Forty-Third, Forty-Fourth, Forty-Fifth, Forty-Sixth, Forty-Seventh and Forty-Eighth Annual Reports of the State Geologist

Of the Forty Fourth Annual Meeting

Forty Years of X-Ray Binaries

In 2012 it was forty years ago that the discovery of the first X-ray binary Centaurus X-3 became known. That same year it was discovered that apart from the High-Mass X-ray Binaries (HMXBs) there are also Low-Mass X-ray Binaries (LMXBs), and that Cygnus X-1 is most probably a black hole. By 1975 also the new class of Be/X-ray binaries was discovered. After this it took 28 years before ESAs INTE...

Forty Data Communications Research Questions Forty Data Communications Research Questions

About ten years ago, Bob Lucky asked me for a list of open research questions in networking. I didn’t have a ready list and reacted it would be good to have one. This essay is my (long-belated) reply.

The IHÉS at Forty

N ot far outside Paris, in a small village, along a busy road, there is a gate leading into a park. The sound of the traffic dissipates as one follows the footpath. The trees are abundant enough to give the impression that one is simply walking through a serene wood, which has a slight incline that amplifies the rustle of the breeze through the treetops. But soon one reaches a small parking lot...

The Forty-Seventh Annual William Lowell Putnam Competition

Done: All A–1 Find, with explanation, the maximum value of f(x) = x−3x on the set of all real numbers x satisfying x +36 ≤ 13x. Solution: Write the constraint as (x − 13/2) + 36 ≤ 169/4 or (x − 13/2) ≤ 25/4. This becomes |x − 13/2| ≤ 5/2 or 4 ≤ x ≤ 9 which is the union of−3 ≤ x ≤ −2 and 2 ≤ x ≤ 3. The given cubic has derivative 3(x−1) which is positive for x > 1 and for x < −1. Thus the maximum...