Dark matter seems like a gigantic hole. Either we don't know what most of the cosmos is made of, or there is a problem with general relativity.

And then dark energy is more than 2x that. Apparently we only have a good explanation for 5% of the total (normal matter we can see).

> 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.)

[0] https://www.quora.com/Which-19th-century-physicist-famously-...

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).

Along the same lines, FTL won't be needed if we merge with technology and live indefinitely long.

One human lifespan will be seen as a trivial amount of time to the next step of humanity.

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.

https://www.forbes.com/sites/startswithabang/2016/05/12/the-...

And at some point we also don't have infinite time - we will have heat death of the universe at some point too.

The remaining 6% is still orders of magnitude larger than would be involved in a typical space opera.

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.

There's also the minor issue that probably our two best physical theories, quantum dynamics and general relativity, are incompatible.

So they can't both be right.

https://www.theguardian.com/news/2015/nov/04/relativity-quan...

Gravity. Still the biggest unknown.

Do we even have a total understanding of light, or electricity? (I may be wrong, but I thought there were still some pretty fundamental unknowns)

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.

Maybe at a certain point "what they are made of" ceases to be a meaningful question.

Quantum electrodynamics is the most precise and accurate theory ever created. So not sure what you mean exactly by understand.

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.