Max Planck was famously discouraged from studying physics by one of his professors because "in this field, almost everything is already discovered, and all that remains is to fill a few holes." [1]
Having studied physics myself, my opinion is that we may very well be at a similar point right now. The big advancements of the last century in physics (quantum theory, relativity, chaos theory, etc.) brought us an era of swift and sweeping technological progress, and now the easy fruit seems to have been plucked. But there are still plenty of known unknowns, dark matter and dark energy being perhaps the most prominent one. Who knows what unknown unknowns are hiding behind those known unknowns?
> Having studied physics myself, my opinion is that we may very well be at a similar point right now.
We're not anywhere near a technological plateau, we just lost track on funding. Until the fall of the Soviet Union, the US invested a lot of money in foundational research, often not even caring if it would prove useful or possible, and with big enough money behind it that people could plan careers.
These days, researchers have to waste half their working time to chasing the few grants that are still available, and forget about a stable career, job security or enough work-life balance to found a family.
It's really too sad ... I (PhD on CompSci) could helping on the research of something groundbreaking for humanity instead of "maximizing shareholder profits". But Academia basically sucks in its current state, and in my country there is less than 0 capabilities to do real research.
I do want us to pour money into foundational research, but form an outsider's perspective, it does seem like a lot of it does require increasingly large capital costs with things like the LHC, and feels all so theoretical.
I think it's worth every penny, but at first glance it feels incredibly abstract and disconnected from practical application, as well as expensive. (Though, to be honest, I just looked up the LHC cost and $9Bn USD doesn't feel expensive. I was expected it to come up in the hundreds of billions.)
Lord Kelvin famously said there were just two "clouds" in left to physics—two mysteries remaining to explain. Those two mysteries let to relativity and quantum mechanics.
There's also this famous quote that is frequently mis-attributed to Kelvin: "There is nothing new to be discovered in physics now. All that remains is more and more precise measurement".[0] (I'm not sure who actually said it.)
Time. We still don't think about time properly - there are likely some huge technological gains if we can unlock time in relation to physics (not in terms of sci fi time traveling).
This isn't entirely accurate. We will not be able to visit the vast majority of the universe even given infinite time if we are not able to travel faster than light. Like 94% of the universe is unreachable without FTL, even without time constraints.
I've never actually looked up what the "quadrants" are in Star Trek. Apparently just our one galaxy divided into four. 6% of the universe is indeed an unfathomably large amount of space.
It depends on what you mean by "understanding". We can explain using a specific set of rules how something works. It doesn't mean that those rules are the best way to explain it or that they are even correct.
For example, we could explain that electricity works because of how electrons move, which would be correct from our point of view, but if we find out that we were living in a simulation, then the explanation would be that this is how "electricity" was coded to behave.
Also, usually in physics a formula is thought to be correct until some new laws/rules are found, then the formula is updated by adding some extra terms and then again thought to be correct.
To summarize: we know how to smash two particles together, but not much about what they are made of. Replace particles with stones and bones. 10000 years of science progress and we are still smashing things. With the occasional lab accident like discovering that mold kills bacteria.
One big difference—the discoveries waiting to be made in the early 20th century all concerned regular matter. As a result, once they were made, they enabled huge technological advancements.
Max Planck was famously discouraged from studying physics by one of his professors because "in this field, almost everything is already discovered, and all that remains is to fill a few holes." [1]
Having studied physics myself, my opinion is that we may very well be at a similar point right now. The big advancements of the last century in physics (quantum theory, relativity, chaos theory, etc.) brought us an era of swift and sweeping technological progress, and now the easy fruit seems to have been plucked. But there are still plenty of known unknowns, dark matter and dark energy being perhaps the most prominent one. Who knows what unknown unknowns are hiding behind those known unknowns?
[1] https://en.wikipedia.org/wiki/Philipp_von_Jolly