Nacht van de Duisternis

Weersvoorspellingen zijn gunstig voor zaterdag 14 oktober, de nacht van de duisternis. Helios zal aanwezig zijn vanaf 19h in Langdorp thv Wolfscafé.

14 Oktober Nacht van de Duisternis

Sterrenvereniging Helios zal aanwezig zijn op zaterdag 14 oktober te Langdorp vanaf 19h ter hoogte van het Wolfcafé. Iedereen is welkom en de leden zullen een woordje uitleg geven over de wondere wereld van sterren en planeten.

Spotless Sun

Since yesterday we have again a spotless sundisk. This year we already counted 50 days without a sunspot.

2018 Solar Probes

Both ESA as NASA will be launching their solar probes next year 2018.
ESA's Solar Orbiter will be launched October 2018 and will orbit the Sun on a distance of 0.28AU closest.

Parker Solar Probe from NASA will be launched in August next year and will be travelling into the Sun's atmosphere as close as 0.04AU.

Eugene Parker visiting Parker Solar Probe at APL

Eugne Parker is an American astrophysicist who developed the theory that the sun's atmosphere expands beyond the sun itself and the fact it's plasma is travelling between the planets. Today we know this as the solar wind.

Onze Zon v22 - new update

Update version 22 of my script of the Sun.  Download available here.

Emergent Gravity by Vonk in Maastricht University

Lieven and myself in front of Maastricht University

On October 4th, Lieven and myself both members from Helios Astronomy club attended a lecture on Emergent Gravity and Dark Energy. The lecture was given by Dr. Marcel Vonk at the University of Maastricht. About 200 people were present in the beautiful Aula and listened for 1,5h to the newly theory from Prof. Erik Verlinde. 

Dr. Marcel Vonk at the Aula of Maastricht University

A couple of new concepts I learned are the concept "Emergent",  the whole idea of  "Information which is Entangled" and a(n) (Anti) De Sitter space. 

The entire lecture can be found back via this link on the website from Quantum Universe

Prof. Erik Verlinde

As a conclusion Emergence, the creation of gravity on a large scale from the distribution of information on a small scale, addresses three problems at the same time. Firstly, gravity as we know it does not exist on a microscopic scale and therefore an understanding of the laws of gravity on a quantum scale is unnecessary. Secondly, space on a quantum scale consists of information bits that are entangled with each other. If the microscopic state of all bits has a high energy, space seen on a large scale is De Sitter space. This explains the origin of dark energy. Thirdly, the creation of a mass in De Sitter space relocates the information associated with the dark energy. This relocation of information has implications for masses that are located, for example, at the edge of a galaxy. This reaction force corresponds to the effects that are attributed to the mysterious dark matter.

Solving three problems in one go is a wonderful prospect, but can Verlinde's ideas be put to the test? They certainly can: we have seen that his theory not only offers qualitative descriptions, but also provides quantitative formulas that can be verified through observational data. Conversely, falsification is, of course, also possible: as soon as one of the many current quests results in finding an actual matter particle to provide an explanation for the dark matter, Verlinde's theory will obviously be incorrect.

But even if Verlinde's theory is correct, there is still much work to be done. One major open question, for example, is how the dynamics of the universe enters into his formulation: can this theory also offer an accurate description of the history of the universe and the movement of matter and ‘dark matter’ over the course of time? Can it be used to explain the properties of cosmic background radiation, the light coming from the early universe that we are still observing today? In addition, in some observations, such as those of the so-called Bullet Cluster, not only the relationship between ordinary and ‘dark’ matter is measured, but also the way in which these two appear to be distributed over space. This distribution does not always prove to be nicely symmetrical, and it therefore offers a wonderful challenge for Verlinde's model to explain such observations.

Whatever the case may be, Erik Verlinde's ideas do sound appealing and offer an interesting alternative view to decades-old fundamental problems concerning gravity. Hopefully, within the not too distant future, his theory will contribute to gaining a clear understanding of the everyday force that we have been experiencing for millions of years.

Dr. Marcel Vonk is beside a string theorist also a Poker player.

Rainbow above Aarschot

After rain ... a rainbow :)