Astrophysics

Jan 13 2021

Premature birth? The most distant quasar raises questions

Astronomers have discovered the most distant quasar yet. The monstrous celestial object called J0313-1806, which existed 670 million years after the Big Bang, shines thousands of times brighter than the Milky Way and is powered by another extreme, the earliest supermassive black hole, more than 1.6 billion times the mass of the Sun. This fully formed distant quasar with a redshift of z = 7.64, formed more than 13 billion years ago, is also the earliest quasar discovered to date, giving astronomers a glimpse of how massive galaxies formed in the early universe. Quasars, powered by the feeding orgies…

I welcome our future rulers, the Artificial Superintelligences

Astrophysics

Jan 12 2021

I welcome our future rulers, the Artificial Superintelligences

An artificial intelligence that is smarter than humans is one of the favorite subjects in science fiction. There are researchers who claim that such an AI is technically impossible. Others believe it is inevitable. If that could be the case, humanity faces a difficult problem. Can we somehow ensure that this superintelligence is benevolent to us? Can we control it? Because if we can't, the survival of humanity would be in its hands alone. A conception, which can please us so little that we would have to do then everything to prevent its emergence. An international team of researchers…

How Earth rocks on the sea of space-time

Astrophysics

Jan 11 2021

How Earth rocks on the sea of space-time

A constant radiation in the microwave range, the background radiation, has long told cosmologists that something important happened 380,000 years after the Big Bang. At that time, electrons and protons recombined to form molecular hydrogen, so that space finally became transparent, allowing light to propagate. We can still measure the remnants of this light, shifted into the infrared. But a lot happened shortly after the Big Bang. The very early universe was determined by time-varying scalar fields, after the inflation phase there should have been an energy transfer from inflaton particles to regular matter, there were various phase transitions,…

Were the first black holes born in the form of baby universes?

Astrophysics

Dec 30 2020

Were the first black holes born in the form of baby universes?

Shortly after the Big Bang, the universe was still impenetrable. Its density was so high that a variation of only 50 percent - a coffee bean in a cake batter - would have been enough to produce a black hole immediately. The density was at least variable enough to let grow whole galaxies from the differences later. However, there seem to have been no "coffee beans" at that time - this is revealed today by the rather uniform cosmic background radiation. Nevertheless, so-called promordial black holes could have been formed at that time, just on other ways. They could…

Intergalactic gas filaments crisscross the universe

Astrophysics

Dec 27 2020

Intergalactic gas filaments crisscross the universe

They crisscross the cosmos like cobwebs in a room that hasn't seen a vacuum cleaner in a long time: In so-called filaments, unfathomably large, threadlike structures of hot gas that surround and connect galaxies and clusters of galaxies, astrophysicists have long suspected the previously hidden half of matter in our universe. We owe our existence to a tiny error. After the big bang 13.8 billion years ago, the matter of the cosmos spread out in a gigantic gas cloud and was almost evenly distributed in it. Almost, but not quite: in some parts the cloud was somewhat denser than in…

Astrophysics

Dec 24 2020

The most distant galaxy in the universe

How large is the universe? As large as the most distant object we can detect, might be one answer. But this is not quite true: The most distant visible object only marks the boundaries of the observable universe. This could be GN-z11. A team of astronomers used the Keck I telescope to measure the distance to this ancient galaxy. They found that GN-z11 is not only the oldest galaxy, but also the most distant. It is so far away that it actually defines the boundary of the observable universe itself. The team hopes its study can shed light on a…

Astrophysics

Dec 4 2020

When the fog dissolves

In winter the fog sometimes does not dissolve the whole day. In space, planetary nebulae usually exist for many millennia, because they are star shells that have been ejected by their stars at the end of their lifetime. In the case of the Stingray Nebula, which was first catalogued in 1976 and is located 18,000 light years from Earth, this seems to be an exception. Images of the system taken by the Hubble Space Telescope in 2016 show a nebula that has drastically lost brightness and changed shape compared to Hubble images from 1996. Light blue gas shells near…

Astrophysics

Nov 26 2020

Milky Way’s Family Tree

From small to large: this is one of the possible ways in which structures are created in the universe. Galaxies like our Milky Way are formed when several small predecessor objects join together. But what exactly did the Milky Way form from? An international team of astrophysicists led by Dr. Diederik Kruijssen from the Center for Astronomy at the University of Heidelberg has succeeded in reconstructing the merging history of our home galaxy and creating its family tree. To this end, the researchers analyzed the properties of globular star clusters orbiting the Milky Way. Globular clusters are dense groups…