ActivityPub Viewer

A small tool to view real-world ActivityPub objects as JSON! Enter a URL or username from Mastodon or a similar service below, and we'll send a request with the right Accept header to the server to view the underlying object.

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{ "@context": [ "https://www.w3.org/ns/activitystreams", { "ostatus": "http://ostatus.org#", "atomUri": "ostatus:atomUri", "inReplyToAtomUri": "ostatus:inReplyToAtomUri", "conversation": "ostatus:conversation", "sensitive": "as:sensitive", "toot": "http://joinmastodon.org/ns#", "votersCount": "toot:votersCount" } ], "id": "https://mathstodon.xyz/users/gregeganSF/statuses/109290905971976809/activity", "type": "Create", "actor": "https://mathstodon.xyz/users/gregeganSF", "published": "2022-11-05T11:14:40Z", "to": [ "https://www.w3.org/ns/activitystreams#Public" ], "cc": [ "https://mathstodon.xyz/users/gregeganSF/followers" ], "object": { "id": "https://mathstodon.xyz/users/gregeganSF/statuses/109290905971976809", "type": "Note", "summary": null, "inReplyTo": "https://mathstodon.xyz/users/gregeganSF/statuses/109283584820105620", "published": "2022-11-05T11:14:40Z", "url": "https://mathstodon.xyz/@gregeganSF/109290905971976809", "attributedTo": "https://mathstodon.xyz/users/gregeganSF", "to": [ "https://www.w3.org/ns/activitystreams#Public" ], "cc": [ "https://mathstodon.xyz/users/gregeganSF/followers" ], "sensitive": false, "atomUri": "https://mathstodon.xyz/users/gregeganSF/statuses/109290905971976809", "inReplyToAtomUri": "https://mathstodon.xyz/users/gregeganSF/statuses/109283584820105620", "conversation": "tag:mathstodon.xyz,2022-11-02:objectId=28211198:objectType=Conversation", "content": "<p>What else consists of two 24-cells in R^4?</p><p>The binary octahedral group, containing the 48 quaternions q, that when construed as rotations via:</p><p>x → q x q^{-1}</p><p>give symmetries of the octahedron with vertices ±i, ±j, ±k.</p><p>So … how can we link the Mermin grid to that group?</p><p>Consider the 3 × 3 grid of pairs of quaternions:</p><p>(j, j) (i, i) (k, k)<br />(i, k) (k, j) (j, i)<br />(k, i) (j, k) (i, j)</p><p>If we treat a pair of quaternions (r,s) as defining a rotation in R^4 via:</p><p>x → r x s^{-1}</p>", "contentMap": { "en": "<p>What else consists of two 24-cells in R^4?</p><p>The binary octahedral group, containing the 48 quaternions q, that when construed as rotations via:</p><p>x → q x q^{-1}</p><p>give symmetries of the octahedron with vertices ±i, ±j, ±k.</p><p>So … how can we link the Mermin grid to that group?</p><p>Consider the 3 × 3 grid of pairs of quaternions:</p><p>(j, j) (i, i) (k, k)<br />(i, k) (k, j) (j, i)<br />(k, i) (j, k) (i, j)</p><p>If we treat a pair of quaternions (r,s) as defining a rotation in R^4 via:</p><p>x → r x s^{-1}</p>" }, "attachment": [], "tag": [], "replies": { "id": "https://mathstodon.xyz/users/gregeganSF/statuses/109290905971976809/replies", "type": "Collection", "first": { "type": "CollectionPage", "next": "https://mathstodon.xyz/users/gregeganSF/statuses/109290905971976809/replies?min_id=109290910932627626&page=true", "partOf": "https://mathstodon.xyz/users/gregeganSF/statuses/109290905971976809/replies", "items": [ "https://mathstodon.xyz/users/gregeganSF/statuses/109290910932627626" ] } }, "likes": { "id": "https://mathstodon.xyz/users/gregeganSF/statuses/109290905971976809/likes", "type": "Collection", "totalItems": 0 }, "shares": { "id": "https://mathstodon.xyz/users/gregeganSF/statuses/109290905971976809/shares", "type": "Collection", "totalItems": 0 } } }