Published May 31, 2016
computers , economy , internet , mathematics , Probability , science
Tags: businesses, economy, information, internet, privacy, software
A new advance on a method known as a randomness extractor makes it easier for machines generate truly random numbers by harvesting randomness from the environment.
The new randomness extractor combines two independent sources of weakly random numbers into one set that is nearly random, with only minor deviations. Then the researchers use a “resilient function,” a method of combining information, to turn the string of numbers into one truly random bit — a 1 or 0.
Compared with the previous state-of-the-art randomness extractors, which required input that was already very close to random, the new method can mine sources that are “much, much, much, much weaker,” says computer scientist Avi Wigderson of the Institute for Advanced Study in Princeton, N.J. The new extractor is a “substantial improvement over the previous results, and it’s very close to the best you can hope for.”
Published October 27, 2015
earth , life , science
Tags: earth, science facts, Trees
The great Richard Feynman was a nobelist, a philosopher and a great teacher. In this video he explains how trees are created from thin air!!
This is not intuitive but it is -of course- absolutely true, and a wonderful example of the difference between learning (that trees get their material from CO2) and understanding (*Air* is transformed in to a living tree). Also a testament of how, the beauty one can see in the cosmos, is enhanced with the better understanding of it….
Published October 25, 2015
earth , history , mars , space
Tags: earth, life on mars, mars
It was earlier this month confirmed that liquid water was found on the surface of Mars. This mean that two things have just skyrocketed :
- The chances that we will find life on Mars.
- The chances our mars missions contaminate the planet.
The second one is what we should worry about: Life on Mars is or Life on Mars isn’t. Nothing we can do about it. But the notion that we can destroy it by mistake is really scary.
The Kepler mission has been a great success up to now. The Kepler space telescope was created to search for solar systems with multiple planets, and the results have been astonishing so far. According to Ian o’Neil’s article on discovery.com :
“The number of known multi-planetary star systems has just tripled. What’s more, the Kepler space telescope science team has just announced that they have doubled the number of confirmed exoplanetary sightings made by the observatory.”
“Prior to the Kepler mission, we knew of perhaps 500 exoplanets across the whole sky,” said Doug Hudgins, Kepler program scientist at NASA Headquarters in Washington, D.C. “Now, in just two years staring at a patch of sky not much bigger than your fist, Kepler has discovered more than 60 planets and more than 2,300 planet candidates. This tells us that our galaxy is positively loaded with planets of all sizes and orbits.”
It seems that it’s only a matter of time before we find the first habitable planet – like earth- in a nearby star system. This could very well be the greatest discovery of all times !
One of the most interesting mathematical problems ever :
There are 100 prisoners who are sentenced to death. However, the prison’s head, being merciful, offers them a possible way out: He puts 100 identical boxes, perfectly arranged in a row, in the death chamber and places the prisoner’s names in them, one name per box. The prisoners wait in a room outside the death chamber. Each prisoner is asked to proceed to the death chamber and open at most 50 boxes. If he finds his name in one of them he is transferred to the mercy room where he waits. If all prisoners succeed in finding their names then they are all spared from death and are released. On the event that one of them fails to find his name in one of the 50 boxes of his choice, the process is stopped and all prisoners are immediately executed. The prisoners can talk to one another whilst in the waiting room, but, once a prisoner gets transferred to the death chamber or the mercy room, he cannot tell the others anything at all.
Can the prisoners devise a strategy to increase their chance of survival?
Without a strategy, each prisoner has a 50% chance to find his name, and the chance that all of them find their names and survive is practically zero (1/2^100). Give it a shot. Hint: The prisoners actually have a good chance of survival.
Professor Takis Konstantopoulos posted this a few weeks ago and he also posted the answer here if you are ready to give up.