Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Ask HN: Is physics moving forward?

news.ycombinator.com

Post reply on HN
Print view View original

41–50 of 75 posts

Re: Ask HN: Is physics moving forward?

#41

Post by btilly »

hellameta wrote: post #27
verelo wrote: post #14

Earlier quoted context omitted.

I do not disagree that things feel slower to some degree, but I'd also bet absolutely anything that 100 years from now people will look at our time and say "Can you believe they didn't understand X? There was so much low hanging fruit in 2015." The issue is that what appears simple, 100 years from now, takes a significant shift in how we're currently thinking. The problems are complex and the prior knowledge needed t…

I agree with you but not with respect to Physics. I believe it is very likely that in 100 years we will think "Can you believe they didn't understand X" in things like psychology and all of the new emerging cross disciplinary fields that have emerged from it. Economics is a good example as well I believe... Up until the second half of the 20th century many economists were not basing their theories on data but rather…

Your belief about economics indicates that you are part of a minority paradigm that has produced interesting data but not managed to transform economics yet. If it does succeed, then your hope for it will be perfectly justified. But most such movements do not succeed.

The problem is that success has to be so compelling that people who are working within different paradigms (economics have many) generally figure out that they are thinking about it wrong and need to restructure everything in terms of behavioral economics, rather than looking at behavioral economics as a low order correction term to their own way of understanding them.

Re: Ask HN: Is physics moving forward?

#42

Post by paulpauper »

While progress may seem slower, we have a lot more people working on these unsolved problems. Also there is the fusion of abstract math and physics, which creates thousands of 'physicists' out of unwitting mathematicians. Due to the physical limitations of experiments, most forthcoming progress in physics will be purely abstract. But just because we can't test some of these theories doesn't mean we should disregard though, provided there are as few logical inconsistencies as possible.

Re: Ask HN: Is physics moving forward?

#43

Post by ghaff »

vezzy-fnord wrote: post #7

Looking back over last 20 years, technology (esp. related to computers) had made extraordinary leaps forward and the pace is accelerating. Largely hardware advances that are heavily interrelated with physics. Even still, it has been incremental (though still impressive) production advances and not radical architectural redesign. Intel only got bounds checking in hardware (MPX extensions) a couple of years ago, even t…

Yeah, as per some of the discussion of another recent post, one of the big things that has happened over the past 20-30 years in computing is that we discovered a technology for use in digital logic circuits that has been amenable to incredible process shrinks. Certainly there's been extraordinary engineering that's gone into that shrinkage coupled with no small amount of semiconductor physics. But, for whatever other advances have been made in computing since 1980 or so, an awful lot comes back to CMOS.

Re: Ask HN: Is physics moving forward?

#44

Post by abdullahkhalids »

I am surprised no one has mentioned quantum information yet. Quantum information is the subfield of physics whose goal is to understand what new information processing tasks are possible/efficient that are not possible/inefficient in the quantum world. Two such tasks are quantum computing and quantum key distribution.

This field was birthed in the early 80s and has seen steady progress since then. Various architectures for quantum computing have been proposed and experimental control over them has steadily increased in each one over the last few years. While we are not there yet the sequence of results shows that we are rapidly approaching the fault-tolerance thresholds after which it will be possible to build quantum computers.

Quantum key distribution is a simpler task and has already been achieved commercially. Now we are trying to increase the rates of transfer. We are slowly also relaxing experimental requirements. For instance there are protocols where you don't have to trust that your devices where not tampered with by an adversary.

These are exciting times in quantum information. While important theoretical results where found in the 80s and 90s the experimental momentum today far outpaces it.

Re: Ask HN: Is physics moving forward?

#45

Post by mdup »

pwnna wrote: post #40
stared wrote: post #6

As a PhD in physics - progress in pure physics is slowing down (or at least progress per scientist). The delay between a discovery in physics and a Nobel prize is getting bigger and bigger [1]. It's true for all fields, but the effect is particularly strong for physics. '''It is safe to say that late 1920s and early 1930s were the “Golden Age” of 20th century physics, when the progress was lightning-fast and new disc…

Do you think there's a limit on how much we can understand in physics/any field? My reasoning on this is that since everyone has a finite lifespan, understanding/work will be lost as the researcher retire, move to a different field, or die, unless this information is transmitted to someone else during their life time. However, as we understand more, we have to teach people more. This brings in two problems that I see…

The point of your comment is disproved by your last paragraph! The more science is discovered, the more it gets compacted into the essentials of this knowledge. If 100 year old PhD level fluid dynamics can be taught to undergrads, this means it got digested into the most useful part of the work.

Similarly, it's considered basic undergrad work to understand Fourier decomposition; but the notations and clarity we get the insight from is the result of two centuries from the 1807 paper by Fourier. It was certainly PhD level at the time.

Certainly science is compacted and that's how it gets transmitted to younger generations. And remember that our brains get bigger, so maybe we'll never hit any "limit" to understanding? :)

Re: Ask HN: Is physics moving forward?

#46

Post by batou »

As someone dipping into physics very late after a long journey on mathematics, this thread is both depressing and terrifying yet at the same time strangely motivating.

I think there are some big questions without answers still. I want to have a bash at them.

Re: Ask HN: Is physics moving forward?

#47

Post by sqrt17 »

ISL wrote: post #13

As someone who's been in physics for much of the last twenty years, I'd guess that things are going at about the same rate. I don't think that the rate is "crawling", though. If you look on log plots of parametrized experimental progress, progress remains linear, so it's a Moore's law like improvement on many fronts. The emergence of precision cosmology has really transformed astrophysics in the last twenty years. Th…

What are the assumptions behind "log plots of parametrized experimental progress"? What do these mean in the real world?

To give an example of why "pouring money into it and getting slower and slower progress" could translate into linear progress on a log plot, imagine you have to pour in x² amount of (money, people, time) to get to level x of progress.

In that case "we go slow" means, "we'll gobble up larger and larger amounts of money, but everytime people get impatient we'll have some bone to throw at them".

Re: Ask HN: Is physics moving forward?

#48

Post by mjfl »

abdullahkhalids wrote: post #44

I am surprised no one has mentioned quantum information yet. Quantum information is the subfield of physics whose goal is to understand what new information processing tasks are possible/efficient that are not possible/inefficient in the quantum world. Two such tasks are quantum computing and quantum key distribution. This field was birthed in the early 80s and has seen steady progress since then. Various architectur…

Don't forget the new field of superconducting quantum annealers! I have high hopes.

Re: Ask HN: Is physics moving forward?

#49

Post by JohnBooty »

PaulHoule wrote: post #17

It is the best of times and the worst of times. In fundamental physics, the LHC is online, neutrino physics is hot, and lots is going on. Now there are a huge number of quantum theories of black holes, but no way to prove anything about them in site. The dark matter problem is a huge "anomaly" left to solve so there are still mountains to climb. In terms of practical stuff there is lots of physics in how you build a…

   Even the "dead" area of chaos theory is looking much 
   better now that people at NASA have made a map of the   
   earth-moon phase space which can give a km/sec or so    
   free propulsion.
This is fascinating - how can I learn more?

Re: Ask HN: Is physics moving forward?

#50

Post by carapat_virulat »

hellameta wrote: post #27
verelo wrote: post #14

Earlier quoted context omitted.

I do not disagree that things feel slower to some degree, but I'd also bet absolutely anything that 100 years from now people will look at our time and say "Can you believe they didn't understand X? There was so much low hanging fruit in 2015." The issue is that what appears simple, 100 years from now, takes a significant shift in how we're currently thinking. The problems are complex and the prior knowledge needed t…

I agree with you but not with respect to Physics. I believe it is very likely that in 100 years we will think "Can you believe they didn't understand X" in things like psychology and all of the new emerging cross disciplinary fields that have emerged from it. Economics is a good example as well I believe... Up until the second half of the 20th century many economists were not basing their theories on data but rather…

I think it's very unlikely that we will see in psychology or economics any kind of progress like what we saw in physics. In physics anything new that we learn doesn't change the experiments at all, that is we can't ignore physical laws just because we are aware of them.

But in psychology or economics as soon as you learn something new, that new knowledge is going to be a new variable to account for, for example as soon as you are made aware of the Bystander effect[1] it is trivial to avoid it, but you can't really predict what will come out of it. You can as well find ways to game any economic prediction by being aware of it, I guess you can find stable models that sort of work until something like the 2008 financial crisis happens and they don't anymore.

So either the investigators stay out of the economy/society or they will mess with their own results by making them public.

[1] https://en.wikipedia.org/wiki/Bystander_effect

Post reply on HN