Photonic Rockets - Mass & Speed Effects

In summary, the conversation discusses powering a photonic rocket with photons and determining the speed it reaches when its mass is half its starting mass. The suggested method involves using the invariance of the 4D vector of momentum, and considering the momentum of the light emitted by the rocket. Alternative methods are also mentioned.
  • #1
liskawc
12
0

Homework Statement


one is powering a photonic rocket with photons. what is the speed it reaches when its mass is half its starting mass.
and per say you would start stoping then ... how would that look like (equations and sentences)


Homework Equations


invariance of the 4D vector of momentum (W/c)^2 - p^2=invariant


The Attempt at a Solution


i know the problem is solvable using the law that energy is constant and that momentum is comstant but i was wondering how would one do this using the above equation ... i d prolly need to consider the momentum of the light the rocket emitted, yes?
 
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  • #2
The four momentum of the total system is (m,0). You aren't going to get much out of that. You need to combine three vectors to get the result. And I gather you already know how to do that.
 
  • #3
aye ...
well i just wondered of alternative methods :D
 

1. What is a photonic rocket?

A photonic rocket is a type of spacecraft propulsion system that uses photons (particles of light) to generate thrust. This is achieved by directing a beam of high-energy photons out of the back of the spacecraft, which creates a reaction force that propels the spacecraft forward.

2. How does the mass of a photonic rocket affect its speed?

The mass of a photonic rocket does not affect its speed in the same way that it would for a traditional rocket. Instead, the speed of a photonic rocket is determined by the intensity and direction of the photon beam, as well as the efficiency of the propulsion system. Generally, a lighter spacecraft will be easier to accelerate and therefore can achieve higher speeds, but the mass of the rocket itself does not have a direct impact on its speed.

3. What are the potential advantages of using photonic rockets?

One potential advantage of using photonic rockets is their potential for extremely high speeds. Since photons travel at the speed of light, a photonic rocket could theoretically reach speeds close to that of light. Additionally, photonic rockets do not require traditional propellants, which could lead to cost savings and reduced environmental impact. They also have the potential to travel long distances without needing to refuel or carry additional propellant.

4. What are the limitations of current photonic rocket technology?

One of the main limitations of current photonic rocket technology is the amount of energy and power required to generate a strong enough photon beam for propulsion. This poses a challenge in terms of the size and weight of the necessary equipment, as well as the energy source needed to power it. Additionally, the efficiency of photonic rockets is still relatively low compared to traditional rockets, making them less practical for use in space missions.

5. Are there any real-world applications for photonic rockets?

While photonic rockets are still in the early stages of development, there are a few potential real-world applications. One is for deep space exploration, as photonic rockets have the potential to travel vast distances and could therefore be used for missions to other planets or even to other star systems. Another potential application is for space debris removal, as photonic rockets could potentially push debris out of orbit using their high-speed photon beams.

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