1377: Fish

2017-12-17T03:50:16Z

Timothy N: /* Explanation */

{{comic
| number = 1377
| date = June 4, 2014
| title = Fish
| image = fish.png
| titletext = [Astronomer peers into telescope] [Jaws theme begins playing]
}}

==Explanation==
The {{w|Fermi Paradox}} is the contradiction that arises between high estimates of the likelihood of {{w|extraterrestial life}} and the fact that no evidence for it has thus far been found.

[[Cueball]] and [[Megan]] are having a conversation regarding this — since new planets are found all the time around distant stars, Cueball comments that this makes it an even greater paradox. Megan suggests that perhaps our search for extraterrestrial life is like looking at a patch of ocean floor looking for a fish. The diver knows that there must be a fish somewhere, but is unable to actually find it. She then goes on to ask why the fish would be hidden — i.e. camouflaged, and what it means about the remaining fish. The suggestion is that the fish would be hidden to avoid being eaten by predators, and perhaps the reason no extraterrestrial life is sending any sign of existence back is that they fear they might be destroyed soon after they revealed their location. Maybe they have even actively tried to hide the presence of their entire planet if they obtain the technological means. This potentially refers to the [http://articles.adsabs.harvard.edu/full/gif/1983QJRAS..24..283B/0000296.000.html Deadly Probes scenario] where a space faring species has developed deadly probes that self replicate and spread through the void between the stars - homing in on radio signals and destroying young civilizations in the cradle...

The camouflaged fish could be identified by using more sophisticated technologies like infrared cameras. Looking at the Earth from space beyond {{w|Low Earth orbit}} only with the naked eye wouldn't show any hint to our {{w|ecosystem}}. This is like the actual possibility in astronomy when observing {{w|Exoplanet|exoplanets}} — the nature of those more than 1,500 known planets is unknown due to the lack of better technologies to the scientists. And there are a couple of hundred billion planets at our galaxy still camouflaged to human scientists.

The final panels take the metaphor further, suggesting that there is literally a planet sized shark swimming through space eating planets, and since the view is panning away from earth and over to the shark, the shark seems to be heading our way. It looks like Earth is the next fish, presumably because we did not reach a high enough technology level in time to recognize the danger and hide.

This also explains the title text that has the theme from the movie ''{{w|Jaws (film)|Jaws}}'' playing while astronomers look into their telescopes. This may also be a reference to the film ''{{w|Alien (film)|Alien}}'', which was pitched with the three word proposal "''Jaws'' in Space."

{{w|Stephen Hawking}} famously warns, "If aliens visit us, the outcome would be much as when Columbus landed in America, which didn't turn out well for the Native Americans." Even {{w|Carl Sagan}} called the practice of Broadcasting and Signaling presence of Life on Earth "deeply unwise and immature," and recommended that "the newest children in a strange and uncertain cosmos should listen quietly for a long time, patiently learning about the universe and comparing notes, before shouting into an unknown jungle that we do not understand."

==Transcript==
:[Cueball and Megan are walking down a hill.]
:Cueball: The Fermi paradox keeps getting worse. If planets are common, where '''is''' everybody?

:Megan: Imagine you're a scuba diver looking at the ocean floor. You know there's a fish there, but you can't see it. Why?

:Cueball: Maybe the fish looks like sand.
:Megan: Yeah...

:[Zoom out to the Earth from space.]
:Megan: ...and what would that tell you about the ecosystem?

:[The Earth is moving out of the panel and then a shark is shown swimming through space towards Earth.]

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Astronomy]]
[[Category:Science]]
[[Category:Sharks]]

1922: Interferometry

2017-11-29T16:54:31Z

Timothy N: Adding another interpretation of the title-text

{{comic
| number = 1922
| date = November 29, 2017
| title = Interferometry
| image = interferometry.png
| titletext = It's important to note that while the effective size of the dog can be arbitrarily large, it's not any more of a good dog than the two original dogs.
}}

==Explanation==
{{incomplete|Do NOT delete this tag too soon.}}
Beret Guy and Cueball are walking Beret Guy's dogs when BG makes a comment on how interferometry is really cool. Interferometry is the practice of overlapping two different waves to get a different signal, which can be used to determine the distance between two reflecting surfaces. Beret Guy states that two dogs placed at a consistent interval will function as a larger dog. While this idea works on waves, it probably won't work on dogs{{Citation needed}}, which is why Cueball is confused and starts to correct him. Before he can respond, however, Beret Guy jumps on this "large" dog and appears to be floating in midair. The large dog is further proved when it gives out a large bark. Cueball looks on confused while Beret Guy appears to break more laws of physics, again (just like in [[1486: Vacuum]]).

This comic is a reference to {{w|Astronomical interferometer|Astronomical Interferometers}}, arrays of separate telescopes that work together as a single telescope to provide the higher angular resolution of a single larger telescope, using a process known as {{w|Aperture Synthesis}}.

The title text states that the effective giant dog is not any more 'good' than the two original dogs. This is analagous to sensitivity for astronomical interferometers. Interferometery does not increase the light-gathering area, so it cannot view dim objects as well as a single large telescope could. It could also be a reference to dog-owners often refer to their dogs as "good dog" or "good boy/girl", and will ask the rhetorical question "who's a good dog/boy/girl?"

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
[Beret Guy and Cueball are walking with their dogs.]
Beret Guy: Interferometry. Is so cool!

[The two dogs are placed a small distance apart.}
Beret Guy: If you put two small dogs a large distance apart, they can function as a larger dog.

Cueball: I'm not sure that's-
[He is cut off by Beret Guy jumping onto an invisible steed, most likely the "bigger dog".]
Beret Guy: HYAH!

Beret Guy: Away!
[He rides away on the invisible dog with the two smaller dogs under him, while the invisible dog gives out a large bark.]

{{comic discussion}}

explain xkcd - User contributions [en]

1377: Fish

1922: Interferometry