top active problems
mathematics - 2017-03-19T17:26:44Z agoEvolutionary theories defined
A gene can be expressed at various stages of life. Therefore, natural selection can support lethal and harmful alleles, if their expression occurs after reproduction. Senescence may be the product of such selection. In addition, ageing is believed to have evolved because of the... Read more
mathematics - 2017-03-19T17:26:44Z agoThe problem of finding the ultimate core model defined
The problem of finding the ultimate core model, one that contains all large cardinals.
mathematics - 2017-03-19T17:26:44Z agoprime quadruplets divided 1 subproblem
Are there infinitely many prime quadruplets?
mathematics - 2017-03-19T17:26:44Z agoChvátals toughness conjecture defined
that there is a number t such that every t-tough graph is Hamiltonian
mathematics - 2017-03-19T17:26:44Z agoLyapunovs second method for stability defined
For what classes of ODEs, describing dynamical systems, does the Lyapunov’s second method formulated in the classical and canonically generalized forms define the necessary and sufficient conditions for the (asymptotical) stability of motion?
mathematics - 2017-03-19T17:26:44Z agoFurstenberg conjecture defined
Is every invariant and ergodic measure for the x2, x3 action on the circle either Lebesgue or atomic?
mathematics - 2017-03-19T17:26:44Z agoPentagonal tiling defined
15 types of convex pentagons are known to monohedrally tile the plane, and it is not known whether this list is complete
mathematics - 2017-03-19T17:26:44Z agoThe einstein problem defined
Is there a two-dimensional shape that forms the prototile for an aperiodic tiling, but not for any periodic tiling?
chemistry - 2017-03-19T17:26:44Z agonature of strong gold-chalcogens in thiols defined
What is the nature of strong gold-chalcogens in thiols and other organochalcogens (i.e., sulfur and higher chalcogen-containing organic compounds)?
chemistry - 2017-03-19T17:26:44Z agoalpha effect defined
What is the origin of the alpha effect, that is, that nucleophiles with an electronegative atom with lone pairs adjacent to the nucleophilic center are particularly reactive?
chemistry - 2017-03-19T17:26:44Z agochirality defined
Is an abiologic origin of chirality as is found in (2R)-2,3-dihydroxypropanal (D-glyceraldehyde), and also in amino acids, sugars, etc., possible?
organic chemistry - 2017-03-19T17:26:44Z agoelectromagnetic energy to chemical energy defined
How can electromagnetic energy (photons) be efficiently converted to chemical energy? For instance, can water be efficiently split to hydrogen and oxygen using solar energy?
chemistry - 2017-03-19T17:26:44Z agoFeynmanium defined
Is Feynmanium the last chemical element that can physically exist? That is, what are the chemical consequences of having an element with an atomic number above 137, whose 1s electrons must travel faster than the speed of light?