Argument Question

TB333

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I have a bit of a question me and my friends were arguing about.......
Is a lack of evidence somthing exists, evidence it doesnt? I think thats ridiculous but it keeps becoming an argument. Maybe becouse it touchs apon personal beliefs? Any thoughts on this?
 
Now that is a good question. I think it all depends on context and a multitude of factors. The lack of evidence of something existing doesn't prove that it doesn't exist, but on the other hand, if something exists there will be evidence it does. I mean, that's what the whole concept of existing is. It will create some measurable change in our universe that can be recorded/observed.

In my opinion, if evidence for the existence of something is being actively sought after and no evidence of its existence is being found, that can be a very valid argument that whatever that thing is probably doesn't exist. The statement "there's no evidence that this exists" holds a lot more weight, then the argument that "there's no evidence this doesn't exist" holds.
 
Absence of evidence is not evidence of absence.
 
ORBaby said:
Absence of evidence is not evidence of absence.

But the absence of evidence can sometimes (I think) help prove theories or lead to accurate deductions.

Say you have an empty box you can't see inside of and you know the mass of. If you weigh the box and the mass hasn't changed, you can deduce that the box is empty. The lack of evidence that there's something in the box can be used to determine that idea of some additional material existing within the box is false
 
That the mass of the box has not changed is evidence, there is nothing in the box.
Suppose you are in a dark room, is there a box sitting in it? You have no evidence, does that mean there is no box?
 
Lack of evidence is not evidence of lack...

...however, lack of evidence is not a strong position in an argument. Yes, something could exist even though there is no evidence for it, but so could lots of things. Lack of evidence doesn't lend more credence to one proposition over any other. For example, it could be the case that the worry-stone on my desk protects me from bears (I have no evidence of this, but it could be). But it could also be the case that it protects me from tigers, cougars, lions, sharks, or beavers too. Without evidence, they are all equally probable.
 
If a tree falls in the forest when no one is there, did it make a sound? We assume it did based on past experience, but there is no evidence that it did. Sometimes you just go on faith or past experiences.
 
ORBaby said:
That the mass of the box has not changed is evidence, there is nothing in the box.
Suppose you are in a dark room, is there a box sitting in it? You have no evidence, does that mean there is no box?

If that's where the investigation stops then ya, based on the information at hand, no one could say whether there's a box in there or not. But if there's further investigation and observations made and no further evidence turns up. As more "non-evidence" turns up, the probability of there being a box in there will keep decreasing until there's 99.999999999999999...% probability that there's no box in there. Unless evidence turns up that proves it's not in there, then the probability of there being no box in there would be 100%, but at some point it could be safely concluded based on the lack of evidence that there's probably no box in there
 
Just because we have not figured something out, or discovered it yet, does not mean it doesn't exist. Did magnetism exist before we discovered it? What about gravity waves? And so on. We had no proof it existed before, so trying to argue it didn't exist before would just be stupid. That's no different in trying to make the same argument for anything else we have yet to discover too.

On the other hand, if there is evidence something doesn't exist, then that is a good basis for ruling it out. As examole, We know the earth isn't flat because we can "circumnavigate" the globe without changing direction, and have been to space with returned photographic evidence. Both proving the earth isn't flat. Trying to argue against the evidence is what then makes someone stupid as well.
 
TB333 said:
Is a lack of evidence somthing exists, evidence it doesnt?

Ah! An interesting philosophical problem. If you have never seen a black swan, is that evidence that swans are never black? (And is that hypothesis confirmed every time you see a white swan?) If the sun has always risen in the East and set in the West, will it do the same tomorrow? In philosophy, this is known as The Problem of Induction.

https://en.wikipedia.org/wiki/Problem_of_induction

Until the 17th Century, Europeans had only ever seen white swans. Then, it made sense to believe that black swans didn't exist (just as it makes sense for us to believe that rainbow-coloured swans don't exist). Yet a single sighting of a black swan completely nullified all those millenia of evidence of there being only white swans.

Hempel's Confirmation Paradox pushes that further. You can have valid evidence that supports a hypothesis, with every observation you make providing further confirmation. Yet, whilst your observations are correct, the more information you have, the more you are steered towards a belief in a false conclusion.

http://staff.washington.edu/lynnhank/Ravens.pdf

TL;DR: A lack of evidence is just that. You can't logically believe in something you don't have evidence for, but you can't discount the possibility that it exists. However, if someone is making a claim, the onus is on them to provide evidence to support that claim.

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TheCaptain said:
Say you have an empty box you can't see inside of and you know the mass of. If you weigh the box and the mass hasn't changed, you can deduce that the box is empty. The lack of evidence that there's something in the box can be used to determine that idea of some additional material existing within the box is false

There's no such thing as an empty box. :smile:

[video=youtube;X5rAGfjPSWE]https://www.youtube.com/watch?v=X5rAGfjPSWE[/video]
 
dogboy said:
If a tree falls in the forest when no one is there, did it make a sound? We assume it did based on past experience, but there is no evidence that it did. Sometimes you just go on faith or past experiences.
This, and the OP's original question, have more to do with definitions than anything else. If sound is defined as airwaves within a specific frequency range then, yes, a tree falling makes sound and we can prove it to the extent we can prove anything else. If the definition of sound requires an element of hearing, then it would depend on how we defined hearing. But, based on the definition, we could still come up with a definite yes or no.

As to the original questions "Is a lack of evidence somthing exists, evidence it doesnt? I think thats ridiculous but it keeps becoming an argument. Maybe becouse it touchs apon personal beliefs? Any thoughts on this?":

The way I see it, "facts" are things we perceive and are as close to being objective observations as we can get, as long as we don't attach any particular meaning to them. "Evidence" is entirely subjective because it relies on personal belief about what a fact or facts mean. Evidence is judged to be strong or weak depending on how well it satisfies our personal beliefs. Science and philosophy have adopted rigid standards in an effort to make conclusions based on "evidence" as objective as possible.

I have never seen any evidence to refute my belief that the flying spaghetti monster is fictitious. So, yes, for me the lack of evidence is evidence it doesn't exist. But evidence is not the same as proof. I remain open to the possibility the flying spaghetti monster actually exists, but that possibility is pretty low on my probability scale.
 
One of the rules of the scientific principle is that you can not prove a negative.
===
The fact that i can't make cold fusion work, is not a sine that it can't be dun.
The fact that I can't find the "missing link" between cavemen and modern humanity is not proof he never existed.
the fact that the engineers of the 1890s couldn't make a train exceed 60MPH is no proof that trains can't exceed 100MPH
===
Never say "never".
 
Drifter said:
This, and the OP's original question, have more to do with definitions than anything else. If sound is defined as airwaves within a specific frequency range then, yes, a tree falling makes sound and we can prove it to the extent we can prove anything else. If the definition of sound requires an element of hearing, then it would depend on how we defined hearing. But, based on the definition, we could still come up with a definite yes or no.

As to the original questions "Is a lack of evidence somthing exists, evidence it doesnt? I think thats ridiculous but it keeps becoming an argument. Maybe becouse it touchs apon personal beliefs? Any thoughts on this?":

Actually, the falling tree question isn't so much about the definition of sound as it is about whether reality exists independent of perception. The way the thought experiment is phrased obfuscates that a bit, unfortunately. Maybe a better one: If a photon passes through a screen with only two small holes in it, and no one measures which hole it went through, did it still definitely pass through one of them but not the other? If a cat in a box is alive or dead depending on which hole the photon went through, is the cat definitely alive or definitely dead if the box remains unopened...? ^.^The question being driven at is really one of counterfactual definiteness. When we come upon a fallen tree in a forest, far from where anyone could have heard or otherwise witnessed the event of its falling, we still infer that such an event took place just as it would have if we (or anyone) had been there to observe it. That inference cannot be proven however, it is merely an inference… and that's the point. ^.^ Asking about which day of the week the tree fell on might be akin to asking about which hole the photon passed through… can you be sure it definitely fell on one particular day and not the others (we'll assume it didn't fall exactly at midnight or anything ^^; )?

As for the OP: I think it depends on the extent that the evidence was expected and yet is still absent. For example, Einstein's theory of General Relativity predicted that the gravity of our Sun ought to bend starlight, changing the apparent position of stars nearby it. If we looked and didn't see that deflection, it would have blown the theory almost entirely… the only hope would be measurement error or some unforeseen circumstance somehow negating the lensing effect. The theory says the light has to bend, so we'd better see it when we look for it.

For a fuzzier example: while the overall lack of evidence cannot constitute proof that the Loch Ness Monster isn't real, it is reasonable to conclude that its existence is unlikely because one would expect far more evidence to materialize if Nessie were present. The absence of evidence is indeed evidence of absence, but in this case it is not conclusive.

Also, as a general note: "proof" is a very slippery concept, yet seems to come up often. Strictly speaking, scientific theories cannot be proven. Ever. Mathematical theorems can be proven to follow from a set of axioms (read: assumptions), but they can never be known to be absolutely True, because the axioms they hinge on can't be proven. I am not sure when others refer to "proof" if they mean it more loosely than that (perhaps short for "proof beyond reasonable doubt"?), or to what extent they mistakenly believe in the literal provability of things…
 
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Sapphyre said:
Actually, it isn't so much about the definition of sound as it is about whether reality exists independent of perception. The way the thought experiment is phrased obfuscates that a bit, unfortunately. Maybe a better one: If a photon passes through a screen with only two small holes in it, and no one measures which hole it went through, did it still definitely pass through one of them but not the other? If a cat in a box is alive or dead depending on which hole the photon went through, is the cat definitely alive or definitely dead before the box is opened...? ^.^
Erwin's cat is definitely dead by now. No cat can survive 85 years without food and water, and the original thought experiment made no mention of cryogenics. :smile1: (Hmmm... I quoted your first paragraph but the cat reference is no longer in your post. Evidence of a worm hole...?)

Philosophically, the universe may exist only in the mind. But if we assume that possibility, the tree falling in the forest question is meaningless. The tree, the forest, and the air through which sound waves propagate, may not be real outside of our perceptions. If the intent of that question was to make that point, then point taken. Still, the reason we can talk about trees and forests and sound is that we share some common experiences regardless of whether those experiences are based on physical reality or just illusions. From that perspective, the answer we give will depend on how the terms are defined.

Scientists run into problems experimenting with particles (such as photons). One of the problems is that the act of observing a particle during the experiment changes the result of the experiment, giving a possible scientific basis for questioning if reality is truly independent of perception.

Edit: Oh no! It's happening again! This time he cat came back and new words appeared out of nowhere. Reality really is dependent on perception!!!
 
Drifter said:
Philosophically, the universe may exist only in the mind. But if we assume that possibility, the tree falling in the forest question is meaningless. The tree, the forest, and the air through which sound waves propagate, may not be real outside of our perceptions. If the intent of that question was to make that point, then point taken. Still, the reason we can talk about trees and forests and sound is that we share some common experiences regardless of whether those experiences are based on physical reality or just illusions. From that perspective, the answer we give will depend on how the terms are defined.

Scientists run into problems experimenting with particles (such as photons). One of the problems is that the act of observing a particle during the experiment changes the result of the experiment, giving a possible scientific basis for questioning if reality is truly independent of perception.

The problem is much deeper than the measurement of photons being problematic. The double-slit experiment (and variations thereon) actually demonstrates that photons only choose one definite path when their path is measured. If no one measures which hole a photon passes through, it sorta-kinda goes through both, like a wave, and the fact that it lacks a definite particle-like path is measurable. To think the photons each pass through only one of the holes leads to wrong predictions about their trajectories. The objective fact of the matter about which hole a given photon passed through (provided no measurement is taken) is not merely unknown, but actually nonexistent. That particular binary bit of information — the photon passed through hole A or hole B — is created by the act of measurement; it was not already there waiting to be discovered. The Elitzur-Vaidman bomb tester leverages this fact to determine the outcome of measurements without needing to perform them. If reality were independent of observation, that thought experiment would not work (nor would the real-world double-slit experiments).

Another example is the Quantum Zeno effect: due to physical systems being quantized, transition from one quantum state to another can be prevented by sufficiently frequent observation. In a very real sense, things can't move if they're being watched closely enough. ^.^ By observing things you force them to be more precisely defined, and that inhibits change.

The point of the falling tree question is, as you suggested, to realize that the notion of a universe outside of the mind is just an assumption, a projected idea, and a very limiting one when it comes to comprehending existence on the whole. Modern physics gives us (another?) good reason not to put too much stock in this idea of an independently extant universe.
 
My current, simplistic belief is that photons, and everything we call particles, are not actually physical particles but waves. When a wave collapses it does so by discharging it's energy at a single point, giving the illusion that it was a particle. Waves collapse when they interact with other waves. Energy is not lost in these "collisions" because new waves are formed, sometimes quite different than the original waves, giving the illusion that new, physical "particles" were created, which they've seen in experiments with particle accelerators.

I can observe a chair in my living room without interacting with it, but it's not the same with what we call "subatomic particles. In order to "observe" a "particle" you need some kind of detector to directly interact with it, and any interaction would, as I understand it, change it in some way. So, at this point, I have no problem at all believing the act of "observing" a photon would change it's behavior, causing the results of a double-slit experiment to differ from when photons are not observed.

These are just my beliefs based on theories I've read about. I think physicists are much closer to to understanding the physical nature of our little corner of the universe than they realize. But I also think if we discover the fundamental building block of the universe we will have to accept it "as is". We will have come full circle with the question, why does this exist?
 
Drifter said:
My current, simplistic belief is that photons, and everything we call particles, are not actually physical particles but waves. When a wave collapses it does so by discharging it's energy at a single point, giving the illusion that it was a particle. Waves collapse when they interact with other waves. Energy is not lost in these "collisions" because new waves are formed, sometimes quite different than the original waves, giving the illusion that new, physical "particles" were created, which they've seen in experiments with particle accelerators.

You're in good company; for a long time many physicists thought so too! It turns out there are phenomena that are impossible to explain by thinking of light as waves however, such as blackbody radiation or (more revealingly, IMO) the photoelectric effect. Long story short, the fly in the ointment is that subatomic entities — whatever they "really are" — can only be emitted or absorbed in discrete, quantized units (hence the name Quantum Mechanics), like particles, whereas waves are continuous by their very definition. Notably, a bunch of low-energy classical waves of the same frequency can combine to create a high-energy wave which, despite still having the same frequency, imparts much greater force on the things it impacts. Yet when light has too low a frequency to knock an electron out of orbit, it doesn't matter how much you crank up the intensity… the energy of the individual photons is not being combined to give additional "kick", like it would if they were waves. Instead, the situation is more akin to displacing a target with particle-like projectiles (always thrown at the same speed, c)... if one ping-pong ball can't move the target, throwing a whole bunch of them won't move it either… but throwing a rock might do the trick.

Drifter said:
I can observe a chair in my living room without interacting with it, but it's not the same with what we call "subatomic particles. In order to "observe" a "particle" you need some kind of detector to directly interact with it, and any interaction would, as I understand it, change it in some way. So, at this point, I have no problem at all believing the act of "observing" a photon would change it's behavior, causing the results of a double-slit experiment to differ from when photons are not observed.

You do realize any observation you make of a chair is nothing more than an aggregate of a large number of subatomic interactions, yes? o_O In any case, the physical interaction involved with the observation is not the cause of the difference in behavior. This is easily demonstrated by so-called "quantum eraser" experiments. In a nutshell… photons behave one way when you don't measure them. They behave differently if you do measure them. But if you go through all the motions of measuring them, and then destroy the information before it can be recorded, they behave just the same as if you didn't measure / interact with them. Have a look down the rabbit hole: Quantum Eraser Experiment. Careful, it goes deep. ^.^

Drifter said:
These are just my beliefs based on theories I've read about. I think physicists are much closer to to understanding the physical nature of our little corner of the universe than they realize. But I also think if we discover the fundamental building block of the universe we will have to accept it "as is". We will have come full circle with the question, why does this exist?

What makes you so sure that there is a fundamental building block to begin with? ^.^
 
The Quantum Eraser Experiment addresses my question about how to detect a photon in the double slit experiment without interacting with it (thanks), but the mechanics involved in the experiment, and therefore the conclusions, will forever be beyond my comprehension. I'm familiar with the concept of entangled particles but I have to accept the existence of this phenomena on faith because, again, I don't understand the science behind it. Still, for me it's fascinating when physicists explain various takes on quantum theory in layman's terms. I accept their findings as actual observations from experiments, but remain skeptical to the conclusions some people draw from them.

It's difficult to talk about this subject without some kind of preset bias. For example, talking about knocking an electron out of orbit seems to imply an electron is like a little rock, capable of being in an orbit around something. Electrons also exhibit wave behavior, so it's possible an electron is not a particle at all in the conventional sense. If it's a wave or an energy field, that could change how we see it's relationship with the nucleus of an atom, or what it means for it to move "out of orbit".

When you talk about increasing the "intensity" of a light wave without increasing the frequency I assume you mean increasing the amplitude, which is how I understand conventional waves. I can envision how increased amplitude would not necessarily create a greater impact at a discrete point along a wave. The wave form would have greater energy overall, but that energy would be distributed across a wider range. But I don't know. Maybe quantum waves are different. :dunno:

I have my biases too. I definitely favor quantum field theory, but for a solid scientific reason: It feels good to me. :)
 
Drifter said:
The Quantum Eraser Experiment addresses my question about how to detect a photon in the double slit experiment without interacting with it (thanks), but the mechanics involved in the experiment, and therefore the conclusions, will forever be beyond my comprehension. I'm familiar with the concept of entangled particles but I have to accept the existence of this phenomena on faith because, again, I don't understand the science behind it. Still, for me it's fascinating when physicists explain various takes on quantum theory in layman's terms. I accept their findings as actual observations from experiments, but remain skeptical to the conclusions some people draw from them.

It's difficult to talk about this subject without some kind of preset bias. For example, talking about knocking an electron out of orbit seems to imply an electron is like a little rock, capable of being in an orbit around something. Electrons also exhibit wave behavior, so it's possible an electron is not a particle at all in the conventional sense. If it's a wave or an energy field, that could change how we see it's relationship with the nucleus of an atom, or what it means for it to move "out of orbit".

Quite so! And actually, I think the difficulty in talking about QM without framing things from a particular interpretive vantage point has hindered its impact upon the public consciousness. QM has been around for about a century now, and its most profound implications have yet to become common knowledge. People still tend to implicitly believe in Local Realism (even if they're not familiar with the specific term), for instance. Few are aware of the Cosmic Interferometer thought-experiment.

Drifter said:
When you talk about increasing the "intensity" of a light wave without increasing the frequency I assume you mean increasing the amplitude, which is how I understand conventional waves. I can envision how increased amplitude would not necessarily create a greater impact at a discrete point along a wave. The wave form would have greater energy overall, but that energy would be distributed across a wider range. But I don't know. Maybe quantum waves are different. :dunno:

If we think of light as waves, then yes, a larger wave amplitude. If we think of light as particles, then it means "more photons". Either way, it's making the light brighter without changing the frequency. ^.^ I'm not sure i follow your reasoning however… the surface area of a particular solar cell is always the same, so if the entire surface is illuminated by light, then whatever is not reflected away is absorbed within that fixed area. No matter what the intensity of light shone upon it, if the frequency is too low, it will never be enough to generate any electricity.

Drifter said:
I have my biases too. I definitely favor quantum field theory, but for a solid scientific reason: It feels good to me. :)

I recently found a name for mine! Quantum Bayesianism (aka QBism). For awhile I thought I was alone in my take on things… ^^;

In summary:
…in this interpretation, a quantum state is not an element of reality—instead it represents the degrees of belief an agent has about the possible outcomes of measurements. For this reason, some philosophers of science have deemed QBism a form of anti-realism. The originators of the interpretation disagree with this characterization, proposing instead that the theory more properly aligns with a kind of realism they call "participatory realism", wherein reality consists of more than can be captured by any putative third-person account of it.
 
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Sapphyre said:
If we think of light as waves, then yes, a larger wave amplitude. If we think of light as particles, then it means "more photons". Either way, it's making the light brighter without changing the frequency.
I'm not sure how "more photons" would not change frequency. If light is a stream of photons then increasing the number of photons over a given period of time would increase the frequency of photons striking or passing an object, wouldn't it? What else could frequency mean if we are talking about particles instead of waves?
 
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