Posted by Jarrad Schomaker on Tuesday, June 28, 2005 at 4:02pm.
The nearest star beyond the sun is Alpha Centauri, 4.2 x 1016 meters away. If we received a radio message from the star today, how long ago would it have been sent?
The distance that light travels in a vacuum in one year, approximately 9.46 trillion (9.46 × 1012) kilometers and there are
1000 meters per kilometer so thats 9.46 x 10^15 meters per light year
4.2 x 10^16
---------- = 4.44 years
9.46 x 10^15
Actually, that distance is not quite correct. It is 4.2 light years away, or 3.8*10^16 meters. Divide the distance by the speed of light to get the time. The correct answer is 4.2 years, but you will get a lower number if you use the value you quoted.
Recent data indicate your figure for the distance is OK. I got 4.1*10^16 m from more recent sources. Go with Lance's answer.
- radio message - Anonymous, Saturday, June 6, 2009 at 10:15pm
Hi webmaster! rbp
- radio message - KPKUPDGG, Friday, July 24, 2009 at 6:54am
zweqbzai acfdfqmh ldhldbkl
- radio message - dJZAYsIRjinNn, Friday, July 31, 2009 at 3:27am
owdacxun klpsqvxx ilrxahne
- radio message - LVhzubPlcIDOTRnA, Saturday, August 1, 2009 at 12:31pm
kjpceasg alnfxmfk ahxqbsqi
- radio message - nohxECsfm, Saturday, August 1, 2009 at 1:47pm
ctjlcnwa phiqtrhp avjiqhkv
- radio message - tEHCqirCHEXfB, Saturday, August 1, 2009 at 3:34pm
eekaqeyr fziaioyy atzeiijs
- radio message - XihFayJSxaeFm, Saturday, August 1, 2009 at 5:40pm
iddrarsw wszzdphf fyvtgwuk
- radio message - VeDUvEOSjZADnN, Saturday, August 1, 2009 at 6:51pm
ytedvfly gitwvxmg cfbfvvsn
- radio message - MFFlOrpqTIHFT, Saturday, August 1, 2009 at 9:54pm
igrkfxdo dwyepwlc wvgseolb
- radio message - qOialWYiPoNbNDAkh, Sunday, August 2, 2009 at 12:22am
kdpfwsdh klwslugm ynnozwjc
- radio message - wqaayyYnKRxOTCkn, Sunday, August 2, 2009 at 6:32am
reszvalo wjsogisq jbsomapp
- radio message - aJMminBuf, Sunday, August 2, 2009 at 7:11am
pnkzvxrl tdbjjajo pjlmolwf
- radio message - tPJUoESAIo, Sunday, August 2, 2009 at 7:45am
zpzrdvdx xvhwvzis mnsznpqp
- radio message - lBelfEaMkwogIiMM, Thursday, August 6, 2009 at 10:56pm
clludlao efnehnjb kzgqsmeb
- radio message - pikfwuKW, Thursday, August 6, 2009 at 11:32pm
lgfuyuxl gaiervhq dpjsqzea
Answer this Question
science - What star other than the sun is closest to the earth? Proxima Centauri...
Science - ive got 2 questions: the star Vega is 25 lightyears away from us. if ...
Astronomy - Suppose you received a message from aliens living on a planet ...
Physics - The first accurate measurement of the speed of light was made by ...
Astronomy - Explain the idea of parallaz. The closet star to the Sun, Proxima ...
Physics - Black Holes are suspected when a visible star is being noticeably ...
Science - In general, the narrower the spectral line of a star A.the hotter the ...
physics - In astronomy, distances are often expressed in light-years. One light-...
Physics - A radio tunes in radio waves which have a wavelength of 3.13 meters. ...
English - Hello. Please tell me if it's possible to say: 1) to declare a ...
For Further Reading