturity, growth stops.
A typical application of the logistic equation is a common model of population growth, originally due to Pierre-François Verhulst in 1838, where the rate of reproduction is proportional to both the existing population and the amount of available resources, all else being equal. The Verhulst equation was published after Verhulst had read Thomas Malthus' An Essay on the Principle of Population. Verhulst derived his logistic equation to describe the self-limiting growth of a biological population.
Letting P represent population size and t represent time, this model is formalized by the differential equation:
where the constant r defines the growth rate and K is the carrying capacity.
In the equation, the early, unimpeded growth rate is modeled by the first term +rP. The value of the rate r represents the proportional increase of the population P in one unit of time. Later, as the population grows, the second term, which multiplied out is −rP2/K, becomes larger than the first as some members of the population P interfere with each other by competing for some critical resource, such as food or living space. This antagonistic effect is called the bottleneck, and is modeled by the value of the parameter K. The competition diminishes the combined growth rate, until the value of P ceases to grow (this is called maturity of the population).
Dividing both sides of the equation by K gives
Now setting x=P/K gives the differential equation
For r = 1 we have the particular case with which we started.>>
That was a fun and thought-provoking read, as always when it comes to xkcd.bystander wrote:Expensive Shoebox
- What would be the most expensive way to fill a size 11 shoebox
(e.g. with 64 GB MicroSD cards all full of legally purchased music)? — Rick Lewis