- Researcher claims solution to P vs NP math problem
- Vinay Deolalikar, a mathematician who works for HP Labs, claims to have proven that P is not equal to NP. The problem is the greatest unsolved problem in theoretical computer science and is one of seven problems in which the Clay Mathematics Institute has offered million dollar prizes to the solutions.
The question of whether P equals NP essentially asks whether there exist problems which take a long time to solve but whose solutions can be checked quickly. More formally, a problem is said to be in P if there is a program for a Turing machine, an ideal theoretical computer with unbounded amounts of memory, such that running instances of the problem through the program will always answer the question in polynomial time — time always bounded by some fixed polynomial power of the length of the input. A problem is said to be in NP, if the problem can be solved in polynomial time when instead of being run on a Turing machine, it is run on a non-deterministic Turing machine, which is like a Turing machine but is able to make copies of itself to try different approaches to the problem simultaneously.
- My thoughts: It will be interesting how this turns out.
- Early puberty for US girls raises health risk
- According to a new study, US girls are reaching puberty earlier than ever, a trend that raises some health concerns.... Though the study didn't address why US girls were reaching breast development earlier, it found that heavier girls reached puberty earlier.... Scientists and researchers are also worried about chemicals like bisphenol A (BPA) and atrazine that could disrupt growth hormones. The chemical industry says that these chemicals are safe and are harmless to humans.
Herman-Giddens also said that it can be confusing to hit puberty at a young age. Girls reaching puberty at a younger age are more likely to attempt suicide. Also, earlier puberty can cause low self-esteem and depression and at adulthood, girls who reached puberty earlier are more likely to have breast cancer and endometrial cancer.