Martin Kroeker

@kroekermartin

Chemist drifted off into programming and mechanical CAD; Acting OpenBLAS maintainer. Always doing things I know too little about. 📍Germany

66 Folgt238 Follower3.059 Posts

Bluesky

Ist das dein Profil?Übernimm es — dann gehört dir kroekermartin.dirty.social.Profil übernehmen

Martin Kroeker@kroekermartin· 28d

Police uniforms have changed a bit, and SA is now ICE, but this is approximately what a joint patrol on election day will look like (add guns to make it more American)

Joint patrol by a Berlin policeman and a Nazi SA militiaman on election day in March 1933. (Policeman in greatcoat and wearing a helmet with a big police star, SA thug in brownshirt, a police dog between them. Pedestrians in hat&coat behind on a paved sidewalk. Picture from German National Archives, #102-14381

Martin Kroeker@kroekermartin· Jul 2

beerwatching ?

Martin Kroeker@kroekermartin· Jun 29

Their sacrifice shall not be forgotten upload.wikimedia.org/wikipedia/co...

Coat of arms of the German village of Poggensee, displaying a big green frog (a pogge in local Frisian dialect) on a yellow background

Martin Kroeker@kroekermartin· Jun 20

Surprise guest

A big stag beetle trying to climb a white flower pot on a garden table

Martin Kroeker@kroekermartin· May 3

Snake's head fritillaries in the meadows of the Jossgrund valley in 🇩🇪 Spessart range for #wildflowerhour

Martin Kroeker@kroekermartin· Apr 26

Hiking in the Black Forest

Martin Kroeker@kroekermartin· Apr 5

Frog on a log, gently swinging left and right in the flowing stream

Martin Kroeker@kroekermartin· Apr 4

actually named chessboard flower in German

Martin Kroeker@kroekermartin· Mar 27

A world atop a fencepost

Close-up of pale green funnel-shaped Cladonia lichens and vivid green cushion moss, with some blueish-gray flakes of some other lichen in the foreground

A zoomed-out view of the moss and lichen landscape, showing that it is the withered top of a dark brown fencepost. The barbed wire and the green pasture beyond the fence are out of focus

Martin Kroeker@kroekermartin· Mar 7

Wood anemones and an ample supply of wild garlic

Martin Kroeker@kroekermartin· Mar 5

Spring at last 🐸

A pair of European grass frogs in amplexus, sitting in shallow water facing right with lots of old leaves around them and at least three other frogs tangled below and behind them

Martin Kroeker@kroekermartin· Mar 5

Scenes of Lübeck, the old Hanse town and Germany's marzipan capital on the Baltic coast

Holsten gate - one of the medieval city gates, made of red brick, darkened with age. A gravel path leads to the wide open gate in the central gatehouse that is flanked on both sides by a thick round tower with a conical black roof.
In the background, twin church towers made of brick and topped by green copper roofs are visible to the left, and a row of old multi-story brick houses with many windows to the right

Castle gate, the other remaining gate of the medieval town - built of red brick with a square central tower with rows of church-like gothic windows over the main opening, flanked on tge right by a huge octagonal tower with white lattice windows, and on the left by a lower bastion with three rows of shooting slits.
A city road leads through the two main openings, its sidewalks passing through smaller archways. There's dark green foliage of shrubs and ivy covering the lower sections of the octagonal tower

The medieval cathedral, entirely built of red brick - two square towers joined by a copper-green support bar at half height, and topped by tapering green copper spires. The stepped gable between them sits above three long and narrow windows. There's an old brick house with a stepped gable immediately to the left of the church, behind barren trees and a couple of cars in tge foreground. To the right is a modern kindergarten building of three identical units with green saddle roofs

A row of old houses along the Trave river canal on the edge of the medieval town - a white timber frame house with two dormers, a bright yellow one with lattice windows and a rounded gable, a light yellow and more modern looking building perhaps from the 19th century - with its owners sitting on a bench by their door.
Trees and a row of parked cars along the cobblestone road to the left, a street lamp covering part of a more recent looking house on the right

Martin Kroeker@kroekermartin· Feb 2

Schaerbeek train station, Brussels - some weird Art Nouveau architecture here, or is it Neo-Renaissance ?

Two train station buildings made of red and white bricks in a dazzling stripe pattern, both feature a strange metal spire with round windows like something out of a Jules Verne movie. There's a modern tram at the three-bay stop in front of the station

Martin Kroeker@kroekermartin· Jan 26

ours before a student dropped it (copied from the lecture page at ruby.chemie.uni-freiburg.de as the picture link did not embed properly)

a layered crystal aggregate of gypsum on a uniform red background - coarse brownish discolored needles at the bottom, followed by a center layer of smaller, clearer crystals and topped with a snow-like sheet of fine white needles. the layers are held together by a few long brown crystals that extend from the lowest, oldest layer

Martin Kroeker@kroekermartin· Dec 11

mistleglow

a meadow with a row of leafless trees covered in mistletoe bushes, photographed against pink clouds at sunset

Martin Kroeker@kroekermartin· Dec 4

Martin Kroeker@kroekermartin· Nov 22

need to convince the council & mayor of Basel

Martin Kroeker@kroekermartin· Oct 18

This could have been a much better picture if I hadn't startled the small colleague who was already admiring the mushroom

a forest floor covered in old leaves, pine twigs and needles, with s big fly agaric mushroom in the bottom right and a small frog in the top left

Martin Kroeker@kroekermartin· Oct 11

me too :) but shaky freehand phone for what could be a decent stacked image

Martin Kroeker@kroekermartin· Sep 7

Video of the DB Class 23 steam locomotive pulling a heritage train (upload limit here appears to be a bit below the advertised 100mb still?)

Martin Kroeker@kroekermartin· Sep 7

German Class 23 on the Three Lakes line at Schluchsee earlier today

A lake front with a steam train crossing a bridge in the background (a row of shrubs and a stretch of lawn separates the lakeside from a paved footpath with people and dogs walking)

Front view of the steam locomotive with black body and red undercarriage (houses in the background)

A heritage train with green passenger carriages and a white freight car right behind its black-and-red steam locomotive, standing on its track between a lake embankment in the foreground and a rural Black Forest town with a bulbous church spire in the background

Martin Kroeker@kroekermartin· Aug 27

#BraggYourPattern Fiona Tan's "Het Grote Raam" in the (secularized) Grote Kerk of Alkmaar🇳🇱

A stained-glass church window consisting of colorful caleidoscopic squares, predominantly yellow and green at the bottom, red tones in the middle and blues towards the top, culminating in dark blue in the tracery.
(A chandelier hands to the right of the window, modern light fixtures to its left)

closer view of 4x5 squares, reds and yellowsvfrom the lower left of the widow

closer view of 4x5 squares from the lower right of the window, yellows giving way to orange and red/blue

Martin Kroeker@kroekermartin· Aug 12

Liminal spaces - inside an Art Nouveau water tower

A narrow stone staircase with black metal handrails leading up along the bare quarry stone wall inside a round tower, and a large vertical pipe to the left, between the stairs and a window

a dimly lit room with several square concrete pillars, bare except for several large diameter pipes in the background and one running towards the viewer. A narrow spiral staircase made of black metal extends from the center of the room through a square opening in the ceiling

another barren storey with a square concrete pillar in the center, and a concrete staircase winding along the quarry stone wall, light flooding in from a small window on the right

The watertower seen from outside against a blue sky. Basalt quarry stone masonry, four windows aligned vertically under the decagonal tank with contrasting white and light brown paint. The black dome roof features a continuous row of windows

Martin Kroeker@kroekermartin· Aug 7

getting stalked by a stork

Martin Kroeker@kroekermartin· Aug 3

so this isn't how magnitudes are determined ?

a figure scating jury with scores of 4.5 and 5.0 displayed on screens set into their bench

Martin Kroeker@kroekermartin· Aug 2

not entirely sure how to dress for this weather, any suggestions ?

an obviously broken weather forecast table for August 15 predicting 500mph winds and a midnight high around 100 Fahrenheit with minus 167 Fahrenheit wind chill

Martin Kroeker@kroekermartin· Jul 12

Freude schöne Gelbbauchunke 🎶 Tochter aus Elysion🎶🎶 (young yellow-bellied toad in a shallow forest pond purpose-built to support their reproduction)

young yellow-bellied toad in the water, looking out among some floating duckweed and leaves of grass. some orange-yellow of the underbelly is visible between the spread hind legs to the left

Martin Kroeker@kroekermartin· Jul 12

The jug topper from the Reinheim grave is weird, wikipedia has a photo of an enlarged replica here upload.wikimedia.org/wikipedia/co... (but if that was their Jesus equivalent, maybe the guys with the leaf crown were something like our 18th century prince-bishops)

Martin Kroeker@kroekermartin· Jun 28

Midsummer scenes

a big field of ripe grain (possibly rye) with a small village surrounded by trees in the background, and wooded hills under summer clouds beyond

Four white storks following a red tractor that is turning hay, with shrubs and trees filling the background

Martin Kroeker@kroekermartin· Jun 13

stag [beetle] night near Freiburg