Quantum gravity, closer to TOE?

@metal-brain said
"However, if there is an effect that depends on the absence of an observer then it is outside physics."

How do you know it is not the other way around? If an effect depends on an observer then perhaps that is outside physics. Observing changes the result, right?

What do you plan to do with the theory? In the end issues of ultimate truth and priesthood are just a fight over undeserved status, the worthwhile purpose of a theory of nature is to alter nature to serve our purposes. We use the theory to make things that improve our lives, hopefully, but these things all exist for our use and have no purpose if we are not there to use and in using observe them. So, if there is an effect that depends on the presence of an observer, then we might not have found ultimate truth, but at least we can do something with it. The converse case I mentioned earlier is useless.

@deepthought said
In the end issues of ultimate truth and priesthood are just a fight over undeserved status, the worthwhile purpose of a theory of nature is to alter nature to serve our purposes.

If you think you can alter nature, you're a fool on the level of Elrond "Mother" Hubbard. Try, rather, to use nature, as she is, for your purpose - and better pray that your purpose accords with hers, or you're one with the dinosaurs.

@Shallow-Blue
I think you are thinking of 'altering nature' in terms of alchemy or some such. He is talking about altering nature by for instance, digging mines, chopping down trees to construct houses, adding two chemicals together to make something not found in nature, that kind of thing.
You said Lrond Mother Hubbard, are you talking about L Ron Hubbard, world class assswipe who invented scientology and Dianetics?

@deepthought said
What do you plan to do with the theory? In the end issues of ultimate truth and priesthood are just a fight over undeserved status, the worthwhile purpose of a theory of nature is to alter nature to serve our purposes. We use the theory to make things that improve our lives, hopefully, but these things all exist for our use and have no purpose if we are not there to use ...[text shortened]... truth, but at least we can do something with it. The converse case I mentioned earlier is useless.

What theory?
As for the rest, I don't know what you are talking about. Improve our lives? Ultimate truth? Where are you getting this stuff?

@Metal-Brain
Are you saying our lives have NOT improved because, DIRECTLY BECAUSE of science?

@sonhouse said
@Metal-Brain
Are you saying our lives have NOT improved because, DIRECTLY BECAUSE of science?

Are you saying that is a point related to what he and I were talking about? It is like he just threw in some unrelated nonsense for some strange reason. Nobody understands why but him.

@metal-brain said
Are you saying that is a point related to what he and I were talking about? It is like he just threw in some unrelated nonsense for some strange reason. Nobody understands why but him.

The point is that it doesn't really matter if nature behaves differently in the absence of an observer, since that won't affect any practical application of the theory. You seemed to want to reject theories on the basis that they can't say anything in the absence of an observer.

@deepthought said
The point is that it doesn't really matter if nature behaves differently in the absence of an observer, since that won't affect any practical application of the theory. You seemed to want to reject theories on the basis that they can't say anything in the absence of an observer.

If it doesn't really matter we would not be talking about it. Observing changes the result. If you want to dismiss any result that is observer dependent then say it so I know what you mean.

The whole assertion that light may travel faster in quantum tunneling is observer dependent and I dismiss that as an illusion not worth paying much attention to. Do you agree with me?

@Metal-Brain
Here is a short bit from Physics answers:


"There are several experiments where photons are claimed to travel faster than the speed of light. Most notable among them are Nimtz double-prism experiment. Here is a bibliography on the subject.

As it is said in the link, physicists basically agree on the observations, but differ in the interpretations of those observations. Confusion between phase velocity and group velocity is usually the culprit.

But last time i checked, a time machine has yet to be done using such "FTL" transmission. Until that happens, i would attribute any such FTL-like behaviour to free human interpretation of things looking like information transfer, which really aren't so."

That post had a link that didn't make it here but here it is:

https://www.aei.mpg.de/~mpoessel/Physik/FTL/tunnelingftl.html

Metal-Brain

Deepthought first said;

@deepthought said
The point is that it doesn't really matter if nature behaves differently in the ABSENCE of an observer, since that won't affect any practical application of the theory. You seemed to want to reject theories on the basis that they can't say anything in the ABSENCE of an observer.

(my emphasis)

Then you respond with

@metal-brain said
If you want to dismiss any result that is observer dependant then say it so I know what you mean.

(my emphasis)

If what you mean by "..dismiss any result.." here is "..say any result is WRONG.." as in it didn't happen, then that is NOT what he was saying.
He also was talking about nature (hypothetically so, as implied by the word "if" ) behaving differently in the ABSENCE of an observer, NOT in the PRESENCE of an observer.

@humy said
Metal-Brain

Deepthought first said;

@deepthought said
The point is that it doesn't really matter if nature behaves differently in the ABSENCE of an observer, since that won't affect any practical application of the theory. You seemed to want to reject theories on the basis that they can't say anything in the ABSENCE of an observer.

(my emphasis)

Then yo ...[text shortened]... OT in the PRESENCE of an observer.
In other words, he said the opposite of what you imply he said.

How do you know what he means? Speak for yourself.

@metal-brain said
How do you know what he means?

I know how to read and know that the word 'absence' doesn't mean 'presence'.

@humy said
I know how to read and know that the word 'absence' doesn't mean 'presence'.

and the only distinction he pointed out was a difference, not the specific difference and the implications of that difference.

I asked him if he agreed with me. He can answer that without you always butting in, but you cannot help yourself. You are now pretending to be a mind reader to help deepthought avoid admitting he agreed with me all along. Did he throw you a scooby snack for it? Did he tell you good boy?

@metal-brain said
and the only distinction he pointed out was a difference, not the specific difference and the implications of that difference.

I asked him if he agreed with me. He can answer that without you always butting in, but you cannot help yourself. You are now pretending to be a mind reader to help deepthought avoid admitting he agreed with me all along. Did he throw you a scooby snack for it? Did he tell you good boy?

In your post on page 1 you wrote:

"However, if there is an effect that depends on the absence of an observer then it is outside physics."

How do you know it is not the other way around? If an effect depends on an observer then perhaps that is outside physics. Observing changes the result, right?

The only effects we can measure are ones in the presence of an observer, we need the observer to do the measuring. There is no way of doing experiments that do not have at least one observer. Observing does not change the results, it creates them, if there were no observer there would be no results - the results being a collection of measurements taken during the experiment.

Theories make ontological claims, some of the claims they make are untestable because it is not a requirement that all claims the theory makes should be verifiable, only that enough of them are testable that the theory can be falsified. So that an effect isn't observable doesn't invalidate the theory, or make it bad in a Popperian sense, it just means that the theory cannot be falsified making measurements of that prediction.

@humy said
What many albeit not all modern physicists claim, rightly or wrongly (and I have no personal opinion on this), is that quantum tunneling involves something going over c. It is a controversial and contentious claim but, regardless of whether that claim is correct, one thing they are generally NOT saying is that this claim being true would CONTRADICT relativity. I don't know what ...[text shortened]... are numerous examples of just such laws. What is the big deal of there being an exception to a law?

Suppose we send an electron towards a potential barrier, call this the in-state electron. Simultaneous to it reaching the barrier in some frame an electron positron pair appear at the other side of the barrier. The electron moves away from the barrier and interacts with our detector, call this the out-state electron, the positron moves into the barrier and annihilates with the in-state electron. The net effect is an electron that has apparently moved faster than light.

Edit: Now, suppose the in-state has spin +1/2. Since spin is conserved we would expect the out-state to also have spin +1/2. This means that we can send information by sending a message encoded in binary in a stream of electrons. So there has to be some mechanism for introducing spin-decoherence to stop us inventing the sub-space radio.