Can some one explain light years to me.?

Question

I would like to know how long is a light year in relationship to earth years.
When travelling in space do they travel in light years or earth years.
What determined what a light year is.
How many light years away is mars?

Answer 1

Despite its name, a light year isn't a measure of time--it is a measure of distance.


Here's how it is defined: light travels at a fixed velocity--about 186,000 miles or 300,000 km per second. A light year is just the distance light will travel in one (earth) year.

So you take the number of seconds in a year and multiply it by the velocity light travels:
300,000 km/sec times 31.5 million seconds (I rounded the numbers off--but thats about how many seconds are in one year)
= 9.45 trillion km (about 6 trillion miles)
Thats about 60,000 times as far as from the earth to the sun--and when Mars is at its closest to earth, it's about 1/150,000 of a light year away.

BTW--the CLOSEST star t ous (other than the sun)--is Proxima Centauri--about 4.3 light years away--or about 26 trillion miles!

Answer 2

You can't compare a light year to an earth year because one is a measure of distance and the other of time. A light year is the distance travelled by light in one earth year, one earth year being 365 days, or the time taken for Earth to complete one orbit of the Sun. It works out to about six million million miles.

Current space travel is too slow to travel any distance that can sensibly be measured in light years. Mars is only light minutes away. Neptune is only light hours away. One light year is a HUGE distance. It is only really needed when talking about distances to stars.

Answer 3

Light year is the distance that light can travel in 1 earth year.
Mars is less then 9 light minutes from earth as thats the time light takes to get from the sun to earth.

Answer 4

Light is believed to travel at a fixed speed, defined in a vacuum at approx 186,000 miles per second.

The Earth is 7,500 miles in diameter or 22,000 miles around and the moon is 250,000 miles away so it takes a tad less than 2 seconds for light to reach the moon from the Earth, as in say, a laser beam.

The Sun is 93,000,000 miles away so the light sent out from the sun takes 8.3 minutes to reach the Earth.

A light year is the distance in miles that light travels from a star or other light emitting object into space.

A year is defined as a solar year of 365.25 days times 24 hours a day times 60 minutes an hour times 60 seconds. You then mutiply the speed of light, 186,000 in one second, times the number of seconds in a solar year, which is 31,557,600 seconds which yelds 5,869,713,600,000 or roughly almost 6 TRILLION miles in a single year.

The closest star OTHER THAN OUR SUN (which is 8.3 light minutes away) is in Centuri and it is 4+ light years away and thus the light from that star has travelled about 26 Trillion miles to reach your eye.

The light you see from our SUN which is 8.3 millioin years old the moment you see it, will be 4+ years old by the time someone on Centauri would see it.

Answer 5

A light year is the distance light can travel in one year year. It is 9,460,536,207,068,016 meters When traveling in space, they travel much slower than the speed of light. For example, the space shuttle travels at 26,000 feet per second. Mars is 142 million miles from the sun (Earth is 93 million miles). The sun's light gets to mars in 11.7 minutes.

Answer 6

A light year is a distance not a time. I light years is how far light travels in one year going at 186,262 miles per second

Answer 7

The universe is a tricky thing to explain as well as to comprehend. It's very clear that indeed many parts, if not all of the universe is very old, according to our studies. And taking your passage from the bible. I can only assume that "heavens" meant that wonderful place where good people go. Earth is very old, but not as old as the universe itself. You make a good observation by pointing out distant objects. But if you think about the Big Bang theory, while huge massive rocks, gas....whatever you want to call it, collided with each other...who's to say that it didn't fling things over to the other side of the universe. This is something we should question more often, but no one really seems interested in science and would rather keep there question here on Earth.

Answer 8

How many seconds in a year?

60 x 60 x 24 x 7 x 52 = 31,449,600 seconds in a year.

seconds in a minute x minutes in an hour x hours in a day x days in a week x weeks in a year = seconds in a years

x="times"

How far does light travel in one second?

about 186,000 miles per second.

How far does light travel in one year?

31,449,600 times 186,000= 5,849,625,600,000

That is about 5.8 trillion miles.

1 light year is about 5.8 trillion miles

1 light year is how far light travels in one Earth year.

Time is measured in years, distance is measured in light years.

Mars distance varies between 4 light minutes at its closest to Earth to 20 light minutes in its farthest from Earth.

Answer 9

A light year is a unit of distance, not of time: it is the distance that light travels in one year -- about 5.8 trillion miles. The closest stars are about four light years away.

Answer 10

Light speed = 299,792,458 meter per second

1 earth year = 365.25 days = 8,766 hours
= 525,9660 minutes = 31,557,600 seconds

1 light year is how far light can travel during 1 earth year

1 light year = 299,792,458 * 31,557,600
= 9,460,730,472,580,800 meter
= 9,460,730,472,580.8 km