When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. List of unsolved problems in chemistry - Wikipedia

    en.wikipedia.org/wiki/List_of_unsolved_problems...

    Protein folding problem: Is it possible to predict the secondary, tertiary and quaternary structure of a polypeptide sequence based solely on the sequence and environmental information? Inverse protein-folding problem: Is it possible to design a polypeptide sequence which will adopt a given structure under certain environmental conditions?

  3. Smale's problems - Wikipedia

    en.wikipedia.org/wiki/Smale's_problems

    Smale's problems is a list of eighteen unsolved problems in mathematics proposed by Steve Smale in 1998 [1] and republished in 1999. [2] Smale composed this list in reply to a request from Vladimir Arnold, then vice-president of the International Mathematical Union, who asked several mathematicians to propose a list of problems for the 21st century.

  4. Problem set - Wikipedia

    en.wikipedia.org/wiki/Problem_set

    A problem set, sometimes shortened as pset, [1] is a teaching tool used by many universities. Most courses in physics, math, engineering, chemistry, and computer science will give problem sets on a regular basis. [2] They can also appear in other subjects, such as economics.

  5. Hilbert's problems - Wikipedia

    en.wikipedia.org/wiki/Hilbert's_problems

    Problems 1, 2, 5, 6, [g] 9, 11, 12, 15, 21, and 22 have solutions that have partial acceptance, but there exists some controversy as to whether they resolve the problems. That leaves 8 (the Riemann hypothesis), 13 and 16 [h] unresolved, and 4 and 23 as too vague to ever be described as solved. The withdrawn 24 would also be in this class.

  6. Perturbation theory - Wikipedia

    en.wikipedia.org/wiki/Perturbation_theory

    In mathematics and applied mathematics, perturbation theory comprises methods for finding an approximate solution to a problem, by starting from the exact solution of a related, simpler problem. [1] [2] A critical feature of the technique is a middle step that breaks the problem into "solvable" and "perturbative" parts. [3]

  7. Ball bearing - Wikipedia

    en.wikipedia.org/wiki/Ball_bearing

    Working principle for a ball bearing; red dots show direction of rotation. A four-point angular-contact ball bearing. A ball bearing is a type of rolling-element bearing that uses balls to maintain the separation between the bearing races. The purpose of a ball bearing is to reduce rotational friction and support radial and axial loads. It ...

  8. Mathematical chemistry - Wikipedia

    en.wikipedia.org/wiki/Mathematical_chemistry

    Mathematical chemistry [1] is the area of research engaged in novel applications of mathematics to chemistry; it concerns itself principally with the mathematical modeling of chemical phenomena. [2] Mathematical chemistry has also sometimes been called computer chemistry , but should not be confused with computational chemistry .

  9. Many-body problem - Wikipedia

    en.wikipedia.org/wiki/Many-body_problem

    Microscopic here implies that quantum mechanics has to be used to provide an accurate description of the system. Many can be anywhere from three to infinity (in the case of a practically infinite, homogeneous or periodic system, such as a crystal), although three- and four-body systems can be treated by specific means (respectively the Faddeev and Faddeev–Yakubovsky equations) and are thus ...