Solve Boggling Questions on Relative Speed of Light and Time Dilation

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In summary, the conversation discusses two hypothetical scenarios related to the speed of light and time dilation. The first scenario involves two crafts moving towards each other at half the speed of light, with each craft emitting a light that appears to be stationary to the other. The questions raised are whether the light from each craft reaches the other before a collision occurs and how it is possible for one pilot to see the other's light but not vice versa. The second scenario involves a person traveling at a whisper of light speed and the discrepancies in time between their watch and an observer's watch. The conversation highlights the need to understand the relativistic addition of velocity and the concept of time dilation in order to resolve these questions.
  • #1
AshsZ
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A couple of simple questions I'm boggled by...

Suppose two people, each in his own craft, set apart by significant distance and stationary to each other. Both crafts accelerate to 1/2 light speed from their origins directly towards each other. This results in a relative speed between the two craft of light speed. Now let's say both crafts have a light, one orange and the other blue so they can discern between each, and once they have reached 1/2 they both turn on their lights, both pointing towards the other craft.
It is obvious that from both crafts the light the light must travel forward away at speed c towards the other craft. But from the other craft's perspective the light would be moving towards him at the same speed as the craft emitting the light resulting in neither seeing each other's light at all. From each craft's perspective though, their light will travel forward at speed c towards the other craft.

Questions are, does the light from each craft reach the other before the two crafts collide head on to each other? How is it possible that each craft's pilot can see their light projecting forward through space when turned on but at the same time the other craft's pilot cannot see the light until the point of collision?

Another hypothetical: Let's put Jim into a particle accelerator. He is wearing a nice watch. You accelerate him to a whisper of light speed in this accelerator and each time he makes the 186,000 mile loop you see how much time has passed on his watch. On your watch he's whizzing by once a second but his watch ticks none. How is it possible that he is traversing distance at such speed but yet no time ticks by on his watch?

Something has to give here but I can't figure out how to resolve these questions.
 
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  • #2
AshsZ said:
Suppose two people, each in his own craft, set apart by significant distance and stationary to each other. Both crafts accelerate to 1/2 light speed from their origins directly towards each other. This results in a relative speed between the two craft of light speed.
No. Each will see the other as moving at 0.8c, not at light speed. Look up the relativistic addition of velocity.
 

1. What is the speed of light?

The speed of light is a constant in the universe, with a value of approximately 299,792,458 meters per second. It is denoted by the letter "c" in scientific equations and is the fastest speed at which all known physical phenomena can travel.

2. How does time dilation relate to the speed of light?

Time dilation is a phenomenon predicted by Einstein's theory of relativity, which states that time appears to pass slower for objects moving at high speeds. This is due to the constant speed of light, as the faster an object moves, the more time it takes for light to reach it, resulting in a perceived slowing of time.

3. What is the formula for calculating relative speed of light?

The formula for calculating relative speed of light is v = c/n, where v is the relative speed, c is the speed of light, and n is the refractive index of the medium through which light is traveling. This formula takes into account the fact that light travels at different speeds in different mediums.

4. How does the relative speed of light affect our perception of time and distance?

The relative speed of light affects our perception of time and distance by causing time dilation and length contraction. As an object approaches the speed of light, time appears to slow down and distances appear to shrink. This can be observed in high-speed travel or in experiments with particles accelerated to near-light speeds.

5. What are some real-world applications of understanding relative speed of light and time dilation?

Understanding relative speed of light and time dilation is crucial in many areas of modern science, such as in space travel, particle physics, and GPS systems. It also plays a role in everyday technologies, such as radar and satellite communication, which rely on precise measurements of time and distance. Additionally, understanding time dilation can aid in the development of future technologies, such as faster-than-light travel or time travel.

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