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85 votes
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Why does Japan use the same type of AC power outlet as the US?

Japanese AC power outlets were first standardised in 1926 with the publication of the "挿込型接続器標準仕様書" (lit., "Standard for a Insertable Connector"), which became JIS C 8303. At the time, Japan was ...
Semaphore's user avatar
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69 votes

Why are so many metros underground? Isn't that more expensive than an elevated system?

In Moscow, under former mayor Yuriy Luzhkov, it was built a line (Butovo line) which is mostly elevated. I think the practice was not considered quite successful as a result. There are many drawbacks: ...
Anixx's user avatar
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59 votes
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Why does the Great Wall of China follow such a bendy route?

The Chinese designed the wall to be an effective barrier; that was the goal. To answer your question, we need to ask: what land barrier stopped foreign troops the best? The answer in China, and ...
Astor Florida's user avatar
57 votes

Why are so many metros underground? Isn't that more expensive than an elevated system?

This is mostly about urban planning, and how much change the local government can or will be able to make to the existing streets. In London, the central parts of the city (Westminster and the City) ...
Carmi's user avatar
  • 3,312
37 votes

Why are most of the world's oldest buildings in Europe and not in the Fertile Crescent?

If you look at the details of the oldest buildings on your list, all of them are built from fieldstone or minimally-shaped quarried stone. Further, the building materials were either found on-site or ...
Mark's user avatar
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30 votes

Why are so many metros underground? Isn't that more expensive than an elevated system?

For New York, the answer is related to real estate value. In New York City, the construction of the metro was performed by real estate developers. The idea was to build homes, then connect them to ...
Astor Florida's user avatar
29 votes

Why didn't pre-Norman English kings build stone town walls?

They did. The Anglo-Saxons still used fortified areas and cities or towns, re-used old ones and build them anew. It just takes a bit of time, effort and money to develop those walls and fortifications,...
LаngLаngС's user avatar
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25 votes
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What is the oldest road tunnel in the world?

There is a tunnel under a mountain in Samos built around 530 BC. It is described by Herodotus, book III, 60. In 1882 a tunnel which matches Herodotus description has been actually found. It is one ...
Alex's user avatar
  • 38.8k
21 votes

Why are most of the world's oldest buildings in Europe and not in the Fertile Crescent?

Actually, some of the oldest known man-made structures are in the Fertile Crescent (FC). The list in your question purposefully excludes sites like Göbekli Tepe, Tell es-Sultan, and Tell Qaramel, each ...
Denis de Bernardy's user avatar
20 votes

Why does the Great Wall of China follow such a bendy route?

The Great Wall of China: It is the longest man-made construction in the world. In the old times, it was of great military importance of preventing the enemies' intrusion and was regarded as the '...
Ken Graham's user avatar
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18 votes
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How long would it take to build 30 miles of Roman road?

Tough to narrow this down, but at least a couple sources make what may be a useful comparison to more recent construction of Scottish military roads in the 1700s. from The Secret History of the ...
justCal's user avatar
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18 votes
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Why didn't pre-Norman English kings build stone town walls?

Pre-Norman English (or Anglo-Saxons) didn't build primarily in stone for their town defenses because a) it would have been prohibitively expensive; b) it would have required much more time than they ...
gktscrk's user avatar
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15 votes
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When during their construction did Bible-era Jewish temples become "holy"?

The point at which The Temple became holy would be from its dedication forward. The Temple was rebuilt a few times. Below is the dedication for the first temple. 1 Kings chapter 8 gives a description ...
David D's user avatar
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14 votes
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What is the purpose of the iron structures seen on the sides of many WW2 flak towers?

These Flak-towers are imposing structures, but rare. The two pieces depicted are only to be found in Vienna. The towers in Berlin didn't have them, and those in Hamburg neither. Only the last two of ...
LаngLаngС's user avatar
  • 80.9k
13 votes

Has the U.S. Navy ever commissioned the building of a warship overseas?

In the mid 1920s the Navy commissioned the construction of several ships for the Asiatic Fleet based on the Yangtze. The ships were built by the Kiangnan Dock and Engineering Works, in Shanghai, ...
ed.hank's user avatar
  • 6,685
13 votes

What is the oldest road tunnel in the world?

There appear to be two candidates which can definitely be considered for oldest road tunnel in the world, and a couple of others which are older but may be disputed. Roughly in chronological order, ...
Lars Bosteen's user avatar
13 votes

Why are most of the world's oldest buildings in Europe and not in the Fertile Crescent?

It's not just Europe but even narrower. You'll notice the top 3 listed are all in France. Of the rest of the top 10, 4 are in the British Isles. I think Mark has about half of the answer: These ...
T.E.D.'s user avatar
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11 votes
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Is a wheel older than a wall?

No, wheels are not older than walls. Walls (as in city walls, designed to protect a group of people) have been discovered at Jericho, and dated to c 8000 BCE. The earliest walls of any kind that we ...
sempaiscuba's user avatar
  • 77.4k
11 votes

Why are so many metros underground? Isn't that more expensive than an elevated system?

Noise, vibrations, and visual impact drop the value of the nearest houses, and decrease quality of life for its inhabitants. The maintenance of an elevated system is expensive, not only economically ...
Vicente J. Bailén Jonker's user avatar
11 votes

Why does Japan use the same type of AC power outlet as the US?

This answers primarily the first version of the question that is still evidenced in the misconception of the title, and thus the rest of this answer is still relevant to read in conjunction with ...
LаngLаngС's user avatar
  • 80.9k
11 votes

Is there evidence of a pagan temple on the site of the Jewish Temple in Jerusalem that predated the Jewish Temple?

No real evidence, but the area was populated by Pagans prior to 957 BC when David's son Solomon built the first temple. According to the Smithsonian Magazine in What Is Beneath the Temple Mount?; ...
Seabas's user avatar
  • 111
10 votes

Why are so many metros underground? Isn't that more expensive than an elevated system?

Quite often subway lines are built to relieve traffic pressure on areas where there is no room to add more roads, including the towers needed to allow for the creation of elevated roads or railways. ...
jwenting's user avatar
  • 11.3k
9 votes

When during their construction did Bible-era Jewish temples become "holy"?

Actually, in Jewish law, non-high priests are allowed in the Holy of Holies not only during the original construction, but when renovations or repairs are needed. Maimonides, in his code of Jewish law ...
Meir's user avatar
  • 1,275
8 votes

Why are most of the world's oldest buildings in Europe and not in the Fertile Crescent?

Civilisations not only build buildings, but destroy and reuse them. Many ruins were effectively used as quarries by local people and stones, e.g. bricks from Roman buildings ended up in an early ...
user2414208's user avatar
7 votes

Why are so many metros underground? Isn't that more expensive than an elevated system?

I can add that Washington DC is still expanding its Metro and the expansion is not underground. The newest line is the Silver Line, and as it goes through Tysons Corner it's almost entirely elevated. ...
Wayne's user avatar
  • 171
6 votes

How close did the French come to digging a canal across the Isthmus of Kra in the 1880s?

tl; dr How close did the French actually come to succeeding at getting the project underway? The project never came close to getting underway. The route chosen for the survey proved to be ...
sempaiscuba's user avatar
  • 77.4k
6 votes

How long would it take to build 30 miles of Roman road?

I don't know if this helps: but the Via Appia between Rome and Capua was built in 4 years (312 - 308 BC) The distance is disputed but was more than 100 miles. See EngineeringRome.org
jemg's user avatar
  • 61
6 votes
Accepted

How did medieval architects determine sizes and numbers of pillars, buttresses etc?

How did medieval architects determine sizes and numbers of pillars, buttresses etc? Mostly, by use of scale models, chalk floor drawings, and elaborate simulations of beam loading constructed by ...
Pieter Geerkens's user avatar
5 votes

Did anyone ever try to beat the Great Wall of China by digging secret tunnels under it?

Most of the Great Wall was never assaulted and was more symbolic than anything. Most of the rest only ever had to deal with small groups of roving/semi-nomadic brigands, not organised armies. And to ...
jwenting's user avatar
  • 11.3k
5 votes

Has the U.S. Navy ever commissioned the building of a warship overseas?

The US Navy has occasionally purchased existing ships that meet a specific need. As Eric Urban notes, US law requires the navy to use US yards for commissioned vessels, unless the president issues a ...
tj1000's user avatar
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