# What is the worst single factual mistake ever made by one person? **URL:** \ **Category:** In My Humble Opinion\ **Created:** [November 10, 2014, 7:29am UTC](https://boards.straightdope.com/t/what-is-the-worst-single-factual-mistake-ever-made-by-one-person/704221 "2014-11-10T07:29:05Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![chappachula](https://avatars.discourse-cdn.com/v4/letter/c/d2c977/32.png) [@chappachula](https://boards.straightdope.com/u/chappachula)\ **Post date:** [November 10, 2014, 7:29am UTC](https://boards.straightdope.com/t/what-is-the-worst-single-factual-mistake-ever-made-by-one-person/704221/1 "2014-11-10T07:29:05Z")
(And please don’t tell me about your marriage. 🙂 ) I’m interested in cases where one person made one mistake; A simple, factual mistake which could easily have been prevented with a little care, and which had huge consequences because the person was not careful. One example is the scientist who ruined the Hubble space telescope because he made a calculation using the right numbers, but didn’t bother to notice that they were in milimeters, not inches. What others? Please note: I’m asking about mistaken _facts_, not mistaken decisions. (For example, in 1938 Prime Minister “Peace-in-our-time” Chamberlain made a terrible mistake in judgement. But that’s not my question) ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [November 10, 2014, 7:35am UTC](https://boards.straightdope.com/t/what-is-the-worst-single-factual-mistake-ever-made-by-one-person/704221/2 "2014-11-10T07:35:55Z")
This won’t place anywhere near the top of your list (in terms of badness), but the [Gimli Gilder](http://en.wikipedia.org/wiki/Gimli_Glider) is still a good one. There were lots off issues surrounding the incident, but ultimately it came down to an incorrect conversion between kilograms and pounds. The airplane ended up with half the fuel it needed to reach its destination and ran out mid-air. Fortunately, it glided to a safe landing at a semi-abandoned runway. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [November 10, 2014, 7:42am UTC](https://boards.straightdope.com/t/what-is-the-worst-single-factual-mistake-ever-made-by-one-person/704221/3 "2014-11-10T07:42:18Z")
Also, I’m not quite sure if these fit your definition of a factual error, but there have been quite a few stock trading errors (sometimes called “fat finger” errors). There [was one recently](http://www.independent.co.uk/news/business/news/tokyo-trader-makes-spectacular-381bn-fat-finger-error-9767506.html): _Share trades worth more than the size of Sweden’s economy had to be cancelled in Tokyo after what is believed to be the biggest “fat finger” error on record. … Mistaken orders for shares in 42 major Japanese companies, including household names such as Toyota, Honda, Canon and Sony, totalling ¥67.78trn (£381bn) were overturned, according to data from the Japan Securities Dealers Association._ The article doesn’t mention the actual source of the error, but it does cite this smaller one from a while back: \*In 2005 a Japanese trader tried to sell one share of an employment recruitment company called J:COM, at a price of ¥610,000 per share. However, he accidentally sold 610,000 shares at one yen each, despite this being 41 times the number of J:COM’s available shares.\* Oops. Still, these tend not to be all that disastrous since they get rolled back quickly. ---
**Author:** ![Donnerwetter](https://avatars.discourse-cdn.com/v4/letter/d/b2d939/32.png) [@Donnerwetter](https://boards.straightdope.com/u/Donnerwetter)\ **Post date:** [November 10, 2014, 8:09am UTC](https://boards.straightdope.com/t/what-is-the-worst-single-factual-mistake-ever-made-by-one-person/704221/4 "2014-11-10T08:09:09Z")
[The Gimli Glider](http://en.wikipedia.org/wiki/Gimli_Glider) > [@](#): > > The Gimli Glider is the nickname of an Air Canada aircraft that was involved in an unusual aviation incident. On July 23, 1983, Air Canada Flight 143, a Boeing 767-233 jet, ran out of fuel at an altitude of 41,000 feet (12,000 m) MSL, about halfway through its flight originating in Montreal to Edmonton. The crew were able to glide the aircraft safely to an emergency landing at Gimli Industrial Park Airport, a former Royal Canadian Air Force base in Gimli, Manitoba.[1] > > The subsequent investigation revealed a combination of company failures and a chain of human errors that defeated built-in safeguards. Fuel loading was miscalculated due to a misunderstanding of the recently adopted metric system which replaced the imperial system. ---
**Author:** ![Peter\_Morris](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/peter_morris/32/359_2.png) [@Peter\_Morris](https://boards.straightdope.com/u/Peter_Morris)\ **Post date:** [November 10, 2014, 8:22am UTC](https://boards.straightdope.com/t/what-is-the-worst-single-factual-mistake-ever-made-by-one-person/704221/5 "2014-11-10T08:22:18Z")
The guy who gave Archduke Franz Ferdinand’s driver the wrong instructions. \*After a short rest at the Governor’s residence, the royal couple insisted on seeing all those who had been injured by the bomb at the local hospital. However, no one told the drivers that the itinerary had been changed. When the error was discovered, the drivers had to turn around. As the cars backed down the street and onto a side street, the line of cars stalled. At this same time, Princip was sitting at a cafe across the street. He instantly seized his opportunity and walked across the street and shot the royal couple. \* > **[Archduke Franz Ferdinand of Austria | Assassination](https://en.wikipedia.org/wiki/Archduke_Franz_Ferdinand_of_Austria#Assassination)** > > On Sunday, 28 June 1914, at about 10:45 am, Franz Ferdinand and his wife were assassinated in Sarajevo, the capital of the Austro-Hungarian province of Bosnia and Herzegovina. The perpetrator was 19-year-old Gavrilo Princip, a member of Young Bosnia and one of a group of assassins organized and armed by the Black Hand. > Earlier in the day, the couple had been attacked by Nedeljko Čabrinović, also a Young Bosnia conspirator, who had thrown a grenade at their car. However, the bomb detonated behind... ---
**Author:** ![panache45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/panache45/32/64_2.png) [@panache45](https://boards.straightdope.com/u/panache45)\ **Post date:** [November 10, 2014, 8:29am UTC](https://boards.straightdope.com/t/what-is-the-worst-single-factual-mistake-ever-made-by-one-person/704221/6 "2014-11-10T08:29:23Z")
Colin Powell and Iraq’s WMDs. ---
**Author:** ![madmonk28](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/madmonk28/32/20811_2.png) [@madmonk28](https://boards.straightdope.com/u/madmonk28)\ **Post date:** [November 10, 2014, 8:34am UTC](https://boards.straightdope.com/t/what-is-the-worst-single-factual-mistake-ever-made-by-one-person/704221/7 "2014-11-10T08:34:24Z")
But that wasn’t a single mistake, rather a series of mistakes, unless you feel that Powell alone is responsible for the Iraq war? ---
**Author:** ![cochrane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cochrane/32/10441_2.png) [@cochrane](https://boards.straightdope.com/u/cochrane)\ **Post date:** [November 10, 2014, 8:50am UTC](https://boards.straightdope.com/t/what-is-the-worst-single-factual-mistake-ever-made-by-one-person/704221/8 "2014-11-10T08:50:37Z")
The [Mars Climate Observer.](http://www.wired.com/2010/11/1110mars-climate-observer-report/) It burned up in the Martian atmosphere 15 years ago today, November 10, 1999, because NASA failed to properly convert standard units of measurement into metric. ---
**Author:** ![Jeff\_Lichtman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jeff_lichtman/32/1531_2.png) [@Jeff\_Lichtman](https://boards.straightdope.com/u/Jeff_Lichtman)\ **Post date:** [November 10, 2014, 9:20am UTC](https://boards.straightdope.com/t/what-is-the-worst-single-factual-mistake-ever-made-by-one-person/704221/9 "2014-11-10T09:20:51Z")
> [@chappachula](#): > > One example is the scientist who ruined the Hubble space telescope because he made a calculation using the right numbers, but didn’t bother to notice that they were in milimeters, not inches. That’s not what caused the problem with the Hubble telescope. You’re probably thinking of the error that caused the Mars Climate Orbiter, as **cochrane** mentioned. The problem with the Hubble telescope was due to a testing device having been assembled incorrectly, causing a mirror to be ground into the wrong shape. ---
**Author:** ![Kevbo](https://avatars.discourse-cdn.com/v4/letter/k/e47774/32.png) [@Kevbo](https://boards.straightdope.com/u/Kevbo)\ **Post date:** [November 10, 2014, 9:25am UTC](https://boards.straightdope.com/t/what-is-the-worst-single-factual-mistake-ever-made-by-one-person/704221/10 "2014-11-10T09:25:28Z")
> [@chappachula](#): > > One example is the scientist who ruined the Hubble space telescope because he made a calculation using the right numbers, but didn’t bother to notice that they were in milimeters, not inches. The above is factually incorrect. The Hubble debacle was due to omitting one spacer that positioned a lens for the Ross null test used with the interferometer to test the mirror. The spacer was omitted when the test rig was moved from a secure area (Spy satellites??) to a non-secure area. Interferometry allows fantastically precise measurements. Part of the failure was due to the common assumption that high precision measurements are as accurate as they are precise. A very crude test (Foucault knife edge test) used by amateur telescope makers would have detected the error. It requires only a flashlight, a pinhole, and a razor blade. There would have been a temptation to keep the Ross null lens when doing the knife edge test, though, which would have given an identical error. Cheap, low tech Coudrè masks would have pointed out the problem, but the opticians would have has to trust the cheap, crude, old fashioned equipment over the spiffy expensive modern instrument. ---
**Author:** ![Donnerwetter](https://avatars.discourse-cdn.com/v4/letter/d/b2d939/32.png) [@Donnerwetter](https://boards.straightdope.com/u/Donnerwetter)\ **Post date:** [November 10, 2014, 10:09am UTC](https://boards.straightdope.com/t/what-is-the-worst-single-factual-mistake-ever-made-by-one-person/704221/11 "2014-11-10T10:09:28Z")
Here’s [another space-related incident](http://en.wikipedia.org/wiki/TV-SAT_1). It occurred in 1987: > [@](#): > > TV-SAT 1 was launched by Arianespace using an Ariane 2 rocket flying from ELA-1 at Kourou. The launch took place at 02:19:00 GMT on 21 November 1987.[2] It was the first Spacebus 300 satellite to be launched. Immediately after launch, one of its solar panels failed to deploy, and as a result of this the main uplink antenna, which was located behind the solar panel, could not deploy either.[3] This failure was later established to have been the result of two hold-down bolts,[4] which should have been removed prior to launch, being left on the satellite.[3] What happened is that a technician actually did remove the hold-down bolts which were used for shipping the satellite from Germany to French Guiana and exchanged them for the type of bolts to be used during operation of the satellite in space. However, this technician put the transit bolts he had just removed into the plastic bag that came with the bolts to be used in space and then went home. The next day, a different crew member started his shift and saw the plastic bag which he believed contained the operational bolts. He concluded that the correct bolts hadn’t yet been installed, so he removed the operational bolts and reinstalled the transit bolts. The satellite subsequently was launched, and lo and behold, the solar panel wouldn’t deploy. The result was a brand new piece of space junk worth several hundreds of millions of dollar. ---
**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\ **Post date:** [November 10, 2014, 11:19am UTC](https://boards.straightdope.com/t/what-is-the-worst-single-factual-mistake-ever-made-by-one-person/704221/12 "2014-11-10T11:19:05Z")
Thomas Midgley made not one but two, probably the worst errors in the history of the Earth. He was the inventor who put lead in petrol and CFCs in fridges. > [@](#): > > Thomas Midgley, Jr. (May 18, 1889 – November 2, 1944) was an American mechanical engineer and chemist. He was a key figure in a team of chemists, led by Charles F. Kettering, that developed the tetraethyllead (TEL) additive to gasoline as well as some of the first chlorofluorocarbons (CFCs). ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [November 10, 2014, 11:35am UTC](https://boards.straightdope.com/t/what-is-the-worst-single-factual-mistake-ever-made-by-one-person/704221/13 "2014-11-10T11:35:19Z")
> [@Dr.Strangelove](#): > > This won’t place anywhere near the top of your list (in terms of badness), but the [Gimli Gilder](http://en.wikipedia.org/wiki/Gimli_Glider) is still a good one. Fictional dwarfs should never be allowed to cover things in gold leaf!:mad: ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [November 10, 2014, 1:13pm UTC](https://boards.straightdope.com/t/what-is-the-worst-single-factual-mistake-ever-made-by-one-person/704221/14 "2014-11-10T13:13:04Z")
One of the Viking mars landers was shut down because someone sent a program update that accidentally told it to shut itself off. ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [November 10, 2014, 1:39pm UTC](https://boards.straightdope.com/t/what-is-the-worst-single-factual-mistake-ever-made-by-one-person/704221/15 "2014-11-10T13:39:31Z")
> [@panache45](#): > > Colin Powell and Iraq’s WMDs. > [@madmonk28](#): > > But that wasn’t a single mistake, rather a series of mistakes, unless you feel that Powell alone is responsible for the Iraq war? Don’t want to turn this into a political rehash, but… More likely, much of the current mess in Iraq was due to the decision (not Colin’s) to fire the top hierarchy of the Iraq government, including all the army and police; they were also forbidden to take part in the replacement government if a member of the Baath party. I believe that was Paul Bremer’s call. After all, if you were educated, if you wanted a career in government or the military, you pretty much had to go through the motions of joining the party, much like the Communist bloc. Bremer effectively unemployed and sidelined the people most able to run the country, including those who had military and explosives training and knew where the weapons of conventional destruction were stored. Meanwhile the police who knew who were the criminals and troublemakers also got the boot. Since the majority of those booted were Sunnis and the replacements were Shiites, it also set in motion the simmering civil war that is still going today. ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [November 10, 2014, 1:57pm UTC](https://boards.straightdope.com/t/what-is-the-worst-single-factual-mistake-ever-made-by-one-person/704221/16 "2014-11-10T13:57:49Z")
Not sure if this counts as a “single failure,” but a failure of the O-rings in the Space Shuttle Challenger’s rocker booster assembly took the lives of seven astronauts. Not sure if it was ultimately due to incorrect specifications or faulty testing. > **[Rogers Commission Report](https://en.wikipedia.org/wiki/Rogers_Commission_Report)** > > The Rogers Commission Report was written by a Presidential Commission charged with investigating the Space Shuttle Challenger disaster during its 10th mission, STS-51-L. The report, released and submitted to President Ronald Reagan on June 9, 1986, both determined the cause of the disaster that took place 73 seconds after liftoff, and urged NASA to improve and install new safety features on the shuttles and in its organizational handling of future missions. > The commission found that the immedi... ---
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [November 10, 2014, 2:31pm UTC](https://boards.straightdope.com/t/what-is-the-worst-single-factual-mistake-ever-made-by-one-person/704221/17 "2014-11-10T14:31:54Z")
The Union Carbide / Dow - [Bhopal Gas Tragedy](http://en.wikipedia.org/wiki/Bhopal_disaster) . 8,000 died within two weeks and another 8,000 or more have since died from gas-related diseases. The factual mistake was in line sizing for the safety system (although a tragedy of this scale has several explanations / causes / conspiracy theories). ---
**Author:** ![GreasyJack](https://avatars.discourse-cdn.com/v4/letter/g/df705f/32.png) [@GreasyJack](https://boards.straightdope.com/u/GreasyJack)\ **Post date:** [November 10, 2014, 2:58pm UTC](https://boards.straightdope.com/t/what-is-the-worst-single-factual-mistake-ever-made-by-one-person/704221/18 "2014-11-10T14:58:32Z")
Columbus’ first voyage (which of course led to the deaths of millions and millions of native peoples) was essentially based on a Mars Climate Observer-style unit conversion error which led him to underestimate the circumference of the Earth and thus the distance west to Asia. ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [November 10, 2014, 2:59pm UTC](https://boards.straightdope.com/t/what-is-the-worst-single-factual-mistake-ever-made-by-one-person/704221/19 "2014-11-10T14:59:39Z")
**Marley**? ---
**Author:** ![AK84](https://avatars.discourse-cdn.com/v4/letter/a/85e7bf/32.png) [@AK84](https://boards.straightdope.com/u/AK84)\ **Post date:** [November 10, 2014, 3:00pm UTC](https://boards.straightdope.com/t/what-is-the-worst-single-factual-mistake-ever-made-by-one-person/704221/20 "2014-11-10T15:00:03Z")
Charge of the Light Brigade, misinterpretation of orders. Soyuz 11, was the cause ever determined as to why the valve failed? [Next page](https://boards.straightdope.com/t/what-is-the-worst-single-factual-mistake-ever-made-by-one-person/704221.md?page=2)