What are the notorious software bugs that have been named in history?

1, the mother of all "bugs", left a name in history.

(The first bug in software history)

1947 At 3: 45pm on September 9th, Grace Murray Huo Po wrote down the first computer bug in history, a moth found in Harvard Mark II's computer. She wrote this kind of moth in her diary and wrote "the first real case of finding this kind of bug". This discovery established the position of the word Bug in the computer world, and also made it a nightmare for countless programmers. From then on, the word Bug indicates errors or omissions in computer programs in the computer world, which will make the program calculate inexplicable results and even lead to program collapse. Grace Murray Hopper is one of the earliest programmers in history, and she is also a female programmer. She served in the United States Navy, from officer to brigadier general.

This is the most popular story about computer Bug, but the historical truth is that the word Bug was widely used to refer to machine failure as early as the inventor Thomas Edison's time, which can also be seen in Edison's own notes 1870 or so. IEEE of the Institute of Electrical and Electronics Engineers also attributed the introduction of the word Bug to Edison.

2, the Millennium bug, the carnival of hype.

(1999 gives grandstanding magazines and tabloids an excellent theme)

In the last century, the software industry never thought that their code and products would enter the new millennium. Therefore, in order to save memory, many software companies omit the first two digits of the year "19" or default the first two digits to "19".

As the calendar approaches 1 99965438+February 3 1, people are increasingly worried that everyone's computer system will crash on New Year's Eve of the Millennium, because the system date will be updated to 1900 1 instead of1in 2000.

Today we can joke about this funny story, because the nuclear missile didn't launch automatically, the plane didn't fall out of control, and the bank didn't lose a lot of deposits of the country and users.

Y2K is real, and the world has spent hundreds of millions of dollars to upgrade the system. In addition, there were some minor accidents:

In Spain, the parking meter is broken; Announced by the French Meteorological Bureau1000+on October1Weather forecast1965438+65438; In Australia, the bus ticket checking system collapsed. That's all. As a result of the final inventory, software companies made a fortune, tabloid sales increased greatly, many programmers' Millennium party fell through, and several illiterate old ladies in China were cheated of their pensions, which is not serious.

3. The Dhahran missile incident, millisecond error.

In the first Gulf War in February 199 1, an Iraqi-launched Scud missile accurately hit the American base in Dharam, Saudi Arabia, causing 28 American soldiers to die on the spot and more than1000 injured, resulting in the loss of more than1000 casualties in the only Gulf War in the United States.

In the later investigation, it was found that due to a simple computer bug, the Patriot anti-missile system at the base failed to intercept Scud missiles in the air. At that time, the Patriot anti-missile system responsible for defending the base had been working continuously 100 hours. Every working hour, the clock in the system will have a slight millisecond delay, which is the root of this failure tragedy. The clock register of Patriot anti-missile system is designed to be 24 bits, so the time accuracy is limited to 24 bits. After working for a long time, this tiny precision error gradually enlarges. After working 100 hours, the system time is delayed by one third of a second.

For the average person, 0.33 seconds can be ignored. But for a radar system that needs to track and destroy air missiles, this is disastrous-the air speed of Hussain Scud missiles reaches Mach 4.2 (1.5km/s), which is a "negligible" 0.33s equivalent to an error of about 600m. In the missile incident in Dhahran, the radar found the missile in the air, but the anti-missile of the base was not launched because the clock error could not be accurately tracked.

(Illustration of Dhahran missile incident)

4. Is it meters or feet? Interstellar travel of Mars climate explorers

Mars climate probe was launched in 1997 to study the Martian climate, but it failed to achieve this task costing more than 300 million dollars.

After flying in space for several months, Explorer finally disintegrated in the atmosphere of Mars due to navigation errors. The control team of the detector uses English units to send navigation instructions, while the software system of the detector uses metric units to read instructions. This error greatly changed the path of navigation control. Finally, the probe entered the low orbit of Mars (the error is about 100 km) and disintegrated under the excessive atmospheric pressure and friction of Mars.

(meters or feet? Deviation 100 km! )

Ariane 5 launch vehicle, expensive simple copy

Programmers must define the variables used in the program and the computer memory required by these variables, which is defined by bits.

The variable of 16 can represent the value between -32.768 and 32.767. What can a 64-bit variable represent? Values between 9.223.372.036.854.775.808 and 9.223.372.036.854.775.807.

1on June 4, 1996, after the first launch of Ariane -5 carrier rocket, the rocket began to deviate from its course and was finally forced to detonate and self-destruct. The whole process is only 30 seconds. Ariane 5 carrier rocket is developed on the basis of the previous generation of 4 rockets. In the No.4 rocket system, a horizontal velocity measurement value uses a variable of 16 and memory, because it has been repeatedly verified in the No.4 rocket system, and this value will not exceed the variable of 16, while the developer of the No.5 rocket simply copied this part of the program without verifying the value of the new rocket, resulting in fatal numerical overflow. After launch, this 64-bit variable with decimal point was converted into 16-bit variable without decimal point, which led to a series of errors, thus affecting all computers and hardware on the rocket and paralyzing the whole system, so we had to choose self-destruction, and 400 million dollars became a huge fireworks.

(Ariane No.5 fireworks costing $400 million, made by software bug)

Eggs: Windows 98 blue screen of death (Bill Gates witnessed the blue screen of the crash with the audience at the live exhibition of Windows 98).