For the second and last time this century, the planet Venus will pass over the visible disk of our Sun for observers located in the Americas (in the evening of June 5th) and western Europe (in the morning of June 6th). The event has a noteworthy scientific value -particularly for exoplanetary searches-, but it is also quite spectacular to observe, if you have some modest equipment (but you should be able to spot it with your naked eye, provided you only look through a thick-smoked glass; never look at the Sun directly!). The added value is that probably none of us will be around the next time this event occurs, in 2117.

Dear readers, your input is appreciated. Please read the following quotes and let me know what are your thoughts on the matter in the comments thread. You need not leave your name if you wish to remain anonymous, but I'd appreciate it if you mentioned your degree of education and whether you are/were/will be a scientist.

Quote 1:

Measuring the value and the impact of a scientist on her field of research using as data her scientific papers, the number of citations these papers got, and the prestige of the scientific journals where these were published is no easy matter.

Grading Researchers: The H-Index

There is a large body of literature on how best to account for all these factors together: the discipline is called "scientometrics". Of course, the goal is to summarize the productivity of a scholar in a single number; possibly one with at most double digits, since decision-makers who hire or fund are usually incapable of handling more complex data. One notable attempt is the Hirsch Index, proposed in 2005 by a physicist, Jorge Hirsch.

Top quarks are most often produced in pairs at hadron colliders. The reason of this fact is that the strong interaction, which produces most of the reactions between the projectiles, is flavor-blind, and it cannot create a single new flavor of quarks out of nothing. In other words, physical processes mediated by strong interactions conserve the quantum numbers describing the difference between the number of quarks and antiquarks of any given kind: U, D, C, S, T, and B.