"But the bigger effect is relativistic. That’s actually a notable example of Paul Dirac being completely wrong about something in physics – he had stated back in 1929 (PDF here if you’re up for it!) that relativistic corrections to quantum mechanics were of “no importance” because they would apply only to very high-speed particles (that is, those moving at an appreciable fraction of the speed of light). But as it turns out, the inner electrons of the heavier elements are moving at such speeds (they get faster as the positively charged nucleus gets bigger and more charged), and this has effects out to the chemically important outer electrons as well. For one thing, relativistic particles are heavier, and this actually shrinks the atomic radius of the heavier elements still more and has complex effects on the various orbitals."
So basically they both seem to act like their larger scale selves, but in this case affecting physical characteristics of atoms. Special relativity is going to make the electrons more heavy and thus change their ionization energies and interactions with other atoms and energy. Gravity is going to affect their physical geometries? Idk.
But this reminds me of muonic atoms. I wonder if there’s some sort of point where the periodic table of electrons and protons/neutrons starts to mirror its lower energy self with heavier muon atoms.
Just thinking in a text box here, don’t kill me please...
Edit:
The muon to electron mass ratio is about 206 for a square root of about 14.4.
I found an equation that says the energy of that electron is on the order of 1/L^2 so to get muonic effects for the electron the box size of the bound electron, L, needs to decrease by about 1.5 magnitude.
> When it comes to gravity, the two theories [quantum theory and classical theory] are completely incompatible, and there is no way to escape the conclusion that one or both of them must be seriously incomplete or even flat-out wrong about something important. ...
Part of the problem lies with the lack of tools for studying gravity through the perspective of quantum mechanics due to the scale involved:
> One of the difficulties of formulating a quantum gravity theory is that quantum gravitational effects only appear at length scales near the Planck scale, around 10−35 meter, a scale far smaller, and equivalently far larger in energy, than those currently accessible by high energy particle accelerators. Therefore, physicists lack experimental data which could distinguish between the competing theories which have been proposed[7][8] and thus thought experiment approaches are suggested as a testing tool for these theories.
Edit: there's an interesting complement to the linked article which talks in more detail about the relativistic basis for why mercury is liquid and gold is yellow:
I think he's speculating that Copernicum and other super heavy elements might offer some angle. Oddly enough I recall reading about a large amount of interest in studying mercury back in the 30s and 40s that tapered off. Maybe there is something there.
Also I would definitely buy "Quantum Physics: A Hand-Wavey Approach" and suspect you could do a whole series of those books.
Some comments on your extracts from the article and wikipedia:
>> the two theories [quantum theory and classical theory] are completely incompatible
Badly put. For starters, if the background spacetime has no curvature then the two theories are exactly compatible because flat spacetime has Lorentz symmetry at every point, and Lorentz symmetry is built in to the Standard Model of Particle Physics, which is a species of Quantum Field Theory. Secondly, in the absence of an extreme and obviously unphysical universe, there will be a large number of points who have a local neighbourhood which is flat spacetime; this is local Lorentz symmetry, and it is a result of General Relativity (https://en.wikipedia.org/wiki/Lorentz_covariance elucidates, but there's a simple reiteration just before the table of comments there). The Standard Model thus is exactly compatible at least in practically every small patch of any remotely plausible spacetime described by General Relativity. (There exists an enormous amount of observational and experimental evidence for this, and the https://en.wikipedia.org/wiki/Lyman-alpha_forest imprinted on quasar/active-galactic-nucleus spectra is very convincing.)
When one does a gauge fixing [in the https://en.wikipedia.org/wiki/Coordinate_conditions sense], by settling on a way of describing lengths and durations, then one can run into a problem where (a) quantum objects' wavelengths are long compared to the local curvature radius or (b) a very high energy is localized into a very small spatial volume. The (b) case is probably the more vexing: General Relativity predicts the formation of an event horizon; adding pretty much any quantum field theory converts the event horizon into a temporary trapping surface -- also, quantum field theories develop unitarily, whereas unitarity appears to be lost when there is this type of temporary trapping surface (if you make a black hole by smashing together a bunch of atoms, you might in principle get only photons out). The (a) case is really a question of assuming that a locally-useful coordinate charge is globally useful. A flat map of a town can accurately describe angles and sizes of objects on the ground. If you add in some identical very tall rectangular skyscrapers, the (laser-reflectometry/theodolite/etc. measured) distances between the midpoints of any pair's roofs will be greater than the distances between the midpoints of their ground floors. Likewise, flat maps of the whole planet will always show significant distortions of many angles or distances or both. The guaranteed neighbourhood mentioned in the previous paragraph is small compared to the global spacetime, and one has to be aware that ignoring that can distort values for things like scattering angles.
Where (a) and (b) are not in play, the Standard Model of Particle Physics and General Relativity play very well together. In fact, they play well together even when curvature starts becoming pretty substantial, like in neutron stars, where descriptions of arrangements of matter can get weird, but not so weird the Standard Model is inapplicable at any point in the neutron star. Even deep inside collapsed neutron stars (where a temporary trapping surface arises) one can use renormalization: we have tools like https://en.wikipedia.org/wiki/Semiclassical_gravity and various species of https://en.wikipedia.org/wiki/Effective_field_theory#Effecti...
These break down at extremes for a variety of reasons; and the problem is that we do not know if the Standard Model changes at arbitrarily high energies, but we do know that we do not "like" the answer General Relativity gives for arbitrarily high energy in the case where we have a temporary trapping surface, because it makes the far future of the quantum field incompletely predictable.
>> quantum gravitational effects only appear at length scales near the Planck scale
Oops. If you bring a large mass into a superposition of position and then use an accelerometer or put one position inside a cavendish device, we have no good prediction about what the measurement devices will report! The broad view is that they should point to where the mass is, but can't agree on what fraction of the mass is where. There are experiments in play to try to probe exactly this problem of low-energy quantum gravity. Again we run into problems with very large masses: large masses generate an exterior metric very similar to that of Schwarzschild's, but the principle of superposition does not work for such spacetimes (intuitively: two isolated planets, unrotating and starting still with respect to each other, will ultimately move towards each other, following the Raychadhuri focusing theorem; the spacetime between the planets looks less and less like Schwarzschild over time). But quantum mechanically we should expect to be able (in principle) to put planet-scale masses into a superposition of position. If we "measure" the planet (the measurement problem in quantum mechanics is an unsolved pain) do we convert the not-like-Schwarzschild "instantly" into Schwarzschild? We don't know, and the theories hint that they give different answers to that question.
So the problem is "only" in the second bit you quoted. There are various situations in which quantum "smearing" should couple with the dynamical spacetime in which it is observed, and we certainly generate some of those situations in laboratories. But there is a lot of gravitational noise in our laboratories, and we need much larger sets of quantum numbers to have much hope of extracting actual signal.
Perhaps someone will be able to fix that part of the C-class wikipedia article.
So if we've got 29 seconds to study copernicium atoms' properties before half of them have decayed into something else, is that sufficient time to create and cluster enough of them to know anything?
There must be some way of defining "liquid" and "melting/freezing point" that's quite different from me putting an ice-cube tray of water into the freezer.
As fascinating as the theoretical relativity/quantum thread here is -- I'd also be interested in knowing more about the plain old observation techniques that let us know anything about predicted liquid properties during this very short observation interval.
They’re formed from smashing zinc and lead atoms at relativistic speed so their perceived lifetimes would be longer at a rest frame. You got me on how to turn that into useful science though.
If we could produce enough Copernicium and magically disable the radioactive decay, the bounds between atoms is predicted to be so low that is predicted to be a liquid in the article, or a gas in Wikipedia.
If we can't disable the radioactive decay, you could look while it disappear in front of your eyes (halving every 30 seconds, I hope you bought a lot of it). But also the radioactive decay will create a lot of heat, so it will get hot, glow and evaporate (and probably destroy the lab). So it's would be difficult to see if it is a liquid at room temperature experimentally.
In Wikipedia there are the description of a few experiments with two or three Copernicium atoms. They get adsorbed over a gold surface for a short time until they decay. To get something like a glass of liquid selenium, you need something like 10^24 atoms, that is much more than the few atoms that is posible to get simultaneously.
Thanks! That's very helpful, and shame on me for not visiting Wikipedia first. That said, the error bounds listed on Wikipedia for a model-generated guess at melting temperature, etc. are gigantic.
At room temperature, copernicium might be a liquid, unless it's a gas or a solid.
I appreciate the audacity of researchers in trying to work up some guesses about physical properties even though the available samples are far too tiny and short-lived to get any lab confirmations. But articles like OP make it seem as if we've got well-tested insights. We don't. We're not nearly there yet. It's very loosely anchored guesswork.
"But the bigger effect is relativistic. That’s actually a notable example of Paul Dirac being completely wrong about something in physics – he had stated back in 1929 (PDF here if you’re up for it!) that relativistic corrections to quantum mechanics were of “no importance” because they would apply only to very high-speed particles (that is, those moving at an appreciable fraction of the speed of light). But as it turns out, the inner electrons of the heavier elements are moving at such speeds (they get faster as the positively charged nucleus gets bigger and more charged), and this has effects out to the chemically important outer electrons as well. For one thing, relativistic particles are heavier, and this actually shrinks the atomic radius of the heavier elements still more and has complex effects on the various orbitals."