Validity (1 Viewer)

[nahi11]

Hi,

I have a question regarding the validity of the Michelson-Morley experiment. I understand the accuracy and reliability bits, but I am not sure what actually makes the experiment 'valid'. I guess it addresses the aim but that sounds pretty weak to me.

Thanks

 

[BadMeetsEvil]

Hi,

I have a question regarding the validity of the Michelson-Morley experiment. I understand the accuracy and reliability bits, but I am not sure what actually makes the experiment 'valid'. I guess it addresses the aim but that sounds pretty weak to me.

Thanks

the experiment is valid if it supports the known data. in this case, the hypothesis. but it doesn't support their hypothesis so the experiment by Michelson morely is invalid.

 

[nahi11]

the experiment is valid if it supports the known data. in this case, the hypothesis. but it doesn't support their hypothesis so the experiment by Michelson morely is invalid.

Thanks for the reply.
Are you sure it is invalid? I mean sure the hypothesis is incorrect, but all that means is that the hypothesis is incorrect and needs to be changed. All the procedures that were carried seem scientifically valid and it has also addressed the aim.

Still open for other opinions.

 

[BadMeetsEvil]

Thanks for the reply.
Are you sure it is invalid? I mean sure the hypothesis is incorrect, but all that means is that the hypothesis is incorrect and needs to be changed. All the procedures that were carried seem scientifically valid and it has also addressed the aim.

Still open for other opinions.

changed my mind. it was valid because even after technological advancement, the result was the same as the original data. however it failed to address and prove the hypothesis. but yeah the coerent was reliable and valid

 

[Fizzy_Cyst]

Well, validity is really asking the question:
Does the experiment measure what it is intended to measure?

In the case of the MM experiment, it was intended to measure the speed of the Earth relative to the aether and it did not do this and never could do it according to ESTOR, hence the experiment is invalid. Basically, observations/measurements in experiments cannot be valid unless they are reliable and accurate. The results from the MM experiment were reliable as they were repeated a number of times with the same results. However, the results are not accurate (accuracy is basically how do the results compare with what is expected), as they were expecting to observe a fringe shift of 0.4, but they only detected a fringe shift of 0.005 -- nowhere near what was expected. Hence, not accurate at all.

That is my opinion, but yeah, different teachers have different opinions and I dont think any textbook really settles that question.

 

[nahi11]

Thanks, Rep+ both of you.

 

[bosresearch]

There's a significant misconception here: validity is NOT just about the "correctness" of the conclusion, but also on the accuracy of the experimental procedure that led to the conlcusion (in this case, the "null" result).
And so, to be technically accurate, you can't really say: M-M is invalid. To be precise, you'll have to answer as follows:
although the experiment's conlusion is singlinifcanly invalid (as it violates the hypothesis), their experimental procedure was, nevertheless, extremely valid as extremely small changes in the intereference pattern were able to be recorded by the apparatus.

Hope this helps!