Do Protons Exist?

Without doing any googling or reading, I’d like to hear people’s views on whether protons exist.

It’s not a “gotcha”, but I do have a point to make that is relevant to the discussions here, so I hope the mods will forgive me the oblique approach.

Do Protons Exist?
  • Yes
  • No
  • I don’t know
  • It’s complicated

0 voters

Let’s make a start with Lucky 13 respondents, but I’m happy to have more people respond.

After voting you should be able to see the current results, but at the moment they’re 62% Yes, 38% ‘It’s complicated’, and 0% for No and ‘I don’t know’.

My point is that no-one has ever seen a proton. They are far too small for us to be able to see with our eyes, and we can’t even see them directly with electron microscopes (can go into what we’re really seeing in ‘pictures of atoms’ in more detail later if that’s helpful).

We have to infer the properties - mass, charge, spin, notional size and so on - from indirect measurements.

In the philosophy of science there are ‘realists’, who argue that we have enough evidence to be able to state that there are actual, physical entities that explain the readings we get in these measurements. That photons exist.

There are also ‘idealists’, who consider that, while they are happy to stipulate protons as theoretical, conceptual entities, we do not have enough evidence to confidently claim that this means there actually exist entities of this kind.

You’ve probably already spotted the point, but just to really hammer it home: inference is a valid part of science. There are things - not just things that happened in the past, but things happening right now, including in our bodies - that we cannot observe directly, but nonetheless we are confident to say that, to the best of our current scientific knowledge, they explain our observations (and this is the case whether one is philosophically idealist or realist).

The creationist canards “Were you there?”, “Have you seen it?” would lead to denial of the existence of protons - as either physical or conceptual entities - if followed through with intellectual consistency.


I’m among the one’s who responded “it’s complicated”, for the case of protons specifically, because the ontology of quantum mechanics / quantum field theory is (under mainstream interpretations) extremely vague or even entirely unspecified. (Just what is the quantum state? How does it relate to things in the 3D world of our perception? That sort of thing.)

In general, though, your point is a good one. :slight_smile:

Surely you must agree that the concept of “protons” exists. Right?

Well, of course the concept of protons exists. And I think protons themselves most probably exist as well. But things are a little murky where quantum mechanics is involved, basically because of the “measurement problem” (and the deeper problem of an unclear ontology that underlies it).

I answered yes because the post doesn’t define what is meant by a proton. Hence I’m just going to refer to protons as that which has certain observable effects we’ve come to understand as the consequences of the existence of protons. It’s what is dissociating from Chlorine when hydrochloric acid is dissolved in water.

Whatever the nature of what is causing those observable effects I’ll leave up to physicists to decide. We’ve decided to call that thing protons, and it’s effects are real. That’s good enough for me.

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Certainly. But the concept of ‘regret’ exists, and we wouldn’t argue that that means it exists as a tangible material entity.

Yes, I think something like ‘exists for all practical purposes’ makes sense, or ‘a set of characteristic interactions in the world exists and we give that the name “proton”’.

See my other comment, though.

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For what it’s worth, my point wasn’t founded in quantum uncertainty. It was on inference from indirect observations.

Let’s take a different example at a more accessible scale (or, if it’s inaccessible, in a different direction): is Earth’s inner core solid?

Our best current science says it is, but we’ve never been there to see, can never conceivably go there to see, have no way to check. We must infer its state from patterns of seismic waves moving through the planet, as we detect them at a web of surface detector stations.

So it’s not about the domain of quantum handwaviness, it’s about things we’re confident we know in science that we do not know through direct observation.

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If that’s your point, you can just as easily discuss the moons of Jupiter discovered by Galileo with a telescope. All observations of the moons are indirect, by way of an instruments like telescopes and interplanetary probes. So do the moons exist or not?

Or the existence of blood cells. All observations of blood cells are indirect, by way of instruments like microscopes. So do blood cells exist or not?

Let’s not even get started with coronavirus…


I think so, yes, but those examples seem more accessible somehow. We know what a magnifying glass does at scales where we can verify with the naked eye, so it’s relatively easy to trust at smaller and larger scales.

The kinds of 3D seismic imaging required to probe the interior of our planet, and the kind of much more sophisticated chains of measurement and inference required to even ‘discover’ protons just take it a little further.

And what we’re talking about is people who can see evolution occurring on a bacterial-antibiotic-resistance scale pretty directly but not then extrapolate that to longer time periods and changes for organisms with longer lifespans.

The philosophical point is essentially just the rejection of the creationist claims that only science that can be immediately replicated in the laboratory setting is legitimate.

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Yes, I recognize that is your point, and it’s a good one. The pedant in me just couldn’t resist pointing out why “it’s complicated” might be a better answer in the case of protons. :smiley:

I think your illustration works better with the earth’s core.

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Nobody is denying that extrapolation is legitimate in science. But the devil is in the details, and not all extrapolations are equal. Some extrapolations can be unwarranted.

We just recently here had yet another of our repeated debates about microevolutionary vs. macroevolutionary change. I’m not going to continue that debate, even if the usual suspects try to bait me, but will refer to it here only to make a point about extrapolation.

If, as many here believe, macroevolutionary change is caused by nothing but repeated rounds of microevolutionary change, then it should be possible (in principle, anyway) to extrapolate back from present-day forms to ancient, very simple forms, imagining a series of steps working by mechanisms we are familiar with. But if, as some evolutionary theorists have suggested (and again, I won’t be baited if some here repeat their claim that no evolutionary theorists hold this view), macroevolutionary change requires more than the type of changes we see in microevolution, then it would be unwarranted to reason back, imagining a whole chain of events entirely like those which lengthen the beaks of Galapagos finches, to the most primitive life forms.

Note that I am not here challenging common descent (which is not surprising, since I’m not a creationist), but talking only about evolutionary mechanism. Granted that the transition from one-celled life to man happened somehow, one cannot assume that it happened solely by additive rounds of microevolutionary change. There might be other things going on.

To take a really crude example, I might observe you walking X miles per hour, and calculate that you can walk X miles per day, and from that, calculate how long it would take you to get from any point to any other point on a globe 25,000 miles in diameter. So, if I find out from a friend (who saw you at the Louvre), that you were in Paris a year ago, and I extrapolate, based on your walking speed, to produce a history in which you walked from Paris to Cleveland, is the extrapolation justified? No, it is isn’t, because you can’t walk across the Atlantic Ocean. (Unless you’re Jesus, of course.) A mechanism other than walking would be necessary to get you from Paris to Cleveland. I can be sure that you got from Paris to Cleveland (since you’re in Cleveland, and you were in Paris), but I don’t know how you got there, not even if I know every conceivable detail about the physics of walking, the length of your legs, the strength of your leg muscles, etc. “Travel from Paris to Cleveland is just travel from Paris to Le Havre carried out over a longer period of time” is an unwarranted extrapolation.

Of course, I think you are attacking the position of people who, unlike me, deny common descent itself, but the point I’m trying to make here is not that all creationist objections to evolution are reasonable (they aren’t), but that it isn’t entirely wrong to question simple extrapolations, where simple extrapolations are suspect. Forensic scientists can tell you, in some cases, that a bullet was fired from such-and-such a height, based on the angle a bullet entered a body, etc., because extrapolation backwards to the source of projectile motion is a comparatively straightforward matter. But if evolution is a multi-level process, with causes at one level being different from causes at another level, analogies from ballistics or other sciences, focusing only on the lower-level tier of evolutionary causes, will be misleading. And some of the people who have made this point are atheist or agnostic scientists who are far from being creationists.

I don’t see much difference between telescopes vs. the naked eye, and seismic vs. the naked ear. But it is possible that I’m biased.

There are a lot of good and relevant thoughts there, @Eddie, thank you. I broadly agree.

I think, though, that it only makes scientific sense to posit ‘extra processes’ when there is a clear need to do so because the proposed mechanism fails to account for the evidence. In your example, it is your knowledge of the intervening ocean that requires you to posit some means of locomotion other than walking to Paris.

If, when and where a demonstration can be made that ‘something extra’ is required, that the summation of small changes cannot account for the observed large changes, then it would be appropriate to posit some other mechanism, or to go looking for one.

Given the added information that the fossil record is tiny - arguably up to 99.9% of species that have ever lived are not represented, despite the vast numbers of fossils we have found - that judgement is being made on a quite scattered trail of ‘sightings of the walker’: perhaps one day in a thousand, for example. Extrapolating a map on that basis is challenging, and apparent anomalies might be lacunae.

The appropriate attitude in science is certainly a level of agnosticism and waiting on the evidence. But I’d argue the challenge needs to be “show that there is a need to posit additional mechanisms because the already identified ones don’t fully account for the facts”, rather than “show that you can comprehensively rule out the existence of any conceivable additional mechanisms”.

No, that doesn’t follow unless you intend “in principle” as an admission that this extrapolation would require perfect knowledge of past populations, genomes, and environments, none of which we will ever have.

Badly stated. There may be different requirements for some macroevolutionary changes than others, and there may be multiple possible pathways to particular changes than the one that was actually realized. Even if some things happened through a macroevolutionary process, that doesn’t show that they could only have happened that way. It isn’t clear what you meant to say or whether that would have made sense.

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You don’t think there are more inferential steps in ‘audio to 3D visualisation’ than in visual-to-visual?

Given what we already know about gene regulation, mutations, natural selection, and so on, it seems to me it is possible in principle to imagine how such transitions could have occurred, even if we don’t have perfect knowledge of how it did occur and thus are likely to get many aspects wrong between the history we imagine and the one that happened.

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That can some times be done not only in principle, but in practice, at least for particular genetic changes at the level of genes and some of the structures they result in. But it does require that the data is really good.

There are many articles describing reconstruction of ancestral states at the level of genes, and their functional characterization in experiments, to determine the order and phenotypic effects of particular historical mutations.


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