Index/Organizations/National Academy of Sciences

National Academy of Sciences

Science branch of the United States National Academies

Fact-Checks

22 results
Nov 25, 2025
Most Viewed

Which conspiracy theories about JFK's assassination have been debunked and by whom?

Major investigations have repeatedly rejected or found no persuasive evidence for many popular JFK conspiracy claims: the Warren Commission concluded Lee Harvey Oswald acted alone , the 1982 National ...

Jan 14, 2026
Most Viewed

are geongineering and chemtrails real

Secret, large‑scale “chemtrails” as a covert atmospheric spraying program lack credible scientific evidence and are rejected by mainstream atmospheric scientists, while geoengineering exists as a legi...

Nov 17, 2025
Most Viewed

How do sanctuary states and cities impact the number of ICE arrests?

Research shows sanctuary policies tend to reduce how often local jails honor ICE detainer requests and are associated with fewer deportations, while most empirical studies find no measurable increase ...

Jan 23, 2026

How do crime rates for undocumented immigrants vary by state or sanctuary city policies in 2025?

Across a broad set of academic and policy studies through 2025, -and-crime-rates-2025">undocumented immigrants as a group are not associated with higher crime rates than residents, and jurisdictions w...

Dec 8, 2025

What credible conspiracy theories suggest multiple shooters in the JFK assassination, and how do experts assess them?

The most prominent “multiple shooter” claims stem from (a) the House Select Committee on Assassinations’ (HSCA) 1979 acoustical analysis that it said indicated a high probability of a second gunman, a...

Nov 7, 2025

What are common criticisms of Donald Trump's handling of the COVID-19 pandemic in 2020?

Donald Trump's 2020 COVID-19 response attracted sustained criticism for publicly downplaying the virus, inconsistent messaging on masks and testing, and perceived mismanagement of federal coordination...

Jan 17, 2026

What measurable effects have sanctuary policies had on crime reporting, public safety, and immigrant access to services?

A growing body of empirical research finds that sanctuary policies do not increase crime and in many analyses are associated with either null or modestly improved public-safety measures, while they me...

Dec 12, 2025

How have ballistic and acoustic analyses for the JFK assassination been validated or challenged by experts?

The acoustic evidence from a Dallas police Dictabelt was central to the 1979 House Select Committee on Assassinations (HSCA) finding that “scientific acoustical evidence establishes a high probability...

Jan 18, 2026

Did usa have technologies to modify weather

The United States has had and continues to have technologies that can modify weather at local to regional scales—most notably cloud seeding, a practice dating to the 1940s and used in the U.S. for dec...

Nov 14, 2025

Higher ed dedication to left indoctrination

Debate over whether higher education is dedicated to “left indoctrination” is contested: several commentators and conservative outlets assert elite universities skew strongly left and promote ideologi...

Oct 6, 2025

Is climate change real and scientifically proven

Climate change is real and extensively documented: multiple large-scale reviews and empirical studies conclude that Earth’s climate is warming and that human activities are a dominant driver, while a ...

Jan 31, 2026

What are the documented technical safeguards and post‑2020 reforms for U.S. voting machines and election infrastructure?

Since election officials, federal agencies and independent experts have doubled down on technically grounded safeguards—paper ballots or voter‑verifiable paper records, pre‑ and postelection testing, ...

Jan 30, 2026

What empirical studies show about sanctuary policies’ impact on crime rates and deportations since 2015?

Empirical studies since 2015 overwhelmingly find that local “sanctuary” or limited-cooperation policies reduce the number of deportations ordered from local contacts—Hausman estimates about a one‑thir...

Jan 17, 2026

What evidence exists on whether sanctuary policies affect crime reporting and public safety in Minnesota?

Evidence from academic reviews and national datasets finds little to no link between sanctuary policies and higher crime rates, and several studies show these policies can increase crime reporting by ...

Nov 20, 2025

What forensic and ballistic disputes fuel theories of a second shooter or grassy knoll shots?

Newly released JFK files from March 18, 2025 expanded public access to FBI documents, photos, audio and video but — according to mainstream reporting — did not produce definitive proof of a second sho...

Nov 18, 2025

How reliable are the forensic, ballistics, and acoustic analyses used to determine the number of shooters in the Zapruder film era?

Forensic analyses of the Zapruder-era evidence — photographic/film analysis, wound and ballistic interpretation, and acoustic studies of Dallas police recordings — have produced competing conclusions:...

Nov 5, 2025

What would be the effects of reducing CO2 concentration to pre-industrial levels?

Reducing atmospheric CO2 to pre-industrial levels (~280 ppm) would lower greenhouse forcing and, over long timescales, move global temperatures toward pre‑industrial values, but the . Existing analyse...

Feb 4, 2026

What empirical evidence links sanctuary policies to public-safety, crime, and deportation rates?

Multiple peer-reviewed and policy studies converge on two empirical findings: substantially reduce deportations—particularly of nonviolent and nonconvicted immigrants—while producing no detectable inc...

Feb 3, 2026

What evidence supports the grassy knoll multiple-shooter theory in the JFK assassination?

The multiple‑shooter theory rests chiefly on three threads of evidence: contemporaneous eyewitness reports that many observers perceived shots from the knoll area, —most famously the 1979 (HSCA) revie...

Feb 3, 2026

What does the National Academy of Sciences/PNAS research say in detail about sanctuary policies and violent crime/deportations?

paper published in PNAS ( 2020) finds that local implemented 2010–2015 significantly reduced overall—about one-third for people fingerprinted by local authorities—while sharply cutting deportations of...