Humanity Greatest leap on Spaceships?

Spaceship using Light as Fuel

Is it possible to use light as fuel?

In Earth, we have plenty of sources of fuel; Hydrocarbons, electricity, solar energy etc. Hydrocarbons are getting reduced due to excessive use in today’s world, however electricity is slowly replacing excessive use of hydrocarbons. But we aren’t able to maximize the use of solar energy yet. The way producers use solar energy to the maximum, we are lacking way behind in the use of solar energy.

Here, solar energy means light energy only. We’re not concerned with thermal energy of solar radiations. Light energy is abundant around us even then we’re not able to use that effectively yet or in another words technological advancement for effective use of light energy is unavailable.

Inside earth light energy is not needed for transportation as electrical energy is more than enough.

So, why we need light energy as fuel?

In space flight, we need to carry fuel. It’s obvious we need to carry fuel but in long space flights like to the mars, the significant requirement of fuel increases even if we use gravitational push to increase our speed. The oxygen for the crew members, hydrogen fuel for 2-way travel, these things make spacecraft heavier and cost a lot. For an instance, if any unwanted event occurred and crew needed to fly away from the destination, we would run out of fuel; resulting in loss of extraordinary people and years of hard work. Due to this, fuel plays crucial part in space flight.

One might think of using solar energy as that’s abundant in space but that won’t be enough to power up the spacecraft. When a spacecraft enters the atmosphere of another planet, the sun rays incoming depends upon the atmospheric condition of that planet which is impossible to predict. So the use of solar energy as we use in Earth is busted.

So, How to use light energy as fuel?

Are there any advantages of using light as fuel over using gases (liquefied)?

Before these things, let’s go through a real life experiment conducted by a youtuber “Veritasium”.

In that experiment, He ran a small vehicle(propeller craft) powered only by wind. That vehicle gas a turbine on its top part which was connected to the wheels with multiple layers of chains. When wind hits the turbine, it starts to rotate which in turn rotates the wheels of vehicle hence vehicle moves due to wind only. A small string was also attached to the front part of vehicle which showed the direction of vehicle. After weeks of preparation, finally they conducted that experiment and when wind kicked, the vehicle started moving, gradually the speed increased and finally propeller craft was moving with speed same as of wind. So, apparently there’s no force pushing the propeller craft anymore. In that case, the string attached in front of craft becomes stationery i.e string won’t point towards any direction. This is condition up to where conservation of motion is defined and that craft won’t pass the speed of wind.

However, on further moving the string pointed backwards meaning that the craft was moving faster than the wind. Apparently, this violated the conservation of motion. But in fact it didn’t. And we achieved the speed greater than the wind even if the cause of motion of craft is the same wind.

For more explanation of that experiment check out this link: Youtube

The main point that I wanted to include in this topic of light as fuel is; we can use light as factor for movement and use the same principle as above experiment to get a lot of speed. One might think, if we’re able to overpass the wind with the help of wind, and then why not overpass the speed of light?

This is not that simple as in the case of wind. To surpass the speed of light or to even go near that speed, the mass of moving object should be very less like less than the mass of proton i.e. less than the mass of sub-atomic particles. That is impossible. So surpassing the speed of light doesn’t make sense. What can we do is, we can use light to gain a lot of speed. Such speed would require hell lot of gaseous fuel.

TO use light as factor of motion, we first require a craft designed to move only due to light.

So for an experiment, a small object is taken and made in such way that its front part is sharp, pointed and is almost perfect black. The making of almost black is to block the interference of light in front part. And the back part must be blunt and should be implanted with photo-sensitive device.

When light ray falls on the back part of the craft, the photo-sensitive device causes the craft to move. As the light will be continuous, the motion of the craft will also be continuous. As only back part of the craft is photo-sensitive, the resulting motion causes the craft to accelerate forward with huge motion. Also we need to keep in mind about stopping the craft, for that counter force is needed to stop accelerating the craft. So multiple dragging forces must be created, for that front part of the craft should contain movable photo-sensitive part such that, it can be used in need.

If this became reality, we no longer need to carry any fuel, and will save huge cost and risk of losing astronauts can be solved easily. However, we’re way behind developing such technology. But for small scale like craft of size of a pencil can be made to test the above theory. If that succeeds, we later can enlarge the craft according to our need.