U+210D DOUBLE-STRUCK CAPITAL H

U+210D was added to Unicode in version 1.1 (1993). It belongs to the block Letterlike Symbols in the Basic Multilingual Plane.

This character is a Uppercase Letter and is commonly used, that is, in no specific script.

The glyph is a Font composition of the glyphs H. It has a Neutral East Asian Width. In bidirectional context it acts as Left To Right and is not mirrored. The glyph can, under circumstances, be confused with 35 other glyphs. In text U+210D behaves as Alphabetic regarding line breaks. It has type Upper for sentence and ALetter for word breaks. The Grapheme Cluster Break is Any.

The Wikipedia has the following information about this codepoint:

In mathematics, the quaternions are a number system that extends the complex numbers. They were first described by Irish mathematician William Rowan Hamilton in 1843 and applied to mechanics in three-dimensional space. A feature of quaternions is that multiplication of two quaternions is noncommutative. Hamilton defined a quaternion as the quotient of two directed lines in a three-dimensional space or equivalently as the quotient of two vectors.

Quaternions find uses in both theoretical and applied mathematics, in particular for calculations involving three-dimensional rotations such as in three-dimensional computer graphics, computer vision and crystallographic texture analysis. In practical applications, they can be used alongside other methods, such as Euler angles and rotation matrices, or as an alternative to them, depending on the application.

In modern mathematical language, quaternions form a four-dimensional associative normed division algebra over the real numbers, and therefore also a domain. In fact, the quaternions were the first noncommutative division algebra to be discovered. The algebra of quaternions is often denoted by H (for Hamilton), or in blackboard bold by (Unicode U+210D, ℍ). It can also be given by the Clifford algebra classifications C0,2(R) ≅ C03,0(R). The algebra H holds a special place in analysis since, according to the Frobenius theorem, it is one of only two finite-dimensional division rings containing the real numbers as a proper subring, the other being the complex numbers. These rings are also Euclidean Hurwitz algebras, of which quaternions are the largest associative algebra.

The unit quaternions can therefore be thought of as a choice of a group structure on the 3-sphere S3 that gives the group Spin(3), which is isomorphic to SU(2) and also to the universal cover of SO(3).

Representations

System Representation
8461
UTF-8 E2 84 8D
UTF-16 21 0D
UTF-32 00 00 21 0D
URL-Quoted %E2%84%8D
HTML-Escape ℍ
Wrong windows-1252 Mojibake ℍ
HTML-Escape ℍ
HTML-Escape ℍ
LaTeX \mathbb{H}

Related Characters

Confusables

  • H
  • ℋ
  • H
  • Ħ
  • Η
  • Н
  • Ң
  • Ӈ
  • Ӊ
  • Ꮋ
  • ᕼ
  • ℋ
  • ℌ
  • ℍ
  • Ⱨ
  • Ⲏ
  • ꓧ
  • H
  • 𐋏
  • 𝐇
  • 𝐻
  • 𝑯
  • 𝓗
  • 𝕳
  • 𝖧
  • 𝗛
  • 𝘏
  • 𝙃
  • 𝙷
  • 𝚮
  • 𝛨
  • 𝜢
  • 𝝜
  • 𝞖
  • 🄗

Elsewhere

Complete Record

Property Value
Age (age) 1.1
Unicode Name (na) DOUBLE-STRUCK CAPITAL H
Unicode 1 Name (na1) DOUBLE-STRUCK H
Block (blk) Letterlike_Symbols
General Category (gc) Uppercase Letter
Script (sc) Common
Bidirectional Category (bc) Left To Right
Combining Class (ccc) Not Reordered
Decomposition Type (dt) Font
Decomposition Mapping (dm) H
Lowercase (Lower)
Simple Lowercase Mapping (slc) ℍ
Lowercase Mapping (lc) ℍ
Uppercase (Upper)
Simple Uppercase Mapping (suc) ℍ
Uppercase Mapping (uc) ℍ
Simple Titlecase Mapping (stc) ℍ
Titlecase Mapping (tc) ℍ
Case Folding (cf) ℍ
ASCII Hex Digit (AHex)
Alphabetic (Alpha)
Bidi Control (Bidi_C)
Bidi Mirrored (Bidi_M)
Bidi Paired Bracket (bpb) ℍ
Bidi Paired Bracket Type (bpt) None
Cased (Cased)
Composition Exclusion (CE)
Case Ignorable (CI)
Full Composition Exclusion (Comp_Ex)
Changes When Casefolded (CWCF)
Changes When Casemapped (CWCM)
Changes When NFKC Casefolded (CWKCF)
Changes When Lowercased (CWL)
Changes When Titlecased (CWT)
Changes When Uppercased (CWU)
Dash (Dash)
Deprecated (Dep)
Default Ignorable Code Point (DI)
Diacritic (Dia)
East Asian Width (ea) Neutral
Extender (Ext)
FC NFKC Closure (FC_NFKC) h
Grapheme Cluster Break (GCB) Any
Grapheme Base (Gr_Base)
Grapheme Extend (Gr_Ext)
Hex Digit (Hex)
Hangul Syllable Type (hst) Not Applicable
Hyphen (Hyphen)
ID Continue (IDC)
Ideographic (Ideo)
ID Start (IDS)
IDS Binary Operator (IDSB)
IDS Trinary Operator and (IDST)
InMC (InMC)
Indic Positional Category (InPC) NA
Indic Syllabic Category (InSC) Other
ISO 10646 Comment (isc)
Joining Group (jg) No_Joining_Group
Join Control (Join_C)
Jamo Short Name (JSN)
Joining Type (jt) Non Joining
Line Break (lb) Alphabetic
Logical Order Exception (LOE)
Math (Math)
Noncharacter Code Point (NChar)
NFC Quick Check (NFC_QC) Yes
NFD Quick Check (NFD_QC) Yes
NFKC Casefold (NFKC_CF) h
NFKC Quick Check (NFKC_QC) No
NFKD Quick Check (NFKD_QC) No
Numeric Type (nt) None
Numeric Value (nv) NaN
Other Alphabetic (OAlpha)
Other Default Ignorable Code Point (ODI)
Other Grapheme Extend (OGr_Ext)
Other ID Continue (OIDC)
Other ID Start (OIDS)
Other Lowercase (OLower)
Other Math (OMath)
Other Uppercase (OUpper)
Pattern Syntax (Pat_Syn)
Pattern White Space (Pat_WS)
Quotation Mark (QMark)
Radical (Radical)
Sentence Break (SB) Upper
Simple Case Folding (scf) ℍ
Script Extension (scx) Common
Soft Dotted (SD)
STerm (STerm)
Terminal Punctuation (Term)
Unified Ideograph (UIdeo)
Variation Selector (VS)
Word Break (WB) ALetter
White Space (WSpace)
XID Continue (XIDC)
XID Start (XIDS)
Expands On NFC (XO_NFC)
Expands On NFD (XO_NFD)
Expands On NFKC (XO_NFKC)
Expands On NFKD (XO_NFKD)