|Our aurora are probably non-toxic but please stop trying to taste them
|| The aurora in the image is now temptingly at head height, and presumably look a lot like cotton candy or other inviting foodstuffs.
|| The plural of "aurora" should actually be "auroras" or "aurorae".
|No breaking off pieces of the ice caps to put in your drink
||An ice cap is a mass of ice that covers less than 50,000 km2 (19,000 sq mi) of land area.
||Breaking off pieces of ice caps would affect the climate of the scale world.
|Warning: Limited cell network coverage above the ionosphere, crouch down to get more bars
|| The ionosphere reflects radio signals, in this case keeping terrestrial cellular phone signals from reaching phones higher up.
||The ionosphere would be at around 48-965 centimeters in the scale world, so visitors would need to place their phones below it to receive cellphone signals.
|Do not step on Mt. Everest
|| Mt. Everest, the highest peak on Earth, is several inches tall at 1:100,000 scale.
|Caution! Ocean floor slippery when wet
|| Due to the smaller scale, the ocean depths would only be a few inches deep at most; this amount of liquid would cause more of a 'slippery surface' than a 'water region'.
|Wear sunscreen; the ozone layer only protects you below the knees.
||The ozone layer is a layer of the Earth's stratosphere that shields the Earth from the Sun's ultraviolet rays.
||The ozone layer is approximately 15-35 kilometers above Earth, or 15-35 centimeters in this scaled world, below knee height. Visitors would need sunscreen to protect them from UV rays. In the real world, most humans live with their bodies entirely below the ozone layer but wear sunscreen anyway, so visitors should probably also wear sunscreen below their knees as well as above if they're going to be visiting around midday.
|Beware of chest-level meteors
||Meteors typically occur (i.e. become more visible than in space) in the mesosphere at altitudes from 76 to 100 km (250,000 to 330,000 ft).
||In the scale world, meteors would occur at 76 to 100 centimeters, around chest height. You'd expect head-level asteroids too, as precursors, but this may be (mutually) covered by the eye-protection against satellite re-entry, below. (I'd personally also suggest a hard-hat.)
| -100° mesopause vest recommended
||The mesopause is the boundary in the earth's atmosphere between the mesosphere and the thermosphere. Due to the lack of solar heating and very strong radiative cooling from carbon dioxide, it is the coldest region on Earth with temperatures as low as -100 °C (-148 °F).
||Without protection, visitors would succumb to hypothermia due to the extremely low temperatures.
|If Lake Tahoe or the Dead Sea dries up, refill them with this 5oz wine glass
||Five ounces, times 100,0003 (because this is volume, so the linear scale factor applies to each of three dimensions), would be about 150 cubic kilometers, which is the approximate volume of Lake Tahoe; the Dead Sea is recently about 115 cubic kilometers, though it used to be somewhat larger.
|Safety glasses required for protection from reentering spacecraft
||It is at approximately head height in this model that de-orbiting spacecraft are at their fastest, depending upon where their decayed or departed original was. At scale, they'd probably equate to a metalworking fragment, perhaps more dangerous in quantity than individually.
||We also tend to know about satellites and fairings returning to Earth and most (unless intended to) won't significantly survive. Meteors (see above) are hard to spot in space unless particularly big, may only be detected when spotted burning up, may be significantly denser/less fragile, and could be traveling five times faster. General head protection may be advised, just in case.
|Do not anger the sprites
|| Sprites are poorly understood electrical phenomena in the upper atmosphere. They are enormous but very short-lived.
|| Sprites are also a name given to a form of forest spirit known for mischievous and sometimes harmful behavior. In some fairy tales, a warning would be given to not anger the spirits in case of grave repercussions.
|Please stop digging through the Moho. Staff are tired of cleaning up large igneous provinces.
||Short for the Mohorovičić discontinuity, the Moho is the boundary surface separating the Earth's crust from the mantle. It can be found at a depth of 6-7 miles under the ocean bed, and about 24-30 miles under the continents.
||Using Randall's 1/100,000th scale world, 6-7 miles would be approximately 4 inches, while 24-30 miles would be about 16 inches, making the Moho easily accessible via digging. It would indeed create large igneous provinces, and make a big mess of lava that the staff would have to clean up, which would not be fun . The lava has a decent chance to burn through a mop or something, so it would be pretty tricky to clean up as well since your cleaning items would light on fire unless soaked in water or something.
|ISS (14 feet up) Returns every 90 minutes - Hit it with a nerf dart, win a prize!
|| The International Space Station is the largest human-made object in space and orbits the Earth once every 90 minutes.
|| This idea of treating modern research as a toy is in the same general panel area as the weather balloon smacking from the previous comic, except instead of a rule preventing people from doing so, this time the visitor is being dared to attempt it (though it is unclear what the "prize" mentioned in the comic is). Hitting the ISS with a nerf dart in this scaled world would have a potentially devastating effect on the ISS. However, at this scale the ISS would be about a millimeter across, so the point of this dare may be that hitting it so far above your head as it goes by overhead would be very difficult.
The title text states that the floor should be slightly curved. In fact, given that the model in the comic is about 10 meters long, it represents about 1000 km of Earth, which spans about 9 degrees of a great circle. Therefore, if the model wasn't larger than the part shown in the panel, its edges would have a very noticeable slope of 4.5 degrees.