The Bedford Level experiment was a series of observations carried out along a 6-mile (10 km) length of the Old Bedford River on the Bedford Level of the Cambridgeshire Fens in the United Kingdom.
Percobaan Bedford Level adalah serangkaian pengamatan yang dilakukan di Sungai Old Bedford sepanjang enam-mil (9,7 km) di Bedford Level, Cambridgeshire Fens, Britania Raya, pada abad ke-19 dan awal abad ke-20 untuk mengukur lengkung Bumi.
Samuel Birley Rowbotham, who conducted the first observations starting in 1838, claimed that he had proven the Earth to be flat.
Samuel Birley Rowbotham melakukan pengamatan pertama pada tahun 1838 dan mengklaim bahwa ia membuktikan Bumi itu datar.
However, in 1870, after adjusting Rowbotham's method to allow for the effects of atmospheric refraction, Alfred Russel Wallace found a curvature consistent with a spherical Earth.
Namun demikian, pada tahun 1870, setelah memperbaiki metode Rowbotham agar tidak dipengaruhi efek pantulan atmosfer, Alfred Russel Wallace menemukan bahwa lengkungan yang diamatinya konsisten dengan prinsip Bumi bulat.
At the point chosen for all the experiments, the river is a slow-flowing drainage canal running in an uninterrupted straight line for a 6-mile (10 km) stretch to the north-east of the village of Welney.
Sungai yang dipilih untuk semua percobaan adalah kanal drainase berarus lambat membentang lurus tanpa hambatan sepanjang enam-mil (9,7 km) ke timur laut desa Welney.
In the second mile the fall will be 32 inches; in the third mile, 72 inches, or 6 feet, as shown in the following diagram: ...
Di mil kedua, deklinasi mencapai 32 inci, di mil ketiga, 72 inci, atau 6 kaki, seperti yang ditunjukkan di diagram berikut ini: ...
The first experiment at this site was conducted by Rowbotham in the summer of 1838.
Rowbotham melakukan percobaan pertama di tempat ini pada musim panas 1838.
He waded into the river and used a telescope held 8 inches (20 cm) above the water to watch a boat, with a flag on its mast 3 feet (0.9 m) above the water, row slowly away from him.
Ia berdiri di dasar sungai sambil memegang teleskop delapan inci (20 cm) di atas air untuk melihat kapal yang mengibarkan bendera putih tiga kaki (0,91 m) di atas air dan pelan-pelan berlayar menjauhi dirinya.
He published this observation using the pseudonym Parallax in 1849 and subsequently expanded it into a book, Earth Not a Globe published in 1865.
Ia menulis pengamatannya dengan nama samaran Parallax pada tahun 1849 dan mengembangkannya menjadi sebuah buku, Earth Not a Globe, yang terbit tahun 1865.
Despite Hampden initially refusing to accept the demonstration, Wallace was awarded the bet by the referee, John Henry Walsh, editor of The Field sports magazine.
Meski Hampden awalnya menolak menerima demonstrasi ini, Wallace dinyatakan sebagai pemenang oleh wasit taruhan, penyunting majalah olahraga The Field.
Hampden subsequently published a pamphlet alleging that Wallace had cheated, and sued for his money.
Hampden kemudian menerbitkan selebaran yang menuduh bahwa Wallace curang dan menuntut uangnya kembali.
Wallace, who had been unaware of Rowbotham's earlier experiments, was criticized by his peers for "his 'injudicious' involvement in a bet to 'decide' the most fundamental and established of scientific facts".
Wallace, tidak tahu bahwa percobaan yang sama pernah dilakukan Rowbotham, dikritik oleh rekan-rekannya karena "'mau saja' terlibat taruhan untuk 'memutuskan' fakta ilmiah yang paling dasar dan banyak buktinya".
In 1901, Henry Yule Oldham, a reader in geography at King's College, Cambridge, reproduced Wallace's results using three poles fixed at equal height above water level.
Pada tahun 1901, Henry Yule Oldham, seorang pakar geografi di King's College, Cambridge, mengulang percobaan Wallace menggunakan tiga tiang yang ditancapkan dengan ketinggian sama di atas permukaan air.
On 11 May 1904 Lady Elizabeth Anne Blount, who was later influential in the formation of the Flat Earth Society, hired a commercial photographer to use a telephoto-lens camera to take a picture from Welney of a large white sheet she had placed, the bottom edge near the surface of the river, at Rowbotham's original position 6 miles (10 km) away.
Namun, pendukung Bumi datar tidak dikalahkan: Pada tanggal 11 Mei 1904, Lady Elizabeth Anne Blount, kelak menjadi pelopor Perkumpulan Bumi Datar, mengontrak seorang fotografer komersial untuk mengambil gambar kertas putih besar yang diletakkan di permukaan sungai, di lokasi percobaan Rowbotham, menggunakan kamera lensa telefoto berjarak enam mil (9,7 km) dari Welney.
The photographer, Edgar Clifton from Dallmeyer's studio, mounted his camera 2 feet (0.6 m) above the water at Welney and was surprised to be able to obtain a picture of the target, which he believed should have been invisible to him, given the low mounting point of the camera.
Sang fotografer, Edgar Clifton dari studio Dallmeyer, meletakkan kameranya dua kaki di atas air di Welney dan terkejut karena ia dapat mengambil gambar targetnya, padahal seharusnya tidak terlihat karena kamera diletakkan di ketinggian rendah.
These controversies became a regular feature in the English Mechanic magazine in 1904–05, which published Blount's photo and reported two experiments in 1905 that showed the opposite results.
Kontroversi-kontroversi ini menjadi artikel rutin di majalah English Mechanic edisi tahun 1904–5 yang menerbitkan foto Blount dan melaporkan dua percobaan tahun 1905 yang menunjukkan hasil sebaliknya.
On 25 July 1896, Ulysses Grant Morrow, a newspaper editor, conducted a similar experiment on the Old Illinois Drainage Canal, Summit, Illinois.
Pada tanggal 25 Juli 1896, Ulysses Grant Morrow, seorang penyunting surat kabar, melakukan percobaan serupa di Old Illinois Drainage Canal, Summit, Illinois.
Unlike Rowbotham, he was seeking to demonstrate that the surface of the Earth was curved: when he too found that his target marker, 18 inches (46 cm) above water level and 5 miles (8 km) distant, was clearly visible, he concluded that the Earth's surface was concavely curved, in line with the expectations of his sponsors, the Koreshan Unity society.
Ketika ia melihat bahwa penanda targetnya, 18 inci (46 cm) di atas permukaan air dan berjarak lima mil (8,0 km), terlihat jelas, ia menyimpulkan bahwa permukaan Bumi melengkung cekung seperti yang diharapkan para sponsornya, perkumpulan Koreshan Unity.