Category Archives: Cosmology

Cosmic dawn

Category : Cosmology , General News

A VHF absorption signal at 78 MHz in the sky-averaged spectrum has been interpreted as a result of the formation of the first stars, a process that illuminated the universe with UV radiation and is called the cosmic dawn, as reported in a comment and article in Nature. The UV radiation would modify the excitation state of the 1420.4  MHz hydrogen spin atomic transition and would indicate the universe temperature. The linewidth suggest that the first stars appear 180 Myears after the Big Bang, while the flatten line profile has been connected speculatively with the interaction between normal matter and dark matter, which, if confirmed, would be truly remarkable.

Nobel Day

Category : Cosmology , General News

The Nobel prize in Physics went to the gravitational waves, not a surprise. The Chemistry prize was for Cryomicroscopy (Method of the Year 2015 according to Nature Methods, but more a software development than a conceptual revolution). The Spanish Journal Investigación y Ciencia is presenting an article on the history of cryomicroscopy. Simultaneously, the Faculty of Sciences and the Spanish Physics Society organized an interesting conference last November 14th by Prof. Mariano Santander and Prof. Santiago Mar to introduce the gravitional waves and the detection technique. You can watch the talks on the YouTube channel of the UVa.

Gravitational waves

Category : Cosmology , General News

Einstein would be happy: Researchers at LIGO announced the detection of gravitational waves. Simulations indicate that the signal is originated by the merging of two black holes which collided 1.3 billion light-years away. The LIGO experiment is made of two facilities separated 3002 km. Each site has two L-shaped ultra-high-vacuum arms, 4 km long on each side, containing several interferometers. Distortions in the space-time caused by a gravitational wave produce an astonishing small -yet detectable- signal equivalent to 1 part in 10²¹. Watch the videos from or download a ring tone for your cell phone! This does not happen everyday.

Molecules on comet

Category : Cosmology , General News

Results from a mass spectrometer on board the Philae lander revealed 16 organic molecules in the surface of the comet Churyumov-Gerasimenko, according to a report in Science. The article is part of a special issue on the comet. The spectrum was recorded about half an hour after the first touchdown and shows four compounds never observed before on comets. Most of the organic compounds contain nitrogen, but not sulphur. The observed molecules include acetone, propionaldehyde, acetamide, glycolaldehyde and etylene glycol. Science has collected other results in his Rosetta web page. Unfortunately these initial results might be also the last since Philae does not communicate since July 9.

F1.mediumsn-BibringPhilaeIn the figure above stars can be seen above the cliff where Philae landed in comet P57.

Pluto Flyby 2015

Category : Cosmology

The spacecraft “New Horizons” completed an impressive flyby of Pluto on July 14, following a trip that started in 2006. The probe will need 16 months to send all data back to Earth.

P_LORRI_FULLFRAME_COLOR_768000kmPluto image from the long-range camera at ca. 768000 km from the minor planet. In the animated figure below Pluto and its bigger satellite Caronte turn around forming a binary system.


Landing in a comet

Category : Cosmology , General News

The European Space Agency put a 98 kg space probe in the surface of the comet 67P/Churyumov–Gerasimenko. The Philae probe bounced back into space a couple of times before landing, since the escape velocity from the comet is only 1.8 km/h. Science went well till Philae batteries exhausted. The Rosetta spacecraft will continue monitoring the comet for at least one year. More results to come.

The orbital approach to the comet is shown in the video below.

Cosmological inflation

Category : Cosmology , General News

Observations in Antarctica with the BICEP2 experiment measuring the polarization of the cosmic background radiation seem to confirm the model of cosmological inflation and the big bang. The inflationary epoch was a practically instantaneous period of the early universe (10-36 to 10-32 seg after big bang) where the space expanded much faster than the speed of light. If you haven’t read it yet buy inmediately the book by Lawrence M. Krauss “A Universe from nothing” (…with an introduction by Richard Dawkins).

Krauss_universe from nothing