Editing Open problem (section)

{{Short description|In science and mathematics, not yet solved problem}}
In [[science]] and [[mathematics]], an '''open problem''' or an '''open question''' is a known problem which can be accurately stated, and which is assumed to have an objective and verifiable solution, but which has not yet been solved (i.e., no solution for it is known).

In the [[history of science]], some of these supposed open problems were "solved" by means of showing that they were not well-defined. 
In mathematics, many open problems are concerned with the question of whether a certain definition is or is not consistent.

Two notable examples in [[mathematics]] that have been solved and ''closed'' by researchers in the late twentieth century are [[Fermat's Last Theorem]]<ref>{{Citation |last=Faltings|first=Gerd|date=July 1995|url=https://www.ams.org/notices/199507/faltings.pdf|title=The Proof of Fermat's Last Theorem by R. Taylor and A. Wiles|journal=Notices of the AMS|volume=42|issue=7|pages=743&ndash;746|issn=0002-9920}}</ref> and the [[four-color theorem]].<ref name=Appel1977a>K. Appel and W. Haken (1977), "Every planar map is four colorable. Part I. Discharging", ''Illinois J. Math'' '''21''': 429&ndash;490. {{MR|543795}}</ref><ref name=Appel1977b>K. Appel, W. Haken, and J. Koch (1977), "Every planar map is four colorable. Part II. Reducibility", ''Illinois J. Math'' '''21''': 491&ndash;567. {{MR|543795}}</ref> An important open mathematics problem solved in the early 21st century is the [[Poincaré conjecture]].

Open problems exist in all scientific fields. 
For example, one of the most important open problems in biochemistry is the [[protein structure prediction]] problem<ref name=Vendruscolo1999>{{citation
 | last1 = Vendruscolo | first1 = M.
 | last2 = Najmanovich | first2 = R.
 | last3 = Domany | first3 = E.
 | year = 1999
 | title = Protein Folding in Contact Map Space
 | journal = Physical Review Letters
 | volume = 82
 | issue = 3
 | pages = 656–659
 | doi = 10.1103/PhysRevLett.82.656
| bibcode=1999PhRvL..82..656V
|arxiv = cond-mat/9901215 | s2cid = 6686420
 }}</ref><ref name=Dill2007>{{citation
 |last1       = Dill
 |first1      = K.A.
 |last2       = Ozkan
 |first2      = S.B.
 |last3       = Weikl
 |first3      = T.R.
 |last4       = Chodera
 |first4      = J.D.
 |last5       = Voelz
 |first5      = V.A.
 |year        = 2007
 |title       = The protein folding problem: when will it be solved?
 |journal     = Current Opinion in Structural Biology
 |volume      = 17
 |issue       = 3
 |pages       = 342–346
 |doi         = 10.1016/j.sbi.2007.06.001
 |url         = http://laplace.compbio.ucsf.edu/~jchodera/pubs/pdf/protein-folding-problem.pdf
 |pmid        = 17572080
 |url-status     = dead
 |archive-url  = https://web.archive.org/web/20110720080804/http://laplace.compbio.ucsf.edu/~jchodera/pubs/pdf/protein-folding-problem.pdf
 |archive-date = 2011-07-20
}}</ref> &ndash; how to predict a [[protein]]'s structure from its sequence.