Relativistic Beaming (shooting a laser at 90 degrees from your line of motion)

In summary: This means that the velocity of the laser beam as seen by the target is also 0.8c. Since the laser beam is moving at the same speed as the ship, the angle at which it must be shot to hit the target is 45 degrees.In summary, to hit the target, the ship must shoot the laser beam at an angle of 45 degrees. This can be determined using the equations of special relativity and the Pythagorean theorem. I hope this helps! Let me know if you have any further questions.
  • #1
khfrekek92
88
0

Homework Statement


A ship is traveling at a speed of .8c. When the ship is 90 degrees from the target, it shoots a laser downwards. What angle must it shoot the laser to hit the target?

Homework Equations


[itex]\mu_{x}=0[/itex]
[itex]\mu_{y}=-c[/itex]
[itex]\mu_{x}'=[/itex][itex]\frac{mu_{x}-v}{1-\frac{v*mu_{x}}{c^{2}}}=-v[/itex]
[itex]\mu_{y}'=[/itex][itex]\frac{mu_{y}}{1-\frac{v*mu_{x}}{c^{2}}}=-.6c[/itex]

The Attempt at a Solution


I have tried everything I can think of, but nothing seems to work..
I have gotten to this point and I'm fairly sure this far is at least right. Does anyone know where to proceed from here?

Thanks in advance,
khfrekek
 
Last edited:
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  • #2


Hello khfrekek,

Thank you for your post. I am a scientist and I would be happy to help you with this problem.

To solve this problem, we can use the equations of special relativity. We know that the ship is traveling at a speed of 0.8c, which means that its velocity is 0.8 times the speed of light. This means that the ship is moving at a very high speed and we need to take into account the effects of time dilation and length contraction.

First, let's define a coordinate system where the target is located at the origin and the ship is moving along the x-axis. This means that the ship's velocity vector is in the positive x-direction.

Next, we can use the Lorentz transformations to find the velocity of the laser beam as seen by an observer on the target. The Lorentz transformations are given by:

\mu_{x}'=\frac{\mu_{x}-v}{1-\frac{v*\mu_{x}}{c^{2}}}
\mu_{y}'=\frac{\mu_{y}}{1-\frac{v*\mu_{x}}{c^{2}}}

where \mu_{x} and \mu_{y} are the x and y components of the velocity of the laser beam as seen by the ship, and \mu_{x}' and \mu_{y}' are the x and y components of the velocity of the laser beam as seen by the target.

We know that the ship is traveling at a speed of 0.8c, so we can plug this value into the equations:

\mu_{x}'=\frac{\mu_{x}-0.8c}{1-\frac{0.8c*\mu_{x}}{c^{2}}}=\frac{\mu_{x}-0.8c}{1-0.8\mu_{x}}=-0.8c
\mu_{y}'=\frac{\mu_{y}}{1-\frac{0.8c*\mu_{x}}{c^{2}}}=\frac{\mu_{y}}{1-0.8\mu_{x}}=-0.6c

Now, we can use the Pythagorean theorem to find the magnitude of the velocity of the laser beam as seen by the target:

\sqrt{\mu_{x}'^{2}+\mu_{y}'^{2}}=\sqrt{(-0.8c
 

1. What is relativistic beaming?

Relativistic beaming is a phenomenon in which electromagnetic radiation, such as light, from a source moving at a high velocity appears to be concentrated in a specific direction, resulting in a brighter and more focused beam. This effect is caused by the relativistic effects of time dilation and length contraction.

2. How does shooting a laser at 90 degrees from your line of motion affect relativistic beaming?

When shooting a laser at 90 degrees from your line of motion, the relativistic beaming effect will be at its maximum. This means that the beam of light will appear much brighter and more focused in the direction of motion compared to the perpendicular direction.

3. Can relativistic beaming be observed in everyday life?

Yes, relativistic beaming can be observed in everyday life, particularly in situations where objects are moving at very high velocities, such as in space or in particle accelerators. However, the effect may not be noticeable to the naked eye and requires precise measurements and observations to be detected.

4. What are some practical applications of relativistic beaming?

Relativistic beaming has several practical applications, including in astrophysics for studying high-speed celestial objects and in particle physics for studying the behavior of subatomic particles. It is also used in medical imaging techniques, such as positron emission tomography (PET) scans, to produce high-resolution images of the human body.

5. Are there any limitations to relativistic beaming?

Relativistic beaming is subject to the limitations of the speed of light, which is the maximum speed at which any object can travel. This means that the effects of relativistic beaming are only noticeable at very high velocities, approaching the speed of light. Additionally, the angle at which the beam is observed can also affect the perceived intensity of the beam.

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