Flashlights
Flashlights
[Cueball carries a flashlight walking towards Megan who is sitting on a couch.] Cueball: Remember how flashlights sucked when we were kids? Always dim and finnicky? Megan: I guess?
[Cueball and Megan walking to the left.] Cueball: Well, I discovered there are now internet flashlight enthusiasts. Cueball: And the technology has... improved. Megan: OK, Let's see.
[It is dark outside where Cueball turns on the flashlight. The beam is very bright and very visible even seen from the side. Backscattered light reflects off Cueball and Megan's faces, turning them into bright white beings in the dark. The facade of the house and the stairs are also visible in the same manner, with deep dark shadows where anything is in the shadow. Megan averts her face from the light holds up a hand to cover her eyes. When the flashlight turns on it even makes a sound, written in white above the beam:] Flashlight: Fwoosh
[Cueball and Megan look at what the beam falls on (outside the frame). Megan has taken her hand down. Both their faces are only lit up like a crescent moon. Cueball is holding the flashlight with both hands as if it is pushing back on him. The text is written in white on the dark sky above them.] Cueball: See how it lights up the whole forest? Megan: ...The trees are on fire. Cueball: Real bright, though.

In this comic, Cueball has acquired or built a new high powered flashlight ("torch" in British English), which he wants to demonstrate to Megan . When Cueball refers to older flashlights as dim and finnicky, this gives reason to assume that the flashlight he is holding is going to be ridiculously overengineered.
Indeed, when he switches it on outside the house, the intense light beam completely drowns out the scene. Only the reflected light from the forest lights up the part of Cueball and Megan's faces that are turned towards it. Megan is holding up a hand, apparently to shield her eyes.
Cueball comments that the flashlight lights up the entire forest, but Megan observes that it is the trees that are on fire, indicating that Cueball's flashlight is so overpowered that the energy of its beam is sufficient to cause the organic matter of trees to combust.
Of course, a flashlight that cannot safely be pointed at things is fairly useless for the traditional purpose of a flashlight, which would be to find things in the dark by directing light over them. This mundane and practical reasoning does not seem to matter to Cueball of course, who appears only interested in the intensity and brightness the device is capable of achieving. The comic may refer to the flashlight forums Budget Light Forum or candlepowerforums , devoted to people discussing new LED emitters and who can build the brightest flashlight using them.
Cueball might allude to a number of technical improvements, notably xenon-based incandescent bulbs, multiple-LED assemblies, Lithium batteries (usually used for photography flashes) or rechargeable batteries. A number of companies market "tactical" flashlights that are supposedly powerful enough to incapacitate an opponent, using terms such as "scorching" to advertise their products. See for instance this video about a Wicked Lasers Torch of the brand Torch that ignites paper and melts stuff. Not strong enough to put a forest on fire but it is not safe to point at anything close by!
Randall has also looked at what lasers could do of damage in two what if? : Laser Pointer and Laser Umbrella .
The title text refers to Fleshlight , a brand of masturbation appliances for phalluses modeled after various human orifices. Cueball (or Randall) claims that he only arrived on a forum for Fleshlight enthusiasts due to a typo. Apart from the "e" vs. "a" in Fleshlight, they are also fashioned to look like oversized flashlights. On that forum he found out that the highest-end models of their product lines was also capable of setting trees on fire. This would probably happen due to violent vibrations inside the orifice, or excessively powerful internal heating. Anything powerful enough to burn trees would indeed cause the user severe burns in a very unpleasant area. But some of the enthusiasts swear that it is still worth it, in the same manner that Cueball only cares about the intensity of the flashlight, regardless of the consequences. Maybe they are just trying to trick you into doing something stupid! Or maybe they're just into that kind of thing.
References to Fleshlight is a recurring theme in xkcd and using powerful "sex toys" that cause severe burns (on a woman though) have previously been alluded to in 596: Latitude .
[Cueball carries a flashlight walking towards Megan who is sitting on a couch.] Cueball: Remember how flashlights sucked when we were kids? Always dim and finnicky? Megan: I guess?
[Cueball and Megan walking to the left.] Cueball: Well, I discovered there are now internet flashlight enthusiasts. Cueball: And the technology has... improved. Megan: OK, Let's see.
[It is dark outside where Cueball turns on the flashlight. The beam is very bright and very visible even seen from the side. Backscattered light reflects off Cueball and Megan's faces, turning them into bright white beings in the dark. The facade of the house and the stairs are also visible in the same manner, with deep dark shadows where anything is in the shadow. Megan averts her face from the light holds up a hand to cover her eyes. When the flashlight turns on it even makes a sound, written in white above the beam:] Flashlight: Fwoosh
[Cueball and Megan look at what the beam falls on (outside the frame). Megan has taken her hand down. Both their faces are only lit up like a crescent moon. Cueball is holding the flashlight with both hands as if it is pushing back on him. The text is written in white on the dark sky above them.] Cueball: See how it lights up the whole forest? Megan: ...The trees are on fire. Cueball: Real bright, though.
