What came first, black holes or galaxies?

What came first, black holes or galaxies?

"For decades, this was an ideological argument primarily between Americans, who favored a bottom-up approach, and Soviets, who favored a top-down approach. Here’s the difference:

Bottom-up: The Universe starts off with large-magnitude fluctuations on small scales and not on large scales. The overdense regions grow over time, producing small mass clumps that grow, merge, and cluster together, eventually growing into large galaxies and clusters of galaxies. In this scenario, black holes would form first along with small stellar clumps, and only at much later times would they grow into what we consider galaxies.

Top-down: The Universe starts off with large-magnitude fluctuations on large scales and not on small scales. The overdense regions, being very large, gravitationally collapse down from irregularly-shaped triaxial ellipsoids along their shortest axis, forming pancake-like structures that fragment apart into galaxies. At later times, these galaxies evolve and grow black holes in their centers; the galaxies would form before the black holes in this scenario.

For a long time, we didn’t have the observational evidence to tell which of these approaches were the right one.”

source:http://is-universe.com/

Comments

Modular housing concept boasts 64 possible combinations

Italian Designer Gabriel Aramu has conceptualized a modular housing system that seems to offer endless possibilities. Dubbed "Sliding Hub," these prefabricated cubes join together to create a temporary housing solution for multiple situations. In the event that emergency shelters are required, the modules can be packed and transported to any destination. On arrival, the modules are easily joined together, with the flexibility to house individuals, small groups or large numbers without limitation. Each module incorporates an insulation system suitable for all kinds of weather conditions. In addition, the temporary accommodation units provide a comfortable standard of living, important to natural disaster victims. Constructed with steel reinforcements, numerous modules can be assembled together to create various sizes and shapes, whilst sliding them open creates large internal spaces. According to Aramu, the system can be configured 64 different ways, wh...

A Father and Son

Father and son relationship are typically formed like this.

Stick ‘Em Up! Clever Concept Adds Number Pads to Laptops

On a lot of laptops, the numeric keypad is usually the first thing to be sacrificed in order to save space. For those of us who just can’t get used to using the numbers above the alpha keys, this concept is a stroke of genius. It’s called Number Pad Film for Touchpad – despite the cumbersome name, it’s a really clever object + program that makes it simple for even laptop users to enter long lines of numeric data. The Number Pad Film is a small piece of plastic film that fits on over a laptop’s touch pad. Accompanying software maps out locations of the virtual “keys” on the touchpad. Switch to the number input with the use of hotkeys and math away to your heart’s content. Another activation of the hotkeys sends the touchpad back to its original function. The virtual keypad lacks the tactile feedback of a physical numeric keypad, but people who do plenty of touch typing on numeric keypads might not mind. They’ll probably just be grateful to have the freedom to ...

Infotainment

Search This Blog