Recent content by Chronos

Correct, the ring speed is unrelated to the rotation speed of the planet it orbits

You got to set the zero point somewhere in the sky and astornomers chose the vernal equinox as the zero point for the measurement known as right ascension. if you think of the sky as a gigantic clock face it all makes sense. Since there are 24 hours in a day and obviously you can only see 12...

A ring is nothing more than a large number of small objects in orbit around a planet. Orbital velocity is a function of distance from the planet. At small distances the orbital velocity must be greater than at larger distances for a body to remain in orbit. A body in orbit cannot exceed escape...

Mars is undoubtedly feasible. While many unknowns remain, we have technologies proven capable of getting there. Alpha Centauri is not yet even a remote possibility. We simply lack the technology needed to even attempt sending a probe that far. IMO, colonization of all the habitable places in the...

Retreating to stark reality is sometime refreshing. Returning to the prospect of anti matter powered engines, a 2016 anti matter projection pegs the production cost of anti matter at $100 trillion [US] per gram. The anti matter needed to power a probe to Alpha Centauri is estimated at 100 -...

A right angle finder scope is on my 'must have' list for a newt or dob..

The technological challenges are currently too great to consider even a probe to Alpha Centauri. The fuel requirements alone are absolutely mind boggling. Even a hypothetical antimatter drive operating at say 50% efficiency [usable propulsion energy vs total liberated] would demand an enormous...

As Drak said your priority should be as much aperture as you can manage. The purpose of a scope is to gather light and the more you can gather the better so long as you can manage to prepare it for a viewing session. There is no accessory at any price that can increase the amount of light your...

Nice list, Dave. The F! has enough aperture to actually see some interesting things. If computer control is not a 'must', the Meade Polaris is virtually the same scope on a much nicer mount at half the price.

Aperture is a word frequently mentioned by telescope reviewers. In a nutshell you want the most aperture available at your price point A 6 inch anything is going to offer way more ROI than a 3 inch anything else. The finest optics and accessories cannot compensate for the light gathering power...

White ls not a color, it is merely a roughly equal mix of all the colors for which the human eye has receptors. 'White', only means the brain cannot perceive a dominant component of the wavelengths being received. The eye only has receptors for three basic colors - red, green and blue and the...

For a sun like star, the molecular cloud fragment from which the protostar forms is probably starts out about 1017meters in diameter, and shrinks to about 1011 meters upon reaching the protostar phase. It needs about a million years before it then stabilizes at solar size [`109 meters.

1. I i meant lithium, not tritium, my mistake. The heaviest brown dwars can achieve lithium fusion, which is la little below the temperature needed for hydrogen fusion. 2. Perhaps you misread the word 'hot' for 'not'. 3 I fail to see the relevance of white dwarf temperatures. These links may...

Adding mass to a degenerate body would cause it to shrink only so far as nothing else changes. For a brown dwarf, that something else would be hydrogen fusion. Once that occurs, the shrinkage would cease and it would expand due to the heat. A brown dwarf can remain degenerate, but initiate...

I think it is fair to assume anywhere conditions similar to those of early Earth are found, abiogenesis is a question of when, not if. Whether or not that life evolves into anything familiar is a different and more difficult question. Despite our impressive technology, we still do not know if...