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by jdjdps 4057 days ago
'You're supposed to question what they're saying; you're supposed to look at logical implications to see if what they're saying is all consistent.' What you are doing here is saying - I will take my model of the world and check that their observations are consistent with what it predicts are physically possible. Then saying I found their observations to be inconsistent with how I expect the world to behave given my model. A natural follow on step from this is to conclude that they have missunderstood how their experiment is constructed - there is something about the way they are performing their experiment which is not accurately reflected in the model of their experiment. For instance there might in fact be conventional exhaust escaping from the device in a manner they had not anticipated. This is fine, this is also my interpretation. But where we differ is that I am very able to imagine a world where my model is innacurate and I appreciate that sometimes things that appear to require radically different models can in fact be produced by relatively minor ammendments. And that many people I meet seem to be very unwilling to question their own models and ammend them where necessary, upsets me. It upsets me because I believe in many instances it is born of the same kinds of irrationality that the whole enterprise of rational thought was designed to fix in the first place. At times, to me, it feels like it has become just another church for people to cling to. The rigid models I percieve within public discourse on these topics are a symptom of the very same creeping irrationality that they are purportedly defending against.
1 comments

> What you are doing here is saying - I will take my model of the world and check that their observations are consistent with what it predicts are physically possible.

Conservation of momentum has been confirmed by many, many experiments; it's not just a feature of my or anyone's "model" of the world.

> there might in fact be conventional exhaust escaping from the device in a manner they had not anticipated.

Yes, that's quite possible. But as far as I can tell, the experimenters are not even considering that possibility, or checking for it.

> I am very able to imagine a world where my model is innacurate

Sure, imagining a world in which momentum is not conserved is easy. But, as I said above, experiments have shown us that we do not live in such a world.

Of course it is logically possible that momentum is conserved almost all the time, instead of absolutely all the time, and these experiments just happened to be the first ones anyone ever ran that poked reality in a place where momentum was not quite conserved. But in Bayesian terms, my prior for that being the case is much, much lower than my prior for the experimenters having made a mistake somewhere. Experimenters make mistakes all the time; but nobody has yet discovered any violation of a conservation law.

'it's not just a feature of my or anyone's "model" of the world.'

This may just be semantics, but I dont see how you could argue that it isnt a feature of a model of the world. A neural representation of the world shared amongst a group of humans. Tested against reality in the best ways we can imagine. But it is still just a model, it is not actual reality. Are you really so sure about those priors? You are also have a very influential prior there which supposes that that if the device functions, it does so because it violates conservation of momentum. Surely you cant know this? Are there really no other explanations which fit more neatly with our current models?

> it is still just a model, it is not actual reality.

We have a model that includes conservation of momentum. But experiments have shown that reality also includes conservation of momentum--that that feature of the model is an accurate representation of reality.

> Are you really so sure about those priors?

Yes.

> You are also have a very influential prior there which supposes that that if the device functions, it does so because it violates conservation of momentum.

That isn't a prior; it's a hypothesis--the one the EmDrive proponents are claiming.

> Are there really no other explanations which fit more neatly with our current models?

"The experimenters have made a mistake somewhere" is another explanation which fits in more neatly with our current models. Their mistake could be that the device isn't actually producing thrust, or it could be that it's producing thrust because it's ejecting radiation out the back end which they aren't detecting. Either one of those invalidates the EmDrive proponents' claims.

I give up. I think you're wrong, you think I'm wrong. I dont have time to iron out all the mistakes you are making and Im sure you feel the same way.