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Comment by ramraj07 | Hacker News Reader

The Walter Issacson biography quoted Kip Thorne as saying if Einstein didn’t come up with relativity, likely no one would have for 30-40 years after. Which is insane and totally sensible. This theory had nothing to do with any observation or conundrum we could measure back then or even today except the weird discrepancy in Mercurys orbit. Truly a great genius with unparalleled originality. Somehow beats newton for this reason imo.

Great spoilers for the book Project Hail Mary below so stop reading if you’ve not finished it (and why havent you?): it was such a brilliant idea in that book to suggest that the space faring alien race never figured out relativity still and could still head out to a nearby star and only then discover there’s a massive discrepancy in their calculations. To use such an obscure observation that relativity is not obvious at all as a plot point needs a lot of kudos to the author.

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> The Walter Issacson biography quoted Kip Thorne as saying if Einstein didn’t come up with relativity, likely no one would have for 30-40 years after.

Even for general relativity, it is not clear whether this statement is true, see

> https://en.wikipedia.org/wiki/General_relativity_priority_di...

According to this Wikipedia article, it seems that David Hilbert came up with a different way of deriving general relativity at about the same time as Albert Einstein.

The great insight IMO was special theory; the General Theory was I suppose a bit more obvious generalization that just needed the math to be figured out..

The fact that Einstein only took a fairly short time (IIRC less than a year once he started working on it in earnest) to develop and publish SR, whereas it took him ten more years before he published GR, strongly indicates that GR was much more difficult.

GR is much more heavyweight in terms of maths. But once SR was clear it was "just" an extension to the same ideas. The leap here was the original idea that gave rise to SR. The rest could have been worked out by most physicist of the time.

> GR is much more heavyweight in terms of maths.

As compared to SR as Einstein originally developed it, yes. But note that modern usage of SR often makes use of the same differential geometry tools that were developed for GR--because those tools turn out to be useful even in flat spacetime.

> But once SR was clear it was "just" an extension to the same ideas.

Again, if that were the case one would not have expected it to take ten years to get to GR. Yes, Einstein had to learn about Riemannian geometry from Grossmann, but that didn't take him anywhere close to the ten years to do. He spent most of that ten years struggling with the physical concepts involved, not learning the math.

> The leap here was the original idea that gave rise to SR. The rest could have been worked out by most physicist of the time.

This is strongly contradicted by the fact that there were many other physicists working on a relativistic theory of gravity at the time--and they all got it wrong. Only Einstein, and Hilbert (who was a mathematician, not a physicist) after getting key input from Einstein, got it right.

For special relativity, see https://en.wikipedia.org/wiki/History_of_special_relativity

The necessary transformations for special relativity (Lorentz transformations) were already developed by Hendrik Lorentz and Henri Poincaré. Einstein's central contribution for special relativity was to reinterpret these equations in a novel way.

Exactly. The innovation was in belief that the theoretical could also be real, that the equations could be trusted. Just as with Maxwell predicting the speed of light or Darwin studying birds—these scientists had the courage to firmly state the conclusion implied by their work.

> David Hilbert came up with a different way of deriving general relativity at about the same time as Albert Einstein

But he did that only after having Einstein visit him for several weeks in the summer of 1915 and having long discussions with Einstein about the latter's ongoing efforts to discover a general theory of relativity. AFAIK Hilbert himself acknowledged that his final effort was only possible because of all the work that Einstein had already done.

> if Einstein didn’t come up with relativity, likely no one would have for 30-40 years after.

This seems like a hyperbole to make a point about how smart Einstein was.

From what I've seen in past discussions like this, including one on HN [0], is that it would've been delayed by 1-5 years. And it wasn't just the Mercury's orbit. There were fundamental questions about electormagnetism that had unclear answers with the predominant theory of aether.

[0] https://news.ycombinator.com/item?id=23450827

Ive gone through the thread and dont see what supports your argument. The top comment quotes Einstein himself, but here’s his own final statement from that quote:

> The new feature of it was the realization of the fact that the bearing of the Lorentz transformation transcended its connection with Maxwell's equations and was concerned with the nature of space and time in general. A further new result was that the "Lorentz invariance" is a general condition for any physical theory.

This seems like a massive leap even given what Lorentz and Poincaré were coming up with, which is all at that point trying to understand what the math leads to and no real intuition on what that means in reality. Einstein on the other hand came up with something that had almost no mathematical underpinning (his first paper had no derivation). The final conclusion of the author in that comment, that this insight was only a year away, is thus completely unfounded in my opinion.

In that thread itself someone quotes Feynman concluding the same. I’ll listen to Kip Thorne, Feynman and my own intuition for now until someone gives a fairly thorough reasoning for their skepticism then.

I would also make a point of not quoting Einstein himself on such nuanced takes. He spent basically 30 years just commenting on his own theory and its motivations every single day. One would assume he would have decided to be more modest on some of those occasions in a mere whim or to placate that particular audience.

I have a ton of love for Andy Weir (Project Hail Mary, The Martian) for the exact reason you describe. Not only does he love the hard sci-fi bits but he clearly loves doing the homework so he gets it right.

Gravitational lensing and time discrepancies with atomic clocks, among others, would be obvious anomalies that would have led to relativity theories. Not to mention the actual speed limit of not being able to make anything move faster than light and the inability to find a reference frame for light to be moving in.

Once you start trying to measure the speed of light compared to your own speed it becomes quite obvious that there’s a problem with not being able to measure anything but c regardless of the movement of source and receiver.

We looked for Gravitational lensing only after Einstein proposed his theory and wanted validation. No one wanted to actually put the effort to do the measurement during an eclipse and iirc Einstein had to lobby for it greatly and only a single lone wolf guy took him up on it. And if I’m not wrong the initial observations weren’t even that solid and were likely artifacts that just in retrospect were interpreted in the right side of truth.

All other observations likely would have taken decades to stumble upon as well. I see no argument still why any other scientist would have made the relativity leap (which to be clear isn’t directly a requirement for deriving E=mC^2).

No, there were a lot of research already done on special relativity. Some even argue that Einstein genius was in reformulating what was already done and boldly putting the main equations first, instead of slowly working out of contradictions towards an equation at the end.

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