Four-vector, an Uncommon card

The card carries these facts from its Wikipedia article.

• Its magnitude is determined by an indefinite quadratic form, the preservation of which defines the Lorentz transformations, which include spatial rotations and boosts.
• Four-vectors describe, for instance, position xμ in spacetime modeled as Minkowski space, a particle's four-momentum pμ, the amplitude of the electromagnetic four-potential Aμ at a point x in spacetime, and the elements of the subspace spanned by the gamma matrices inside the Dirac algebra.
• The Lorentz group may be represented by a set of 4 × 4 matrices Λ. The action of a Lorentz transformation on a general contravariant four-vector X, regarded as a column vector with Cartesian coordinates with respect to an inertial frame in the entries, is given by X ′ = Λ X, where the components of the primed object refer to the new frame.

Rarity in WikiCards follows a year of Wikipedia page views: the most read articles become Epic and Legendary cards. The Four-vector article was read about 32,000 times in a year. ATK comes from the length of the article and DEF from its quality, so this card hits with 76 and blocks with 52: each hit it takes is cut by 21 %.

Open packs. Each pack holds five cards drawn from real Wikipedia articles, the rarest last, and the fifth card is always Rare or better. The odds are shown in the game. A free pack arrives every hour and two can wait, and the Coins you win in duels buy more packs.

The cards just above and just below Four-vector in the power ranking, all domains together.