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light years to miles

Posted: Fri Jun 27, 2008 2:32 am
by jesusfreak16
It's a challenge converting light years to miles (i.e. the Dumbell Nebula is around 6,902,858,931,840,000 miles from earth or 1,200 light years)
By the way that number is 6 quadrillion,902 trillion,858 billion,931 million,840 thousand.
Anybody wanna convert the distance from the nearest galaxy(or something else)?


Just for clarity in the poll question,let's just pretend that light can actually follow the curvature of the earth (which it can't) :roll:

Re: light years to miles

Posted: Fri Jun 27, 2008 2:47 am
by neufer
1) Everyone should know the beautifully simple formula for the speed of light in kilometers per second.

2) Everyone should know the size of the earth in kilometers (since kilometers were originally defined by the size of the earth).

Re: light years to miles

Posted: Fri Jun 27, 2008 3:26 am
by BMAONE23
jesusfreak16 wrote:It's a challenge converting light years to miles (i.e. the Dumbell Nebula is around 6,902,858,931,840,000 miles from earth or 1,200 light years)
By the way that number is 6 quadrillion,902 trillion,858 billion,931 million,840 thousand.
Anybody wanna convert the distance from the nearest galaxy(or something else)?


Just for clarity in the poll question,let's just pretend that light can actually follow the curvature of the earth (which it can't) :roll:
938,511,360,000,000,000
938 quadrillion, 511 trillion 360 billion miles to LMC (160000ly)
1,231,796,160,000,000,000
1 quintillion, 231 quadrillion, 796 trillion, 160 billion miles to SMC (210000ly)
13,139,159,040,000,000,000
13 quintillion, 139 quadrillion, 159 trillion, 40 billion miles to andromeda

Posted: Fri Jun 27, 2008 12:52 pm
by orin stepanek
186/25 =7.44 therfore about 7 for your poll.
http://www.calculateme.com/Length/Kilom ... oMiles.htm

Orin

Re: light years to miles

Posted: Fri Jun 27, 2008 12:57 pm
by bystander
neufer wrote:1) Everyone should know the beautifully simple formula for the speed of light in kilometers per second.
~ 300,000 km/sec
neufer wrote:2) Everyone should know the size of the earth in kilometers (since kilometers were originally defined by the size of the earth).
~ 40,000 km circumference

300/40 = 7.5

Re: light years to miles

Posted: Fri Jun 27, 2008 3:14 pm
by Orca
jesusfreak16 wrote:It's a challenge converting light years to miles...
neufer wrote:1) Everyone should know the beautifully simple formula for the speed of light in kilometers per second.

2) Everyone should know the size of the earth in kilometers (since kilometers were originally defined by the size of the earth).
As Neufer suggests, why would we want to figure this out in imperial units?

SI >> Imperial

Re: light years to miles

Posted: Fri Jun 27, 2008 5:28 pm
by bystander
Orca wrote:
jesusfreak16 wrote:It's a challenge converting light years to miles...
neufer wrote:1) Everyone should know the beautifully simple formula for the speed of light in kilometers per second.

2) Everyone should know the size of the earth in kilometers (since kilometers were originally defined by the size of the earth).
As Neufer suggests, why would we want to figure this out in imperial units?
Why do light years, light seconds are more appropriate for the poll.

~ 186,000 mi or 300,000 km

Posted: Sat Jun 28, 2008 2:56 am
by jesusfreak16
my bad :oops:

Posted: Sat Jun 28, 2008 3:09 am
by jesusfreak16
I just realized this,but I forgot to limit the number of times people could vote
only one vote per user please(thanks) 8)

Posted: Sat Jun 28, 2008 4:24 am
by BMAONE23
jesusfreak16 wrote:I just realized this,but I forgot to limit the number of times people could vote
only one vote per user please(thanks) 8)
I believe the polling works that way at least one vote per poster ID

Posted: Sat Jun 28, 2008 5:47 pm
by makc
I dont get it why it has to be a poll. It is well-defined math problem, with exact solution (that seems to be already posted). Why would someone vote for number other than that?

Posted: Sat Jun 28, 2008 6:28 pm
by henk21cm
makc wrote:I dont get it why it has to be a poll.
Join the club!
makc wrote:Why would someone vote for number other than that (correct number)?
There may be just one reason: it is a kind of intelligence test. Since the correct answer is not any of the items to choose, -only integers are listed, the answer is considerably more than an integer- the correct vote is not to vote, since none of the answers is exactly correct.

This thought is so farfetched and the type of poll used is so inappropriate -how do you count 'not voted' (=read - number of votes) and distinghuish from 'i do not know' / 'what is the status now'?- that i have to let go this thought.


_ _ _ _ _ _ _

Regards,
 Henk

Posted: Sun Jun 29, 2008 11:07 am
by makc
on the other thought, one could actually vote for any of 2, 5, and 7.

since the exact solution is 7 point something, and the question is: "How many times could light go around the earth"... if it could go 7 point something, it could as well go 7 times, and so 6, and 5, and 4, and 3, and 2 etc. It could not go 10 times, though, or 14, or 20.

Posted: Mon Jun 30, 2008 5:01 pm
by jesusfreak16
Ok,Ok so let's just forget the poll

*rolls eyes*

Posted: Mon Jun 30, 2008 7:10 pm
by Arramon
LOL

even a simple poll is squished and prodded to see if it holds any scientific data or substance.... how FUNNY.

It was just a question and he posed it with a simple poll that many people don't even use in forums anymore.

It wasn't a question as to the validity of the poll itself. Just another way of posing a scientific mathematical question in a simple laymans way using multiple choice... ie having fun.

And out of all the nonsensical 'scientific' responses I see that people don't think that light can curve, although lensing does just that and the earth's atmosphere also affects what we see of the spectrum of light from the Sun as it passes our planet. So the arguments weren't really needed, because nothing was trying to be proven.

OKAY then. Let's say an arranged assortment of mirrors were placed in orbit around the Earth, and the light reflected from those mirrors created a continual stream of light bouncing from mirror to mirror, following a circular path around the planet. How long would it take for that light moving from mirror to mirror in this fashion take to get from the first mirror, around the earth and back again?

*Place your answers from above here*

=b

Not only that, could this continual stream of light be used in any way to collect energy from? Maybe directed to certain types of stations or satellites that could convert the light to energy.

Posted: Tue Jul 01, 2008 3:19 am
by BMAONE23
The answer to the first part would depend on the orbital alitude of the mirrors and also on the distance the light would travel but anywhere from approx. 1/7th second at 200mi alt to 1/5th second at 2000 mi alt.

As to the second part, If they were of sufficient size (monsterously large) Mirrors could be used to transfer light to the night side of the planet to light up small areas though not nearly as bright as daylight which means most current solar technology wouldn't function properly if at all.

Posted: Wed Jul 02, 2008 12:44 am
by harry
G'day from the land of ozzzzzzz

What about gravity, how many times can it go around the earth in one second.

Posted: Wed Jul 02, 2008 5:37 pm
by Arramon
gravity travels? O.o

You just made my brain fart. It cannot comprehend.. =b

Posted: Wed Jul 02, 2008 9:09 pm
by jesusfreak16
harry wrote:
What about gravity, how many times can it go around the earth in one second.
I might answer if I knew how that would be possible :)

Posted: Thu Dec 18, 2008 4:38 pm
by harry
G'day from the land of ozzzzzzzzzz


Since there are several opinions as to the speed of gravity and that there is no evidence to prove such a speed.

Two opinions, one is that gravity travels at the speed of light and the other is, that it travels at over 10 times the speed of light.

Google for the info.

Re:

Posted: Thu Dec 18, 2008 8:22 pm
by Chris Peterson
harry wrote:Since there are several opinions as to the speed of gravity and that there is no evidence to prove such a speed.

Two opinions, one is that gravity travels at the speed of light and the other is, that it travels at over 10 times the speed of light.
You'll not find many physicists with an "opinion" that the speed of gravity is anything other than c. Why is that? For two reasons. First, it is predicted by GR, and if gravity propagated at a different speed, it would probably break GR in ways that we would have already observed. Keep in mind that GR is one of the most strongly substantiated physical theories we have. Second, the speed of gravity has been indirectly measured in a couple of different ways, and found to be close to c- between 1% and 20%, depending on the method. This is very far from a factor of ten.

I don't believe any observation has been made supporting a speed substantially different from c. Thus, in the usual way of science, c is recognized as the most likely speed of gravity.

Re: Re:

Posted: Thu Dec 18, 2008 8:46 pm
by neufer
Chris Peterson wrote:
harry wrote:Since there are several opinions as to the speed of gravity and that there is no evidence to prove such a speed.

Two opinions, one is that gravity travels at the speed of light and the other is, that it travels at over 10 times the speed of light.
You'll not find many physicists with an "opinion" that the speed of gravity is anything other than c. Why is that? For two reasons. First, it is predicted by GR, and if gravity propagated at a different speed, it would probably break GR in ways that we would have already observed. Keep in mind that GR is one of the most strongly substantiated physical theories we have. Second, the speed of gravity has been indirectly measured in a couple of different ways, and found to be close to c- between 1% and 20%, depending on the method. This is very far from a factor of ten.

I don't believe any observation has been made supporting a speed substantially different from c. Thus, in the usual way of science, c is recognized as the most likely speed of gravity.
Gravitational (Quadrupole) Radiation is inversely proportional
to the speed of gravity TO THE FIFTH POWER.

If the the speed of gravity were ten times the speed of light
then the loss of energy in the Hulse-Taylor binary
would be 100,000 less than it is observed to be:

Image

<<It was theorized that the Hulse-Taylor binary
pulsar was the Star of Bethlehem. About it, the famous sci-fi novelist Arthur C. Clarke said,
How romantic, if even now, we can hear the dying voice of a star, which heralded the Christian era.">> :roll: