| Topic: |
Science > Physics |
| User: |
"Todd Roarke" |
| Date: |
03 Mar 2006 09:45:51 AM |
| Object: |
Speed of Light: 186,000 or 186,282 |
The speed of light is always quoted at 186,000 MPS. On more than
one occasion, I've seen the speed of light defined as 186,282 MPS.
The first time, I figured, they just got the number wrong, or did
not do their research. I've seen it more times than coincidence
would allow.
So, is it 186,000 MPS as we're taught from birth or 186,282 MPS?
.
|
|
| User: "Greg Neill" |
|
| Title: Re: Speed of Light: 186,000 or 186,282 |
03 Mar 2006 09:52:49 AM |
|
|
"Todd Roarke" <tjr@roarkenet.net> wrote in message news:Xns977B63527777E00000000@216.196.97.142...
The speed of light is always quoted at 186,000 MPS. On more than
one occasion, I've seen the speed of light defined as 186,282 MPS.
The first time, I figured, they just got the number wrong, or did
not do their research. I've seen it more times than coincidence
would allow.
So, is it 186,000 MPS as we're taught from birth or 186,282 MPS?
Neither. It's defined precisely in the metric system:
http://physics.nist.gov/cgi-bin/cuu/Value?c
.
|
|
|
| User: "PD" |
|
| Title: Re: Speed of Light: 186,000 or 186,282 |
03 Mar 2006 11:03:07 AM |
|
|
Greg Neill wrote:
"Todd Roarke" <tjr@roarkenet.net> wrote in message news:Xns977B63527777E00000000@216.196.97.142...
The speed of light is always quoted at 186,000 MPS. On more than
one occasion, I've seen the speed of light defined as 186,282 MPS.
The first time, I figured, they just got the number wrong, or did
not do their research. I've seen it more times than coincidence
would allow.
So, is it 186,000 MPS as we're taught from birth or 186,282 MPS?
Neither. It's defined precisely in the metric system:
http://physics.nist.gov/cgi-bin/cuu/Value?c
And since that number is *exact* by definition, and since the
conversion from meters to miles is *exact* by definition, you can do
that conversion to however many digits you want to declare. To the
precision of the calculator I just used, that's
186282.3970512208701185079137835 miles per second.
PD
.
|
|
|
| User: "" |
|
| Title: Re: Speed of Light: 186,000 or 186,282 |
06 Mar 2006 12:17:43 PM |
|
|
And for an exact value as a rational number, c = 186282 and
638992/1609344 miles/second
The denominator comes from:
299792458 X 1000 / ( 25.4 X 12 X 5280 )
I don't know how long it takes for the decimal representation of a
fraction, with 1609344 as the denominator, to start repeating...
.
|
|
|
| User: "Henning Makholm" |
|
| Title: Re: Speed of Light: 186,000 or 186,282 |
06 Mar 2006 12:52:49 PM |
|
|
Scripsit "jmorriss@idirect.com" <jmorriss@idirect.com>
c = 186282 and 638992/1609344 miles/second
I don't know how long it takes for the decimal representation of a
fraction, with 1609344 as the denominator, to start repeating...
The period is 42 digits long, and the first repetition starts 3 digits
after the decimal point.
--
Henning Makholm "Wir kommen nun ans Ziel unserer Ausführungen."
.
|
|
|
| User: "" |
|
| Title: Re: Speed of Light: 186,000 or 186,282 |
06 Mar 2006 01:51:58 PM |
|
|
Thank you... I really needed to know that... :)
.
|
|
|
|
|
|
| User: "" |
|
| Title: Re: Speed of Light: 186,000 or 186,282 |
03 Mar 2006 12:42:06 PM |
|
|
PD wrote:
Greg Neill wrote:
"Todd Roarke" <tjr@roarkenet.net> wrote in message news:Xns977B63527777E00000000@216.196.97.142...
The speed of light is always quoted at 186,000 MPS. On more than
one occasion, I've seen the speed of light defined as 186,282 MPS.
The first time, I figured, they just got the number wrong, or did
not do their research. I've seen it more times than coincidence
would allow.
So, is it 186,000 MPS as we're taught from birth or 186,282 MPS?
Neither. It's defined precisely in the metric system:
http://physics.nist.gov/cgi-bin/cuu/Value?c
And since that number is *exact* by definition, and since the
conversion from meters to miles is *exact* by definition, you can do
that conversion to however many digits you want to declare. To the
precision of the calculator I just used, that's
186282.3970512208701185079137835 miles per second.
PD
Speed of light in vacuum: Value 299 792 458 m s-1
It is exact because the meter is now defined (as of 1983) as the
distance traveled by light in vacuum during 1 / 299 792 458 of a
second.
http://www.mel.nist.gov/div821/museum/timeline.htm
.
|
|
|
| User: "The Ghost In The Machine" |
|
| Title: Re: Speed of Light: 186,000 or 186,282 |
04 Mar 2006 02:00:07 PM |
|
|
On Fri, 03 Mar 2006 10:42:06 -0800, onehappymadman wrote:
PD wrote:
Greg Neill wrote:
"Todd Roarke" <tjr@roarkenet.net> wrote in message
news:Xns977B63527777E00000000@216.196.97.142...
The speed of light is always quoted at 186,000 MPS. On more than
one occasion, I've seen the speed of light defined as 186,282 MPS.
The first time, I figured, they just got the number wrong, or did
not do their research. I've seen it more times than coincidence
would allow.
So, is it 186,000 MPS as we're taught from birth or 186,282 MPS?
Neither. It's defined precisely in the metric system:
http://physics.nist.gov/cgi-bin/cuu/Value?c
And since that number is *exact* by definition, and since the conversion
from meters to miles is *exact* by definition, you can do that
conversion to however many digits you want to declare. To the precision
of the calculator I just used, that's 186282.3970512208701185079137835
miles per second.
PD
Speed of light in vacuum: Value 299 792 458 m s-1
It is exact because the meter is now defined (as of 1983) as the distance
traveled by light in vacuum during 1 / 299 792 458 of a second.
http://www.mel.nist.gov/div821/museum/timeline.htm
Admittedly, that does not answer the question as to how precisely the
meter can be defined, as the question of how precisely that second can be
measured (and how far light has traveled during that measurement) is an
issue. AIUI, the old KR-86 standard was abandoned because it simply
wasn't precise enough (as in a few parts per billion).
For what it's worth, in Google one gets
(299 792 458 (m / s)) / (1 (mile / s)) = 186 282.397
which is about what one would expect given significant figures, and
consistent with the calculator answer above.
For back of napkin calculations, 3 * 10^8 is a reasonable substitute,
giving an error of about 0.07% at most.
--
#191,
It's still legal to go .sigless.
.
|
|
|
|
|
|
|
| User: "srp" |
|
| Title: Re: Speed of Light: 186,000 or 186,282 |
03 Mar 2006 11:33:53 AM |
|
|
Todd Roarke a écrit :
The speed of light is always quoted at 186,000 MPS. On more than
one occasion, I've seen the speed of light defined as 186,282 MPS.
The first time, I figured, they just got the number wrong, or did
not do their research. I've seen it more times than coincidence
would allow.
So, is it 186,000 MPS as we're taught from birth or 186,282 MPS?
Both are right in context. When speaking generally, texts are fine
with 186,000 mps if no computation is required or involved.
When you want to use the speed of light in actual calculation, then
of course you need the more precise figure 186,282 mps. All
calculations will however be more precise using the metric system
since the speed of light has been defined as an exact integer in
this system, which is not the case for the english system.
André Michaud
.
|
|
|
|
| User: "Sam Wormley" |
|
| Title: Re: Speed of Light: 186,000 or 186,282 |
03 Mar 2006 09:56:22 AM |
|
|
Todd Roarke wrote:
The speed of light is always quoted at 186,000 MPS. On more than
one occasion, I've seen the speed of light defined as 186,282 MPS.
The first time, I figured, they just got the number wrong, or did
not do their research. I've seen it more times than coincidence
would allow.
So, is it 186,000 MPS as we're taught from birth or 186,282 MPS?
See: http://www.google.com/search?q=c+in+mile%2Fs
Speed of Light
http://scienceworld.wolfram.com/physics/SpeedofLight.html
.
|
|
|
|
| User: "" |
|
| Title: Re: Speed of Light: 186,000 or 186,282 |
03 Mar 2006 11:37:43 AM |
|
|
Todd Roarke wrote:
The speed of light is always quoted at 186,000 MPS. On more than
one occasion, I've seen the speed of light defined as 186,282 MPS.
The first time, I figured, they just got the number wrong, or did
not do their research. I've seen it more times than coincidence
would allow.
So, is it 186,000 MPS as we're taught from birth or 186,282 MPS?
Check out the concept of 'significant digits'.
--
FF
.
|
|
|
|
| User: "PD" |
|
| Title: Re: Speed of Light: 186,000 or 186,282 |
03 Mar 2006 11:45:37 AM |
|
|
Todd Roarke wrote:
The speed of light is always quoted at 186,000 MPS. On more than
one occasion, I've seen the speed of light defined as 186,282 MPS.
The first time, I figured, they just got the number wrong, or did
not do their research. I've seen it more times than coincidence
would allow.
So, is it 186,000 MPS as we're taught from birth or 186,282 MPS?
We also frequently hear that the distance between the sun and the earth
is 93,000,000 miles, though with a moment's thought it might seem just
a tad unlikely that the last six digits would be all zero. After all,
why should it be exactly 93,000,000 miles and not, say, 93,000,003
miles?
In fact, the mean sun-earth distance is 92 955 887.6 miles, and that
measurement is only good to the 9 digits quoted (that is, the next
digit is not known to be zero), and on top of that, it's only correct
twice a year because the earth's orbit is really elliptical and so half
the time it is closer than that and half the time it is further away
than that.
So why is it quoted as 93,000,000 miles? Because that number is good to
3-digit precision, which is all you need for most calculations.
PD
.
|
|
|
| User: "Todd Roarke" |
|
| Title: Re: Speed of Light: 186,000 or 186,282 |
03 Mar 2006 06:15:15 PM |
|
|
"PD" <TheDraperFamily@gmail.com> wrote in news:1141407937.902879.16130
@z34g2000cwc.googlegroups.com:
Todd Roarke wrote:
The speed of light is always quoted at 186,000 MPS. On more than
one occasion, I've seen the speed of light defined as 186,282 MPS.
The first time, I figured, they just got the number wrong, or did
not do their research. I've seen it more times than coincidence
would allow.
So, is it 186,000 MPS as we're taught from birth or 186,282 MPS?
We also frequently hear that the distance between the sun and the earth
is 93,000,000 miles, though with a moment's thought it might seem just
a tad unlikely that the last six digits would be all zero. After all,
why should it be exactly 93,000,000 miles and not, say, 93,000,003
miles?
That's true, but I think it's safe to say that a vast majority of people
do not believe the sun is EXACTLY 93 million miles away and the distance
is never given in absolutes, whereas light is always described as the
ABSOLUTE speed limit of the universe and with a few exceptions is said
to equal 186,000 mps.
Anyway, thanks for the replies. This is a bigger letdown than the Santa
Clause fiasco.
--Todd--
.
|
|
|
| User: "Richard Tobin" |
|
| Title: Re: Speed of Light: 186,000 or 186,282 |
06 Mar 2006 10:07:01 AM |
|
|
In article <Xns977BB9B037CBC00000000@216.196.97.142>,
Todd Roarke <tjr@roarkenet.net> wrote:
with a few exceptions is said
to equal 186,000 mps.
That's strange. I almost always see it as 300,000 km/s.
-- Richard
.
|
|
|
| User: "QCD Apprentice" |
|
| Title: Re: Speed of Light: 186,000 or 186,282 |
06 Mar 2006 10:54:51 AM |
|
|
Richard Tobin wrote:
In article <Xns977BB9B037CBC00000000@216.196.97.142>,
Todd Roarke <tjr@roarkenet.net> wrote:
with a few exceptions is said
to equal 186,000 mps.
That's strange. I almost always see it as 300,000 km/s.
The obvious solution is to have the two of you duel to the
death.
.
|
|
|
|
|
|
|
|
Related Articles |
Re: Star Gates Was there a civilization that existed 13 000 years ago?
More than 6,000 Kg of thrust by pnn
1,000 coalition troops killed in Iraq
20,000-lb. Bus vs. Pedestrian -- Analogy Sought
Hurricane Charle has power of 100,000 A bombs
Car that does 10,000 miles per gallon
NASA 'Scramjet' Soars at Almost 7,000 Mph
Dyson's 100,000 Gs ?
| 38 MW 20 inch 500 psi 600 si 300,000 pound thrust
Giant Blob headed to Earth by 5500 AD ? Blame it on the Gum Nebula star explosion @15,000 years ago, it may have melted last ice age, caused ozon hole, volcanos and earth quakes, (Supernova Remnant in Puppis & Vela)Covering 40-60% of the Southern Sk
From the Messiah to the 144,000 and the 200 million of the 12 tribes of Israel. On Jewish science.On the Global Holocaust of the Gentiles. The secrets of dephypotising humanity (Jewish science). To the Seven Servants of war. The end of the Matrix (hy
From the Messiah to the 144,000 and the 200 million of the 12 tribes of Israel. On Jewish science.On the Global Holocaust of the Gentiles. The secrets of dephypotising humanity (Jewish science). To the Seven Servants of war. The end of the Matrix (hy
Article: Cosmic CAT Scan - Observing the early universe--with 10,000 TV antennas
Re: 40,000 V vs. 350 mV
TURN $6 INTO $15,000 IN ONLY 30 DAYS...HERES HOW - "paypal.rtf" 12.4 KBytes yEnc
|
|
|
