You know, those generated by computers on weekdays (such as the Random() function) are all predictable pseudo-random numbers. If used to generate passwords, absolute security cannot be guaranteed.
As a result, researchers began to look for random numbers from nature, such as atmospheric noise, quantum mechanics, and cosmic microwave background radiation.
So how do bananas ensure the generation of true random numbers?
According to the little brother’s explanation, it is to first detect the decay of radioactive substances in bananas and then generate random numbers in the range of 0-255 after simple algorithm processing.
Wait a minute, something doesn’t seem, right? Bananas, radioactivity, radiation…
I’ve eaten bananas for more than 20 years, are you telling me this??
“The King of Radiation” in the Fruit World
After careful study, I found that bananas do have radiation, and they are not small.
In the fruit world, there is even the title of “King of Radiation”.
The core reason is that the potassium element rich in bananas is at work: 100g of bananas contain about 350 mg of potassium.
Currently naturally occurring potassium consists of three isotopes. Only a small fraction of the nuclei (about 0.015%), potassium-40, are radioactive.
These atoms decay spontaneously, releasing energy that separates electrons (beta rays) and gamma rays, which can damage biomolecules such as proteins or DNA, causing radiation sickness or cancer.
Based on this principle, it is determined that bananas belong to ionizing radiation, that is, nuclear radiation.
Well, the one listed by the WHO as a Class I carcinogen.
But don’t worry, to reach the true lethal dose, humans would need to eat 35 million bananas.
In addition, our body contains about 120g of potassium naturally, through metabolism, the potassium content will be maintained at a constant level.
It is not easy for potassium-40 to accumulate in the body.
In order to better popularize the radiation intensity to the public, physicists like to use it for comparison, so they have specially designed a term.
Banana equivalent dose, an informal unit used to describe the intensity of radiation.
The radiation dose of a banana = 0.0778 microsieverts (official unit of calculation);
Chest CT scan = equivalent dose of 70,000 bananas;
The maximum allowable radiation exposure of the nuclear power plant to the surrounding environment = the equivalent dose of 2500 bananas per year;
Yep, let’s refute this rumor.
Some friends may have seen this conclusion: the radiation of bananas is higher than that of mobile phones? !
In fact, the two are not comparable at all. One is ionizing radiation and the other is non-ionizing radiation.
The biggest difference between the two is whether the energy is high enough to cause changes at the atomic level, such as the separation of electrons.
Non-ionizing radiation, on the other hand, is the lower-energy radiation, which, while not enough to separate electrons from atoms or molecules, can make those molecules vibrate and generate heat. This is how microwave ovens work.
A banana + more than 300 yuan of hardware
This time I understand that bananas are a natural source of potassium-40 radiation.
Using the principle that the radioactive decay of potassium-40 is completely random, a true random number generator can be made.
If so, how is it done?
Simple. On the hardware, you only need to prepare an Arduino development board + a Geiger counter.
The two add up to only more than 300 pieces (about 40 yuan for the board and about 300 yuan for the counter).
The full name of the Geiger counter is the Geiger-Müller counter, which has been a counter dedicated to detecting the intensity of ionizing radiation since 1928.
The algorithm it involves is very simple, write a main loop, let the register add from 0 to n, and when n is equal to n, the register is reset to 0.
Once the decay of potassium-40 in the banana above the unit is detected to emit particles in the process, the main loop is suspended, the interrupt routine is executed, the last value in the register is returned as a random number, the register is then reset to 0, and the process continues cycle.
For example, we can add registers from 0 to 15 and represent these numbers in hexadecimal (0-15 is also 0-9, A-F), so two hexadecimal numbers can form a word The random number of the section, and finally you can get any number in the decimal range 0-255.
ps. A hexadecimal number such as 6F converted into a binary number is equal to 0110 1111, a total of 8 bits, and a byte is exactly equal to 8 bits of binary number.
This is how a banana random number generator was born.
In the past, in order to obtain real random numbers, a common practice was to convert random quantities generated by some natural physical phenomena into digital information.
Such as resistance thermal noise, avalanche effect in semiconductor, circuit chaotic effect, etc.
Others use even more complex quantum phenomena, such as shot noise, the photoelectric effect, and the cosmic microwave background radiation, the aforementioned radioactive decay.
Now, it only needs a banana and more than 300 pieces of hardware to make it, which is not too convenient.
In fact, there are already many similar projects on GitHub, and there is an account on Twitter that has been sending more than 200 random numbers every day for a year.
It turns out that bananas are not only edible
In fact, the wonderful benefits of bananas do not stop there.
For example, it can become a gamepad.
Just this year, Sony filed an interesting-looking patent that aims to turn “cheap, simple, non-electronic devices into gaming peripherals.”
No, they used some equipment and technology to project virtual keys onto bananas and turn them into handles.
For another example, bananas can also be used to feel the magic of physics, that is, positrons.
Because potassium-40 will emit a positron at the same time when β+ decays into argon 40. So a netizen from Nutshell provided a method:
Buy a banana, smash it and apply it to your hands.
On average, one positron annihilates in your hand every 1 hour and 51 minutes! ”
Well, interested friends, you can try it.
Of course, bananas can also be used as a spoof tool on weekdays.
Prepare a combination of “banana + jujube”, “banana + sprite”, etc., which will make your friends discover a new world.
In the virtual world, bananas also have unexpected uses.
In the “Hitman 3” game, it is set as a weapon! Portable and easy to hide, even bullet attacks cannot penetrate.
As a result, it has become an “assassination” tool that is extremely well-received by players. Not to mention a tall base guard who stuns a man in minutes, once it becomes a “landmine”, the enemy will immediately fall and lie down when stepped on.
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