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

Be the first pioneers to continue the Astronomy Discussions at our new Astronomy meeting place...
The Space and Astronomy Agora
Re: Relativity Acceleration Or Velocity

Forum List | Follow Ups | Post Message | Back to Thread Topics | In Response To
Posted by Zephram Cochrane/">Zephram Cochrane on February 9, 2000 01:15:30 UTC

: If your in a car, Travelling at the speed of light...... and you turn on your head lights........ What happens? :-)

: this is my question exactly : if a object is moveing at nearly or at the speed of light relative to say the earth : and emits a photon or light in the direction it is moveing : will that light be moveing away from the object that has emitited it at the speed of light in other words 2*the speed of light relative to the earth or would the light be nearly standing still in front of the object that has emited it since both are moveing at the speed of light

: : if the first is true then doesnt relativeity only apply to acceleration not actual velocity

: if the second is true then doesnt that mean that all speeds are relative to a central point of fixed 0 motion from which the universe began

Neither are true. The photon moves at c in both coordinate frames. That is what is meant by the local invariance of the vacuum speed of light.


Follow Ups:

Login to Post
Additional Information
About Astronomy Net | Advertise on Astronomy Net | Contact & Comments | Privacy Policy
Unless otherwise specified, web site content Copyright 1994-2024 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