You sit down with a specialist. She looks at your scan and says operate. You get a second opinion. He looks at the same scan and says wait. Both of them trained for years. Both are looking at the same body.
You have to choose. You are not qualified to referee them. This module is about that moment. It is not about who is right.
Sources
Brown & Williamson, "Smoking and Health Proposal" (internal memo), 1969 — Truth Tobacco Industry Documents, UCSF, doc xqkd0134. VERIFIED VERBATIM: the primary OCR was fetched and the quoted sentence matches word for word, including the internal single quotes around 'body of fact'. Page is marked CONFIDENTIAL. https://www.industrydocuments.ucsf.edu/docs/xqkd0134 (OCR: https://download.industrydocuments.ucsf.edu/x/q/k/d/xqkd0134/xqkd0134.ocr)
US District Court for the District of Columbia (Judge Gladys Kessler), United States v. Philip Morris USA Inc., Final Opinion and Order, 17 August 2006. VERIFIED: the opinion finds defendants "have engaged in and executed... a massive 50-year scheme to defraud the public". The court's own verb is "defraud"; "deceive" also appears in the RICO findings ("conspiracy to deceive the American public about the health effects of smoking"), so the module's plainer wording is faithful. Upheld on appeal 22 May 2009. https://www.justice.gov/civil/case-4 · https://www.publichealthlawcenter.org/sites/default/files/resources/tclc-fs-DOJ-litigation-overview-2015.pdf
US Public Health Service, Smoking and Health: Report of the Advisory Committee to the Surgeon General, 1964. VERIFIED: "more than 7,000 articles"; released 11 January 1964 by Surgeon General Luther Terry. NOTE FOR ACCURACY: the committee's conclusion was that smoking causes lung cancer in men and is a probable cause in women. The module states the causal conclusion without the sex qualifier — the standard summary, and the load-bearing claim is unchanged. https://profiles.nlm.nih.gov/spotlight/nn/feature/smoking
Gannon J, Bach K, Cattaruzza MS, et al., "Big tobacco's dirty tricks: Seven key tactics of the tobacco industry", Tobacco Prevention & Cessation, 2023 — the named tactics (front groups, funded research, media, lobbying, litigation). The module lists six of the seven. https://pmc.ncbi.nlm.nih.gov/articles/PMC10731746/
Brandt AM, "Inventing Conflicts of Interest: A History of Tobacco Industry Tactics", American Journal of Public Health 102(1), 2012 — background only; it does NOT contain the verbatim "doubt is our product" sentence, which is why the primary memo is the citation used. https://pmc.ncbi.nlm.nih.gov/articles/PMC3490543/
Chiarenza AA et al., "Asteroid impact, not volcanism, caused the end-Cretaceous dinosaur extinction", PNAS 117(29), 2020 — the impact-primary side. https://www.pnas.org/doi/10.1073/pnas.2006087117
Zhang et al., "Deccan volcanism's influence on Chicxulub impact signatures at the continental Cretaceous–Paleogene boundary in the Sichuan Basin, China", Earth and Planetary Science Letters, 2024 — the volcanism-contribution side, still publishing. Confirms the disagreement is live in 2024+ and is described in the literature as "fiercely contested" over the RELATIVE role of each trigger — which is the module's claim. https://www.sciencedirect.com/science/article/abs/pii/S0012821X24003650
Petersen SV et al., "End-Cretaceous extinction in Antarctica linked to both Deccan volcanism and meteorite impact via climate change", Nature Communications, 2016 — the both-mattered position. Extinction magnitude: ~75% of species at the K-Pg boundary ~66 Ma. CORRECTION APPLIED: the module said "most life on Earth died out" (now "about three quarters of all species") and "near what is now Mexico" (Chicxulub is IN Mexico, on the Yucatán Peninsula — now "hit what is now Mexico"). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4935969/
The Nobel Prize in Physiology or Medicine 2005 (Barry J. Marshall and J. Robin Warren) — H. pylori, gastritis and peptic ulcer disease. Self-experiment detail verified: Marshall drank the culture in July 1984, was nauseated and vomiting within days, and a repeat endoscopy and biopsy showed marked gastritis with a positive H. pylori culture; protocol published in the Medical Journal of Australia, 1985. The module correctly says the experiment showed INFLAMMATION, not an ulcer. https://www.nobelprize.org/prizes/medicine/2005/press-release/ · https://www.lindau-nobel.org/on-man-and-microbes-barry-marshall/
US Geological Survey, This Dynamic Earth: The Story of Plate Tectonics — Wegener (1912), the missing mechanism, Hess and sea-floor spreading, and the 1960s shift. VERIFIED via corroborating geoscience sources (the USGS pages return 403 to automated fetches): Wegener described continental drift in 1912, was dismissed because he could not supply a force, and the hypothesis was accepted once sea-floor spreading supplied the mechanism in the 1960s. https://pubs.usgs.gov/gip/dynamic/wegener.html · https://pubs.usgs.gov/gip/dynamic/developing.html
Hemilä H & Chalker E, "Vitamin C for preventing and treating the common cold", Cochrane Database of Systematic Reviews, CD000980.pub4, 2013. CURRENCY CHECKED: pub4 is still the current version, not withdrawn. Regular supplementation had no effect on incidence in the ordinary population (29 comparisons, 11,306 participants) and modestly shortened duration. CORRECTION APPLIED: the review also found vitamin C roughly halved cold risk in 5 trials of people under heavy short-term physical stress (marathon runners, skiers, soldiers) — omitting the one positive subgroup was a selective omission, and the module now names it. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD000980.pub4/full
GRADE Working Group. VERIFIED VERBATIM against the Working Group's own site: "More than 120 organizations from over 20 countries around the world have endorsed or are using GRADE." Four certainty levels confirmed: high, moderate, low, very low. https://www.gradeworkinggroup.org/ · handbook: https://gradepro.org/handbook/
National Academies of Sciences, Engineering, and Medicine, "Our Study Process". VERIFIED: "All National Academies' publications undergo a rigorous review by independent experts with a range of views and perspectives", governed by "Guidelines for the Review of Products"; committee composition is governed by "Composition and Balance, Conflicts of Interest, and Independence: Policies and Procedures". Consensus Study Reports reflect the consensus of the study committee. https://www.nationalacademies.org/about/our-study-process
Kent A. Clark Center for Global Markets (University of Chicago Booth), Economic Experts Panel surveys. VERIFIED: the Center polls 80+ economists; questions are statements answered on a Likert scale including "Uncertain", and every panellist's individual response is published. CORRECTION APPLIED: the module claimed "the same fixed list... every time" — it is a standing panel whose membership evolves, and there are now several panels (US, European, Finance), so the wording is now "keeps a standing list". https://www.kentclarkcenter.org/surveys/ · https://kentclarkcenter.org/us-economic-experts-panel/participants/
Tetlock PE, Expert Political Judgment: How Good Is It? How Can We Know?, Princeton University Press, 2005 — roughly twenty years of dated forecasts from hundreds of professional commentators; average accuracy poor and below simple extrapolation; the one-big-idea vs many-small-ideas split (hedgehogs vs foxes); an inverse relationship between media prominence and accuracy. NOTE: published summaries disagree on the counts (284 experts with ~28,000 forecasts in some, 82,361 in others), which is exactly why the module states only "hundreds of people" and "tens of thousands of forecasts" — do not add a figure. CORRECTION APPLIED: "close to what you would get by spreading your bets evenly" overstated the result and is now "not much better than" — his experts modestly beat uniform guessing but lost to trend-following rules. https://press.princeton.edu/books/hardcover/9780691178288/expert-political-judgment · https://faculty.wharton.upenn.edu/wp-content/uploads/2012/08/Tetlock-16.pdf
Mellers B, Ungar L, Baron J, et al., "Psychological Strategies for Winning a Geopolitical Forecasting Tournament", Psychological Science 25(5), 2014; Tetlock, Mellers, Rohrbaugh & Chen, "Forecasting Tournaments", Current Directions in Psychological Science, 2014. VERIFIED: the IARPA tournament ran four years from 2011 with thousands of forecasters, ~500 questions and over a million forecasts; skimming top talent into elite teams and cognitive-debiasing/probability training both raised accuracy, with training worth roughly 10% on Brier scores from under an hour's instruction a year. https://journals.sagepub.com/doi/10.1177/0963721414534257 · https://web.stanford.edu/~knutson/jdm/mellers15.pdf
Murphy AH et al. (1985), reliability of subjective probability-of-precipitation forecasts, via NOAA/SPC verification material. VERIFIED: "NWS forecasters responsible for probability of precipitation (PoP) forecasts have shown the ability to calibrate themselves and produce very reliable forecasts". https://www.spc.noaa.gov/publications/mkay/probver/
US Preventive Services Task Force, Final Recommendation Statement: Breast Cancer Screening, 2024. CURRENCY CHECKED — still the current recommendation: biennial screening mammography, ages 40 to 74 (Grade B); evidence insufficient at 75+. https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/breast-cancer-screening
American Cancer Society breast cancer screening guideline, page last revised 23 July 2026. CORRECTION APPLIED — this is the one stale claim in the module. ACS current wording: 40–44 "have the option to start screening with a mammogram every year"; 45–54 "should get mammograms every year"; 55+ "can switch to a mammogram every other year, or can choose to continue yearly". The module described ACS as starting at 45, which made ACS look like the later-starting panel when the actual disagreement is about FREQUENCY. Rewritten. https://www.cancer.org/cancer/types/breast-cancer/screening-tests-and-early-detection/american-cancer-society-recommendations-for-the-early-detection-of-breast-cancer.html
Sagan C, Broca's Brain: Reflections on the Romance of Science, 1979, chapter 5 ("Night Walkers and Mystery Mongers: Sense and Nonsense at the End of Science"), p. 75. VERIFIED VERBATIM against the sourced Wikiquote citation; page number added to the module's attribution. https://en.wikiquote.org/wiki/Carl_Sagan · https://archive.org/details/brocasbrainrefle0000saga