# Zeitpyramide

The Zeitpyramide (lit. 'time pyramid') is a work of public art by Manfred Laber (1932–2018) under construction in Wemding, Germany. The pyramid began in 1993, the year of the town's 1,200th anniversary. With a new block added every ten years, the structure should consist of 120 blocks when complete after 1,190 years, in the year 3183.

## Concept

The town of Wemding dates back to the year 793 and celebrated its 1,200th anniversary in 1993. The Zeitpyramide was conceived by Manfred Laber (a local artist) in June 1993 to mark this 1,200-year period and to give people a sense of what the span of 1,200 years really means.
One block is scheduled to be placed every ten years, taking 1,190 years. This time includes the initial block placed at the beginning of the project, which explains the apparent off-by-one error of ten years. So far, the blocks have all been concrete, but the material of future blocks may be altered in future generations depending on availability of materials.
The artwork is intended to take its own path without the artist, directed by the community, and will "make time itself more concrete, more tangible".

### Artist

Manfred Laber was born in Wemding on 5 May 1932 and studied painting at the Hochschule für Bildende Künste in Berlin in the 1950s. He has other artwork on permanent display on the Isla San Antonio; in Alcanar, Spain; and Mormoiron, France. Alcanar was also his part-time place of residence. Laber died in Wemding on 17 August 2018, aged 86.

## Construction

The time pyramid is located on a concrete pad on a rounded hilltop, the Robertshöhe, on the northern edge of Wemding. The first block was placed in October 1993. The 6.5-tonne (6.4-long-ton; 7.2-short-ton) fourth and most recent block was placed at 15:06 on 9 September 2023. Following the construction schedule, the fifth block will be placed in 2033.
The project's initial financing was mostly achieved through donations by local companies, which, for example, supplied the materials for the concrete slab for free. The project is administered by a foundation based in Wemding.
A model of the final artwork is exhibited at Wemding, at the Haus des Gastes. If the time pyramid project proceeds according to plan, it will fall into four stages based on tier layer:
* The base layer, measuring 13.8 by 13.8 m (45 by 45 ft), will consist of 64 blocks arranged in 8 rows and 8 columns and has a stage completion date of 2623.
* The second layer will consist of 36 blocks, in a 6-by-6 format with a stage completion date of 2983. This is the first layer that requires a block to be placed atop another block, which would require a crane or some form of scaffolding such as an earthen ramp used as an incline, although, by at least 2023, placement was already using a crane.
* The third layer will consist of 16 blocks arranged in a 4-by-4 format with a stage completion date of 3143.
* The final, fourth layer will consist of 4 blocks, arranged in a 2-by-2 format, which upon completion will complete the structure. The completed pyramid will have taken just shy of a decade less to build than Wemding's age at the time that the first block was laid.
The pyramid, when completed in the year 3183, is scheduled to consist of 120 stone or concrete blocks, each measuring 1.2 m (3.9 ft) long, 1.2 m (3.9 ft) wide and 1.8 m (5.9 ft) tall. Adjacent blocks are separated by gaps of half a block or 0.6 m (2.0 ft).

### Longevity of concrete

Unlike ancient human structures such as the Great Pyramid of Giza—which is made from limestone, mortar, and granite, and which has lasted more than 4500 years—the lifespan of reinforced concrete and regular blocks of concrete is typically only 50–100 years. However, concrete blocks can last indefinitely when properly maintained or weatherproofed.

### Off-by-one error

According to YouTuber Matt Parker, the Zeitpyramide has a mathematical issue known as the "picket fence error". For a picket fence of n elements, n + 1 posts are required. The error arises because the project started with the placement of the first block in 1993, rather than waiting for the first decade to pass. This means the pyramid will be completed in 3183, which is only 1,190 years from the start date, not 1,200 as was promised. Parker pointed out this error during his visit to the placement of the fourth block in 2023. He also proposed an alternative design that would take 121 blocks to complete. His design is not a pyramid and would be 19.8 meters tall.

## Construction schedule

| Block number | Date placed | Tier | Notes |
| – | between July 1993 and 23 October 1993 | N/A | This is the concrete pad of the Zeitpyramide. Local donations supplied the materials for the concrete slab for free in early 1993. |
| 1 | 23 October 1993 | First tier | The first block placed, and the only block to be placed during the 20th century. |
| 2 | 15:58, 6 September 2003 | First tier | The first block to be placed during the 21st century. |
| 3 | 16:14, 29 June 2013 | First tier | The last block to be placed before the death of Manfred Laber. |
| 4 | 15:06, 9 September 2023 | First tier | The latest block to have been placed, and also the first block whose placement was live-streamed. Also the first block placed after the death of Manfred Laber in 2018. |
| 5 | 2033 | First tier | The next block scheduled to be placed. |
| 6 | 2043 | First tier | |
| 7 | 2053 | First tier | |
| 8 | 2063 | First tier | The last block to be placed on the first row. |
| 9 | 2073 | First tier | |
| 10 | 2083 | First tier | |
| 11 | 2093 | First tier | The last block scheduled to be placed during the 21st century. Block 11 also marks 100 years since Block 1 was placed. |
| 64 | 2623 | First tier | The last block scheduled to be placed within the first tier. |
| 65 | 2633 | Second tier | The first block scheduled to be placed within the second tier, and the first block which is assumed to require scaffolding. |
| 100 | 2983 | Second tier | The last block scheduled to be placed within the second tier. |
| 116 | 3143 | Third tier | The last block scheduled to be placed within the third tier. |
| 119 | 3173 | Fourth tier | The penultimate block scheduled to be placed. |
| 120 | 3183 | Fourth tier | The last block scheduled to be placed during the 32nd century, the last block to be placed within the fourth tier, and also the last block overall scheduled to be placed. Block 120 also marks 1,190 years since Block 1 was placed. |