> Beware that semi-educated guesses are sometimes worse than uneducated
> ones, since they are more plausible and not necessarily more correct.
This is why we shouldn't take medical advice from people who have read a few Wikipedia articles. This is why years of experience in e.g. software are necessary to even begin to understand how deeply hidden security issues can be. This is why self-driving cars still elude us, but will be so much safer than human drivers when they finally do arrive.
Generally speaking, you should trust someone whose professional or experienced more than some random stranger. Especially if it's not one person but a large group of experienced professionals (most of the controversial "anti-science" issues today).
But it's actually important to "do your own research", and not just listen to authority. Provided you actually know how, i.e. you can find accurate sources and distinguish fact from fiction. Because even the most qualified, unbiased, genius authority are occasionally wrong. The big issue today is that a lot of people don't know how to research and distinguish lies, but (although it's probably impossible for most) finding a way to teach someone how to find the truth, will always be more effective having some authority tell them the truth.
Key example: doctors often miss symptoms and diagnoses that a patient can discover on their own. It's not that the doctor is stupid or unqualified, in fact they have way more medical knowledge than you. But the doctor only has a series of questions and maybe a few tests to make a diagnosis, whereas you have the full experience of symptoms and an internal understanding of your "normal". IMO people actually should "play Internet doctor" and research their symptoms, not to reach any 100% conclusions, but to suggest diagnoses and tests to their real doctor.
> IMO people actually should "play Internet doctor" and research their symptoms, not to reach any 100% conclusions, but to suggest diagnoses and tests to their real doctor.
Even if you don't outright say it, you should never convince yourself you have a diagnosis. The human body is extremely complex and some particularly weird issues need patient research, doctor's research, and experimentation to solve.
I recently had an appointment with specialist for my son. My son has ADHD but was never diagnosed within Kaiser and so Kaiser won't prescribe medication.
The appointment started with, "My son has ADHD, was first diagnosed at 7 by _____, here are volumes of paperwork demonstrating that he had this diagnosis, has continued to have symptoms, and documenting what we have done for him. He wants to go back on medicine despite the side effects from last time. Here is more documentation that he continues to have symptoms."
There really ARE times when you're coming with enough background that the diagnosis is never in doubt.
For a less recent but more trivial example, I once showed up to the doctor and said, "I broke this bone in my hand while playing volleyball, what should I do about it?" Again, the diagnosis was never in doubt.
>sometimes the experienced doctor or researcher made a mistake, and the guy who posted something on Reddit is correct
Both of those points are true, and we can reconcile them thusly:
Broadly, the doctor is the fully educated, while the layman-interested-in-subject is making semi-educated guesses. However this relationship inverts on narrow subjects, like a particular rare disease: the doctor ends up making a semi-educated guess (based on his general medical education), whereas a layman with intense interest in this particular rare disease can easily be the fully educated one - again, on this particular narrow subject.
If a researcher made a mistake and if 50 people on reddit said 50 different things, at random, one might be correct by chance.
Being correct once means nothing unless you are correct most of the times, but by then you are the researcher in the scenario above.
Except if the large group is mostly a handful of experts with non-scientific private interests (say, to publish papers, to get grants, paid by companies with a product to sell), plus a large mass of professionals who seldom/never question the information they receive and just follow everything they read from their research and protocol-setting breathen.
When non-reproducible papers with BS mistakes get top citation counts and are held as gospel without any researcher/peer reviewer bothering verify them for decades, does anyone really think the average "professional doctor" really questions what they're told to follow?
And to know if you’re only seeing narrative-approved sources, when contra-narrative sources have been suppressed.
Lots of folks got fooled by Iraq WMD because you couldn’t say anything to the contrary without being fired. Other examples, some more recent, are available.
You should probably not play internet doctor if you’re a hypochondriac or prone to anxiety. The least probable cause of almost any symptoms is cancer or another deadly condition and you can probably find a gruesome description of someone’s experience online somewhere. If your nervous system can’t grasp that, stay away from googling your symptoms!
> IMO people actually should "play Internet doctor" and research their symptoms, not to reach any 100% conclusions, but to suggest diagnoses and tests to their real doctor.
> some doctor can get quite upset if you dare to suggest a diagnosis
Don't tell the doctor your diagnosis. You didn't go through a decade of medical training. Tell the doctor what you've observed, let him conclude the diagnosis.
> When the client tells you what the cause is, he's wrong.
Lots of anecdotal stories of people doing just that and having doctor after doctor failing them.
Doctors are like everyone else: 90% of them are kinda shit at their job.
On the other hand, if I’m in the market for a guess, I’ll probably go for the educated guess rather than the uneducated one, because even though I recognize it’s not necessarily more correct, it probably is less wrong.
Medical advice on the internet can be n=1, but read enough to get to n=100+, while still limited, can be quite valuable. I can't ask 100 doctors what’s wrong with me, but I can ask my question to hundreds in an online forum. They might lead me astray, but so can a single doctor’s misdiagnosis. A doctor can prescribe treatment that helps or harms, but I can ask a forum of people, with the same problem I have, if I should take his advice. I can't, however, ask 100 of his colleagues or peers if I should trust his advice, and that's why we end up with so many charlatans in medicine. But he's a doctor. Of course you can trust him! I don't know about the rest of you, but I've found a fair number of doctors to be mostly useless.
Isn't that just a by definition thing?
My Tesla can already drive itself, I don't trust it and I don't think it's safe. When I get one that I trust and is safe then it will be safer than me, and by extension other humans.
The problem is that the current generation of algorithms are brittle.
Specially for subtle but critical concepts:
"Researchers misunderstand confidence intervals and standard error bars"
Our Quantum Field Theories naively predict an infinite energy density all throughout space time. A naive guess at regularizing this leads to absurd predictions 120 orders of magnitude off [1]. So there has to be something else happening here. One of the things that supersymmetry brings to the table is that it makes this energy density exactly zero (but then it get's complicated because you need to break super symmetry...).
The thing is though, without gravity the absolute energy density of a quantum field is just some unobservable number. But how to reconcile gravity and quantum field theory is an unsolved problem to begin with, so it's completely unclear what that naive infinite number actually means. We are working without a firm theoretical (or empirical for that matter) foundation here.
However, the Casimir effect is remarkable exactly because it appears that the local energy density between two conducting plates is lower than in the ambient space. This is an energy difference that can and has been measured [2].
It is entirely plausible that it interacts with gravity in the right way to cause an effective negative energy density. This has been speculated by serious physicists for a long time. However: The Casimir effect is exceptionally weak. Space time is exceptionally hard to bend. So the idea of an actual warp bubble from Casimir effect geometry seems extremely far fetched[3] right now.
How stiff is space time? LIGO the gravitational wave observatory, measures changes to a 4000m distance that are smaller than an atomic nucleus, at its full design it will detect changes that are many time smaller than a proton. This is a feat of experiment that is the more astonishing the more you know. If you had told me you want to build something like this I would have assumed that it's likely impossible. Now, the first signal that could be detected by LIGO was a black hole merger that radiated away the energy equivalent of three solar masses. The peak power output of this event was larger than the combined energy output of all visible stars in the observable universe.
How small is the Casimir effect? Micro Newtons/m force gradients for micro meter distances [4]. Again we are talking about an effect so subtle that it's only been measured reliably in recent decades.
So these are the orders of magnitudes involved: White et.al. claim they can use an effect so small as to be barely perceptible, to manipulate space time in such a way to create interesting effects, when it takes the energy output of the entire universe to generate a ripple in space time strong enough to be detectable (a few galaxies over) by the most sensitive instrument ever devised. So I am sceptical.
[1] https://en.wikipedia.org/wiki/Cosmological_constant_problem#...
[2] https://en.wikipedia.org/wiki/Casimir_effect
[3] My physicist intuition says: Far fetched but not impossible. One of the heuristics for looking at this result though is this: The lead author is Harold White, one of the people who really pushed the EMDrive. The EMDrive is not far fetched but simply impossible (to a physicist the EMDrive is in exactly the same category as perpetuum mobiles). Worse, the original EMDrive paper by Harold White, despite supposedly showing evidence overthrowing three centuries of established physics, did not attempt to get published in a physics journal (which would have required extraordinary proof for such an extraordinary claim). Finally it involved some theoretical speculation that were just abject nonsense. These things mean I will not spend serious time on understanding and analyzing the details of this latest work.
I'll just put my back-of-the envelope calculation here to insert some optimism. While the energy emitted is immense, since the event was so far away (1.6e9 lt-yr), then if we plug in the solid angle subtended by the detector (~4000m4000m) I'm only seeing about ~2 kJ of energy passing through LIGO.
Caveats:
I assume the gravitational wave pattern is spherical; probably wrong but I'm not sure what the radiation pattern looks like for these event and in where we lay in relation to it.
The tone of this paper seemed less like an academic assertion of an effect, and more like "hey, found something cool, someone should look into this, I gotta get back to what I was doing."
I'm also not going to blame the guy for being interested in space-age propulsion systems.
A lot of the writing falls woefully short of being a serious effort at science. It's more "wouldn't it be cool if" science fiction.
The entire "attempt" to link the EMDrive to Bohmian quantum mechanics is just a grand amalgamation of conceptual confusion.
So this isn't about getting published in peer reviewed venues, this is about getting published in a particular, selective, high visibility venue.
So as far as I can see none of this has any bearing on anything you replied to.
Just curious, why can't fluctuations happen inside matter?
Isn't matter 99% vacuum anyway?
Matter just ordinarily isn't structured to produce a strong version of an interesting effect - which when you get down to it is essentially what all human technology is based on.
It's quite possible there are some weird molecular structures (if this paper is correct) which could also induce natural warp-field structures out of their crystal lattice.
They don't use the term 'cold fusion', and obviously the fusion sites would be hot, but the bulk material isn't.
Ansatz reduce the search space of possible solutions because it adds various constraints that makes it possible to get to solutions much faster.
For example, without these constrained searches we will never have developed any analytical solutions to differential equations that are pervasive across science, engineering, finance among others.
No, it isn't. It is spatially flat (if we choose appropriate coordinates), but the spacetime of the universe is not flat, because it is expanding.
The rest of your reasoning is wrong because it starts from this false premise.
The issue with your reasoning is not what kind of curvature the drive needs, but the idea that there is a "natural" bending of spacetime at all. There is no such thing.
I might have a non-educated theory that could explain negative energy; could you tell me if this is potentially correct or am I completely wrong here?
Disclaimer: I haven't read the article (it doesn't load), and I am (probably) lacking even the basics of the required knowledge.
Let's assume the law of energy conservation applies to the universe: if you assume the total energy in the universe is constant, the negative energy is a relative imbalance instead of an absolute one, caused by the universe expanding at a different speed relative to the "things" it contains.
As the universe is "expanding" constantly, the "energy amount per expanding area" gets "less dense", so the "things" that are not "expanding" at the same speed get "more dense" in comparison. This imbalance creates different types of energy perturbation. From the point of view of the things that do not expand as fast, the energy levels relative to yours seem to evolve in a "negative way".
It's like looking at a stationary train from a train that is moving: from the point of view of the moving train, the train standing still seems to go backwards.
Does this make any sense at all, or am I completely missing the mark here?
Updated: reworded some things and provided extra context.
[1] https://www.preposterousuniverse.com/blog/2010/02/22/energy-...
Relatively more or less dense "things" (to each other) will always generate positive curvature of spacetime. What you want is relatively less dense area than vacuum in another region of space, since vacuum is (for now) what we constitute as (somewhat) flat.
That's what Casimir effect tries to accomplish: define a small enough region of spacetime where some larger quantum fluctuations don't have enough space to happen, thus lowering its energy below vacuum.
Since the idea is to define small enough space-like interval in spacetime to curb some energies off, could defining small enough time-like interval help the same purpose, multiplying the former?
The Casimir effect is about creating a spacetime "corset" so to speak, that is so tight that even the regular quantum fluctuations don't have "enough room to pass", so they "almost freeze", and when they "come out on the other end", they could for example break or delay entanglement?
On the other hand I think your assumption about the time aspect might be correct as we are talking about spacetime after all. The biggest issue might be that measuring time deltas might be harder than space deltas?
Regarding working with time-interval, it might as well just be the opposite: minimize space-interval and maximize time-interval for maximum effect. It's just wild guesses at my side. But minimizing time-interval should be trivially doable by just slinging the plates past each other at high speed.
Anyway, thanks for taking the time to try to explain this to a total layman, but I'll defer engaging into subject matters that I never heard about before; lesson learned...
The Alcubierre warp drive requires both positive and negative curvatures. Positive curvatures are "easy" to make, since mass and energy bend space positively. Negative curvatures are typically said to require negative energy to produce, but the full story is thankfully more complex.
The universe, despite being filled with mass and energy, is roughly flat. That means that the natural bending of spacetime, without any stuff inside it, has to be negative - otherwise all the mass would make it extra positive. If you believe the consequence of vacuum energy in QED, that the fields filling the universe are VERY heavy, even when no particles are around, then you must believe the natural curvature to be very negative indeed.
So, it stands to reason, if you want to bend the universe backwards, take the weights off of it - really off of it, in this case using metal plates to forbid certain vacuum fluctuations, and let it unbend itself.