# UFOs and skepticism

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I understand what you mean, but I don't understand how this changes the situation. If two objects have a mutual relative constant velocity with respect to each other, the Lorentz transformation applies.
The Lorentz transformation is a transformation between reference frames, not objects. Sometimes we can be sloppy and say things like "the Earth's reference frame", but it is important to understand that what this means is that we're picking a reference frame where the Earth is at rest. If an object moves at least as fast as light, no reference frame exists where the object is at rest, and trivially there can't be a Lorentz transformation to a non-existing frame.
The carrier for superluminal communication can be a tiny container driven by a hypothetical Alcubierre warp drive. Its velocity relative to the sender would be 7.884.000c. Since it is an object that has a velocity relative to both the sender and the receiver of the message, the Lorentz transformation applies. Alas, this transformation does not yield sensible results for v>c, so we're left in the dark. I do not agree with Markus that "we use v<c throughout".
It is not a matter of agreement -- all Lorentz transformations I used use v < c, which can be readily checked since I was very explicit and showed every step in the argument. You would use a hypothetical v > c Lorentz transformation, should one existed, to describe what happens from the perspective of one of the bubble's occupants -- but that is precisely the regime where the theory is inapplicable because of high spacetime curvature (in Miguel Alcubierre's original formulation, there is no time dilation with respect to Earth for the bubble's occupants, but you'd never know that from special relativity alone). Instead, we use the Lorentz transformation to a different observer, Alice, who's moving subluminally and merely watching the bubble. Relativity says her perspective is valid and she sees the bubble move backwards in time. Either you reject the bubble, or relativity, or causality. It's airtight.

Relativity says her perspective is valid and she sees the bubble move backwards in time. Either you reject the bubble, or relativity, or causality. It's airtight.

The standard ufologist retort is: "So what if we reject? The history of science is replete with such rejections in the wake of revolutionary theories."

The appropriate response to the retort, imho, is: "Feel free to reject. But like those revolutionary theories you mention, such a rejection should also accept the onus to predict all the observations that were successfully predicted by the rejected theories in order to be deemed a serious scientific exercise. There's no shortcut nor quick fixes in physics to arrive at an alien craft hypothesis just because it's personally appealing."

Consider the same mechanism on a much smaller scale: Earth.

No, there's no analogue at all.

It's funny, I posted that post in a rush, I was just heading out to the pub, and as I walked there I joked with my g/f that I was sure someone would attempt to say that our (repeated) daily-monthly-yearly expansion across the almost homogeneous and resource-dense globe that we evolved to be specialised for upon was somehow analogous to flinging pods into the emptyness of outer space over multi-million-year timescales. It was a good start to the evening, we all like a laugh.

Consider the same mechanism on a much smaller scale: Earth.
I took a lot of time for the first humanoids to arise from evolution but once they started spreading over the Earth's surface, the 'colonization' of Earth by Homo Sapiens went very quickly, measured on an archeological time scale. It wasn't intentional, either. It just happened because of our natural curiosity and search for new resources and new real-estate.

Fermi calculated what a similar scenario would mean on a galactic scale. And he discovered it would take in the order of 10^6 - 10^8 years for an expanding species to 'colonize' the entire galaxy. They do not even have to travel close to light speed, travelling at a fraction of light speed is sufficient. That is why he came up with his famous Fermi paradox: Where are they?
Enclosed is an interesting article discussing galactic colonization scenarios. It contains a table with several studies done earlier:

The authors of the article developed a simulation program and computed some additional scenarios. They all more or less confirm the Fermi paradox: We should be able to detect an expanding alien civilization by now. Maybe we do occasionaly, but we don't want to face it...
Or: maybe we never had any contact with aliens, but we (some of us, at least) do not want to face it...

All the studies you quoted, which try to quantify a galactic expansion rate, start with a big assumption: interstellar travel is possible on the scale needed to create a self-sufficient colony (or a self-replicating 'probe': 'probe' is quite misleading here because it suggests something small, but how something 'small' could be able to self-replicate in space is left to the imagination of the reader)

We have no reasons to think that's true, but we have many reasons to think it's at best very improbable: even interstellar travel in its most basic form (a true 'probe', say 100kg or even less, just meant to dart at a small fraction of light speed near the closest star and relay back some pictures) turns out to be so difficult to have been always relegated to the category of 'dreams' (barring magick, of course).

Then Fermi's paradox gives us some evidence: we have never observed any reliable evidence of alien civilization whatsoever and this is 100% what we would expect in a model where interstellar travel is impossible on the scale needed, while it's not what we would expect from a model where interstellar travel is possible and intelligent life with a technologically advanced civilization is relatively common and long-lived. In order to rescue the possibility of interstellar travel one can start questioning the other assumptions, ie. technologically advanced civilizations are rare (but this does not bode well for aliens) or they are short-lived (but this does not bode well for us too), or invent ad hoc hypothesis which remove the 'badness', rescuing at the same time interstellar travel, aliens, and ourselves. Fantasy is the only limit here: ie. civilizations are indeed short-lived, buy they undergo 'transcendence', whatever that might mean, and become some sort of out-of-this-universe demi-gods. Or aliens are here (and they are many too, and in different forms and since a long time, judging from the 'sightings'), just they have some mysterious reason of their own to always hide in the LIZ giving 'plenty' of 'hints' thay exist while never giving a single piece of solid evidence. This reasoning borders religious beliefs, those being even more improbable because they usually posit both transcendence (afterlife) and a LIZ-living 'alien' deity, while 'just aliens' requires only one of the two hypothesis to be true. One does not need as much faith, but surely needs some.

Either you reject the bubble, or relativity, or causality. It's airtight.
If you accept that the Alcubierre bubble can only move forward in time in one particular reference frame, causality violations in any other reference frame are prevented. This is explained in the enclosed paper, paragraph 3.1:

Obviously, there can be no paradox if, in one particular reference frame, tachyons can only propagate forward in time.
[footnote:] Of course such a restriction is anathema in the standard approach to special relativity since it picks out a preferred frame. However if you have good physical reasons for picking out a preferred frame (e.g., the rest frame of the Casimir plates) this sort of restriction can make good physical sense.
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Is this rejecting relativity? Perhaps, but there may be good physical reasons for picking out a preferred frame for the Alcubierre bubble.

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Then Fermi's paradox gives us some evidence: we have never observed any reliable evidence of alien civilization whatsoever
According to scientists like Avi Loeb, this is mainly because we have not been seriously searching for this evidence in our own backyard. I agree with him.

they have some mysterious reason of their own to always hide in the LIZ
Not all UFO sightings are in the LIZ. Fravor, for example, observed the tictac from a few thousand feet (this was his closest point of approach) on a bright and sunny day with clear skies. The LIZ is the favorite area for ambiguous sightings, yes, but Hynek did not introduce his categorization of close encounters for nothing:
Sightings more than 150 metres (500 ft) from the witness are classified as "Daylight Discs," "Nocturnal Lights," or "Radar/Visual Reports."
Sightings within about 150 metres (500 ft) are subclassified as various types of "close encounters." Hynek and others argued that a claimed close encounter must occur within about 150 metres (500 ft) to greatly reduce or eliminate the possibility of misidentifying conventional aircraft or other known phenomena.
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Source: https://en.m.wikipedia.org/wiki/Close_encounter

There have been numerous close encounters in UFO history.

Mauro said:

Then Fermi's paradox gives us some evidence: we have never observed any reliable evidence of alien civilization whatsoever
According to scientists like Avi Loeb, this is mainly because we have not been seriously searching for this evidence in our own backyard. I agree with him.

Even if that were true, it has no bearing on Fermi's paradox. The model 'interstellar travel is possibile' + 'there are aliens out there' + 'spacefaring civilitazions live long enough' predicts there should be abundant signs of aliens, including numerous colonized worlds and spaceships buzzing around, it should not be difficult to see those signs (unless one adds ad hoc hypothesis). It even predicts we should have been visited and contacted many times, without even the need for 'seriously searching for this evidence' (unless one adds ad hoc hypothesis as above and as discussed before).

Not all UFO sightings are in the LIZ. Fravor, for example, observed the tictac from a few thousand feet (this was his closest point of approach) on a bright and sunny day with clear skies. The LIZ is the favorite area for ambiguous sightings, yes, but Hynek did not introduce his categorization of close encounters for nothing:
Sightings more than 150 metres (500 ft) from the witness are classified as "Daylight Discs," "Nocturnal Lights," or "Radar/Visual Reports."
Sightings within about 150 metres (500 ft) are subclassified as various types of "close encounters." Hynek and others argued that a claimed close encounter must occur within about 150 metres (500 ft) to greatly reduce or eliminate the possibility of misidentifying conventional aircraft or other known phenomena.
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Source: https://en.m.wikipedia.org/wiki/Close_encounter

There have been numerous close encounters in UFO history.

What do you mean by 'Fravor's tic-tac is not in the LIZ'? Are you arguing we have enough information to positively identify it? Then why is it an 'UFO', as you say? The distance from where an observation was taken means nothing, it's the quantity and quality of the data at hand which matter. We can be pretty sure there are planets around stars 100 light-years away because we have good data, yet we cannot say with certainty (say, with 95% confidence) what the tic-tac exactly was because we lack the necessary data, thus it's in the LIZ.

There have been numerous close encounters with ghosts and spirits in human history (many more than with aliens I'd bet), are they out of the LIZ too?

I'd like briefly to revert to the 'thought experiment' I mentioned in my #41 above. An observer A sends an FTL message to observer B, who sends an FTL message acknowledging receipt back to A. I suggested, what I hoped was uncontroversial, that the time at which A sent his message to B would always be earlier than the time at which he received the return message from B, as recorded on A's own clock, static in A's inertial reference system. We could specify the procedure more precisely as follows:

- A's message reads: 'Dear B, I am sending you this message at time T1 as shown on my clock. Regards, A'. The time T1 could be printed automatically in the message, and simultaneously recorded as a mark on a moving tape in A's system, as in a seismograph.

- B's return message reads 'Dear A, I received your message sent at time T1 as shown on your clock, and I am sending this return message at time T2 as shown on my clock. Regards, B.'

- On receiving the return message, A would note the time T3 as shown on his clock, which could also be simultaneously recorded on A's moving tape.

Since A and B may be static in different inertial reference systems, with clocks which may be running at different rates, it is conceivable that T2 is chronologically earlier than T1, (e.g. if T1 reads as '3 p.m.' , T2 might conceivably read as '2 p.m.') But I contend that even if this is the case, T3 is still bound to be later than T1, which are times recorded in the same reference system. If the recording tape is running to the left, T3 will be recorded to the right of T1. Or we might imagine that the recording device uses a system of concentric circles, with later times recorded in circles 'further out' than earlier times. This would make the order of recorded times topologically as well as quantitatively recognisable.

If this is denied - if it is contended that T3 would be earlier than T1, and the mark recording T3 to the left of the mark recording T1, or in a circle closer to the center - then I think we are approaching physical absurdity of the 'killing one's grandparent' kind. Suppose A looks at his tape before sending his message: would he see a mark showing that he has already received a reply? Suppose he then has a heart attack (which would be understandable) and never sends the message at all? If I understand Markus's post #48 correctly, he would see this situation as a necessary result of the Lorentz transformations. If so, I would just see it as showing the inapplicability of the Lorentz transformations in this case. Moreover, if I am right that T3 must be later than T1 in A's reference system, then I think T3 must also appear later than T1 in any other reference system. According to STR, clocks may run at different rates in different inertial reference systems (as viewed from one another) but they never actually run backwards.

What do you mean by 'Fravor's tic-tac is not in the LIZ'? Are you arguing we have enough information to positively identify it?
With a clear view on the object from a few thousand feet on a clear day, how do you reckon would Fravor be able to positively identify it as something extraterrestrial? What information would give that away?

The model 'interstellar travel is possibile' + 'there are aliens out there' + 'spacefaring civilitazions live long enough' predicts there should be abundant signs of aliens, including numerous colonized worlds and spaceships buzzing around, it should not be difficult to see those signs
What signs would you expect to see?

... an FTL message ...

According to STR ...

You can't pick and chose subsets of a theory that you wish to hold. Add a contradiction into the mix, and any of your later conclusions can look like paradoxes.

You can't pick and chose subsets of a theory that you wish to hold. Add a contradiction into the mix, and any of your later conclusions can look like paradoxes.
Surely it is common enough in science to have theories or 'laws' which are valid and useful in some circumstances but not others. E.g. Boyle's Law and Hooke's Law are only valid within a certain range of applied forces. Or in fluid mechanics, where theories or equations that work for laminar flow don't work for turbulent flow. Or classical electromagnetic theory, which breaks down for sub-atomic particles (the Ultraviolet Catastrophe). More generally, quantum theory and general relativity are widely considered inconsistent with each other, but physicists seem to live with this by using the two theories in different domains of application. Of course they would ultimately like to unify the two theories, but in the meantime they don't seem too distressed by the inconsistency!

If FTL were proven to occur, wouldn't the obvious pragmatic response be to keep using STR for sub-light velocities, but avoid it for FTL velocities? Once again, I don't believe in FTL velocities, I just don't think the idea can be dismissed by the argument that FTL would involve a violation of causality.

With a clear view on the object from a few thousand feet on a clear day, how do you reckon would Fravor be able to positively identify it as something extraterrestrial? What information would give that away?
I don't need to reckon anything, it was you who said "Not all UFO sightings are in the LIZ. Fravor, for example, observed the tictac from a few thousand feet....", not me.

What signs would you expect to see?
From a galaxy fully colonized by aliens, you mean? As suggested in your post #73?

On the hypothesis tthat aliens colonized the whole galaxy I expect to see aliens everywhere, including on our planet, what else?

Yeah, they might be hiding very well (Aliens of the gaps?), while at the same time keeping giving us tantalizing (but always ambiguous) signs of their existence for some mysterious reason ("Aliens work in mysterious ways"), but we are back again to faith-based reasoning here.

Fravor, for example, observed the tictac from a few thousand feet (this was his closest point of approach)
I believe Fravor observed it from what he estimated to be a few thousand feet, but we do not even have enough information to be sure of that distance, therefore we have no way to verify any conclusions he may have reached about size or speed.

I believe Fravor observed it from what he estimated to be a few thousand feet, but we do not even have enough information to be sure of that distance, therefore we have no way to verify any conclusions he may have reached about size or speed.
I think my wording "a few thousand feet" implied an estimate. And given a clear, wide angle view from his cockpit on a clear and sunny day it is safe to assume Fravor could estimate distance with this accuracy purely from parallax.

On the hypothesis tthat aliens colonized the whole galaxy I expect to see aliens everywhere, including on our planet, what else?

Yeah, they might be hiding very well (Aliens of the gaps?), while at the same time keeping giving us tantalizing (but always ambiguous) signs of their existence for some mysterious reason ("Aliens work in mysterious ways"), but we are back again to faith-based reasoning here.
These types of analysis are mainly useful to get some idea about the time scale at which an advanced civilization spreading out in the galaxy could be in our neighbourhood. They do not necessarily involve "aliens colonizing the whole galaxy". The estimated time scale is short enough to lead to Fermi's paradox.

The "signs" often are not ambiguous to the witnesses. They are only ambiguous in a scientific sense because we impose rigorous scientific quality requirements to evidence that was obtained during an unexpected transient event in unconditioned circumstances ("exraordinary events require extraordinary evidence").

These rigorous scientific requirements are hard to meet for any unexpected transient event, not just UFO sightings. Example: I just saw a crow fly by. It's impossible for me to provide undisputable scientific evidence for that. Even a picture won't suffice, nor other witnesses who claim they saw it, too. You are only inclined to accept my story because you already know crows exist. And you are inclined NOT to believe me if I told you the crow was white.

The 'evidence' is inevitably scientifically ambiguous in both cases, simply because they both are unexpected transient events. Your acceptance of the existence of black vs white crows makes the difference, not the ambiguity of the evidence.

If we somehow already knew of the existence of extraterrestrial intelligences and their capability to visit us, nobody would complain about the ambiguity of the evidence and use that as an argument for the non-existence of such events. They would just be "black crow stories". But we see these events as "white crow stories", i.e., "extraordinary" because of arguments like the ones proposed by Brian Dunning. I think the discussion in this thread has shown that these arguments are not as iron-clad as they seem.

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Fravor could estimate distance with this accuracy purely from parallax.
Without knowing the size and speed of the object, I'm not sure how that would work.

This is Brian Dunning's new article, received today in the Skeptoid Companion. It's about his upcoming independent movie on the topic, and is a good discussion of the practical aspects of UFOs as well as skepticism in general.

In the movie, we talk to astrophysicists and astrobiologists who explain that the laws of physics are not laws that human scientists made up. They are observations grounded in physics equations, and math is math, everywhere in the universe. We look at how we've been able to verify that the laws of physics today are the same as they were billions of years ago, and how we've been able to verify that the laws of physics here are the same as they are on the other side of the universe. Math is math. The aliens' math will give them the same answers that our math does. If you try to brush that aside with the illogical "The laws of physics don't apply to aliens," then you've abandoned our shared goal of better informing our beliefs with science. Instead, you're informing your beliefs with the magic of leprechauns and genies.
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The laws of physics demand that when a UFO appears, the observer has to have the worst camera possible, with the worst possible settings, worst possible focus, and preferably most gullible photographer. That is the most tried and tested law of physics of all time.

That is the most tried and tested law of physics of all time.
I suspect Bigfoot has a slight edge there.

These rigorous scientific requirements are hard to meet for any unexpected transient event, not just UFO sightings. Example: I just saw a crow fly by. It's impossible for me to provide undisputable scientific evidence for that. Even a picture won't suffice, nor other witnesses who claim they saw it, too. You are only inclined to accept my story because you already know crows exist. And you are inclined NOT to believe me if I told you the crow was white.

The 'evidence' is inevitably scientifically ambiguous in both cases, simply because they both are unexpected transient events. Your acceptance of the existence of black vs white crows makes the difference, not the ambiguity of the evidence.

Hmmm. I would think the standard default position when dealing with "ambiguous" information is to compare it to less ambiguous information. In your example of the crows, yes I would likely take your word for it that you saw a black crow as there is overwhelming evidence for the existence of crows and crows are almost always black.

However, if you simply told me, you saw a black crow, I might want to further disambiguouize (?) by asking about the location you saw the crow. For example, something I only learned recently, if you say you saw a crow in my yard, you in fact more likely saw a raven. Close but different.

If you say you saw a crow in the Portugues Azore islands, I might be more hesitant to take your word for it:

## ​

The following tags have been used to highlight several categories. The commonly occurring native species do not fall into any of these categories.

• (A) Accidental - a species that rarely or accidentally occurs in the Azores
• (E) Endemic - a species endemic to the Azores
• (I) Introduced - a species introduced to the Azores as a consequence, direct or indirect, of human actions
• {Extinct} Extinct globally - a species that no longer exists

## Crows, jays, and magpies​

Rook
Order: Passeriformes Family: Corvidae

The family Corvidae includes crows, ravens, jays, choughs, magpies, treepies, nutcrackers and ground jays. Corvids are above average in size among the Passeriformes, and some of the larger species show high levels of intelligence.

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Crows are listed as accidental A, so maybe you saw one or maybe you were mistaken. Certainly possible, but uncommon. Is it more likely that you saw something else and thought it was a crow? Some other large mostly black bird that is more common in the Azores?

Now if you said you saw a white crow, we have a similar situation. We have overwhelming evidence for the existence of black crows, but we know albinism occurs in most species, so an albino crow is possible, though rare like a crow on the Azores. Is it more likely that you saw some other white bird that you mistook for a white crow? A seagull perhaps?

Likewise, as we have seen, many, many reports of UAPs have turned out to be mundane things that were misinterpreted. Lots of seagulls that were thought to be white crows, if you will.

If so, then we want to eliminate all the seagulls first, before accepting the very possible, white crow.

Itsme said:
You are only inclined to accept my story because you already know crows exist. And you are inclined NOT to believe me if I told you the crow was white.
I've been thinking about Itsme's 23 January post (and NorCal Dave's reply).
If I've understood correctly, Itsme is raising the possibility that the scientific community (etc.) are less likely to accept reports of unusual occurrences because the evidence is scientifically ambiguous, although witnesses may be totally unambiguous about what they have experienced. The implication is that a sighting of a physically real vehicle of non-human origin is likely to be dismissed; that the hypothesis that 'aliens' are visiting Earth is prone to a sort of type 2 error.

Perhaps this is correct to some degree, but understandable: some people report seeing UFOs that they are convinced are of extra-terrestrial origin, but in the absence of corroborating evidence it's surely valid not to make the (momentous) conclusion that Earth is being visited. People around the world report strange observations and experiences on a daily basis, but we'd be remiss to shape policy according to advice from appearances of The Blessed Virgin Mary, or a talking mongoose, I think.
We might be more amenable to claims of visitation if we knew that ET craft (or the BVM, or faeries) regularly came here, but that seems to verge on tautology to me.

To take the white crow example literally- I have to admit, it was several days before I noticed the "no black swans" resonance!- I think I disagree.
If someone told me they'd seen a white crow, I'd be interested. A blackbird with patches of white plumage used to visit my garden, and I'm aware that, as NorCal Dave points out, albino birds, including crows, exist. But a report of a white crow is essentially inconsequential for most of us, it doesn't matter if we believe it or not.
The "No black swans" argument is useful in illustrating the limits of inductive reasoning, but shouldn't be confused with the historicity of de Vlamingh's party discovering black swans in 1697. There was no paradigm shift- I've not read of any resistance to the claim that black swans had been found, although the number of people who saw the swans sent back to Europe must have been small. It seems that the existence of black swans was accepted by those who studied natural sciences- presumably de Vlamingh's contacts were seen as a credible source. No establishment scepticism impeded the spread of this new knowledge.

Much of our knowledge of birds, particularly their distribution, comes from records kept for many years by enthusiasts, mostly amateurs. Many of their sightings must have been fleeting, transient, and without supporting evidence. But over the years, a broadly consistent, checkable, body of knowledge emerged, accepted by professional naturalists/ ornithologists, etc. There are parallels in other sciences (astronomy comes to mind).

We don't see this with UFO sightings. No (convincing) physical evidence has ever been found. There is no predictive validity: despite large numbers of reports, we can't estimate where the next will appear, what it might look like, how it will behave. Where 'themes' emerge in UFO (and contact) reports- a supposed interest in nuclear sites, dead cattle, an interest in human reproductive systems- they often coincide with subjects of deep social and personal angst, whilst leaving no physical (or biological) effects which aren't open to more mundane explanations.
Nothing has been learnt about engineering, physics, biology or astronomy from any of the sightings/ contacts/ abductions reported. This isn't necessarily because UFO sightings are under-researched or dismissed out of hand by a sceptical establishment; I think there just isn't much- apart from subjective reports and the occasional blurred 'photo- which can be investigated.

'Extraordinary claims' are investigated when there's something amenable to investigation, e.g. Fleischmann and Pons' 1989 cold fusion claim; the OPERA faster-than-light neutrino findings at CERN, 2011; Ohio State University's 1977 "Wow!" signal; and the observations of 'Oumuamua in 2017, where the possibility of intelligent control was seriously considered.

Of course, as per "No black swans", no number of satisfactorily explained UFO sightings or uncovered hoaxes can rule out that the next UFO sighting will be of a "nuts 'n' bolts" extra-terrestrial craft visiting Earth...
...but I suspect I'm more likely to have a white crow plop on my head first.

This is Brian Dunning's new article, received today in the Skeptoid Companion. It's about his upcoming independent movie on the topic, and is a good discussion of the practical aspects of UFOs as well as skepticism in general.

In the movie, we talk to astrophysicists and astrobiologists who explain that the laws of physics are not laws that human scientists made up. They are observations grounded in physics equations, and math is math, everywhere in the universe. We look at how we've been able to verify that the laws of physics today are the same as they were billions of years ago, and how we've been able to verify that the laws of physics here are the same as they are on the other side of the universe. Math is math. The aliens' math will give them the same answers that our math does. If you try to brush that aside with the illogical "The laws of physics don't apply to aliens," then you've abandoned our shared goal of better informing our beliefs with science. Instead, you're informing your beliefs with the magic of leprechauns and genies.
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There are good skeptics and there are bad skeptics, and I have never really found Dunning to be a good skeptic as he tends to come across with a sort of haughty ' you don't really believe in that nonsense, do you ?' stance and introduces far too many red herrings and straw men.

The whole 'aliens can't defy the speed of light' thing is a straw man...designed to cut off the debate right at the start and imply that because aliens cannot defy physics therefore there cannot be any aliens here. It's not that the particular argument is wrong, but that hardly anyone on the UFO side is arguing in the first place that aliens are flying around in the USS Enterprise and doing warp factor 10.

It also completely ignores the concept of Von Neumann probes, and robot aliens spreading our across the galaxy over a time period of a million years or so. But even more so, it totally ignores the trend in UFOlogy to argue that the 'aliens' are actually from here. That argument takes the form of time travelers, or extra-dimensional beings, or other variants of 'from here'. No light speed needing to be violated...though there is still the problem of how many-worlds beings could jump across timelines, or whatever.

I would make the point that UFO skeptics should not be arguing the physics of how UFOs work, or how they 'get here', or how they defy gravity, as it is akin to arguing over the attributes of God when the real argument is whether God even exists in the first place. Otherwise it is like arguing over whether unicorns have one horn or two. Likewise with UFOs, arguing over how aliens might get here is diverting off the issue of whether any of the sightings are actually aliens in the first place. To me it is an ass backwards form of skepticism. People need to prove a phenomenon even exists at all....before the issue is muddied with 'how' it might exist.

That argument takes the form of time travelers, or extra-dimensional beings, or other variants of 'from here'. No light speed needing to be violated...though there is still the problem of how many-worlds beings could jump across timelines, or whatever.
the general argument goes like this:
a) the aliens are constrained by the rules of physics
b) these rules don't allow them to be here
c) therefore, they're not

this works the same whether you apply it to space travel, time travel, or "inter-dimensional" travel. if you accept it, you can immediately stop looking, depriving thousands of people of a hobby, and dozens if not hundreds of people of a steady income (more if you include scientology). These people are all pushing back against the idea of alien visits being essentially impossible.

The whole 'aliens can't defy the speed of light' thing is a straw man...designed to cut off the debate right at the start and imply that because aliens cannot defy physics therefore there cannot be any aliens here.
I would make the point that UFO skeptics should not be arguing the physics of how UFOs work, or how they 'get here', or how they defy gravity, as it is akin to arguing over the attributes of God when the real argument is whether God even exists in the first place. Otherwise it is like arguing over whether unicorns have one horn or two. Likewise with UFOs, arguing over how aliens might get here is diverting off the issue of whether any of the sightings are actually aliens in the first place. To me it is an ass backwards form of skepticism. People need to prove a phenomenon even exists at all....before the issue is muddied with 'how' it might exist.
Not all UFO believers come at it from the same direction. Not all claims require the same counter-arguments. Nevertheless Dunning goes a long way toward explaining why the experts he refers to (astrophysicists) are, in general, dismissive of the whole question right from the start. I think almost all of the scientific community agree that there's a vanishingly small possibility of actual visitation from another planet.

Whether or not there is any actual entity to investigate is, quite frankly, not their department. Someone else would have to provide the evidence for that.
it totally ignores the trend in UFOlogy to argue that the 'aliens' are actually from here. That argument takes the form of time travelers, or extra-dimensional beings, or other variants of 'from here'.
Since Metabunk is more concerned with the analysis of genuine information, I'm unsure how we could provide anything to unravel THAT, any more than we could tackle "did god ever exist?" or "do unicorns come in a variety of colors?"

People need to prove a phenomenon even exists at all....before the issue is muddied with 'how' it might exist.
Which I think is the value of the general one-claim-at-a-time approach normal on Metabunk -- look at the claim, if it turns out that the interesting light seen out your plane window can be shown to be flight AA1234 heading from Montreal to St. Louis, then it doesn't matter whether UFOs are believed to be from other planets, Dimension X, the Depths of Hell (though the "UFOs are Demons" forced meme does not seem to be catching on) or "The Distant Future, the Year 200!!!"

Because THIS one is known to come from Montreal, and just be an airliner.

the general argument goes like this:
a) the aliens are constrained by the rules of physics
b) these rules don't allow them to be here
c) therefore, they're not

this works the same whether you apply it to space travel, time travel, or "inter-dimensional" travel. if you accept it, you can immediately stop looking, depriving thousands of people of a hobby, and dozens if not hundreds of people of a steady income (more if you include scientology). These people are all pushing back against the idea of alien visits being essentially impossible.

I find the 'argument' somewhat absurd. Aliens are constrained by the known rules of physics. We cannot possibly say what rules a civilisation a million years ahead of us may have discovered. What's more, the whole argument relies on assumptions about aliens jumping 1000 light years at a time, when they could spread out a few tens of light years at a time. And there is the absurd assumption that aliens set out just to abduct Arizonan loggers and then return home for tea....which is all just a caricature and straw man as we have no idea whatever of how aliens might operate.

We have no idea if there even are any aliens at all, what their science or technology might be, what new science they may have discovered, or how near they may be. If find the certainty of the 'they can't be here' argument unscientific.

Arguments to the effect of 'they can't be here' are pointless and unprovable. It's a good deal more scientific to simply point out that someone's prize UFO is most likely a Batman balloon and that aliens and whether they 'can' get here don't even need to enter the equation at all. Why argue over what colour unicorns are when you can show that every unicorn sighting is actually a horse.

I find the 'argument' somewhat absurd. Aliens are constrained by the known rules of physics. We cannot possibly say what rules a civilisation a million years ahead of us may have discovered.

Technically correct. However, it has always struck me as intellectually dishonest for a claimant of superior alien technology to be selective about when to appeal to known physics and when to science fiction in order to fit a personally appealing alien narrative. In a reasonable conversation we are justified to expect that, if the claimant of alien theories of physics challenging our most successful theories of physics also selectively accepts our theories in their argument such as the existence of mass and light (which they always do), then they also must accept the somewhat formidable onus to demonstrate how these alien theories account with equally amazing broadness, accuracy and consistency to countless repeatable observations and measurement outcomes across the universe as our best theories do. Anyone can claim magic and withdraw from further discussion by not even attempting to provide any evidence for it. That's not really an honest dialogue imho.

The success of received theories of physics impose a formidable standard of rigour for any future scientific claims attempting to challenge these theories because any new 'revolutionary' theory must be able to be at least as successful in predicting these very same observations, and not only the anomalies within these theories they've set out to highlight to prove a point about their fallibility (which is a correct point).

Theories of supernatural beings do not need to obey these conversational constraints of scientific discussion. They can be just as true and just as false in any universe. However, theories of superintelligent natural beings do. That's why it's not "absurd" for the reasonable skeptic to appeal to the power of the 'known' rules of physics when discussing with a claimant of a superintelligent natural being.

Arguments to the effect of 'they can't be here' are pointless and unprovable. It's a good deal more scientific to simply point out that someone's prize UFO is most likely a Batman balloon and that aliens and whether they 'can' get here don't even need to enter the equation at all.

By and large correct. When it comes to hypothetical alien civilizations, both the Drake Equation, and the Fermi Paradox that critiques it, are highly speculative. A 'believer' shouldn't be overly enamoured by the former inasmuch as the 'skeptic' shouldn't read into the latter.

Given the vast number of known variables as well as an unknown number of unknown variables to consider for such a calculation, there is no scientifically viable, let alone rigorous, mathematical model to produce a reliable probability value for alien communication or visitation.

If all sides to the argument wish to be pedantically scientific and unbiased, and as much as I am personally emotionally averse to admitting it, I must also accept on the basis of the foregoing paragraph in italics, that there is currently no sound mathematical model that can reliably demonstrate that undetected alien visitations are unlikely.

However, the available consistently sketchy UAP evidence which fails to prove anything extraordinary casts serious doubt on any hypothesis whereby such visitations, if they have occurred, have ever been detected.

the general argument goes like this:
a) the aliens are constrained by the rules of physics
b) these rules don't allow them to be here
c) therefore, they're not
I'd replace (c) with "therefore we are not going to worry about them until someone comes up with some much more compelling evidence."

That hasn't happened, and given the past cases it would seem that any interested parties would have to wait and twiddle their thumbs until a member of the public comes up with another video, another radar image, another fragment of scrap metal from a remote desert location, another breathless verbal description from an inebriated pensioner, etc. It's not as if there's a UFO home territory where people can go to hunt them.

I would make the point that UFO skeptics should not be arguing the physics of how UFOs work, or how they 'get here', or how they defy gravity, as it is akin to arguing over the attributes of God when the real argument is whether God even exists in the first place. Otherwise it is like arguing over whether unicorns have one horn or two. Likewise with UFOs, arguing over how aliens might get here is diverting off the issue of whether any of the sightings are actually aliens in the first place. To me it is an ass backwards form of skepticism. People need to prove a phenomenon even exists at all....before the issue is muddied with 'how' it might exist.
I'm staring at the end of your comment. What your describing is basically what Metabunk does, as JMartJr pointed out. Presented with a fuzzy photo of a unicorn, some may point out that there is little to no evidence for the existence of unicorns, but most of the discussion will center around trying to identify and understand what is in the photo.

In regards to @BrianDunning and Skeptoid, I've found that's what he usually does. Each episode is relatively short and centers on a single subject, like the Malmstrom AFB case or The Philadelphia Experiment. The upcoming movie seems to be different.

The whole 'aliens can't defy the speed of light' thing is a straw man...designed to cut off the debate right at the start and imply that because aliens cannot defy physics therefore there cannot be any aliens here. It's not that the particular argument is wrong, but that hardly anyone on the UFO side is arguing in the first place that aliens are flying around in the USS Enterprise and doing warp factor 10.

I don't think it's a strawman firstly because UFOlogists such as UAPx astrophysicist Dr. Szydagis have made that exact claim. Namely that FLT may be possible with unknown physics. Unfortunately, he has taken down his article, but one can start with this thread which has many parts of it:

Secondly, I'm thinking this film can't debunk each and every UFO case. We know how that works, if one started with Roswell, then Rendlesham, then Malmstrom, the Chilian airforce sighting, GoFast, by the time one gets to various balloons and Xmas lights, the UFOlogist have circled back to Roswell or the old Trinity case.

I think that's why it seeks to set up "boundaries" if you will right from the beginning.

First that any alien culture is subject to the same rules of physics as we understand them, and those rules make FTL travel very difficult if not impossible.

Secondly, any alien culture is subject to the same rules of evolution as we understand them. If there is an age to the universe and it took a set amount of time for the various factors needed to have our species evolve, then a similar length of time is needed for other alien species to evolve. Go back to many hundreds of millions of years, and the universe hasn't settled into a state where planets that can evolve intelligence. If our, and the aliens evolution is constrained by the age of the universe, its unlikely they have evolved intelligence greatly beyond us and have mastered FTL travel or that they evolved long, long ago as to have sent out slow moving Von Neuman type probes in a time frame for them to arrive here. That's the argument as I understand it at least.

I think it' a first round aimed at the UAPx types, those that see UFO/UAPs as actual physical "things" from beyond our solar system that have arrived here. How that applies to the more Magonian UFOlogist that mix physical with interdimensional, time traveling or spiritual versions of UFOs, I'm not sure.

the more Magonian UFOlogist that mix physical with interdimensional, time traveling or spiritual versions of UFOs
Article:
Magonia is the name of the cloud realm whence felonious aerial sailors were said to have come, according to commonly-held beliefs denounced in the polemical treatise by Carolingian bishop Agobard of Lyon in 815, where he argues against weather magic.

In his treatise Agobard complains that in his region it is widely believed that there is a land called Magonia whose inhabitants travel the clouds in ships and work with Frankish tempestarii ("tempest-raisers" or weather-magi) to steal grain from the fields during (magically raised) storms.[1] He denounces such beliefs as ignorant and refutes them with many quotations from Scripture, to prove that God alone causes hail and thunder.

Magonia is featured in Jacques Vallee's book Passport to Magonia, which explores the link between modern UFO visitations and reports from antiquity of contact with these "space beings" where he quotes Agobard's description. The former British magazine Magonia was devoted to articles about UFOs and other Forteana.[2]

Theories of supernatural beings do not need to obey these conversational constraints of scientific discussion. They can be just as true and just as false in any universe. However, theories of superintelligent natural beings do. That's why it's not "absurd" for the reasonable skeptic to appeal to the power of the 'known' rules of physics when discussing with a claimant of a superintelligent natural being.
No, I don't accept the whole notion of constraining aliens to our current knowledge of physics. I mean, why not constrain them to 1901 physics, or 1835 physics, or 1610 physics ? We've only been at physics for 400 years, so am I seriously to believe that any beings that might be a million years ahead of us are constrained by the laws of physics as defined in 2023 on Earth ? That comes across as very anthropocentric.

One can argue 'as far as we currently know' aliens cannot get here, and I'd accept that, but that is not the argument being made. I just see a blanket dismissal.

Even with our current knowledge of physics, it will be incredibly difficult...though not impossible...to reach the nearest star. The difficulty arises primarily from human life spans. Advanced robotics will have no such issues and I tend to the view that robots would take over the galaxy long before squishy biological beings would. I simply don't accept the 'impossibility' of aliens getting here.

And again...I don't think it's an argument that should be made against UFO sightings.

No, I don't accept the whole notion of constraining aliens to our current knowledge of physics. I mean, why not constrain them to 1901 physics, or 1835 physics, or 1610 physics ? We've only been at physics for 400 years, so am I seriously to believe that any beings that might be a million years ahead of us are constrained by the laws of physics as defined in 2023 on Earth ? That comes across as very anthropocentric.
well, pre-Einstein they could've travelled faster than light. 1610 already knew rockets. It's not the lack of knowledge that constrains, it's the knowledge.

No, I don't accept the whole notion of constraining aliens to our current knowledge of physics. I mean, why not constrain them to 1901 physics, or 1835 physics, or 1610 physics ? We've only been at physics for 400 years, so am I seriously to believe that any beings that might be a million years ahead of us are constrained by the laws of physics as defined in 2023 on Earth ? That comes across as very anthropocentric.

The notion that successful revolutionary theories of physics have refuted successful earlier theories is a false narrative of the history of physics. Let it be clarified that by a 'successful theory' is hereby meant any hypothesis consistently generating accurate predictions that can be verified by reliable observation. 'Old science is refuted by newer science in our own history' is a simplistic common trope used by the ufologist to appeal to magic without sounding anti-science.

Extremely fast-accelerating objects with a mass generated heat and sonic booms within the atmosphere as consistently in 1901, in 65,003 BC and 2 bllion years ago as they do now utterly regardless of what our theories of physics claimed or didn't -- hell, regardless of whether we existed or any civilization for that matter would ever exist. The earth remained round for thousands of years of us being flat-earthers, but once discovered as round, no new revolutionary theory of physics was going to change our confidence of this fact. How does a theory, a product of our minds, change objective mind-independent fact anyway? Photons are massless particles traveling at the speed of light and nothing with a mass can go faster than a massless particle consisting solely of kinetic energy, not now, not in the past nor in the future. This confidence is based on empirical evidence, not blind belief. Gravity causes attraction between all massive objects or energy in the universe completely irrespective of whether we describe it at lower velocities and distances on earth using Newtonian mechanics or across the universe using Einstein's relativity.

Yes, a successful scientific theory is always but an approximation (rather than a perfectly accurate inviolable description) of objective truth. However, the history of physics has demonstrated an ever-increasingly accurate approximation of that truth as a theoretical continuum across time. The objective truth (the physical universe and its fundamental properties) being described has remained one and the same, and the successful approximations of that objective truth made by past physical theories have never ceased to be successful in their calculations.

If you think superluminal speed may well be within the reach of future science, whilst accepting a superluminal craft has mass, you're contradicting yourself. All I'm saying, don't sloppily and selectively mix established human science with revolutionary alien science fiction whilst throwing stones at human science as primitive and obsolete. You have to entirely redefine mass and energy and not mix any old physical terms with your 'new science' in order to even undertake such a formidable task. Good luck with that.

It also completely ignores the concept of Von Neumann probes, and robot aliens spreading our across the galaxy over a time period of a million years or so.
I'm inclined to agree with Scaramanga on this point, particularly the possibility of long-duration "missions".

When originally expressing his paradox, Enrico Fermi seemed to be thinking in terms of sub-light-speed travel, and physical 'visits'.

The Fermi paradox is usually interpreted nowadays as the conflict between the assumption that extra-terrestrial intelligence is widespread, and the fact that we haven't observed any evidence of its existence. It was mooted by Fermi in conversation with fellow scientists Edward Teller, Emil Konopinski and Herbert York.

In 1984, Doctor Eric M. Jones of Los Alamos National Laboratory, in correspondence with Teller, Konopinski and York, attempted to recreate the conversation that led to Fermi formulating his paradox and the subsequent discussion

(Jones, E.M., March 1985 "Where Is Everybody?" An Account of Fermi's Question" Los Alamos: Los Alamos National Laboratory)
http://www.fas.org/sgp/othergov/doe/lanl/la-10311-ms.pdf -Courtesy of Internet Archive Wayback Machine:

Teller relates Fermi asking him about the chances of detecting a material object travelling >C, Teller effectively discounts the possibility, Fermi thinks 10% (although I don't know how serious he was being in the given context) . Teller continues that the men then discussed whether "...flying saucers might be due to extraterrestrial people", their conclusions were "...purely negative".
It was after this conversation- in which Teller had ruled out superluminal travel, and the men had agreed that 'flying saucers' are not from ETI's- that Fermi asked "Where is everybody?".

York recounts that after posing the question, Fermi did some calculations to estimate the possibility of ETI arising (see text, 11th image above, marked p.10). If York is correct, Fermi's musings anticipated the thematically identical Drake equation by a decade.
"He [Fermi] concluded on the basis of such calculations that we ought to have been visited long ago and many times over."
(My emphasis).

It seems that Fermi thought that it was paradoxical that we had not been visited even in the context of subluminal travel.
If Fermi's paradox had been dependent on the assumption that ETI travel >C, it wouldn't be a paradox for Teller, who had just made his scepticism of FTL travel clear.

the general argument goes like this:
a) the aliens are constrained by the rules of physics
b) these rules don't allow them to be here
c) therefore, they're not

Point (a), whatever level of technology is postulated, must be correct. But I don't think point (b) follows from this. We know material objects from interstellar space visit the solar system ('Oumuamua). AFAIK there is no absolute reason that an alien artefact couldn't traverse interstellar distances given enough time.

An interstellar "message in a bottle" vehicle, able to convey that its designers exist(ed) and perhaps deliver some information, needs to be able to retain functionality at approx. -270 Celsius and have protection or redundancy from effects of cosmic rays for prolonged periods. I don't think this is physically impossible. A hypothetical messenger could remain dormant for most of its voyage, reactivating when stellar radiation provides a useful power source.

I'm more sceptical of self-replicating probes. Unless ETI have mastered transmutation of elements, which would seem to require overcoming the strong nuclear force, a probe 'scavenging' asteroids etc. would presumably have to identify and visit several different bodies to acquire diverse elements. A rocky planet (like Earth) might have everything necessary, but then you have to build another substantial launch vehicle. Maybe a versatile nanotechnology would enable construction of functionally complex 'daughter' probes from common materials.

If such a messenger has visited our solar system, it either failed or we didn't notice (we've only been using radio for some 127 years). Personally, I think "the big silence", and the absence of evidence, might well be evidence of absence (and is more convincingly so as time passes and our instruments probe further). But if technological ETI exists, a message-in-a-bottle is not impossible, and isn't too big a conceptual (or engineering) leap from Pioneers 10 and 11, Voyagers 1 and 2.

Secondly, any alien culture is subject to the same rules of evolution as we understand them. If there is an age to the universe and it took a set amount of time for the various factors needed to have our species evolve, then a similar length of time is needed for other alien species to evolve. Go back to many hundreds of millions of years, and the universe hasn't settled into a state where planets that can evolve intelligence. If our, and the aliens evolution is constrained by the age of the universe, its unlikely they have evolved intelligence greatly beyond us

This only holds true, as an argument against ETI existing and possessing superior technology to us, if we accept it as axiomatic that Earth is the youngest world (or exactly the same age as the youngest worlds) on which life could evolve- a form of Earth exceptionalism.
There are no observations that support this.
It also requires biological evolution to somehow follow a schedule over the same timescale in different environments. But evolution is not deterministic or prescriptive like that- it isn't comparable to a chemical reaction or radionuclide decay.

There are stable Sun-like main-sequence stars more than 3 billion years older than the Sun, HD 197027 in Capricornus, 255 ly away is very similar- with very close metallicities- and is 2.32 to 3.4 (upper estimate) billion years older.
There is no scientific reason to doubt that in our galaxy there are millions of main-sequence solar analogues older than the Sun.
This might be of interest (sorry, it's Wikipedia, but it is a good outline of the topic), "Solar analog"

https://en.wikipedia.org/wiki/Solar_analog#:~:text=These stars are photometrically similar to the Sun,,less), because such a companion stimulates stellar activity

You would have to go back billions of years- not many hundreds of millions- to have an environment which might be less amenable to life (early generations of stars- and their planets, if any- had lower metallicity; the complex chemistry required by life might not have been found).

There are too many unknown variables in our own natural history to realistically state that it would take the same length of time- within a thousand years ?!- for a technological culture to evolve elsewhere, even if Earth were one of the first planets to form which could support life. -I use "within a thousand years" because (hopefully) our own technology in 1000 years time will be significantly superior to what it is now.

Life on Earth may have appeared 3.7 billion years ago or earlier. But it took perhaps 2.9 to 2.95 billion years for true multicellular life to evolve from unicellular organisms
(Erwin, D.H., Early metazoan life: divergence, environment and ecology, 19 December 2015, Philosophical Transactions of the Royal Society B, Royal Society Publishing, London)
https://royalsocietypublishing.org/doi/full/10.1098/rstb.2015.0036
Abstract

- If it took 2.95 billion years, are we really saying that it has to take exactly that long, or longer, on any world with unicellular life?
If we posit an alien world exactly the same age as Earth, where multicellular life arose from unicellular life in 99% of the time it took on Earth, it gives the alien biosphere a mere 29.5 million years head-start.

We don't know how often life arises, how often it makes the leap to multicellular organisms, how often this leads to a technological culture- it might have only happened once. But if life can arise elsewhere, I don't think that there are any scientific objections to there being biospheres older than our own.

Edited by me, 04:56: Removed a long chunk where I make a ridiculously optimistic assumption about the time required to cross 10 ly based on my own flawed arithmetic.

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Extremely fast-accelerating objects with a mass generated heat and sonic booms within the atmosphere as consistently in 1901, in 65,003 BC and 2 bllion years ago as they do now utterly regardless of what our theories of physics claimed or didn't -- hell, regardless of whether we existed or any civilization for that matter would ever exist.
Very true; we (of course) have only had claims about UFOs once they're already here and are visible to earthlings. As has been pointed out before, they would still have to contend with what's been referred to as "Air 1.0", no matter what fanciful methods of interstellar travel have been postulated. Any account that mentions fantastic speeds or maneuvering powers gets my skeptical antenna vibrating, and in such cases I'd mistrust any claimed speed/size/distance estimates.

If you think superluminal speed may well be within the reach of future science, whilst accepting a superluminal craft has mass, you're contradicting yourself. All I'm saying, don't sloppily and selectively mix established human science with revolutionary alien science fiction whilst throwing stones at human science as primitive and obsolete. You have to entirely redefine mass and energy and not mix any old physical terms with your 'new science' in order to even undertake such a formidable task. Good luck with that.
You're only contradicting yourself in the theory of special relativity, not in that of general relativity. The concept of a 'warp drive' is based on the latter.

A key question to ask in these discussions:
Are we talking about something that is strictly forbidden by our current understanding of the laws of physics? Or are we "merely" talking about a massive engineering challenge that we might be able to tackle in a few 1000 years?

In the attached paper on warp field mechanics, Dr. Harold “Sonny” White from the NASA Johnson Space Center writes:

While it would appear that the model has nearly all the desirable mathematical characteristics of a true interstellar space drive, the metric has one less appealing characteristic – it violates all three energy conditions (strong, weak, and dominant [9]) because of the need for negative energy density. This does not necessarily preclude the idea as the cosmos is continually experiencing inflation as evidenced by observation, but the salient question is can the idea be engineered to a point that it proves useful for exploration.
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One should not treat (massive) engineering challenges as absolute laws of physics that 'prove' the impossibility of something.

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You're only contradicting yourself in the theory of special relativity

The concept of a 'warp drive' is based on the latter.

If you're referring to a kind of Alcubierre drive which assumes negative mass, then you're violating general relativity wth said assumption.

As I wrote to you earlier in post #35, adding this 'one' little assumption (i.e. negative mass) happens to violate energy conditions in general relativity which predict extremely successfully observations across the universe. Even the Casimir effect, which was thought to violate certain energy conditions, can satisfy an appropriately defined energy condition (i.e. averaged null energy condition).

In other words, conveniently 'tweaking' a highly successful general theory of physics to satisfy an alien spacecraft hypothesis in order to explain a modest set of low quality UAP data is bad science at best, pure science fiction pretending as science at worst.

Whilst general relativity surely has its limitations, to seriously even entertain an alternative theory without energy conditions, this alternative must be able not only to predict the anomalies which do not comfortably satisfy relativity, but to also account for all the observations which relativity predicts with amazing accuracy across the universe. For an alien hypothesis to account for a particular radar return to be seriously considered as a scientific one, it must take on the formidable burden to prove an alternative general theory to Einstein's relativity which is more successful in its predictions. Now that's quite a tall order.

Until such a serious well-formulated scientific theory, all talk of negative mass is science fiction rather than science. Which is fun. As long a we don't put too much stock on it.

In the paper I attached to my previous post:

Is there a way within the framework of current physics models such that one could cross any given cosmic distance in an arbitrarily short period of time, while never breaking the speed of light? This is the question that motivated Miguel Alcubierre to develop and publish a possible mathematical solution to the question back in 1994 [5]. Since the expansion and contraction of space does not have a speed limit, Alcubierre developed a model (metric) within the domain of general relativity that uses this physics loop hole and has almost all of the desired characteristics of a true interstellar space drive, much like what is routinely depicted in science fiction as a “warp drive”.
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As I wrote to you earlier in post #35, adding this 'one' little assumption (i.e. negative mass) happens to violate energy conditions in general relativity which predict extremely successfully observations across the universe.
See my quote from that same paper in my previous post. General relativity nor any other of our current theories of physics predicts this inflation, so there are observations which require an update of our laws of physics. An update which must include the inflation observed and currently labeled as "dark energy".

No, I don't accept the whole notion of constraining aliens to our current knowledge of physics. I mean, why not constrain them to 1901 physics, or 1835 physics, or 1610 physics ? We've only been at physics for 400 years, so am I seriously to believe that any beings that might be a million years ahead of us are constrained by the laws of physics as defined in 2023 on Earth ? That comes across as very anthropocentric.

The realm in which any new theories would apply would be fields that do not interact with us to any appreciable extent.

Maybe there are giant dark matter robots 10^40km in size living their merry dark matter robot lives. But we'll never encounter them, and they'll never encounter us, even if they walk right through us.

I'm not saying we know everything about the realms that we do interact with - far from it, the muon g-2 anomaly proves that QFT is a wrong. But we know where we're wrong - that's where scientists are looking, progress of science is explaining the prior wrongs - and the difference between prediction and measurement are so small they don't make any difference to how the world behaves. SR didn't throw out Newton. GR didn't throw out SR. Maxwell didn't throw out Snell, QED didn't throw out Maxwell. In the realms where the solid science was demonstrably reliable, it remained demonstrably reliable even after we had better theories that explained broader realms.

And we're running out of broader realms. We're understanding the masses of the smallest subatomic particles to the largest galactic superclusters, distances from less than the width of a subatomic particle to distances greater than that of the largest galactic superclusters, and velocities up to one part in 10^10 from the speed of light.

Which realm do you think we've not probed?

and the difference between prediction and measurement are so small they don't make any difference to how the world behaves.
Are you serious? "How the world behaves" depends a lot on what beings with any intelligence can do with new discoveries:
SR gave us nuclear energy
GR gave us accurate gps (and possibly a warp drive in the future, if combined with dark energy)
Maxwell gave us wireless communication
QED gave us quantum computers

And this list of about 100 years of new scientific discoveries is far from complete, of course.

So yes, these new theories have a HUGE impact on how our world behaves. But they need to be combined with some creative intelligence to make a difference. And I do hope we are not the most intelligent beings in the universe. What a waste of space that would be...

In the attached paper on warp field mechanics, Dr. Harold “Sonny” White from the NASA Johnson Space Center writes:

While it would appear that the model has nearly all the desirable mathematical characteristics of a true interstellar space drive, the metric has one less appealing characteristic – it violates all three energy conditions (strong, weak, and dominant [9]) because of the need for negative energy density. This does not necessarily preclude the idea as the cosmos is continually experiencing inflation as evidenced by observation, but the salient question is can the idea be engineered to a point that it proves useful for exploration.
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One should not treat (massive) engineering challenges as absolute laws of physics that 'prove' the impossibility of something.
There's been interesting physics done on warp-drive-like solutions, but none of it was done by Harold White. The errors in that document are too numerous to list individually, but here's some highlights:

1. The right-hand side of Einstein's field equations is not the mass/energy density alone, but the full 4x4 stress-energy tensor. The energy density in Alcubierre's solution is symmetric with respect to a direction flip, but the T^(0i) momentum components are not, so there is no ambiguity in the direction the bubble might go and therefore nothing to resolve by some weird heuristic argument. This should be fairly obvious, right? Einstein's field equations are... well, equations, meaning the left-hand side is equal to the right-hand side. It can't be the case that the right-hand side has a symmetry that the left-hand side lacks.

2. On the matter of weird heuristic arguments, look at this passage:

Consider the following to help illustrate the point – assume the spacecraft heads out towards Alpha Centauri and has a conventional propulsion system capable of reaching 0.1c. The spacecraft initiates a boost field with a value of 100 which acts on the initial velocity resulting in an apparent speed of 10c.
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So, let me get this -- if I travel alongside the spacecraft, White's spacecraft will be stationary. Then the warp drive should have no effect. Or, say my friend Bob reaches a speed of 0.2c with respect to Earth, so that White's rocket moves backwards with a velocity of -0.1c. Logically, then, when the warp drive is turned on it must travel at -10 c. According to Earth the rocket reaches Alpha Centauri, according to me it gets to Alpha Centauri in 50 years, and according to Bob it reaches somewhere in the constellation Cassiopeia. Hopelessly inconsistent.

3. Related to point 1, a toroidal ring of negative energy density won't give you the right metric because it's missing the other components of the stress-energy tensor.

4. A charged capacitor ring won't give you negative energy at all. Here it's obvious some kind of game of telephone happened, where White heard from someone that the Casimir effect is a way of generating negative energies in the lab, and that the Casimir effect is typically described in a situation with two parallel conducting plates, like a capacitor. But charging said capacitor would drastically overwhelm the minute negative energy associated with the Casimir vacuum, and is actively counterproductive.

5. White's key contribution to this debate, as reported in news articles and the like, is "reducing the required energy" to create a warp bubble. Trouble is, he didn't actually reduce anything. He used the exact same equation Alcubierre already had in his 1994 paper, verbatim, and just plugged in a parameter in it. The entire reason why the warp bubble was said to require an entire universe's worth of negative energy was because of conjectured "quantum inequalities" that constraint the amount of negative energy that may be concentrated in a single place. These imply that the bubble walls must be sufficiently thin. Now, as it is a conjecture, it's not necessarily a rock-solid argument, but actually 'decreasing the required energy' would demand at least engaging with the argument in some fashion rather than merely ignoring it, probably out of ignorance.

I could go on, and even examine his other writings, the emdrive fiasco, etc., but in the interest of time and avoiding going further off-topic I'll stop here. My blanket recommendation is to be aware that reading anything written by White on the subject of physics is likely to leave you more ignorant than if you hadn't.

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