412 Science claim verifications avg. score 5.9/10 212 rated true or mostly true 152 rated false or mostly false
“Animals, plants, and microbes release carbon dioxide through respiration.”
The statement matches established biology. Animals, plants, and microbes all can release carbon dioxide as part of cellular respiration, and major scientific sources describe this as a standard component of the carbon cycle. The omitted nuances about photosynthesis in plants and metabolic diversity in microbes do not materially change the claim’s core meaning.
“Decomposers break down dead organisms and return carbon to soils and the atmosphere.”
Decomposers are a core part of the carbon cycle. Evidence from major scientific and educational sources shows they break down dead organisms, release carbon to the atmosphere, and contribute carbon to soils through organic matter formation. The exact pathway and proportion vary by environment, but the claim accurately states their general role.
“Some carbon is stored long-term in soils, oceans, sediments, rocks, and fossil fuels.”
The evidence clearly supports this statement. Major scientific sources identify soils, oceans, sediments, rocks, and fossil fuels as carbon reservoirs that contain at least some carbon stored for long periods. The main nuance is that storage times vary widely across and within these reservoirs, especially in soils and the ocean.
“Human activities, especially burning fossil fuels and land-use change such as deforestation, are altering the global carbon cycle by increasing atmospheric carbon dioxide concentrations.”
The evidence firmly supports this statement. Multiple authoritative scientific assessments and direct atmospheric measurements show that burning fossil fuels and land-use change have raised atmospheric CO2 and altered the global carbon cycle. Natural sources of CO2 exist, but they do not explain the sustained modern increase, which is attributable to net human emissions.
“Higher ocean temperatures can stress corals and cause them to expel symbiotic algae (zooxanthellae), leading to coral bleaching.”
Elevated ocean temperatures are a well-established cause of coral bleaching. Major scientific and governmental sources agree that heat stress can disrupt the coral-algae partnership, leading corals to lose or expel zooxanthellae and turn white. The claim is accurate, though bleaching can also be triggered by other stressors and is not always irreversible.
“Win probability models used in sports analytics (for example, ESPN's NBA win probability model) are generally well-calibrated, and their probabilities align reasonably well with observed outcomes, at least compared with typical human intuition.”
The available evidence indicates these win-probability models are broadly calibrated over many games and usually align reasonably well with actual outcomes. They are not perfect: some studies find underdog bias and phase-specific quirks, and they are not clearly superior to simple baseline models. The comparison to human intuition is supported more indirectly than directly, but the overall claim is largely accurate.
“Scientists in relevant fields widely agree that the health and environmental effects of the 1979 Three Mile Island nuclear accident were very low.”
The evidence strongly supports a broad scientific view that Three Mile Island caused very low off-site radiological health and environmental harm. Government reviews, academy assessments, and long-term epidemiology generally found exposures near background and no detectable population-level physical effects. A few studies raised limited cancer-signal concerns, and the claim is broad enough to understate psychosocial impacts, so some caution is warranted.
“Chickens existed before chicken eggs existed.”
The evidence does not support this statement. In evolutionary terms, the first true chicken would have emerged from an egg laid by a proto-chicken ancestor, so an egg containing a chicken existed before any chicken did. The only route to the opposite conclusion is a narrow definition of “chicken egg” as an egg laid by a chicken, which materially changes the claim’s meaning.
“Research sponsored by a company is always biased toward selling that company's products or services.”
The evidence shows a higher risk of sponsor-favorable outcomes in company-funded research, not an iron rule that it is always biased. Authoritative reviews and guidance explicitly state that some industry-sponsored studies are neutral or unfavorable and that funding alone does not prove bias in every case. The claim overstates a documented tendency into a universal certainty the evidence does not support.
“The railway line being constructed between London and Birmingham (High Speed 2, HS2) can be seen from space.”
Available satellite imagery supports that the HS2 route is visible from orbit as a large construction corridor. The important caveat is that this does not mean astronauts could clearly see a finished rail line with the naked eye; what shows up is mainly the wide earthworks and disturbance in satellite images. The claim is broadly right but imprecise.
“Water has the chemical formula H2O.”
Authoritative chemistry sources uniformly identify water’s chemical formula as H2O. The claim matches the standard molecular composition of water: two hydrogen atoms bonded to one oxygen atom. Objections based on liquid-water behavior or hydrogen bonding do not change that formula.
“Olympus Mons on Mars is the largest volcano in the Solar System.”
Current scientific references support this claim. Multiple authoritative NASA and JPL sources explicitly identify Olympus Mons as the largest volcano in the Solar System, and no credible evidence in the record disputes that conclusion. Minor qualifiers such as “largest known” reflect normal scientific caution, not a real challenge to the claim.
“Olympus Mons on Mars is thought to have formed about 3.5 billion years ago.”
Evidence from USGS and peer-reviewed Mars geology studies supports an origin for Olympus Mons around 3.5 billion years ago, more broadly about 3.5 to 3.7 billion years ago. The claim matches the accepted estimate for when the volcano began forming. The main caveat is that Olympus Mons continued growing and resurfacing for billions of years afterward.
“Over the last century, scientists have recorded five eruptions of Olympus Mons with a Volcanic Explosivity Index (VEI) of 8.”
The claim is not supported by any credible evidence. No eruption of Olympus Mons has been recorded in the last century, and authoritative Mars sources do not list five events or assign VEI 8 ratings there. The statement also conflates Olympus Mons with separate research on ancient explosive volcanism elsewhere on Mars.
“Olympus Mons formed several billion years ago after two of Mars' largest tectonic plates collided.”
Olympus Mons did not form from a collision between major Martian tectonic plates. Scientific sources describe it as a shield volcano built by repeated eruptions over a long-lived hotspot on Mars’ mostly stagnant crust. While parts of the volcano are billions of years old, the claim’s central explanation is unsupported and contradicts the evidence.
“By May 29, 2027, at least one Chinese launch provider will be conducting routine commercial orbital launches using a recovered and reflown first stage.”
The evidence shows rapid Chinese progress toward reusable orbital launch, but it does not support the stronger claim that routine commercial reflights will be underway by May 29, 2027. As of July 2026, booster recovery has been demonstrated, while the first booster reflights remain planned rather than completed. That leaves a substantial gap between an important technology milestone and an established commercial launch cadence using recovered first stages.
“Classical non-homologous end joining (c-NHEJ) in humans requires DNA ligase IV (LIG4) to seal DNA double-strand breaks.”
The evidence strongly supports this statement. In humans, canonical/classical NHEJ uses the XRCC4–DNA ligase IV complex to complete ligation of DNA double-strand breaks, and major reviews describe LIG4 as required and specific to c-NHEJ. Reports of other ligases acting in end joining refer to alternative, non-classical pathways rather than c-NHEJ.
“MRI and fMRI neuroimaging studies have demonstrated that certain mental illnesses are associated with abnormal activity in specific brain regions involved in fear, emotional regulation, and decision-making.”
The evidence shows a well-established association between several mental illnesses and altered activity in brain circuits involved in fear, emotion regulation, and decision-making. Reviews and meta-analyses consistently implicate regions such as the amygdala, prefrontal cortex, and anterior cingulate. These findings are real, though often shared across disorders and not sufficient on their own for diagnosis.
“Research on anxiety disorders and OCD demonstrates that changes in neural circuits can strongly influence behavior and thought patterns.”
The available evidence strongly supports this statement. Across OCD and anxiety research, converging findings from neuroimaging, circuit models, and especially circuit-targeted interventions show that altering specific neural networks can change symptoms, behavior, and patterns of thought. The main caveat is that these relationships are often bidirectional and differ across disorders.
“Non-homologous end joining (NHEJ) repairs a DNA double-strand break by ligating the two cut ends directly together without requiring a homologous template.”
The claim captures the core mechanism of NHEJ. NHEJ repairs double-strand breaks by rejoining DNA ends without needing a homologous template, which is the key distinction from homologous recombination. However, the wording is somewhat simplified because NHEJ often processes damaged ends before ligation and can be error-prone rather than a perfectly clean end-to-end join.