Brandon Q. Morris's Blog, page 12

Two pairs of quasars in the early universe

Quasars are loners. This is not because they do not get along with their colleagues, but has something to do with their nature. They are nuclei of active galaxies. And every galaxy has only one nucleus. Billions of stars can rotate badly around several cores. Nevertheless, astronomers have now found two quasar pairs at a distance of about ten billion light years as they report in Nature Astronomy.

How is that possible? The researchers have only one explanation for it: It concerns in each case t...

Even the core of the Milky Way gives birth to stars

Since Star Trek V we know that the core of the Milky Way is a very special area. There is no galactic barrier there, but there is a gigantic black hole (Sagittarius A*) with the fields it produces and a lot of stars in a small space. With average distances of less than one light year the night sky of a planet must be very bright there.

New stars are formed from clusters of gas and dust clouds. The process is disturbed when magnetic fields waft through it or passing stars deform the cloud with th...

The very first structures of the cosmos

In one of my newest books astronomers are trying to use a solar gravitational lens to look at the beginning of the universe. Whether they succeed, I will not reveal here. But physicists at the Universities of Göttingen and Auckland (New Zealand) have now determined what they would see with the help of greatly improved computer simulations. The scientists discovered that a complex network of structures can form in the first trillionth of a second after the Big Bang. But these are not just any ran...

Basic structure of the cosmos pictured for the first time

Stars group together to form galaxies. Galaxies form galaxy clusters. These form superclusters, between which vast, largely empty regions extend, the voids. All superclusters are connected by a honeycomb-like basic structure, the “cosmic web”, which consists of filamentary gas structures of hydrogen. That these filaments must exist has been known for some time. On the one hand, they are known from simulations based on theories of the structure of the universe, which predict such a basic structur...

What a volcano would look like on a metal world

On Earth it rains water, on Titan liquid methane comes from the sky. On some planets it rains iron or even diamonds. Such differences also exist in volcanology. On Ceres, researchers have discovered ice volcanoes, while terrestrial volcanoes spew cinders of liquid rock. On the asteroid Psyche, which consists primarily of metal, there may once have been iron volcanoes. Perhaps elsewhere, too.

But what would such volcanoes look like? Knowing that is important for detecting them on distant celestia...

News from the warp drive: one problem less

Sometimes there are strange coincidences. Yesterday I reported here that “passable” wormholes could be realizable also without the addition of negative energy. This is an important advance because there is no natural source for negative energy.

The only thing we can do to get a little bit of negative energy is to trick the universe. We take the negative energy from it while it is not looking and give it back before it has even noticed. This gap offers us the uncertainty principle of quantum phys...

Quasar transmits from the early days of the universe

In the 1950s, astronomers discovered radio sources to which point-like, i.e. star-like objects could be assigned in the visible light range. Until then, whole galaxies had been identified as radio sources. The findings were called “quasi-stellar objects”, or quasars for short. Later, however, researchers realized that quasars are embedded in galaxies after all, and in fact constitute their active nuclei radiating in many wavelength ranges. That they had been seen only as point sources was simply...

Super Venus in our cosmic neighborhood

Wolf 437, also called Gliese 486, is a red dwarf fairly close to the Sun – just 26 light-years away. What makes it interesting is a planet that astronomers now present in Science. Gliese 486 b moves around its parent star in a circular orbit within 1.5 days and at a distance of only 2.5 million kilometers (Earth: 150 million kilometers). Since its rotation around its own axis always takes the same time, the planet always turns the same side to its sun – similar to the moon to the earth.

Although...

Merging boson stars instead of colliding black holes?

Bosons are particles with an even spin. They include the fundamental particles that mediate the individual interactions (such as photons for electromagnetism), but also composite particles such as helium-4 atoms. Their peculiarity is that any number of them can occupy the same ground state. They are then indistinguishable from each other and form a Bose-Einstein condensate with unusual properties. Among other things, the density of the condensate can approach infinity.

This would make bosons goo...

Can supermassive black holes collapse directly from dark matter?

At first glance, a black hole and dark matter sound like a perfect combination. However, there is a problem: dark matter is mainly found in the outer regions of galaxies, in massive halos. Supermassive black holes, on the other hand, form the core of a galaxy. Does there nevertheless go something together, which belongs together?

Perhaps. As far as supermassive black holes are concerned, cosmology still has a problem. Because how exactly they originally formed is one of the biggest problems in t...