What does Twitter's new logo really represent?

It has a meaning in mathematics, and even more interested parties than you might expect

Logowatch Twitter's new logo isn't just an X, it's a very specific form of X, and not only does it have a meaning, it also has some history behind it.

As The Reg reported earlier this week, Twitter has a new logo. The blue bird logo the site has used since 2012 is no more, but we found its co-creator Martin Grasser's thread about how they designed it fascinating. We learned that it was constructed like a geometrical diagram, from 15 overlapping circles.

The new logo, though, isn't just any old X; it's a double-struck capital 𝕏. Although the character can be found in several specialized fonts, such as Monotype Special Alphabet 4, it's also a Unicode character, at code point U+1D54F (if your hexadecimal is rusty, we make that 120143 in decimal).

There is a whole set of double-struck characters in Unicode 3.1. Double-stroke letters, or blackboard bold as they're sometimes called, have specific meanings in mathematics, some of them to do with set theory. The double-struck capital X is sometimes used to denote an arbitrary metric space, for example.

Those familiar with the logo of X.org, the custodians of the soon to be 40-year-old X window system, may also find the design, with a thin ascending stroke but wide descending one, to be rather familiar – although that logo is already inadequately defended as it is.

Mr Musk's X.com was one of the companies that ended up as part of PayPal, and back in 2010 we were reporting on PayPal using the domain. There is a good brief history of the deal on Twitter, along with another of the incident that led to the destruction of Mr Musk's Mclaren F1 supercar. A number of famous people have crashed these brutally rapid – and brutally expensive – vehicles, including actor Rowan Atkinson and Micromuse co-founder Chris Dawe, who sadly did not survive the experience.

As boffin's boffin Ken Shirriff describes, the stylized double-struck X was added to Unicode in 2001 – just after the merger of the original X.com and Paypal. This particular form of the symbol was already being used by Indian electronic musician Kxlider, although as he has noted, as a Unicode character, it can't be trademarked or otherwise protected.

The letter X in general, though, is also a registered trademark of multiple companies, including both Microsoft since 2003, in the context of its Xbox video games console, and Meta since 2019, in the context of social networks. Reuters reports that there are some 900 other claims. ®