412 Science claim verifications avg. score 5.9/10 212 rated true or mostly true 152 rated false or mostly false
“Every semialgebraic function defined on the unit interval [0,1] is real analytic on [0,1] except possibly at finitely many points.”
The claim matches a standard one-dimensional semialgebraic geometry result. Such functions can be partitioned into finitely many subintervals where they are real analytic, with any failures of analyticity confined to finitely many boundary points. Those exceptional points may include genuine discontinuities or cusps, so the statement is about piecewise analyticity, not global analytic extension.
“Enzymes in the human body have changed their chemical structures in order to survive in an OH⁻-rich internal environment.”
The claim is not supported by biochemistry or human physiology. The human body is tightly buffered and is not generally an OH⁻-rich environment, and excess alkalinity tends to impair or denature enzymes rather than help them "survive" by changing structure. Enzyme adaptation to different pH conditions occurs through evolution across generations, not by individual enzymes chemically redesigning themselves inside the body.
“The AGS cell line is derived from human gastric adenocarcinoma.”
The available evidence consistently identifies AGS as a human gastric adenocarcinoma cell line. Authoritative repositories, especially ATCC and Cellosaurus, state this directly, and the cited research literature uses AGS with that same provenance. The remaining caveat is only that many downstream sources rely on repository records rather than original 1979 pathology documents.
“Mars was much more volcanically active early in its history than it is today.”
Evidence strongly supports a major decline in Martian volcanism over time. Early Mars built enormous volcanic provinces and experienced widespread, high-volume eruptions, while the best evidence for later activity is limited to smaller, localized, geologically recent flows. Recent volcanism does not overturn the basic comparison; it confirms Mars became much less active than in its early history.
“Artificial intelligence methods can be used to select the optimal mining method for a given mineral deposit.”
Published mining-engineering research shows that AI methods, including expert systems, fuzzy logic, and neural networks, have been used to recommend or select the most suitable mining method for specific deposits. The claim is supported as a capability statement. The main caveat is that “optimal” usually means best under defined criteria and constraints, not an absolute universal optimum.
“Carbon is an essential building block of life.”
Carbon is a core structural element of known life. Scientific sources consistently show that carbon forms the backbone of the main biological macromolecules because it can make stable, complex bonds in ways crucial to biochemistry. The claim is accurate as stated, though it refers to life as known on Earth and does not imply carbon is the only essential element.
“Photosynthesis by plants, algae, and some bacteria removes carbon dioxide from the atmosphere and converts it into sugars using sunlight.”
The core description matches standard biology. In plants, algae, and photosynthetic bacteria such as cyanobacteria, sunlight drives carbon fixation, turning CO2 into carbohydrates including sugars. The main caveat is that bacterial photosynthesis is diverse, so the exact pathway is not identical across all bacteria.
“The ocean stores more carbon than the atmosphere.”
The scientific evidence shows the ocean holds far more carbon than the atmosphere. Standard carbon-cycle estimates put ocean carbon at roughly 38,000 gigatons of carbon, compared with about 800-900 gigatons in the atmosphere. Caveats about deep-ocean storage or exchange rates do not change the basic comparison the claim makes.
“Human activity has significantly altered the natural balance of the carbon cycle, especially since the Industrial Revolution.”
The evidence shows a major human-driven disruption of the carbon cycle since the Industrial Revolution. IPCC, NASA, and NOAA assessments document a large rise in atmospheric CO2, fossil-fuel isotopic fingerprints, and partial uptake by land and oceans that still leaves substantial net accumulation. The core claim is strongly supported.
“Stellar nucleosynthesis inside stars combines smaller nuclei into heavier elements.”
The statement accurately describes the core process of stellar nucleosynthesis in stars. Standard astrophysics sources explain that stars build heavier nuclei from lighter ones mainly through nuclear fusion. Important nuance remains: ordinary stellar fusion mostly makes elements up to iron, while many heavier elements require neutron-capture or explosive events.
“Hydrogen and helium were the first elements formed after the Big Bang.”
The evidence shows that the earliest primordial elements were hydrogen and helium, formed in the first minutes after the Big Bang. Authoritative cosmology sources consistently describe them as the first and dominant products of Big Bang nucleosynthesis. Small amounts of other light nuclides, especially lithium-7, were also produced, but that does not overturn the claim’s core meaning.
“Red giants and red supergiants produce elements up to iron through nuclear fusion.”
The statement mixes two very different kinds of stars. Red supergiants can build up to iron in their cores through successive fusion stages, but ordinary red giants do not get that far and generally stop around carbon and oxygen. It also blurs the fact that much iron-peak material released into space is made during the supernova explosion, not just during the red-supergiant phase.
“Supernova explosions create and scatter elements heavier than iron across space.”
The evidence shows that supernovae do both produce some elements heavier than iron and disperse them through space. NASA, DOE, and review literature support that role in nucleosynthesis and galactic enrichment. The main caveat is that supernovae are not the only major source of heavy elements, and may not be the dominant source for the very heaviest r-process elements.
“In a ball-and-stick model of oxygen gas (O2), the bond between the two oxygen atoms is curved because of technical issues with the plastic stick.”
Standard ball-and-stick models of O2 do not use a curved bond. Reliable chemistry sources describe oxygen as linear and represent the O–O bond with a straight connector. If a classroom model appears curved, that usually reflects a bent or worn piece in a particular kit, or an intentional kit design choice, not a general fact that O2 models are curved because of plastic technical problems.
“A dioxygen molecule (O2) has a bent (curved) molecular geometry.”
Standard chemistry definitions do not support this statement. O2 is a diatomic molecule, and diatomic molecules are classified as linear because two nuclei define a straight line. References to electron density or vibration do not change the formal molecular geometry to bent.
“In English chemical nomenclature, when a compound contains more than one cation or more than one anion, the ion names should be listed in alphabetical order (A–Z).”
The evidence does not support a general A–Z rule for ion names across English chemical nomenclature. Authoritative IUPAC sources consistently preserve the cation-before-anion order, while alphabetical ordering appears only in narrower contexts, such as some cases with multiple ions of the same class. As written, the claim overstates a limited convention as a universal rule.
“"Dihydrogen dioxide" is an incorrect or nonstandard name for hydrogen peroxide (H2O2) in chemical nomenclature.”
The evidence does not support calling “dihydrogen dioxide” an incorrect name for H2O2. It is an accepted IUPAC compositional name, although “hydrogen peroxide” is the preferred and overwhelmingly standard name in scientific and regulatory usage. The claim conflates “not preferred” with “not accepted,” which materially changes the takeaway.
“Electrical resistance in microbial fuel cell circuits can be analyzed using Ohm's law (V = I·R).”
The statement is well supported by standard microbial fuel cell practice. Peer-reviewed reviews and methods papers routinely use Ohm’s law to calculate current through known external resistors and to estimate effective resistance, especially in the linear ohmic region. MFCs can depart from simple ohmic behavior outside that region, but that limits precision rather than the basic applicability of V = I·R.
“For a reversible Hamiltonian flow with reversor R, for any point x on a reversible orbit, the points x and R(x) are related by a conjugacy of the dynamics restricted to that orbit.”
The claim is correct if “reversible orbit” means an orbit invariant under the reversor R. In that standard sense, the relation R∘φ_t=φ_{-t}∘R makes R a time-reversing conjugacy on the orbit, carrying x to R(x). The wording is the main weakness: not every orbit in a reversible Hamiltonian system is itself R-symmetric.
“Glow-in-the-dark luminous pearls store energy absorbed from sunlight, and their afterglow occurs because electrons trapped at lattice defects are slowly released and recombine, emitting light.”
The claim captures the standard mechanism of persistent glow-in-the-dark materials. Sunlight can charge these materials, and their afterglow is generally explained by charge carriers being trapped in defect-related states and later released to recombine and emit light. The main caveat is that real phosphors often involve dopants, multiple trap types, and sometimes hole trapping or light-assisted release as well.