Oh-Lee and Ray - how can you challenge an almost 80yr old woman with all that physics on a morning before she had her coffee! - Since I shall be with the Lord or in that distant land rather sooner than later I shall submit to the assertion that eternity is like a day or a second or a blink of an eye , an Augenblick or totally outside the measure of time, but hope to have a device up there, or perhaps down there, to keep participating in your email exchanges. You know what? I went down to the basement and looked up my old German highschool Physics book to read about the speed of light!. Anybody wants an antique like that ? I can add the book on Chemistry for good measure. Marta On Jan 28, 2005, at 9:06, RWhite at neffpackaging.com wrote:
> > > > > In a vacuum, light always travels at a speed of 299,792,458 meters per > second, no matter how its speed is measured. > ...Just in case anyone was think that m/s was miles per second! > > Ray White > Neff Packaging Solutions > 1700 Watterson Trail > Louisville, KY 40299 > Tel: 502-491-1820 ext.330 > Fax: 502-491-7701 > www.neffpackaging.com > > > > > Lee Larson > <leelarson at mac.com> To: > macgroup at erdos.math.louisville.edu > Sent by: cc: > owner-macgroup at erdos.math.lou Subject: > Re: MacGroup: High speed access newbie > isville.edu > > > 01/28/2005 08:57 AM > Please respond to macgroup > > > > On Jan 28, 2005, at 12:19 AM, Nelson Helm wrote: > >> I read that persons standing on the sidewalk below hear Big Ben, the >> bell at the Houses of Parlement, after Australian listeners to the >> BBC. Signal goes to Australia at speed of light, in less time than to >> sidewalk at speed of sound. > > Being my usual persnickety self, I checked the facts, and you're right. > (Google knows everything!) > > Big Ben is 106 m tall, so it takes the sound about 0.3 s to reach the > ground at 340 m/s. > > The mean circumference of the earth is 12,742 km and the speed of light > in a vacuum is 299,792,458 m/s. As a worst case, Australia is halfway > around the world, so use 6500 km as the distance from London to > Australia, giving 0.02 s as the time to get there. > > Light is quick, but not quick enough to help satellite broadband. A > satellite in geostationary orbit is 35,768 km above the equator. It > takes at least 0.12 s to get a signal there. Since we're talking > round-trip time, this is about a quarter second to squirt something up > there and get it back. > > I've tried satellite broadband. > > It works great for downloading big files because once the file starts > coming, it comes really fast. > > Using a terminal is pretty frustrating because the echo of what you've > typed takes at least a half second to appear. > > Complex Web pages are made up of dozens, or even hundreds of little > pieces. You can watch in slow motion as your computer requests them and > they arrive. The satellite broadband companies are fighting the latency > by caching commonly requested pages so they can send all the pieces at > once without waiting for the individual requests. > > Email is OK because you just get it all in one shot, so the half second > isn't noticeable. > > > > | The next meeting of the Louisville Computer Society will > | be January 25. The LCS Web page is <http://www.kymac.org>. > | List posting address: <mailto:macgroup at erdos.math.louisville.edu> > | List Web page: <http://erdos.math.louisville.edu/macgroup> > > > > > > | The next meeting of the Louisville Computer Society will > | be January 25. The LCS Web page is <http://www.kymac.org>. > | List posting address: <mailto:macgroup at erdos.math.louisville.edu> > | List Web page: <http://erdos.math.louisville.edu/macgroup> | The next meeting of the Louisville Computer Society will | be January 25. The LCS Web page is <http://www.kymac.org>. | List posting address: <mailto:macgroup at erdos.math.louisville.edu> | List Web page: <http://erdos.math.louisville.edu/macgroup>
