the speed of light question

standardg60

standardg60 wrote: »

I like that.
Now all you have to do is imagine being the needle. If you then run around the record at the same speed as it's turning you won't hear any music ie. you've reached the speed of light.

You will still hear music. Music comes from the speakers, not the needle. And even if it came from the needle, you would still hear music. You need to travel at the speed of sound or greater away from the record player to not hear the music, not at the speed that the record is spinning.

Also, it has nothing to do with the speed of light nor relativity.

standardg60 wrote: »

But what you can't perceive, and playing a record is a great analogy as you don't really notice it, is at the same time the needle is moving from the outer edge inwards.

I won't notice it? If I'm running around the record, I'll certainly see the needle moving inwards and outwards (left and right in my frame of reference) and I'll even collide with it at some point.

standardg60 wrote: »

That is time, that is what makes yesterday yesterday and today today. It is the needle moving inwards that actually plays the song. If it wasn't you would just hear the same line over and over, sure if you run faster and faster the line would play slower and slower, but it's still the same line!

In order to hear anything time must exist, regardless of whether it's the same line over and over again or a full song.

That Calvin and Hobbes strip is merely a demonstration of the difference between angular and linear velocity, but here's some homework to get you thinking standardg60. As the comic correctly demonstrates, the linear speed of the particles in the record is greater for particles further from the centre. Therefore, why can't we simply just make a record big enough such the particles near the outer edge are going faster than the speed of light?

Capt'n Midnight

Deleted User wrote: »

Therefore, why can't we simply just make a record big enough such the particles near the outer edge are going faster than the speed of light?

Because the colour of gold.

Cordell

why can't we simply just make a record big enough such the particles near the outer edge are going faster than the speed of light?

Because it will require an infinite amount of energy to make it go almost at the speed of light.
On a purely theoretical attempt, there is no model that allow it. Classical mechanics do not apply at that speed, and relativistic mechanics don't allow the speed of light to be exceeded.

Capt'n Midnight

Capt'n Midnight wrote: »

Because the colour of gold.

Cordell wrote: »

Because it will require an infinite amount of energy to make it go almost at the speed of light.
On a purely theoretical attempt, there is no model that allow it. Classical mechanics do not apply at that speed, and relativistic mechanics don't allow the speed of light to be exceeded.

Ssshhhhh why is everyone doing standardg60's homework?! :pac:

standardg60

Deleted User wrote: »

You will still hear music. Music comes from the speakers, not the needle. And even if it came from the needle, you would still hear music. You need to travel at the speed of sound or greater away from the record player to not hear the music, not at the speed that the record is spinning.

Aargh, you're still not getting it! You are the needle! The closer you get to the speed of the spinning record the slower the record will spin relatively. I'm not talking about the speed of sound at all, i am equating it to the speed of light relative to how fast you are travelling.

Also, it has nothing to do with the speed of light nor relativity.

Try imagining it to do with that.



I won't notice it? If I'm running around the record, I'll certainly see the needle moving inwards and outwards (left and right in my frame of reference) and I'll even collide with it at some point.

You are the needle! If you run around your block you are not going to collide with yourself when you get back.



In order to hear anything time must exist, regardless of whether it's the same line over and over again or a full song.

You're nearly there..it can't be the same line over and over, it must be the whole song, the whole album , the second album etc.

That Calvin and Hobbes strip is merely a demonstration of the difference between angular and linear velocity, but here's some homework to get you thinking standardg60. As the comic correctly demonstrates, the linear speed of the particles in the record is greater for particles further from the centre. Therefore, why can't we simply just make a record big enough such the particles near the outer edge are going faster than the speed of light?

WE can't, because we are trapped on the needle wherever it's positioned on the record. We can only reach the speed the record is travelling at that position.
The record was travelling at a faster speed relative to the needle earlier, and it will travel at a slower speed later, we have no control over either.

Here's the seriously head melting bit. Within the confines of the speed at which the record is currently travelling under the needle, we can see as far as that speed allows back across the record that has just been played, but this is constantly disappearing as the needle moves inwards.

Just because we can't see it anymore doesn't mean the outer edge of the record doesn't exist. But it must. There's some homework for you too.

standardg60

standardg60 wrote: »

WE can't, because we are trapped on the needle wherever it's positioned on the record. We can only reach the speed the record is travelling at that position.

Again, this sentence demonstrates that you do not understand basic science. Sound waves travel out in all directions from a point source, just like water waves when you throw a rock into a lake. The only way you cannot interact with those water waves is if you move away from them at a speed equal to or greater the speed of the waves, and likewise for sound. Travelling in a circle in the vicinity of the waves does nothing.

And please, do not start a sentence with "we can't" when you know you are talking to someone who is an expert in this field and when you evidently know less about science than an average junior cert student. It's quite demeaning, especially when we're talking about basic things like sound waves and angular velocity. Instead, say something like "I don't see how that it can be possible that we can", otherwise it sounds like you don't want to learn, you just want to be right. I am starting to side with others in thinking that you are just a troll.

standardg60 wrote: »

Here's the seriously head melting bit. Within the confines of the speed at which the record is currently travelling under the needle, we can see as far as that speed allows back across the record that has just been played, but this is constantly disappearing as the needle moves inwards.

Just because we can't see it anymore doesn't mean the outer edge of the record doesn't exist. But it must. There's some homework for you too.

What homework do you have for me? You didn't state a question? And there is nothing head melting to me about what you just said.

Quantum Erasure

What happens if we play the record backwards...

Quantum Erasure

Quantum Erasure wrote: »

What happens if we play the record backwards...

Yvan eht nioj

standardg60

Deleted User wrote: »

Again, this sentence demonstrates that you do not understand basic science. Sound waves travel out in all directions from a point source, just like water waves when you throw a rock into a lake. The only way you cannot interact with those water waves is if you move away from them at a speed equal to or greater the speed of the waves, and likewise for sound. Travelling in a circle in the vicinity of the waves does nothing.

And please, do not start a sentence with "we can't" when you know you are talking to someone who is an expert in this field and when you evidently know less about science than an average junior cert student. It's quite demeaning, especially when we're talking about basic things like sound waves and angular velocity. Instead, say something like "I don't see how that it can be possible that we can", otherwise it sounds like you don't want to learn, you just want to be right. I am starting to side with others in thinking that you are just a troll.



What homework do you have for me? You didn't state a question? And there is nothing head melting to me about what you just said.

Again. I am not talking about sound. I have said it three times now. Why can't you actually read my posts and respond to them rather than making petty statements about me?
If you are such an expert then you should understand my concept regarding the record, but nothing in your replies conveys that, which makes me think that you are only an expert within the confines of what you have actually been taught to think.

standardg60

standardg60 wrote: »

Again. I am not talking about sound. I have said it three times now. Why can't you actually read my posts and respond to them rather than making petty statements about me?
If you are such an expert then you should understand my concept regarding the record, but nothing in your replies conveys that, which makes me think that you are only an expert within the confines of what you have actually been taught to think.

You are talking about sound. You are trying to use a terrible analogy between listening to sound while moving on a record player and us moving through spacetime, even though you evidently don't even understand the physics of sound from a record player.

If you then run around the record at the same speed as it's turning you won't hear any music

This statement is false, and a 12 year-old can tell you why. This statement alone shows a severe lack of understanding of basic science.

But what you can't perceive, and playing a record is a great analogy as you don't really notice it, is at the same time the needle is moving from the outer edge inwards.

This statement is also false, and it's so easy to see why that I do indeed believe that you are trolling.

Remember, I am expert in this field, and we are talking about very basic physics. I am not giving an opinion on what you are saying, I am telling you it is wrong. I am not expecting you to disagree with what I say, I am only expecting you to go and do some research to try to understand why you are wrong.

If you were also an expert and we talking about a more advanced topic, then we can debate it. And hopefully that will be true in a few years if you actually spend time studying physics properly instead of posting whatever shower thought pops into your head next.