If (as you seem to be suggesting) relativity was effectively lying there on the table waiting for Einstein to just pick it up, how come it blindsided most, if not quite all, of the greatest minds of his generation?
That's the case with all scientific discoveries - pieces of prior work get accumulated, until it eventually becomes obvious[0] how they connect, at which point someone[1] connects the dots, making a discovery... and putting it on the table, for the cycle to repeat anew. This is, in a nutshell, the history of all scientific and technological progress. Accumulation of tiny increments.
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[0] - To people who happen to have the right background and skill set, and are in the right place.
[1] - Almost always multiple someones, independently, within short time of each other. People usually remember only one or two because, for better or worse, history is much like patent law: first to file wins.
Science often advances by accumulation, and it’s true that multiple people frequently converge on similar ideas once the surrounding toolkit exists. But “it becomes obvious” is doing a lot of work here, and the history around relativity (special and general) is a pretty good demonstration that it often doesn’t become obvious at all, even to very smart people with front-row seats.
Take Michelson in 1894: after doing (and inspiring) the kind of precision work that should have set off alarm bells, he’s still talking like the fundamentals are basically done and progress is just “sixth decimal place” refinement.
"While it is never safe to affirm that the future of Physical Science has no marvels in store even more astonishing than those of the past, it seems probable that most of the grand underlying principles have been firmly established and that further advances are to be sought chiefly in the rigorous application of these principles to all the phenomena which come under our notice. It is here that the science of measurement shows its importance — where quantitative work is more to be desired than qualitative work. An eminent physicist remarked that the future truths of physical science are to be looked for in the sixth place of decimals." - Michelson 1894
The Michelson-Morley experiments weren't obscure, they were famous, discussed widely, and their null result was well-known. Yet for nearly two decades, the greatest physicists of the era proposed increasingly baroque modifications to existing theory rather than question the foundational assumption of absolute time. These weren't failures of data availability or technical skill, they were failures of imagination constrained by what seemed obviously true about the nature of time itself.
Einstein's insight wasn't just "connecting dots" here, it was recognizing that a dot everyone thought was fixed (the absoluteness of simultaneity) could be moved, and that doing so made everything else fall into place.
People scorn the 'Great Man Hypothesis' so much they sometimes swing too much in the other direction. The 'multiple discovery' pattern you cite is real but often overstated. For Special Relativity, Poincaré came close, but didn't make the full conceptual break. Lorentz had the mathematics but retained the aether. The gap between 'almost there' and 'there' can be enormous when it requires abandoning what seems like common sense itself.
It is. If you're at the mountain, on the right trail, and have the right clothing and equipment for the task.
That's why those tiny steps of scientific and technological progress aren't made by just any randos - they're made by people who happen to be at the right place and time, and equipped correctly to be able to take the step.
The important corollary to this is that you can't generally predict this ahead of time. Someone like Einstein was needed to nail down relativity, but standing there few years earlier, you couldn't have predicted it was Einstein who would make a breakthrough, nor what would that be about. Conversely, if Einstein lived 50 years earlier, he wouldn't have come up with relativity, because necessary prerequisites - knowledge, people, environment - weren't there yet.
You are describing hiking in the mountains, which doesn’t generalize to mountaineering and rock-climbing when it gets difficult, and the difficulties this view is abstracting away are real.
Your second and third paragraphs are entirely consistent with the original point I was trying to make, which was not that it took Einstein specifically to come up with relativity, but that it took someone with uncommon skills, as evidenced by the fact that it blindsided even a good many of the people who were qualified to be contenders for being the one to figure it out first. It does not amount to proof, but one does not expect people who are closing in on the solution to be blindsided by it.
I am well aware of the problems with “great man” hagiography, but dismissing individual contributions, which is what the person I was replying to seemed to be doing, is a distortion in its own way.
Don't tell the current administration that there's something so un-American about the currency: they will insist on fixing it, and probably retire Jefferson as well.
Fun fact: While the US spent more than 3 cents for every penny minted and distributed, it spends about 14 cents for every nickel minted and distributed!
When they decided to stop minting pennies I think they should have gotten rid of nickels and (I know this will be controversial) quarters as well!
Keep dimes and ramp up production of half dollars. Then we can just drop the second decimal place and standardize pricing everything in 0.1 dollar increments.
The fact that quarters are still somewhat commonly used in machines (vending machines, parking meters, laundry) is probably the biggest practical obstacle.
This may be the most practical go-forward plan. The Euro's .20 coins are also attractive too. But you're correct that quarters, as the smallest common currency that you can plausibly buy something with just a couple of them, are just everywhere, from laundry to car washes, so the pain in retiring them would be widely felt.
What I've learned from the penny retirement is that people are deeply distrustful of simple high school level statistics! Millions of people have angrily seethed that somehow stores are or will be using the penny retirement to rob them, despite knowing that most transactions have an unknowable amount of different items, and sales tax, so attempting to manipulate prices to gain a statistical advantage out of rounding would be incredibly difficult and would yield a pitiful return. Let alone how the cash transaction share is declining every year.
We need to keep the physical dimensions and material properties of the quarter, but why not change the face value? Demote them to 20 cents, or even better, make them 50 cents because the real half dollar coin is obnoxiously huge and impractical.
What of the economic impact of doubling the value of all quarters? Eh, it'll probably be fine. We'll just write it off as an AI datacenter loan somehow
I have long believed that changing coin value upward would be the #1 way to get 100% of citizens on board with currency reform. Or at least buy them from citizens at above face value.
Unfortunately, I think that vending machines specifically would frustrate this scheme though, because you can bet that most operators of them would, rather than reprogramming the machines which would be expensive (especially given how many old machines must be out there without any manufacturer support available), just leave everything the same physically and double all their prices.
Do you mean in the zinc mining and Coinstar? Pennies have been a bizarre ritual for years, wherein the government made zinc worth less than its pre-minted value, distributed them to banks nationwide, banks in turn to stores, stores using them once to give meaningless amounts of money to customers, customers in turn immediately throwing them on the ground or at best eventually dumping them into a coinstar, and coinstar returned those to banks.
Nothing of value was going on there. I'd rather pay any zinc miners and coinstar drivers who have been displaced to play video games all day while still saving all those resources, fuel, and most of all, time.
I, for one, look forward to the new 5oz "Donald Trump Freedom Nickel". Probably resulting from a deal he did with the Big Trousers lobby groups to wear out coin pockets faster.
(I would have made a gag about a 7g replacement nickel, but you people have already used up the team "quarter" for different denomination. Although the idea of a new 40 cent coin called an "eight ball" amuses me...)
As the ratio used is a rational approximation of an irrational, I would guess that the ratio-preserving feature breaks down well before you get to atomic sizes, though I have neither proved that to be so nor figured out how to calculate the divergence.
That's interesting. Do you know if they are used to keep track of the trains' positions with axle-spacing precision everywhere, or only at stations and track-section boundaries? (my somewhat cursory search suggested probably the latter.)
I don't know for certain, but they'd have to have at least one set on both tracks in each ventilation section, to enforce ventilation rules (read the rest of the article about the tunnel's ventilation management). It also points out that axle counters can sense backward movements, should a stuck train require the ones following it to reverse out of the tunnel
Quite often, when my search returned a 'closed as duplicate' reply, I found the allegedly duplicate question did not accurately describe my problem, and the answers to it were often inferior, for my purposes, than those which had been given to my original question before the gate was closed.
I think many would agree that this policy was the single biggest moderation failure of the site. And it would
Have been so easy to fix. But management believed fewer high quality answers were better. Management was wrong.
Hardcore proponents of this style often incant 'DRY' and talk about reuse, but in most cases, this reuse seems to be much more made available in principle than found useful in practice.
There's also the "it makes testing easier because you can just swap in another interface and you don't need mocks" argument - sure but half of the stuff I find like this doesn't even have tests and you still tend to need mocks for a whole bunch of other cases anyway.
That’s a fair point, but a combination of “fake it ‘til you make it” together with extracting massive “compensation” before you actually make it amounts to pretty much the same thing.
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