Comments about "Oort cloud" in Wikipedia

This document contains comments about the document "Oort cloud" in Wikipedia
In the last paragraph I explain my own opinion.

Contents

Introduction

In this section we read.
The outer Oort cloud is only loosely bound to the Solar System, and thus is easily affected by the gravitational pull both of passing stars and of the Milky Way itself
The idea that the trajectories of the individual objects in the Oort Cloud are affected by passing stars is considering the present, wrong. When a stars comes in the neighbourhood of the solar system it will effect the whole of the solar system and not only the Oort cloud. Anyway this is a rare event and can take millions of years (?) if the speed resembles the speed of our solar system.
The primary cause of the movement of the solar system is the Milky Way. To claim that the Milky Way is the cause of comets is "wrong".
These forces occasionally dislodge comets from their orbits within the cloud and send them towards the inner Solar System.
The objects in the Oort cloud generally speaking follow all parallel straight lines in the same direction as the Sun. There will be small tiny angles between different objects. As such that close encounters can take place or even collisions. As a result for these close flyby's one of the objects can be directed towards the Sun which is observed as a comet.
The chances of commets is higher when the sizes of the objects in the Oort Cloud are larger.
See document (3) "ORIGIN AND DYNAMICAL EVOLUTION of comets and their reservoirs: http://arxiv.org/pdf/astro-ph/0512256v1.pdf This document does not discuss dark matter.
At page 30 we read:
At such large distances from the Sun, the evolution of the comets in the Oort cloud is strongly affected by the overall gravitational field due to the mass distribution in the galaxy (the so–called galactic tide), and by sporadic passing stars and giant molecular clouds (GMCs).
At page 31 we read:
The role of passing stars and GMCs is to reshuffle the comet distribution in the Oort cloud, and to refill the high inclination region where comets are pushed into the planetary region by the disk ’s tide.
Of course, stars and GMCs can also directly deflect the cometary trajectories, injecting the comets into the inner solar system without the help of the galactic tide.
I have my objections.
See also page 33:
This suggests that the direct injection of comets from the Oort cloud due to passing stars and/or GMCs (neglected in the simulation) has non-negligible importance.

1. Hypothesis

2. Structure and composition

3. Origin

The Oort cloud is thought to be a remnant of the original protoplanetary disc that formed around the Sun approximately 4.6 billion years ago.[3]
If the Oort cloud is created during the evolution of the solar system than its structure and composition is mostly unknown.
The most widely accepted hypothesis is that the Oort cloud's objects initially coalesced much closer to the Sun as part of the same process that formed the planets and minor planets,
The evolution of the Solar System started from the condensation of a gas cloud which initially first formed small objects which slowly builded up to the Sun and the planets. This process is still going on which is observed as colliding comets with the Sun.
This same sentence continues as:
but that gravitational interaction with young gas giants such as Jupiter ejected the objects into extremely long elliptic or parabolic orbits.
The chance that very small objects are ejected by Jupiter is small. That they were ejected to very large distances is even smaller.
The chance that larger objects are ejected outside the solar system (and stay inside the Oort cloud) is much larger.

9. See also

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Created: 21 Juli 2015

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