## Friday, January 30, 2015

### Two Supposedly Fun Things I'll Never Do Again

Writing a review is like pregnancy (as far as I can imagine being pregnant and with due respect to real mothers...), one starts super-excited, then begins to realize the initial expectations were too optimistic and that the entire experience is going to be much tougher than originally expected; and while the "baby" is growing, everything becomes tougher and tougher, to the point that one starts looking forward to the delivery (and THAT is probably the toughest part).

This is why finishing two reviews (here and here) in the same week is pretty much like having a twin childbirth, and now I feel like one of those exhausted mothers who stares at their babies with extreme joy.

 For those who missed the reference in the title, one of the best books ever..nothing less than a must-read!

The first work is an overview on superradiance. [If you are curious about what superradiance is... well, read the book! Meanwhile, in very few words superradiance is a broad class of phenomena related to energy amplification in dissapative systems. Because of dissipation, in special kinematic configurations the energy stored in some body/medium can be transferred to another body or to radiation, thus producing a sort of amplifier].

## Monday, January 26, 2015

### The Century of Strong Gravity

The following is a popular science article that Richard, Vitor and I have written for the IST Physics Magazine "Pulsar" (here is the Facebook page) and that will also appear in the Portuguese Physics Magazine "Gazeta de Fisica". A pdf version is available here (in English), and here (in Portuguese).

1. One Hundred Years of Gravity

The latest Christopher Nolan's movie, Interstellar, is about a future human civilization able to undertake cosmic travels to black holes using special shortcuts, wormholes''. Science-fiction as it might seem, Interstellar screenplayers --who happen to be the Nolan brothers-- have worked side by side with Kip Thorne, a professor of Theoretical Physics at the California Institute of Technology and one of the fathers of modern General Relativity, the theory that explains what wormholes and black holes are and how they form in the Universe.

Thorne's contribution is to ensure that the movie --starring Matthew McConaughey and Anne Hathaway among others-- doesn't contain scenes that would make Albert Einstein cringe.
Does this mean that travel agencies are about to sell (roundtrip!) tickets to a black hole? Not quite, but in a few years from now, theoretical physicists and astronomers will be able to study them as never before. The scientific payoff of these studies will largely overcome Interstellar's box-office, with all due respect to Mr. Nolan!

## Saturday, January 17, 2015

### Visit to AEI

This week I was visiting the Max Planck Institute for Gravitational Physics (aka Albert Einstein Institute, AEI) in Golm, in the outskirts of Potsdam, in the outskirts of Berlin (this more or less reflects the number of connections that commuters living in Berlin have to take everyday). The location of the institute is really its only weakness because otherwise the place looks great.

 Jan and I taking a selfie with Albert. The statue is located at the middle of a beautiful large indoor yard  at the Albert Einstein Institute in Potsdam (Germany)

I was there to collaborate with Jan Steinhoff (see pic above) who was postdoc in Lisbon in the last few years and recently moved to the AEI to work in gravitational-wave group lead by the new Director of the institute, Prof. Alessandra Buonanno, a world-leading expert in gravitational-wave phenomenology (and also one of the key speakers of this upcoming workshop). While there, I gave a seminar on "Black holes as stong-gravity labs", presenting some recent results related to black-hole superradiance (a topic that I will cover in this blog soon). I've also took the opportunity to discuss with a lot of interesting people working at the AEI (and to have some German beers with Jan and Jordi Casanellas, who also moved to AEI from Lisbon).

## Sunday, January 4, 2015

### Workshop: "Compact Objects as Astrophysical and Gravitational Probes" at the Lorentz Center (Feb 2-6, 2015)

It's a pleasure to advertise the workshop  "Compact Objects as Astrophysical and Gravitational Probes", to be held at the Lorentz Center (Leiden, The Netherlands) from February 2 through February 6.

 One version of the workshop's poster, the official one will soon appear in the official webpage. Here young Subrahmanyan Chandrasekhar and Albert Einstein are looking towards the most urgent questions in relativistic astrophysics, a field that has essentially emerged from their seminal works. The two young guys respectively symbolize the astrophysical and the general-relativistic communities that will gather together at this workshop, to share expertize and try to fill the gap between them.
Last June, Enrico Barausse (at the Institut Astrophysique de Paris), Tamara Bogdanovic (at Georgia Tech in Atlanta), Vitor Cardoso (at CENTRA - Instituto Superior Tecnico in Lisbon) and Elena Maria Rossi (at Leiden University in the Netherlands) and myself have applied to an international call at the Lorentz Center to organize a workshop. We initially had in mind a small-size workshop with ~20 participants, but the proposal was selected for a large-size event. Thus, in less than one month, more than 50 world-leading experts in relativistic astrophysics will gather together in what will hopefully be a fruitful and exciting meeting (here is the program and at list of participants).