{var%20f='http://v.t.sina.com.cn/share/share.php?appkey=1515056452',u=z||d.location,p=['&url=',e(u),'&title=',e(t||d.title),'&source=',e(r),'&sourceUrl=',e(l),'&content=',c||'gb2312','&pic=',e(p||'')].join('');function%20a(){if(!window.open([f,p].join(''),'mb',['toolbar=0,status=0,resizable=1,width=440,height=430,left=',(s.width-440)/2,',top=',(s.height-430)/2].join('')))u.href=[f,p].join('');};if(/Firefox/.test(navigator.userAgent))setTimeout(a,0);else%20a();})(screen,document,encodeURIComponent,'','','https://www.manongdao.com/data/attach/logo/logo.png', '推荐 ゆ 、 Hurt° 的问题《Why is it hard for a program to generate random nu》','https://www.manongdao.com/q-201177.html','页面编码gb2312|utf-8默认gb2312'));){kind=link}
My kids asked me this question and I couldn't really give a concise, understandable explanation.
So I'm hoping someone on SO can.
相关问题
- Unity - Get Random Color at Spawning
- How to generate a random number, then display it o
- how to randomly loop over an array (shuffle) in ba
- How to fill an array with random numbers from 0 to
- Upper bound of random number generator
相关文章
- why 48 bit seed in util Random class?
- Need help generating discrete random numbers from
- Get random records with Doctrine
- Looking for a fast hash-function
- Oracle random row from table
- Generate a Random Number between 2 values to 2 dec
- What does Random(int seed) guarantee?
- What’s the best way to shuffle an array in Perl?
Had to be done really
Source: http://xkcd.com/221/
Its probably helpful to distinguish between a number that is hard to predict (which a computer can create) from something that is not deterministic (which is a bit tougher for computers, and theoretically, any physical being).
Because the only true source of randomness exists at the quantum level. With suitable hardware assists, computers can access this level. for example, they can sample the decay of a radioactve isotope or the noise from a thermionic valve. But your basic PC doesn't come with this cool stuff.
Because there is no such thing as a random number.
Random is a human concept that we use when we cannot comprehend data and do not understand it. If we are to believe that science will ultimately lead to an understanding of how everything works then surely everything is deterministic.
Take away the human and there is no random there is only "this". It happens because it happens, not because it is random.
It is relevant to note that humans perform very poorly at generating random numbers. Computers are worse because they just follow a strict set commands. Humans can only generate good (pseudo) random numbers when following an algorithm, a set of commands. Computers are the same.
Although it should be noted that computers can gather entropy from the "environment" connected to it, like keyboard and mouse actions, what aids in generating random numbers (either directly or by seeding a PRNG).
Primarily because computers don't have any functions that behave in discrete, non-random ways. A computer is predictable, which allows us to program reliable software. If it wasn't predictable it would be easier to generate a random number (since our software could rely on this unpredictable method).
While it's possible to generate pseudo-random numbers, and numbers that are distributed randomly, you cannot generate truly random numbers without separate hardware. There is hardware that generates truly random numbers based on "quantum" interactions (at least according to the manufacturers). Online poker sites sometimes use these adapters for their generators.
Apparently there are even online services to provide random numbers - random.org for example.