# Please explain this light speed question.

• ollybygolly
In summary, the conversation discusses the concept of traveling at extreme speeds and the effects of time dilation and mass increase. It also mentions the possibility of turning into a black hole and asks for recommendations on free online physics courses. The main point is that traveling at .6C away from a point of origin in opposite directions does not result in a combined speed of 1.2C.
ollybygolly
If you are traveling .6C away from your point of origin and your friend is traveling .6C away from the same point of origin but in the opposite direction, why are you not traveling 1.2C away from your friend?

I want to ask a couple more here that may have been covered in that other thread, but In an effort to keep things clear and not to hijack that other thread I am going to post them here.

in my original question that was ansered in the other thread it shows that .6c+.6c is not 1.2c.

However, let's go a step further. Let's say the two objects start coasting once they hit .6c. So I'm in my spaceship and I no longer feel any acceleration. I'm floating around in the cabin. My frame of refference is that I am not moving at all. I'm just sitting there floating.

Now I hit my thruster again and I accelerate to .6c again from my original frame of refference.

Why can't I do this over and over until I am going faster than light as measured from my original starting point? Is it that every time I make a speed jump time dialates in response?

In your original frame, the energy you impart would mostly go into apparent mass. This is how the LHC and other devices work. Energy is imparted to the protons, but as they get close to the speed of light, it shows up as mass rather than speed increase.

Just try it and see what the Velocity Addition formula gives you for each additional burst of acceleration.

So instead of going faster, my mass increases. As my mass increases, I exert more gravity on the space around me. And as my gravity grows time dialates. So in essence I would turn myself into a black hole about the same time I reached the speed of light, if I could get that fast.

Any good free on line physics courses out there? Ones that expain how a particular mathamatician came up with their equations and the proofs they used?

I have a lot of probably stupid questions that I'm sure would be answered by taking some classes.

ollybygolly said:
So instead of going faster, my mass increases. As my mass increases, I exert more gravity on the space around me. And as my gravity grows time dialates. So in essence I would turn myself into a black hole about the same time I reached the speed of light, if I could get that fast.
No, that's not what happens. You will go faster. But no observer watching you will see you reach c. You definitely won't become a BH.

Any good free on line physics courses out there? Ones that expain how a particular mathamatician came up with their equations and the proofs they used?

I have a lot of probably stupid questions that I'm sure would be answered by taking some classes.
I recommend classes, but I can't name any specifics wothout knowing your level of mathematics.

ollybygolly said:
[..] in my original question that was ansered in the other thread it shows that .6c+.6c is not 1.2c. [...]
That would conflict with the basics of mathematics: .6c+.6c=1.2c by mathematical definition of addition. What was perhaps not made clear is that you asked about a transformation between coordinate systems.

See for an elaboration some earlier threads, for example:

## 1. What is light speed and why is it important to understand?

Light speed is the speed at which light travels in a vacuum, which is approximately 299,792,458 meters per second. It is important to understand because it is the fastest speed at which anything in the universe can travel, and it has significant implications for our understanding of time and space.

## 2. How is light speed measured and what tools are used to measure it?

Light speed is measured using a variety of methods, including experiments with lasers and mirrors, observations of astronomical objects, and particle accelerators. Tools such as high-speed cameras, spectrometers, and interferometers are used to measure light speed.

## 3. How does light speed compare to other speeds in the universe?

Light speed is significantly faster than any other speed in the universe. For example, the speed of sound is only 343 meters per second, and the fastest human-made object, the Voyager 1 spacecraft, travels at a speed of about 17 kilometers per second.

## 4. Can anything travel faster than light?

According to our current understanding of physics, nothing can travel faster than light. This is because as an object approaches the speed of light, its mass increases, and it would require an infinite amount of energy to accelerate it to the speed of light.

## 5. How does light speed affect our perception of time and space?

Light speed has a profound effect on our perception of time and space. According to Einstein's theory of relativity, time slows down as an object approaches the speed of light, and space itself can be distorted by the presence of massive objects. This means that our understanding of time and space is not absolute and can vary depending on our relative speed and position in the universe.

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