Thinking Science: Using well-defined terms.

Let's say we are in contact with the Zorgons (an alien race that has no idea what a meter is). We want to tell them about our measurement system.

1. First we have to make sure they know how we count, and learn the integers.

2. Then we tell them to count vibrations in the Cesium-133 atom. That teaches them the period of time that is a second.

3. Then we tell them to calculate the distance of a light second . They can do this by seeing the distance light travels in a second.

4. Then we tell them to take 1/299792458 and call that a meter.

These steps require that they count vibrations of a Cesium-133 atom and measure the distance travelled by light in a second. If they do these steps, their meter will be the exact same length as our meter.

There is nothing circular here. It is just a matter of measurement.

So, to be on the same page, what's the definition of the speed of light?

The definition of the speed of light is "the distance that light travels per unit time".

Cite, please.

https://www.thoughtco.com/speed-2699009

(Or any Physics 101 textbook).

Think of it this way... you can not have circular definitions in science. Science would literally break, and any measurement would be impossible.

It doesn't make any sense.

The only place that light was mentioned on that website was in a link to another article that doesn't define the speed of light.

You are wrong, IfraBlue. I am trying to teach you what you have wrong. The definition of speed is the "distance travelled per unit time". The speed of light is the "distance travelled by light per unit time". That is what the word "speed" means.

I think I have explained it well, if you don't understand what I am saying then ask. This is silly to argue. You are either going to accept what I am saying, or you aren't.

The development of these measures is interesting. Our current definition of a "second" involves counting vibrations of a Cesium-133 atom. Obviously we were measuring "seconds" long before we had the equipment to measure these vibrations. Actually we were counting time in seconds before Cesium atoms, and even atoms in general, were discovered.

The original second was measured by the length of a day, divided into hours then minutes than seconds. This is rather difficult to use accurately since the length of a day differs. It is fine if you don't need to make accurate measurements, but once we started measuring milliseconds...

The original meter was based on the circumference of the Earth. Again this has problems in accuracy (depending on where and when you measure). For a while there was an official "meter" (I think it still exists)... people would come an carefully cut meters copied from the official meter. Of course this had to be carefully controlled in an airtight temperature controlled room or the meter could wear down.

The current measurements are specifically designed to be

1) Measurable by experiment.
2) Constant (i.e. not changing).
3) Exact and accurate.

Given that these measurements can be derived from the unchanging speed of light, and the vibrations of a specific isotope, then can be derived from scratch.

I was just thinking about my hypothetical aliens from my first post on this page... if they didn't have access to Cesium-133, I think they would be screwed.

So, where’s your cite for your definition?

I cite myself. I spent years studying Physics and taught it at both college and high school. I am teaching you basic Physics, you can either learn it or reject it. If you don't want to learn from me, any basic Physics course will teach you the same. This isn't a subject that is up for debate.

Think of it this way, I just detailed for you (on the top of this page) a perfectly good way to define all of these measurements in a way that isn't circular.

Either....

1. I am simply telling you the way science simply does things, repeating what I was taught.

2. Or, I am a genius who has come up with a way to make definitions non-circular in a way that no one else has ever considered.

I am telling you it is definitely #1.

This is simply how things work. It isn't up for debate.

Ah, you cite yourself. Your thread would have been better titled “Thinking maxdacona’s pseudoscience: using maxdancona’s definitions.”

1. I explained to you why you had to be wrong.
2. I carefully outlined how measurements are defined in a way that is clearly non-circular.
3. I provided a cite.
4. In addition I provided a narrative of how measurements were defined in the past that I think is interesting.

I am trying to cut down on the number of silly arguments I get into here. I don't know what else I can do.

You will believe what you want. I tried to answer your questions. This is something that I have both studied and thought about. Hopefully someone finds what I write to be interesting and informative.

Your argument is based on a weasel word definition of your own creation.

I don't want to continue a silly argument.... but I am curious. Which "weasel word definition" do you mean? Are you disagreeing with the definition of the word "speed"?

If I can explain this more clearly, I would like to know how.

I'm referring to your definition of the speed of light.

Ok. Do you at least see how if we define the speed of light as the distance travelled by light per unit time, that resolves any circular references?

Your question-begging red herring doesn't address the issue of the circularity of the definitions of the speed of light and the meter.

I have addressed the definitions of the speed of light and the meter multiple times. I suspect that it has become personal now, and that you won't change your mind no matter what I say.

Are you willing to even accept the possibility that you might be misunderstanding this? If your problem is me, you can ask Farmerman, or Engineer... or anyone else with a scientific education. They will say almost certainly say the same thing that I am saying because that is the correct answer.

I have done everything I can think of to explain this to you. I explained point by point how it is not circular; you can derive the length of a meter without knowing the length of a meter. If that doesn't prove to you that your statement is wrong, I don't know what will.

If you have legitimate questions about the example I gave to you (the first thread on this page) that would be useful. What you are doing is just stubborn denial of what is correct.


You are not getting it. I am not sure if you are trying to understand or just to argue. I don't know what else to do to help you here.

You've addressed the definition of the speed of light with your own definition.

That dog won't hunt.