science

Have a Pi, Maybe Two Today

The number π is a mathematical constant, the ratio of a circle's circumference to its diameter, commonly approximated as 3.14159. It has been represented by the Greek letter "π" since the mid-18th century, though it is also sometimes spelled out as "pi" (/paɪ/).

The number π is a mathematical constant, the ratio of a circle’s circumference to its diameter, commonly approximated as 3.14159. It has been represented by the Greek letter “π” since the mid-18th century, though it is also sometimes spelled out as “pi” (/paɪ/).


Being an irrational number, π cannot be expressed exactly as a fraction (equivalently, its decimal representation never ends and never settles into a permanent repeating pattern). Still, fractions such as 22/7 and other rational numbers are commonly used to approximate π. The digits appear to be randomly distributed. In particular, the digit sequence of π is conjectured to satisfy a specific kind of statistical randomness, but to date no proof of this has been discovered. Also, π is a transcendental number, i.e., a number that is not the root of any non-zero polynomial having rational coefficients. This transcendence of π implies that it is impossible to solve the ancient challenge of squaring the circle with a compass and straightedge.

Being an irrational number, π cannot be expressed exactly as a fraction (equivalently, its decimal representation never ends and never settles into a permanent repeating pattern). Still, fractions such as 22/7 and other rational numbers are commonly used to approximate π. The digits appear to be randomly distributed. In particular, the digit sequence of π is conjectured to satisfy a specific kind of statistical randomness, but to date no proof of this has been discovered. Also, π is a transcendental number, i.e., a number that is not the root of any non-zero polynomial having rational coefficients. This transcendence of π implies that it is impossible to solve the ancient challenge of squaring the circle with a compass and straightedge.


MIT Uses CRISPR to Engineer Synthetic DNA Capable of Event Memories

MIT Research

Score another win for CRISPR. Scientists at MIT are using the ever-intriguing genome-editing system to engineer human cells capable of recording and reporting the intensity and duration past events.

The analog memory storage system builds upon past work developed by scientists that programed cells to flip DNA sections when events – like exposure to specific chemicals – occurred. What sets the new research apart, however, is the addition exposure duration and intensity to the cell-reported information.

The older research has also largerly been relegated to bacteria. Moving the technology to human cells means, among other things, a potential method for studying the ways in which cellular events like gene regulation impact disease, according to MIT associate professor of electrical engineering and computer science, and of biological engineering, Timothy Lu.

The researchers are also able to get a bit fancier with things, with cells capable of recording multiple different input sources – in the case of this demo, doxycycline (an antibiotic and the lactose-like molecule, IPTG.

All of the information allows for a much closure study on the impact of infections and diseases like cancer. It could also potentially be used to follow the role of specialized cells during development from an embryo to full grown adult.

— Source [MIT]: MIT engineers human cells to store ‘memories’ in DNA