What is a light year?
344107
distance travlled by light in one year.\n\nso, mathematically, that is:\n\n299792458*365*24*3600\n\n= 9.45425496 × 10^15 metres
172339
Normally you'd describe shorter distances like that in AU (astronimical units - 1 AU=distance from earth to sun).\nBut - The distance is almost exactly 499 lightseconds - ie \nearth2sun in lightseconds/(days per year*seconds per day).\n499/(365.25*86400)=0.000016 lightyears.
75380
There is a surprisingly simple answer to your great question: Each month we see different stars, so to answer for a specific night of the year at your specific location on Earth depending on your eyesight and how bright the city lights around you are might be hard to pin down. \n However there is a magnitude scale that astronomers use to describe how bright objects in the sky are. Without getting into details on how that works, the average human being can see down to about magnitude 6 ( brighter objects have lower magnitude until you reach zero. Then even brighter objects use negative numbers for their magnitudes which is a bit weird, isn't it?) Therefore, all you have to do is get a map of the whole sky showing anything brighter than magnitude 6 and count the stars. If you are fortunate to be away from bright city lights and you can see the Milky Way, you would be really surprised to know that you can only see about 6,000 stars. That's the number of stars above magnitude 6 in the entire sky.
342843
About 93 million miles.  It's a distance used to measure distance of certain space objects.  It is called 1 AU or Astonomical Unit.\n\nIt is NOT 1 light year.  It's actually about 8 light minutes.
825824
Neptune is what, 2 or 3 billion miles away?  A light year is 6 trillion miles, so the distance is less than .001 light years.  Light years are practical only when measuring interstellar distances.
81010
Jupiter is way too close to be using light years.\n\nOne "Astronomical Unit" is the earth-sun distance and is approximately eight light minutes. Jupiter orbits at about five A.U. from the sun.  So even when Earth and Jupiter are at their most distant I would still expect that distance to be less than one light hour.
990179
time is not the movement of light. \nit is only perceived that way because it's the fastest thing we know of.  \n\nIf you traveled to a planet that is 4 lightyears away in only 3 years, time has still passed, and you are still older, you have simply managed to get to that planet faster than light waves were able to.
19286
The light-year is a measure of distance, not time. It is the total distance that a beam of light, moving in a straight line, travels in one year. To obtain an idea of the size of a light-year, take the circumference of the earth (24,900 miles), lay it out in a straight line, multiply the length of the line by 7.5 (the corresponding distance is one light-second), then place 31.6 million similar lines end to end. The resulting distance is almost 6 trillion (6,000,000,000,000) miles!
376769
light years isn't a time, it is a distance \nso it would be 2 light years
297501
I'm sure you are spekaing strictly hypothetically, but don't forget the closer you get to the speed of light (c), the slower time moves around you.  So if you were to go like 90% of c for 1 year, more than 1 year would pass for everyone else.
537507
1 lightyear = 9.4605 × 10^15 meters\n70 miles/hr = 9.875*10^8 meters/year\n\n9.4605 × 10^15 meters/ 9.875*10^8 meters/year = 9.58*10^6 years
162749
The light had to travel 14 billion years.  Earth travels much slowly.
545233
870436 billion light years. If u disagree, go and measure it urself
114012
My brain is saying, "4 light years" but I could be wrong about that. Been a while since I read "Contact" by Carl Sagan (part of which takes place around Vega).\n\nWait, wait ... let's Wikipedia this together. Let's see ... click, click ... v-e-g-a ... read, read ...\n\nWe, the jury, find Vega to be 25.3 light years from Earth.
259168
Light travels at 670,616,629.4 miles per hour, so you multiply that by the number of hours in 35 years.\n\n35 years x 365 days/year x 24 hours/day x speed of light in miles/hour.\n\nIt's like 205,611,058,574,040 miles.
281399
1) Light is both a wave and a particle phenomenon. Experiments can be devised to demonstrate either the particle or wave properties of light, just not at the same time (see 'particle wave duality').\n2) About 1,000 seconds. An astronomer named Christian Huygens (I think... might've been Oersted) first observed a 1,000 second discrepancy in the observation of Jupiter's moons eclipsing when observed in the summer as opposed to in the winter. This led him to the first good approximation for the speed of light, i.e. the extra time it took the light to cross the diameter of Earth's orbit could be measured, and since the approximate diameter of Earth's orbit was already known: Speed = Distance/Time or 186,000,000 miles divided by 1,000 seconds = 186,000 miles per second.\n3) The light year is a unit of DISTANCE, not TIME!! It is the distance that light travels in one year, or about six TRILLION miles. However even at this staggering speed it takes light over four years to reach the nearest star to Earth (other than the sun).
235335
If it's the big picture you're looking at, a year is the time it takes for the earth to make one revolution around the sun. The earth is thought to be some 4 billion years old.\n\nA decade is ten years. A century is one hundred years. A millenium is one thousand years.