science
Get flash to fully experience Pearltrees
Physics
Vertebrates are modified segmented worms; that is, their body plan is made up of sequentially repeated units, most apparent in skeletal structures like the vertebrae. Arthropods are also modified segmented worms. Look at a larval fly, for instance, and you can see they are made up of rings stacked together.
Pharyngula
Physicist : There are several algorithms, but almost all of them are all based on “trap-door encryption”. The idea is that you find some kind of mathematical process that’s easy to run forward, but effectively impossible to run backward, unless you know a trick (which you keep secret). It’s likened to a trap-door because (as every super-villain knows) it’s easy to go through a trap-door in one direction, but difficult in the other. This is fundamentally different from the encoding schemes most people are familiar with, like “A=2, B=15, C=…” or Igpa Atinla , which are called “substitution cyphers”.
Ask a Mathematician / Ask a Physicist
Steven Weinberg has a new article in The New York Review of Books on The Crisis of Big Science , which is based on a talk he gave this past January at the American Astronomical Society meeting in Austin (for some discussion of this, see here and here ). Weinberg is rather gloomy about prospects for particle physics, seeing dim prospects for a new generation of particle accelerators, especially in the US. He goes over the sorry story of the SSC, which he was deeply involved in, and worries that the same thing is happening to the James Webb Space Telescope project. He argues that progress is particle physics will be difficult without going to higher energies:
Not Even Wrong
study