When we consider the distance for traveling a light year it is a big distance and a big number, and before we even go there and we have to understand that the light year is not time and it is a distance.
The distance traveled will depend upon how are you covering the distance and at Lightspeed, it would take almost a year.
Another point we have to consider is that humans will have a lot of issues while even traveling because it will feel like there is a relentless movement in space when we are considering the space environment and the relativity theory of Einstein.
1. How Long is a Light Year?
A light year tells you exactly the distance traveled by light in one year when it is traveling in space following a straight line path.
We can not use the kilometer or miles system of units because the distances are so large that these will require an enormous number of zeroes to bring it close to approximation.
When we consider the movement in space it is assumed that there are no effective gravitational fields or strong magnetic fields existing between these heavenly bodies.
To get a more numerical approach we can say that the speed of light is 299792458 m/s.
According to modern physics, it is believed that it is far from possible to have speeds greater than the speed of light, although there are theories and assumptions supporting the Alcubierre drive which is traveling with a speed faster than the speed of light there is no robust explanation that is to be followed for the same, and hence this remains unverified.
So, now when we consider a car, like our regular cars, then consider supercars and then spaceships we will have different variations in time, with a normal car it would take around 4 billion years, and with the help of super powerful engines in spaceships this can be covered in 20,000 – 40,000 years.
2. How Long Would it Take for 1 Light Year to Travel at the Speed of Light?
The one thing that we need to understand here is that time flows differently when its speed changes, and when the speed becomes as large as the speed of light the changes are tremendous.
To have a clear view of this let us take an example if a spacecraft is traveling at the speed of light it would take one human year to travel one light year; so when the speed becomes half or double the time taken by the spacecraft to cover that distance will get half or doubled
Based on the principle that speed is equal to the ratio of distance with time, meaning that speed is directly proportional to distance and inversely proportional to time.
Now, when we’re traveling at the speed of light it will take us approximately one-eighth of a second to take a round of the earth, implying almost 7-8 rounds around the earth in 8 seconds.
So, now that you have the idea of fleeting time and that too rapidly you will probably understand why it feels like humans in the aircraft will not age.
Contrasting it with our current speed it takes us almost three days to reach the moon but when the speeds reverse it will hardly take us 2 seconds to cover the same distance.
3. Will Light-Speed Space Travel Ever be Possible?
By Einstein’s theory of Relativity, the speed of light is a cosmic limit and it cannot be surpassed; on top of it if it involves a mass of humans or space vehicles it is nearly impossible.
Considering the technology in hand, it seems impossible only, because the probe that we currently support has only reached 2 parts of a thousand, in 40 years. So, only 0.2% of a light year is traversed in 40 years.
Extrapolating the same mathematics using the same probe, we will take a very long time to cover this distance, long before which the probe will become non-functional due to many reasons.
Another theory that supports quick and possible travel to this distance is Project Orion which dates back to the 1960s.
According to this if you build an enormous spacecraft and power it up by using atomic bomb droppings from the back, and simultaneously protect the crew upfront by using large metal plates and shock absorbers; you can achieve 10% of the speed of light.
Now, another problem would be that such a travel would again require close to 50-70 years but once the vehicle reaches the destination it will not have atom bombs left to give in the initial acceleration.
4. Closer to Mathematics
A light year is approximately 63241.1 astronomical units (AU). When light travels from the sun to reach us at 1 AU, it takes 499 seconds. Considering an aircraft traveling at 1000 kmph it will take us approximately 29 years to reach the sun.
So, this implies that it will take close to 2200 years to travel 1 AU.
If the speed is further increased to a few lakh kilometers per hour, we will then take 49 days to travel 1 AU and similarly, 8500 years to travel a light year.
Light is traveling at 186,000 miles per second, it is fast beyond imagination but the bodies that it is trying to reach are also equally far.
Sun is the closest star to us, now since we are very far away from the sun it takes a lot of time for light to travel from the sun and reach us but if we equate it to light years then those 93 million miles just take 8.3 minutes to reach us.
This is just another example explaining the enormity of the universe and the extremity of the speed of light.
5. Final Thoughts
About thirty-seven thousand years will be required to travel a distance of 1 light year, as far as the present technology is concerned.
Now to travel 1000, you can multiply this number by 1000, I think I’ll leave the mathematics to you now!