Comments about "Primordial black hole" in Wikipedia
This document contains comments about the document "Primordial black hole" in Wikipedia
- The text in italics is copied from that url
- Immediate followed by some comments
In the last paragraph I explain my own opinion.
Contents
Introduction
The article starts with the following sentence.
-
A primordial black hole is a hypothetical type of black hole that is formed not by the gravitational collapse of a large star but by the extreme density of matter present during the universe's early expansion.
-
It is interesting to study the words "hypothetical", "theoretical", "predicted" and "speculated" in the documents of wikipedia.
IMO they mean all the same. They all describe concepts which can be false.
-
It has been proposed that primordial black holes, specifically those forming in the mass range of 10^14 kg to 10^23 kg, could be a candidate for dark matter.
-
See Reflection 1 - Pmc's as a possible solution for the dark matter issue.
-
-
-
-
-
-
-
-
-
-
1. Creation
-
According to the Big Bang Model, during the first few moments after the Big Bang, pressure and temperature were extremely high.
-
What this model more or less shows that the starting point of the Big Bang was a Black Hole. The problem here is what in this context means pressure and what means temperature.
-
Under these conditions, simple fluctuations in the density of matter may have resulted in local regions dense enough to create black holes.
-
You can easily write this, but is it true.
What are simple fluctuations? How do they start?
When there are fluctuations the universe becomes non-uniform.
Also what are the implications with the inflation theory.
-
Although most regions of high density would be quickly dispersed by the expansion of the universe, a primordial black hole would be stable, persisting to the present.
-
A primordial black hole of a certain mass is as stable (or instable) as a normal baryonic object of the same mass. With stable I mean life cycle time. They both can be captured by a Sun like object or a massive BH like in the center of our Milky Way.
-
-
-
-
2. Possible detection
-
One way to detect primordial black holes is by their Hawking radiation.
-
But than you first have to prove that Hawking radiation is an unique signature of a Black Hole.
-
Stephen Hawking theorized in 1974 that large numbers of such smaller primordial black holes might exist in the Milky Way in our galaxy's halo region.
-
In principle, as a matter of argument, they can also exist in the disc of our Galaxy.
-
-
All black holes are theorized to emit Hawking radiation at a rate inversely proportional to their mass.
-
This is a sentence which makes to claims.
The first one is the most important.
-
-
-
-
-
3. Implications
-
-
-
-
-
-
-
-
-
-
-
4. String theory
-
-
-
-
-
-
-
5. See also
Following is a list with "Comments in Wikipedia" about related subjects
Reflection 1 - Pmc's as a possible solution for the dark matter issue.
The Galaxy Rotation Curve is curve which describes the average speed of the stars around the center of a Galaxy as a function of distance. The GRV can directly be calculated by measuring the speed of the stars (doppler shift). The GRV can also be calcuted as a function of the visibility or mass of stars in each region of the Galaxy. The two curves do not match. That means a certain amount of mass is missing or invisible. To solve this problem the concept of dark matter is introduced.
In the classical solution dark matter is proposed to be non-baryonic. In this document the solution is: Primary Black Holes.
Feedback
If you want to give a comment you can use the following form Comment form
Created: 9 April 2016
Go Back to Wikipedia Comments in Wikipedia documents
Back to my home page Index