Now I'm tempted to start telling people that I secretly don't actually know how to do any physics calculations, and so all the answers in What If are based on me actually trying to do the thing and then reporting what happened, but phrased as if it's hypothetical.
This comic references various questions submitted by people and used in the what if? blog, What If?, and What If? 2 books. In particular, promoting Randall's new book, What If? 2, released 6 days after the comic's release. This comic has a list of things not to do, an extension of a previous list, and is purportedly things Randall discovered as he was doing research for his book. The page What If? chapters contains the titles, publishing date, thumbnail, question, and explanation for each article. Many of the acts described under the "new" section of the list are depicted in these thumbnails (see table below); others are references to examples or hypotheticals explored within the articles. The entries are all in order of their appearance in the book.
The title text says that Randall is tempted to tell people that all the things in the book were things that he actually tried to do, not that he calculated the solutions for their problems. Many of the questions and answers in his new book are borderline impossible and/or fatal to attempt in real life.
Number Entry What If? 2 chapter referenced Explanation From existing list 156,812 Eat Tide Pods N/A Tide Pods are a brand of laundry detergent sold in small packets ("pods") of water-soluble gel. Many children have tried to eat them, thinking them to be candy, and have had to go to the hospital to treat poisoning. In 2017 and 2018, a satirical "challenge" originated around eating Tide Pods. 156,813 Walk on stilts in a thunderstorm N/A Taller objects are more likely to be struck by lightning, so walking on stilts outdoors would increase the risk of death by electrocution. It would also presumably risk falling and injuring oneself that way, since the ground becomes wet in a rainstorm. 156,814 Set off fireworks at a gas station N/A This has the risk of potentially causing an explosion in the gas station, from the sparks of the fireworks. 156,815 Feed your cat treats that are the exact shape and texture of a human hand N/A This probably runs the risk of the cat learning that treats are in the shape of your hand, resulting in the cat attempting to eat your hand, instead of the cat treat. New! 156,816 Lean over a geyser vent and try to look down into it Geyser Geysers shoot steam and hot water upward. If a person were to lean over the geyser and look down during an eruption, they would be struck in the face by this hot liquid and gas mixture and severely injured or killed.[actual citation needed] This is a reference to the question from What-If? 2 (called, appropriately enough, "Geyser"), in which it is asked what might happen to a person if they stood on top of the Old Faithful geyser as it erupted. 156,817 Fly a hot-air balloon over a firing range Catch! A hot air balloon could present an irresistible target to the people firing their weapons at the range. The balloon could be shot and you could fall to your death. Shooting bullets up and over the designated backstop and berm is also a public danger to anyone past downrange. 156,818 Peel away the Earth's crust Lose Weight the Slow and Incredibly Difficult Way Theoretically, because weight is dependent on gravity, peeling the Earth's crust away would reduce its mass and therefore your weight. However, this would not work because the Earth gets denser the farther you go down. It would also destroy the Earth. An image of what it would look like is shown in 2575: What If? 2, where a potato peeler is used to remove the crust of the Earth. Several What If blog posts also result in massive damage to the earth's crust, including what happened to Texas here. 156,819 Try to paint the Sahara Desert by hand Paint the Earth This would be difficult and require more paint than humanity has ever produced. 156,820 Remove someone's bones without asking Short Answers #2 A reference to a short answer question in What If? 2. 156,821 Spend 100% of your government's budget on mobile game in-app purchases Expensive Shoebox A reference to one of the examples listed in the answer. 156,822 Fill a lava lamp with actual lava Lava Lamp A lava lamp is a glass lamp, which contains a wax mixture inside, and heats so that the wax rises and falls. Putting actual lava inside a regular lava lamp would most likely cause the lamp to melt and the glass to shatter, not to mention handling lava is very dangerous, all of which has been proven to be true. However, in this entry, Randall says it would be fairly easy to find a material that would be able to handle the heat of the lava and thus this would be rather anticlimactic. 156,823 Drink the blood of someone with a viral hemorrhagic [sic] fever Blood Alcohol Drinking someone else's blood is a bad idea unless you are a vampire bat/vampire, and even then it is not a very nutritious diet. If someone has a viral hemorrhagic fever, it is much worse, as they have a very serious and likely deadly disease which can be transmitted by sharing bodily fluids, such as blood. Drinking blood is the theme of this answer. Randall teaches us that drinking blood would induce vomiting, and would be a VERY bad idea. 156,824 Eat meat from rabid animals Short Answers #4 Eating meat from rabid animals could give you rabies, a virus which is nearly always fatal if not treated prior to the appearance of initial symptoms. Pathogen contamination in cooked foods can persist on the surface of e.g. tongs, chopsticks, or a fork used to grill, which is why the USDA doesn't generally allow kitchen utensils to touch raw or ready to eat foods at all. Exceptions for utensils which touch only raw or partially cooked foods, such as grill spatulas and the like, are often allowed and can be negotiated on a case-by-case basis when they would otherwise be prohibited. The rabies virus permeates essentially all nerve tissue before symptoms appear. 156,825 Perform your own laser eye surgery Eyeball Refers to an answer in the book regarding seeing your own eyeball as well as the end of this answer. 156,826 Tell California poultry regulators that your farm is selling Pokémon eggs Read All the Laws While issuing false statements to government regulators is a violation of both California and Federal law, for which prison sentences can reach ten years and fines can reach ten thousand dollars plus any compensatory damages, as per California Penal Code § 132 and 18 U.S. Code § 1001, there is some question about whether any competent regulatory authority would ever take such an assertion seriously, and whether they would be liable for greater damages for doing so than the potential liability of the original culprit involved. Actually doing this, even to county level regulators, could result in a series of events very disadvantageous to you, your farm, and your employees. However, declaring that you're producing Pokémon eggs to your local municipality is probably harmless, and likely to brighten the day of your local regulators.[citation needed] Furthermore, as mentioned in What If? 2, California Food and Agricultural Code § 27637 bars anyone from making false or misleading statements about eggs, and Poké Balls could be considered a type of egg. 156,827 Funnel the entire flow of Niagara Falls into the open window of a physics lab Niagara Straw An oblique reference to the image near the end of this answer. 156,828 Pump ammonia into your abdomen Ammonia Tube Ammonia is an extremely hazardous substance and pumping it into your abdomen would result in a painful death due to ammonia toxicity. As the book mentions, however, at the very least some of it would be neutralized with your stomach acid. 156,829 Suspend yourself inside a 10-meter ball of sunscreen and fall into the Sun Sunscreen Despite its name, sunscreen only protects against some types of radiation from the Sun. No amount is going to be adequate protection if you are right inside the Sun.[actual citation needed] Also, sunscreen, being a gel, would evaporate when exposed to vacuum. When exposed to the plasma of the coronal surface or the Sun's interior, it would quickly ionize along with anything inside it, becoming plasma like the rest of the Sun.