DOUBLE-STRUCK ITALIC SMALL E·U+2147

Character Information

Code Point
U+2147
HEX
2147
Unicode Plane
Basic Multilingual Plane
Category
Lowercase Letter

Character Representations

Click elements to copy
EncodingHexBinary
UTF8
E2 85 87
11100010 10000101 10000111
UTF16 (big Endian)
21 47
00100001 01000111
UTF16 (little Endian)
47 21
01000111 00100001
UTF32 (big Endian)
00 00 21 47
00000000 00000000 00100001 01000111
UTF32 (little Endian)
47 21 00 00
01000111 00100001 00000000 00000000
HTML Entity
ⅇ
URI Encoded
%E2%85%87

Description

The Unicode character U+2147, known as the Double-struck Italic Small E, is a typographical symbol that holds significant importance in digital text. Its primary usage lies within mathematical notation, where it is employed to represent the 'esper' operator, which signifies an expectation value in quantum mechanics and wave function theory. This character is specifically utilized in equations and formulas to denote the expected or average value of a physical quantity, making it an essential tool for scientists and researchers dealing with quantum phenomena. The Double-struck Italic Small E is distinct from its single-struck counterpart due to its double-struck or 'sans serif' style, which gives it a bold appearance that sets it apart in text. This unique visual characteristic makes it easily identifiable and helps to avoid confusion with similar characters in digital text. Despite its specific role within mathematical notation, the Double-struck Italic Small E has managed to maintain a level of cultural significance due to its association with advanced scientific concepts and the ongoing exploration of quantum mechanics. In summary, the Unicode character U+2147, or the Double-struck Italic Small E, is a crucial symbol in digital text for representing expectation values in mathematical notation, particularly within the context of quantum mechanics. Its unique style and cultural significance make it an indispensable tool for scientists, researchers, and anyone delving into advanced scientific concepts.

How to type the symbol on Windows

Hold Alt and type 8519 on the numpad. Or use Character Map.

  1. Step 1: Determine the UTF-8 encoding bit layout

    The character has the Unicode code point U+2147. In UTF-8, it is encoded using 3 bytes because its codepoint is in the range of 0x0800 to 0xffff.

    Therefore we know that the UTF-8 encoding will be done over 16 bits within the final 24 bits and that it will have the format: 1110xxxx 10xxxxxx 10xxxxxx
    Where the x are the payload bits.

    UTF-8 Encoding bit layout by codepoint range
    Codepoint RangeBytesBit patternPayload length
    U+0000 - U+007F10xxxxxxx7 bits
    U+0080 - U+07FF2110xxxxx 10xxxxxx11 bits
    U+0800 - U+FFFF31110xxxx 10xxxxxx 10xxxxxx16 bits
    U+10000 - U+10FFFF411110xxx 10xxxxxx 10xxxxxx 10xxxxxx21 bits
  2. Step 2: Obtain the payload bits:

    Convert the hexadecimal code point U+2147 to binary: 00100001 01000111. Those are the payload bits.

  3. Step 3: Fill in the bits to match the bit pattern:

    Obtain the final bytes by arranging the paylod bits to match the bit layout:
    11100010 10000101 10000111