
Science resources
Get flash to fully experience Pearltrees
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Spider & the Web
Space
Beyond space and time: Fractals, hyperspace and more
The Universe is commonly defined as the totality of existence, [ 1 ] [ 2 ] [ 3 ] [ 4 ] including planets , stars , galaxies , the contents of intergalactic space , and all matter and energy . [ 5 ] [ 6 ] The broadest definition of universe is that it is simply everything, while a narrower definition is that the universe is limited to what can be observed. [ dubious ] Similar terms include the cosmos , the world and nature .
Universe
Black hole
Observable Universe
Visualization of the 93 billion light year – or 28 billion parsec – three-dimensional observable universe.Galaxy
A galaxy is a massive, gravitationally bound system consisting of stars , stellar remnants , and interstellar medium of gas and dust , and, it is hypothesized, an important but poorly understood component called dark matter . [ 1 ] [ 2 ] The word galaxy is derived from the Greek galaxias ( γαλαξίας ), literally "milky", a reference to the Milky Way .Nebula
An example of a spiral galaxy, the Pinwheel Galaxy (also known as Messier 101 or NGC 5457) A is a certain kind of galaxy originally described by Edwin Hubble in his 1936 work [ 1 ] and, as such, forms part of the Hubble sequence .
Spiral Galaxy
Virgo
The Virgo Supercluster ( Virgo SC ) or Local Supercluster ( LSC or LS ) is the irregular supercluster that contains the Virgo Cluster in addition to the Local Group , which in turn contains the Milky Way and Andromeda galaxies.Educational video on supernovae explosions from NASA
Supernova
{*style:<b> Get a quick start by scrolling down to the introduction below this menu table. Basic Electronics - Course Table

