Back to Home

Blackholes Forum Message

Forums: Atm · Astrophotography · Blackholes · Blackholes2 · CCD · Celestron · Domes · Education
Eyepieces · Meade · Misc. · God and Science · SETI · Software · UFO · XEphem
RSS Button

Home | Discussion Forums | Blackholes I | Post
Login

Be the first pioneers to continue the Astronomy Discussions at our new Astronomy meeting place...
The Space and Astronomy Agora
Re: DO INDEFINITE CYCLE EXISTS IN THE UNIVERSE?

Forum List | Follow Ups | Post Message | Back to Thread Topics
Posted by Bruce Jensen on May 1, 1997 10:59:35 UTC

: Fabien - your question about "indefinite cycles" in the universe is a little vague; anything with the word "cycle" or "cyclic" usually implies sense of definition, that is, it has a period and amplitude. There are many, many definite cycles in the universe. Every solar system, galaxy and planet with moon experiences orbital cycles, which are often very definite and well-defined. Our Earth is in one of these orbits around the sun, with a period of 365.26 days and an amplitude of approximately 93,000,000 miles. If you trace this out on a graph of amplitude versus time, you woudl see a very regular sinusoidal wave/cycle pattern. Other types of cycles are the cycles of starbirth, star-death and rebirth (in the form of new stars); although these cycles are more or less indefinite in terms of amplitude and period (that is, they will vary and be less than predictable for any given star), they nonetheless are a cycle of sorts - the stuff that makes a star is ejected back into the interstellar medium upon the star's death, and eventually finds its way to reignite in the nuclear furnace of a new star. It could be said that the universe itself is in a cyle of sorts (assuming a closed universe), in which the universe expands from a point, stops and reverses, and then deflates into a big crunch singularity. Whether this cycle actually occurs or theoretically repeats is a darn good question! There are many other cycles, mostly more subtle, that exist, but most are fairly definite in terms of period and amplitude. perhaps you could explain a little more specifically what an indefinite cycle would include...?

Follow Ups:

Login to Post
Additional Information
Google
 
Web www.astronomy.net
DayNightLine
About Astronomy Net | Advertise on Astronomy Net | Contact & Comments | Privacy Policy
Unless otherwise specified, web site content Copyright 1994-2018 John Huggins All Rights Reserved
Forum posts are Copyright their authors as specified in the heading above the post.
"dbHTML," "AstroGuide," "ASTRONOMY.NET" & "VA.NET"
are trademarks of John Huggins