|Universe from Hubble Deep Field|
Image credit: Robert Williams and the Hubble Deep Field Team (STScI) and NASA
‘Dark matter’ is an essential ingredient to form stars naturally given only standard known physics. ‘Dark matter’ is a hypothetical exotic form of matter, unknown to laboratory physics, which does not interact with or emit light in any way, hence it is invisible to all forms of detection within the electromagnetic spectrum, from radio-waves to gamma radiation. ‘Dark matter’ itself, therefore, is outside of standard known physics. It is made-up stuff that has been given one special property, which is that it gravitates, that is, unlike normal matter, it is a source of gravity only.To read the rest, click on "Stars just don’t form naturally—‘dark matter’ the ‘god of the gaps’ is needed".