Bitcoin 2100 trillion
at present, the computing power of bitcoin in the whole network has reached 2.36 billion hash collisions per second, which is equivalent to the number of water droplets in more than 200000 50 meter long standard swimming pools. But even with such a large amount of computing power, it will take about 10 minutes to hit a hash value that meets the requirements
in 2012, bitcoin's output was halved for the first time, and in July 2016, bitcoin's output was halved for the second time. At present, 12.5 bitcoins are awarded for recording one page of account book. The next halving will take place around 2020, and the total number of bitcoins will not increase by 2040, with a total of 21 million. In other words, the difficulty of digging bitcoin is increasing, while the time required is increasing
Bitcoin is a kind of network virtual currency. Bitcoin network generates new bitcoin through "mining". In essence, the so-called "mining" is to use computers to solve a complex mathematical problem to ensure the consistency of bitcoin network distributed accounting system. Assuming that the mining computing power is 100 mhash / s and the total computing power is 4000 ghash / s per day, 3600 bitcoins can be g out every 24 hours
China's computing power has accounted for more than 75% of the world, that is to say, 75% of bitcoin in the world is made in China. How long does it take to dig a bitcoin
bitcoin used to be very good at "digging", which can be done by ordinary computer CPU, and it can automatically "solve problems" by downloading software. But with the rise of currency price, more and more people want to "solve the problem", and the difficulty of mining is also increasing. Now, the amount of computation needed to dig a bitcoin is beyond the reach of ordinary people. Ordinary computers can't afford it
instry insiders said that in 2014, 100 bitcoins were generated from 500000 yuan of electricity charge per day, and the cost of electricity charge alone was 5000 yuan per coin. But now, the same cost has more than doubled, and the electricity cost of each bitcoin is as high as 10000 yuan
in the generation mechanism of bitcoin, mining reward is decreasing. At the beginning of the birth of bitcoin, the miners could get 50 bitcoins for each page of the ledger, and then 25 bitcoins for each page of the ledger, decreasing in turn. It's like digging gold. At first, it's more and less. The time point at which each new reward is reced by half is called half bitcoin proction
assuming that the mining computing power is 100 mhash / s, the total computing power is 4000 ghash / s per day in 2014, and 3600 bitcoins are g out every 24 hours
now, we can understand the difficulty of bitcoin digging in this way, which is equivalent to 100 million dice throwing numbers less than 100 million and 50 million. Whoever throws them first will get the bookkeeping right. At this point, 1050 million is a hash value. The process of throwing dice is called hash collision. The unit of mining power is the number of hash collisions per second
at present, the computing power of bitcoin in the whole network has reached 2.36 billion hash collisions per second, which is equivalent to the number of water droplets in more than 200000 50 meter long standard swimming pools. But even with such a large amount of computing power, it will take about 10 minutes to hit a hash value that meets the requirements
in 2012, bitcoin's output was halved for the first time, and in July 2016, bitcoin's output was halved for the second time. At present, 12.5 bitcoins are awarded for recording one page of account book. The next halving will take place around 2020, and the total number of bitcoins will not increase by 2040, with a total of 21 million
Related videos: how long does it take to dig a bitcoin
I think it is certain to give up
17 years to participate in a dinner, drink half of the wine. People in the group let me share what bitcoin is. Then a big man said: & lt; It's Nakamoto that invented bitcoin, right? How many bitcoins does he have? The first bitcoin system can only run on its own computer, so it is paid for the previous block, which is estimated to be about one million
big brother also said that this is too little, a total of 21 million. As the founder and chairman of the board, Sun Tzu should have at least 67% of the shares and absolute control, or worse, 51%. Moreover, he will separate every transaction in the future
I don't think the boss is going to stop. Pull the boss to say drink. Who knows, Nakamoto is an idiot. Mom, I think I just told another interesting story. Yes, the maximum amount of a bitcoin is more than 100000. If you think of bitcoin as a company, its market value is more than 2 trillion, ranking among the top ten in the world. If Nakamoto had given himself more marks, he would now be the first rich man in the world. Both Bezos and Bill Gates have to call dad{ RRRRR}
Yes, human beings are selfish. The world is the jungle. There are common genes in human DNA. That makes us feel the same emotions. It's one of the guarantees that we humans can help each other and live to the present
the highest price is 1 million bitcoin, worth 20 billion US dollars. Since the birth of bitcoin in 2009, there has been no bitcoin in Nakamoto's wallet address
every time I think about this, considering the struggle against humanity and ugliness, I think life is worth it. If we calm down, we can win
It's hard to say that the value of bitcoin depends entirely on other digital currencies. Many digital currencies anchor the rise and fall of bitcoin. Moreover, although bitcoin itself limits the number of issues, its lower limit is wireless issuance. Compared with the most popular 21 million, it has been issued nearly 100000 times. Moreover, it lacks supervision, Its price is completely controlled by some capital parties and teams, becoming a tool for capital to harvest leeks
according to my estimation, the value of bitcoin will continue to rise, and it will continue to be issued, which is equivalent to a big plate. In order to attract more people into the pit, bitcoin must rely on the rise to attract investors, and then harvest through the control panel. This can also be seen from the rise and fall of bitcoin in the past five years, And the change of funds< br />
secondly, however, there is a smaller threshold for the total number of "smart": the largest possible integer that can be represented in floating-point format. Integers are not the only numbers that computers can store; To deal with decimals, computers & gt; Use a format for floating point representation. Floating point notation is essentially a binary version of scientific notation. For example, here is a value you will encounter when you study physics:
mass of the earth: 5.972 1024 kg
mass of the sun: 1.989 1030 kg
speed of light: 2.998 108 M / s
light year: 9.460 1015 m
mass of proton: 1.672 10-27 kg
Planck length: 1.616 10-35 m
we can notice that, How does scientific notation allow you to represent all of these values with reasonable accuracy, even though they vary greatly in size. Floating point notation is essentially a binary scientific notation; When you store numbers & gt; When the word is 9.625, what your computer stores is "1.001101
* 1011" (in other words, it stores 0100000000100011
& gt; This is the same thing with high-precision sequence form). In this high-precision form, the coefficient (that is, the part that is not the exponent) has 52 bits. This means high precision (more refined & gt; Double precision floating point number is enough to store up to 253 numbers, but it can't be any higher. If it exceeds 253, you have to start cutting off the numbers at the end. Bitcoin's 250.9, the total number of "smart" in the form of index, is just & gt; OK, below this maximum
if we have integers, why should we care about floating-point values? Because more high-level programming languages (such as JavaScript) do not open low-level "floating point" and "integer representation", but only provide "number" representation for programmers; Concepts
– of course, in floating-point form. If Nakamoto chose 210 million instead of 21 million at that time, bitcoin programming in many languages would be much more troublesome than it is now
note that Stefan Thomas unfortunately didn't notice this in time when he wrote bitcoinjs, so that the library used a special "big number big
number" object instead of an ordinary number to store the tutorial output value; My own bifurcated bitcoin JS (along with other improvements) uses ordinary numbers.
theoretically, 2100 trillion, or 250.899. In terms of selecting this value, this number is far less than 264-1, which is the largest integer that can be stored in the form of standard integer in a computer. If it exceeds that value, the bitcoin value will return to zero like a odometer
but this is only theoretical, just theoretical. Just like the previous IP address regulations, no one expected that V4 would be used up so quickly. Now it is necessary to use V6. This so-called "maximum integer that can be stored in the form of standard integer" may be broken by the technology upgrade one day a year later, followed by the collapse of the whole bitcoin computing.
1. Take close-up pictures of small still objects, such as flowers, birds and insects:
use AV file, the aperture should be f5.6 or below, the focal length should be more than 50, and try to shoot within 1m to make the background virtual
if the light is good, ISO 100, if the light is bad, ISO should be within 400<
2. Shooting people:
basically use a large aperture (within f5.6) and a focal length of more than 50 mm. The shooting distance depends on the whole body, half body and big head, which makes the background virtual. Use AV file
good light, iso100, bad light, iso400
people in motion use tracking to reflect the sense of motion (see the shooting of moving objects below for details)<
3. Shooting:
AV file, use the appropriate aperture, above F8, the focal length is arbitrary, but generally the wide-angle end has distortion, use it as appropriate<
4. Shooting night scene:
upper tripod, AV gear, custom white balance or incandescent lamp, aperture above F8, small aperture can make the light proce starlight effect, use the reflector pre rising function to rece the vibration caused by the reflector lifting after pressing the shutter; And cover the viewfinder with the square cover on the strap to prevent stray light from entering from the back and affecting the image quality; ISO 200, as far as possible to make the exposure time longer, so that some people who have no intention to walk away from the screen disappear, leaving no traces, clean the scene
for example, when taking a square with people coming and going, you can use a very small aperture of about F20 and iso100. In this way, the exposure time will be very long, and the moving figures will not stay in the photos! The square will be clean<
5. Shooting fireworks:
using shutter line and B shutter, you can shoot multiple fireworks overlapping effect<
6. Shooting things:
when the light is good: AV, the aperture size should be handled according to the circumstances; Large depth of field can be obtained by using aperture above F8, and shallow depth of field can be obtained by using small aperture
if you want to have a very dynamic effect, you can use the TV gear, the shutter is about 1 / 30, when you focus and press the shutter, the lens will follow the object at an appropriate speed, which will proce a very dynamic effect
poor lighting: we can only handle it according to our own discretion, plus use the follow-up camera<
7. Shooting running water or fountain:
using TV and about 1 / 50 shutter speed, you can shoot Satin effect. If you use too fast shutter speed, the fountain will shoot discontinuous water drops<
8. Taking photos at night:
use tripod to adjust white balance, and automatically or custom white balance; iso100-400 AV gear, aperture about F8, use slow synchronous flash, rear curtain flash mode; At this time, the flash will flash twice, press the shutter to flash once, and flash again before the end of exposure, so don't leave before flashing twice
in this way, the characters can be clear and the background neon is beautiful, so that the background will not be too dark e to insufficient exposure< No matter what you shoot, don't shoot with the maximum aperture unless you want to keep a safe shutter
2. Please use the aperture of F8 ~ F11 as much as possible when shooting scenery
3. The maximum aperture can be reced by 1-2 levels when taking close-up of people and still life
4. The safety shutter should be controlled above the reciprocal of the focal length as far as possible. The wide-angle shutter should also be more secure at more than 1 / 30 second. If the shutter is insufficient, please increase the aperture or ISO<
metering method:
1. Don't measure the light to the sky or the darkest place. Go to the middle value
2. According to your subject matter, make good use of the metering mode (balance metering, point metering, central key metering...)
3. If the light measurement is not accurate, please use AE lock to expose and lock the gray things around you before shooting
4. Try not to measure the light on white or black objects, otherwise remember to rece eV for black and increase eV for white<
EV is exposure compensation.
exposure compensation is also an exposure control method, which is commonly used in ± If the ambient light source is dim, the exposure value (such as + 1eV, + 2eV) can be increased to highlight the clarity of the picture
most of the small digital cameras adjust the exposure compensation through the menu
in the process of shooting, if you press half of the shutter, the LCD will display pictures similar to the final effect picture, focusing and exposure will start. The exposure at this time is exactly the exposure of the final picture. If the picture is obviously bright or dark, it means that the automatic metering accuracy of the camera has a large deviation, and the exposure compensation should be enforced, but sometimes the brightness displayed ring shooting is different from the actual shooting result. Digital camera can browse the picture immediately after shooting, at this time, you can more accurately see the brightness of the picture, there will be no difference. If the shooting result is obviously bright or dark, it is necessary to re shoot and force the exposure compensation
the shooting environment is dim, and the brightness needs to be increased. When the flash cannot work, the exposure can be compensated and the exposure can be increased appropriately. For exposure compensation, if the photo is too dark, increase the EV value. Every 1.0 increase in EV value is equivalent to doubling the amount of light intake. If the photo is too bright, decrease the EV value. Every 1.0 decrease in EV value is equivalent to doubling the amount of light intake. The compensation interval can be adjusted in 1 / 2 (0.5) or 1 / 3 (0.3) units according to different cameras
when the white object to be photographed looks gray or not white enough in the photo, it is necessary to increase the exposure. In short, "the whiter the object is, the more white the object is." this seems to run counter to the basic principles and habits of exposure. In fact, it is not. This is because the main body of the camera is often the center of the light measurement, and the White main body will make the camera mistakenly think that the environment is very bright, As a result, the exposure is insufficient, which is also a common problem for most beginners
because the shutter time or aperture size of the camera is limited, it is not always able to reach the 2eV adjustment range, so the exposure compensation is not omnipotent, and it may still be underexposed in too dark environment. At this time, it is necessary to consider cooperating with the flash or increasing the ISO sensitivity of the camera to improve the brightness of the picture
generally speaking, the smaller the brightness contrast of the scene, the more accurate the exposure, otherwise, the larger the deviation. The grade of the camera is high and low. If the grade is high, the metering is more accurate, and if the grade is low, the deviation will be increased. If it is a traditional camera, the tolerance of film is relatively large, and the exposure deviation will not have a big problem within a certain range, but the CCD tolerance of digital camera is relatively small, and slight exposure deviation may affect the overall effect
in a word, the adjustment of exposure compensation is determined by experience and sensitivity to color. Users must compare the image quality, clarity, restoration degree and noise size under different exposure compensation to get the best picture
note:
the aperture in Canon's manual refers to the F value. The larger the aperture, the greater the depth of field
generally speaking, aperture refers to aperture, which is inversely proportional to F. the larger the aperture, the smaller the depth of field
AV -- aperture priority auto exposure
TV -- shutter priority auto exposure
AE auto exposure
AF auto focus
AF-S -- single auto focus, the same as saf. The opposite is continuous autofocus
MAF - monitor AF, which can shorten the focusing time. The camera will adjust the focus before half pressing the shutter button, so that you can compose with the adjusted focus. When the shutter button is half pressed and AF locking is completed, the focus will be locked
ev - exposure value, which is usually used in exposure compensation
ISO sensitivity. Each difference of sensitivity is equivalent to the corresponding exposure value of aperture or shutter
brother, if you have time, go to ZhongGuanCun video forum and see the forum.
In fact, there is one more detail that we need to pay attention to, that is, the price of bitcoin has been directly reced from US $60000 to US $52000, and countries have directly indicated that they will strengthen supervision. Before that, you should know that the price of bitcoin soared from more than 10000 US dollars to 60000 US dollars. It's boring. Why didn't the regulators of various countries directly intervene in such a long period of time? So today we will discuss the factors that affect the fluctuation of bitcoin{ Third, the confidence of consumers or investors
in the past few months, bitcoin's long-term success is that the manual has brought her a high degree of popularity, and at the same time, its price has gone up by leaps and bounds. But everyone is tired. After seeing some information about bitcoin for a long time, we are not very interested. The visual impact of tens of thousands of dollars has lost any freshness. In this case, everyone's investment enthusiasm for bitcoin will naturally decline, which will lead to its price decline