8 ms·

How Much More Can We Learn About the Universe?

116 points by ernesto95 10y ago

agentgt 10y ago
I'm curious how many people think about the Universe and how frequently. I think about it all the time and I'm not a physicist. Probably a solid 30 minutes a day usually before falling asleep. Almost religiously (ironic). I have tried to talk about it with my family and friends but so many of them just don't seem to have the passion for it. Some times I feel even seriously guilty wasting so much energy thinking/reading about it. Sometimes even wondering if I'm even in right profession (even though I do love technology). My current theory is that it just my personality type (INTP).
- cgriswald 10y ago
  I think about it constantly, but I've had an interest in astronomy and cosmology since I was a small child and I'm currently studying astrophysics at university.
- czep 10y ago
  I get it too. It's incredibly soothing and comforting to contemplate the vastness of space, the amazing features of this reality we barely comprehend and in which we live for a flicker of an instant. Whenever I'm stressed, all I need to do is look up at the night sky, or read wikipedia articles about quasars, dark matter, stellar wind, the event horizon of supermassive black holes, how galaxies can pass through each other without any of the billions of stars ever coming close to hitting each other. It comforts me in a "the problems of two little people don't amount to a hill of beans" kind of way. Oh, and another INTP here :)
- chriswarbo 10y ago
  > Some times I feel even seriously guilty wasting so much energy thinking/reading about it. It's your energy, so if you find it worthwhile then that's all that matters. I sometimes feel the same way regarding my passion for computer science, when there are so many immediate problems in the world (energy production, food/wealth/opportunity distribution, war, etc.). The good news is that you're having such guilty thoughts at all; that makes you more conscientious than if you didn't! You're also devoting that energy to a meaningful topic, compared to cultural norms like sports, celebrities, fashion, etc. If you feel like there's nothing to show for your efforts, maybe you could try writing down some of your thoughts. They wouldn't have to be "correct", as long as they're intellectually honest; that would provide a progression of ideas, offer insight into the learning process, etc. and maybe you can look back over them to either find inspiration in ideas you'd forgotten, or be able to look at your old questions and know that you've found answers to some of them.
  - pc86 10y ago
    How is someone thinking about the universe for half an hour before bed any more meaningful than someone thinking about the Denver Broncos?
    - CoryG89 10y ago
      Eh.. meaningful depends on the observer, but I doubt Einstein would have come up with relativity if he thought about the Denver Broncos instead of the universe.
      - thr0waway1239 10y ago
        It is interesting that you make this statement, because I have sometimes heard that Einstein was able to make so many profound contributions because he had a multitude of interests which was generally above average with respect to his peers. Unfortunately, I don't have a reference, but I think it was mentioned in his biography by Walter Isaacson. And not just that, reading that book will give you the general sense of a man who was quite the eclectic, intentionally creating masterminds with people from a broad swath of occupations.
    - kirykl 10y ago
      https://en.wikipedia.org/wiki/False_equivalence https://en.wikipedia.org/wiki/False_equivalence They're both subjects of thought therefore they are both equally meaningful to think about. false
      - pc86 10y ago
        I was asking why one is more meaningful than the other. Your response is basically "it's possible that one of them is more meaningful than the other" which doesn't help much.
    - chriswarbo 10y ago
      It depends what you do with it, which is why I suggested turning it into something concrete like writing. If thinking about something makes it 'click', that's useful to make a note of, as it may help someone else come to understand it. If something is still unfathomable after lots of thought, that's useful to make a note of, as someone else may be able to help, it may uncover a misunderstanding, or it might give someone else comfort to know they're not alone in their struggle. Less trivially (and less likely, but worth pursuing) it may lead to original thoughts, new perspectives or analogies, inspiring others, revealing previously ignored aspects of the world, etc. I don't know if amateur reflection on sports would actually have any impact, and even if it did (e.g. calling the Denver Broncos to tell them about some new strategy/etc. you've come up with), it wouldn't have much impact on the world. The names in Marty McFly's sports almanac might change, but even after just 1000 years those ripples would probably have faded to nothing.
- CoryG89 10y ago
  Personally, I have always had a love for physics (especially physics I can't really understand). If I hadn't gone into software, physics would have been it for me. Perhaps I will study physics after I retire or if I ever get tired of software. I don't ever really feel guilty about thinking about physics though. If someone can't feel free to at least think about what they want, then what freedom do you really have at all?
- deleted 10y ago
  [deleted]
- mindcrime 10y ago
  I did, a lot, when I was younger. My original plan out of high-school was to major in physics, stay in academia, get a phd, do research, etc. That got derailed when I took a computer programming class, and for most of the past couple dozen years I haven't spent as much time thinking about physics and cosmology. Just recently though, I've kinda had my passion for that stuff renewed (can't say why, though). I've been reading a lot of books on physics and cosmology again and spending a lot of time thinking about things like "what is 'space'" and the like. The biggest regret I have is that since I did not major in physics after all (and dropped out of school before graduating in c.s. anyway), I never got the level of certain things (especially maths) I would need to really understand physics at the deeper levels. I can read and largely understand books written for lay-people, like your average Brian Greene or Michio Kaku book, but I can't really go to arxiv.org and read the papers in the physics section. It's frustrating, but at the same time, the field I chose has been good to me and it affords me enough money and free time to sit around reading physics books now and trying to learn/re-learn stuff I always wanted to learn.
- vectorpush 10y ago
  Most people think about it, it's just that most people process these ideas through the filter of religion.
- enrmarc 10y ago
  I do it every day, although my background in maths/physics is not enough to do it "the scientific way". There is one topic I'm constantly thinking about: "Where is the data, e.g. the mass of a planet, stored in our universe?". I guess this question arise because of my computer science background (algorithms + data = universe?) and because even simple formulas like the Newton's Law of Universal Gravitation deals with data (e.g. the mass of a planet). So, where is that number stored so the universe know how to apply its formulas (laws, algorithms)? I know these laws we have are just models of our reality that are getting more precise over time, but I can't help but think that at the end our universe has to do "some calculations" and has to deal with data (numbers). I know three devices that can store information: our brains, our DNA, and our computers. The color of our eyes are stored in our DNA, but the mass of a planet is not stored anywhere? As I've said, my limited maths/physics background doesn't let me think about the universe the right way. I'm just a dilettante. And sorry for my English.
  - AnimalMuppet 10y ago
    Seems to me that the data is stored in the positions of the particles that make up the planet.
  - logfromblammo 10y ago
    How would we know if we were in a real universe or a perfectly accurate simulation of one? If we were in a simulation, how would we know whether it modeled the same rules as the host universe, or an imagined fantasy universe? If we are living in a nonfictional simulation, mass data are stored in a colossal server farm. If we are living in a fictional simulation, the mass data are stored in a thing we cannot possibly comprehend. If we are living in a real universe, mass data are not "stored" anywhere, in the same sense that consulting a map at 1:1 scale is indistinguishable from actually visiting the landscape it represents. Storing that data elsewhere is neither useful nor necessary.
    - jtrip 10y ago
      I ask, what is the qualitative difference?
- calgoo 10y ago
  Don't worry, there are lots of us. Currently I chat with people on some twitch channels that are dedicated to space games. We watch launches together and comment and talk about space.
- nkrisc 10y ago
  I do quite often. Sometimes when I think about the entirety of the universe (at least the one we are aware of) I start to wonder what I'm doing here at my job, or what are any of us doing existing at all? I can't help but think what's "outside" the universe (a very human and naïve way of thinking), what's the meaning of it all? I conclude there isn't any meaning, then I recalibrate my mindset and return to caring about all the meaningless things in my brief life.
- Esau 10y ago
  I spent this past weekend reading about Heat Death Of The Universe and Black Dwarf stars.
  - csn 10y ago
    I have a bizarre love for the heat death theory, partially because it goes so well with Lovecraft's "And with strange aeons even death may die" in my mind.
    - agentgt 10y ago
      I too like it as well but because of a different author and story: "The Last Question" by Asimov [1]. It is a short but a must read (and it is free to read as well). It is one of the most beautiful and optimistic scifi stories. Asimov was and still is so ahead of his time. [1]: http://multivax.com/last_question.html http://multivax.com/last_question.html
- no1youknowz 10y ago
  I think about it all the time as well and I am thankful for these types of videos [1]. What I think about most, is how awesome it is to be alive right now. Where this video (and others like it) tell me about the universe and what discoveries have been found. At the end of this video, I am always wondering that if the Universe is as big as they claim. There must be discoveries waiting to be found that we can't even comprehend! Sometimes I find myself wishing we had probes that could be much faster than they are now. Instead of taking decades to go to the edges of our solar system, it takes months. Maybe within 50 years, by the end of my lifetime. We'll start to see images from Alpha Centauri and beyond. That I am hoping for! [1]: https://www.youtube.com/watch?v=GoW8Tf7hTGA https://www.youtube.com/watch?v=GoW8Tf7hTGA
- udkl 10y ago
  Do you think about the universe or your place in the universe and why you are here ? If it's the latter, I read somewhere a long time ago that these thoughts are caused due to a temporary chemical imbalance (serotonin I think) in the brain. Can't find the source right now, but something worth adding to the conversation.
  - TheSpiceIsLife 10y ago
    Any mental state has a physical / chemical correlate. I find the idea these are imbalances unhelpful. And, we're not even certain which way round the causality flows. A bit of both, surely.
- nathan_f77 10y ago
  Yes I have phases where I spend a lot of time thinking about things like this. But there's only so much you can think about on your own, so it's important to keep reading and talking about it with others. Right now I'm enjoying "The Vital Question". I also enjoy writing I've also heard that Myers-Briggs personality types are not very useful or reliable, but for what it's worth, my personality type is INFP.
- agumonkey 10y ago
  Black matter and finiteness come back on a regular basis in my mind.
- unexistance 10y ago
  1. Now you know you're not alone :) 2. For me, it's more like lingering in the back of my mind, always thinking / imagining in terms of space-time continuum & the math related to it 3. I'm always trying to go to the next step, by learning the math (or the concept anyway), and quantstart[0] seems to be helping [0] https://www.quantstart.com/articles/How-to-Learn-Advanced-Mathematics-Without-Heading-to-University-Part-3 https://www.quantstart.com/articles/How-to-Learn-Advanced-Ma...
hashmp 10y ago
Maybe someone can chip in here but I was under the impression virtual particles didn't actually exist, they were just used to simplify our understanding of particle interactions. The uncertainty principle hasn’t gotten in the way of learning the rules of quantum mechanics, understanding the behavior of atoms, or discovering that so-called virtual particles, which we can never see directly, nevertheless exist. After recently getting to grips with QFT it seems there aren't actually any particles, just fields which are excited at certain locations giving the impression of particles.
- snowwrestler 10y ago
  I believe the Casimir Effect is usually taken as proof that virtual particles physically exist.
  - cygx 10y ago
    No, it's generally taken as a proof of vacuum energy. However, it's arguably just the van der Waals force in disguise.
    - snowwrestler 10y ago
      We don't disagree. The theory is that vacuum energy creates virtual particles, which are what interact with the plates in the Casimir experiment.
- criddell 10y ago
  If you keep reducing, I think you end up a Tegmark's mathematical universe.
  - dTal 10y ago
    I got to that point, then I read a LessWrong thing about subjective probability and none of it makes sense again. The basic problem is - what does "subjective probability" i.e. your personal anticipation of events, even mean in a world where every instance of you (experiencing all possible versions of events) is equally 'real'? http://lesswrong.com/lw/pt/where_experience_confuses_physicists/ http://lesswrong.com/lw/pt/where_experience_confuses_physici...
gregfjohnson 10y ago
Some of the great developments of th 20th century were proofs of limits, of what cannot be achieved even in principle: for example the incompleteness theorem and halting problem, and the uncertainty principle. IMHO, there is an "abstraction boundary" that limits what humans can ever know even in principle. There are some phenomena that are inherently "unabstractable". We may know that a glass of water has a wave function, but we will never know the particular wave function of any glass of water ever. The phenomena in our universe that we can "understand" are those that can be modeled, those for which abstractions can be created that will fit in our brains. There may well be phenomena in the universe (or elsewhere) that are not amenable to modeling in any way that is compatible with human cognitive machinery.
- fluxquanta 10y ago
  >There may well be phenomena in the universe (or elsewhere) that are not amenable to modeling in any way that is compatible with human cognitive machinery. Could these phenomena collectively be considered a "higher power"?
  - udkl 10y ago
    If by "higher power" you mean things that humans can never comprehend, then yes. But us not ever being able to understand it does not mean there is no reasoning behind it. In the end it depends on perspectives & dictionary. You might call it a "higher power" .... I'm contended to end your sentence at 'phenomena'.
    - fluxquanta 10y ago
      >But us not ever being able to understand it does not mean there is no reasoning behind it. I didn't mean to imply that. But honestly, the idea that there exist physical systems in the universe that are too complex for the human brain to ever fully comprehend or model (dashing physicists hopes of a "theory of everything") sounds a lot like a higher power in the more traditional sense. I'm pretty sure that's close to the definition of the Tao, actually.
craigching 10y ago
Anyone know what galaxies are in the "Colliding Galaxies" image?
- tdy721 10y ago
  Here you go: http://apod.nasa.gov/apod/ap041121.html http://apod.nasa.gov/apod/ap041121.html > Billions of years from now, only one of these two galaxies will remain. Until then, spiral galaxies NGC 2207 and IC 2163 will slowly pull each other apart, creating tides of matter, sheets of shocked gas, lanes of dark dust, bursts of star formation, and streams of cast-away stars. Astronomers predict that NGC 2207, the larger galaxy on the left, will eventually incorporate IC 2163, the smaller galaxy on the right. In the most recent encounter that peaked 40 million years ago, the smaller galaxy is swinging around counter-clockwise, and is now slightly behind the larger galaxy. The space between stars is so vast that when galaxies collide, the stars in them usually do not collide.
  - craigching 10y ago
    Awesome, thanks!
user731955373 10y ago
No. [0] [0] https://en.wikipedia.org/wiki/Betteridge%27s_law_of_headlines https://en.wikipedia.org/wiki/Betteridge%27s_law_of_headline...
AnimalMuppet 10y ago
There was a time (just over a hundred years ago) when people thought that there was nothing more to learn about the universe. There were just these two little problems that needed explained... Now, that was because they thought they understood everything there was to know, not because they worried that there were limits beyond which they could not know. But, as the article says, trying to guess how much we will learn (or not learn) in the next, say, 100 years, is a very hazardous business.
Roboprog 10y ago
Glad to hear about testing for gravitational waves. That's really the first observation I have heard about that covers anything older than the cosmic microwave background radiation. Otherwise, who is to say that the universe didn't start out as a somewhat lumpy (not too much, not tool little) blob of gas measured with a few K's (thousands of kilometers across and a few thousand/million degrees Kelvin -- k of Km x k of K)? You can run the numbers back to a geometric point, but what would that even mean without observations of some kind to prove or disprove it?
- Roboprog 10y ago
  ... vs the idea that "inflation" is mentioned as the way to get a mostly, but not quite, smooth universe which (as an article of faith???) MUST have started as a geometric point. How would you rule out "one day there was a blob"? (which is really a crummy hypothesis, but as something to throw out vs inflation -- "for a while, relativity didn't apply, but then it did, because space itself decided to grow, until it didn't, so there!")

116 points by ernesto95 10y ago

I'm curious how many people think about the Universe and how frequently. I think about it all the time and I'm not a physicist. Probably a solid 30 minutes a day usually before falling asleep. Almost religiously (ironic). I have tried to talk about it with my family and friends but so many of them just don't seem to have the passion for it. Some times I feel even seriously guilty wasting so much energy thinking/reading about it. Sometimes even wondering if I'm even in right profession (even though I do love technology). My current theory is that it just my personality type (INTP).

cgriswald 10y ago
I think about it constantly, but I've had an interest in astronomy and cosmology since I was a small child and I'm currently studying astrophysics at university.
czep 10y ago
I get it too. It's incredibly soothing and comforting to contemplate the vastness of space, the amazing features of this reality we barely comprehend and in which we live for a flicker of an instant. Whenever I'm stressed, all I need to do is look up at the night sky, or read wikipedia articles about quasars, dark matter, stellar wind, the event horizon of supermassive black holes, how galaxies can pass through each other without any of the billions of stars ever coming close to hitting each other. It comforts me in a "the problems of two little people don't amount to a hill of beans" kind of way. Oh, and another INTP here :)
chriswarbo 10y ago
> Some times I feel even seriously guilty wasting so much energy thinking/reading about it. It's your energy, so if you find it worthwhile then that's all that matters. I sometimes feel the same way regarding my passion for computer science, when there are so many immediate problems in the world (energy production, food/wealth/opportunity distribution, war, etc.). The good news is that you're having such guilty thoughts at all; that makes you more conscientious than if you didn't! You're also devoting that energy to a meaningful topic, compared to cultural norms like sports, celebrities, fashion, etc. If you feel like there's nothing to show for your efforts, maybe you could try writing down some of your thoughts. They wouldn't have to be "correct", as long as they're intellectually honest; that would provide a progression of ideas, offer insight into the learning process, etc. and maybe you can look back over them to either find inspiration in ideas you'd forgotten, or be able to look at your old questions and know that you've found answers to some of them.
- pc86 10y ago
  How is someone thinking about the universe for half an hour before bed any more meaningful than someone thinking about the Denver Broncos?
  - CoryG89 10y ago
    Eh.. meaningful depends on the observer, but I doubt Einstein would have come up with relativity if he thought about the Denver Broncos instead of the universe.
    - thr0waway1239 10y ago
      It is interesting that you make this statement, because I have sometimes heard that Einstein was able to make so many profound contributions because he had a multitude of interests which was generally above average with respect to his peers. Unfortunately, I don't have a reference, but I think it was mentioned in his biography by Walter Isaacson. And not just that, reading that book will give you the general sense of a man who was quite the eclectic, intentionally creating masterminds with people from a broad swath of occupations.
  - kirykl 10y ago
    https://en.wikipedia.org/wiki/False_equivalence https://en.wikipedia.org/wiki/False_equivalence They're both subjects of thought therefore they are both equally meaningful to think about. false
    - pc86 10y ago
      I was asking why one is more meaningful than the other. Your response is basically "it's possible that one of them is more meaningful than the other" which doesn't help much.
  - chriswarbo 10y ago
    It depends what you do with it, which is why I suggested turning it into something concrete like writing. If thinking about something makes it 'click', that's useful to make a note of, as it may help someone else come to understand it. If something is still unfathomable after lots of thought, that's useful to make a note of, as someone else may be able to help, it may uncover a misunderstanding, or it might give someone else comfort to know they're not alone in their struggle. Less trivially (and less likely, but worth pursuing) it may lead to original thoughts, new perspectives or analogies, inspiring others, revealing previously ignored aspects of the world, etc. I don't know if amateur reflection on sports would actually have any impact, and even if it did (e.g. calling the Denver Broncos to tell them about some new strategy/etc. you've come up with), it wouldn't have much impact on the world. The names in Marty McFly's sports almanac might change, but even after just 1000 years those ripples would probably have faded to nothing.
CoryG89 10y ago
Personally, I have always had a love for physics (especially physics I can't really understand). If I hadn't gone into software, physics would have been it for me. Perhaps I will study physics after I retire or if I ever get tired of software. I don't ever really feel guilty about thinking about physics though. If someone can't feel free to at least think about what they want, then what freedom do you really have at all?
deleted 10y ago
[deleted]
mindcrime 10y ago
I did, a lot, when I was younger. My original plan out of high-school was to major in physics, stay in academia, get a phd, do research, etc. That got derailed when I took a computer programming class, and for most of the past couple dozen years I haven't spent as much time thinking about physics and cosmology. Just recently though, I've kinda had my passion for that stuff renewed (can't say why, though). I've been reading a lot of books on physics and cosmology again and spending a lot of time thinking about things like "what is 'space'" and the like. The biggest regret I have is that since I did not major in physics after all (and dropped out of school before graduating in c.s. anyway), I never got the level of certain things (especially maths) I would need to really understand physics at the deeper levels. I can read and largely understand books written for lay-people, like your average Brian Greene or Michio Kaku book, but I can't really go to arxiv.org and read the papers in the physics section. It's frustrating, but at the same time, the field I chose has been good to me and it affords me enough money and free time to sit around reading physics books now and trying to learn/re-learn stuff I always wanted to learn.
vectorpush 10y ago
Most people think about it, it's just that most people process these ideas through the filter of religion.
enrmarc 10y ago
I do it every day, although my background in maths/physics is not enough to do it "the scientific way". There is one topic I'm constantly thinking about: "Where is the data, e.g. the mass of a planet, stored in our universe?". I guess this question arise because of my computer science background (algorithms + data = universe?) and because even simple formulas like the Newton's Law of Universal Gravitation deals with data (e.g. the mass of a planet). So, where is that number stored so the universe know how to apply its formulas (laws, algorithms)? I know these laws we have are just models of our reality that are getting more precise over time, but I can't help but think that at the end our universe has to do "some calculations" and has to deal with data (numbers). I know three devices that can store information: our brains, our DNA, and our computers. The color of our eyes are stored in our DNA, but the mass of a planet is not stored anywhere? As I've said, my limited maths/physics background doesn't let me think about the universe the right way. I'm just a dilettante. And sorry for my English.
- AnimalMuppet 10y ago
  Seems to me that the data is stored in the positions of the particles that make up the planet.
- logfromblammo 10y ago
  How would we know if we were in a real universe or a perfectly accurate simulation of one? If we were in a simulation, how would we know whether it modeled the same rules as the host universe, or an imagined fantasy universe? If we are living in a nonfictional simulation, mass data are stored in a colossal server farm. If we are living in a fictional simulation, the mass data are stored in a thing we cannot possibly comprehend. If we are living in a real universe, mass data are not "stored" anywhere, in the same sense that consulting a map at 1:1 scale is indistinguishable from actually visiting the landscape it represents. Storing that data elsewhere is neither useful nor necessary.
  - jtrip 10y ago
    I ask, what is the qualitative difference?
calgoo 10y ago
Don't worry, there are lots of us. Currently I chat with people on some twitch channels that are dedicated to space games. We watch launches together and comment and talk about space.
nkrisc 10y ago
I do quite often. Sometimes when I think about the entirety of the universe (at least the one we are aware of) I start to wonder what I'm doing here at my job, or what are any of us doing existing at all? I can't help but think what's "outside" the universe (a very human and naïve way of thinking), what's the meaning of it all? I conclude there isn't any meaning, then I recalibrate my mindset and return to caring about all the meaningless things in my brief life.
Esau 10y ago
I spent this past weekend reading about Heat Death Of The Universe and Black Dwarf stars.
- csn 10y ago
  I have a bizarre love for the heat death theory, partially because it goes so well with Lovecraft's "And with strange aeons even death may die" in my mind.
  - agentgt 10y ago
    I too like it as well but because of a different author and story: "The Last Question" by Asimov [1]. It is a short but a must read (and it is free to read as well). It is one of the most beautiful and optimistic scifi stories. Asimov was and still is so ahead of his time. [1]: http://multivax.com/last_question.html http://multivax.com/last_question.html
no1youknowz 10y ago
I think about it all the time as well and I am thankful for these types of videos [1]. What I think about most, is how awesome it is to be alive right now. Where this video (and others like it) tell me about the universe and what discoveries have been found. At the end of this video, I am always wondering that if the Universe is as big as they claim. There must be discoveries waiting to be found that we can't even comprehend! Sometimes I find myself wishing we had probes that could be much faster than they are now. Instead of taking decades to go to the edges of our solar system, it takes months. Maybe within 50 years, by the end of my lifetime. We'll start to see images from Alpha Centauri and beyond. That I am hoping for! [1]: https://www.youtube.com/watch?v=GoW8Tf7hTGA https://www.youtube.com/watch?v=GoW8Tf7hTGA
udkl 10y ago
Do you think about the universe or your place in the universe and why you are here ? If it's the latter, I read somewhere a long time ago that these thoughts are caused due to a temporary chemical imbalance (serotonin I think) in the brain. Can't find the source right now, but something worth adding to the conversation.
- TheSpiceIsLife 10y ago
  Any mental state has a physical / chemical correlate. I find the idea these are imbalances unhelpful. And, we're not even certain which way round the causality flows. A bit of both, surely.
nathan_f77 10y ago
Yes I have phases where I spend a lot of time thinking about things like this. But there's only so much you can think about on your own, so it's important to keep reading and talking about it with others. Right now I'm enjoying "The Vital Question". I also enjoy writing I've also heard that Myers-Briggs personality types are not very useful or reliable, but for what it's worth, my personality type is INFP.
agumonkey 10y ago
Black matter and finiteness come back on a regular basis in my mind.
unexistance 10y ago
1. Now you know you're not alone :) 2. For me, it's more like lingering in the back of my mind, always thinking / imagining in terms of space-time continuum & the math related to it 3. I'm always trying to go to the next step, by learning the math (or the concept anyway), and quantstart[0] seems to be helping [0] https://www.quantstart.com/articles/How-to-Learn-Advanced-Mathematics-Without-Heading-to-University-Part-3 https://www.quantstart.com/articles/How-to-Learn-Advanced-Ma...

hashmp 10y ago

Maybe someone can chip in here but I was under the impression virtual particles didn't actually exist, they were just used to simplify our understanding of particle interactions. The uncertainty principle hasn’t gotten in the way of learning the rules of quantum mechanics, understanding the behavior of atoms, or discovering that so-called virtual particles, which we can never see directly, nevertheless exist. After recently getting to grips with QFT it seems there aren't actually any particles, just fields which are excited at certain locations giving the impression of particles.

snowwrestler 10y ago
I believe the Casimir Effect is usually taken as proof that virtual particles physically exist.
- cygx 10y ago
  No, it's generally taken as a proof of vacuum energy. However, it's arguably just the van der Waals force in disguise.
  - snowwrestler 10y ago
    We don't disagree. The theory is that vacuum energy creates virtual particles, which are what interact with the plates in the Casimir experiment.
criddell 10y ago
If you keep reducing, I think you end up a Tegmark's mathematical universe.
- dTal 10y ago
  I got to that point, then I read a LessWrong thing about subjective probability and none of it makes sense again. The basic problem is - what does "subjective probability" i.e. your personal anticipation of events, even mean in a world where every instance of you (experiencing all possible versions of events) is equally 'real'? http://lesswrong.com/lw/pt/where_experience_confuses_physicists/ http://lesswrong.com/lw/pt/where_experience_confuses_physici...

gregfjohnson 10y ago

Some of the great developments of th 20th century were proofs of limits, of what cannot be achieved even in principle: for example the incompleteness theorem and halting problem, and the uncertainty principle. IMHO, there is an "abstraction boundary" that limits what humans can ever know even in principle. There are some phenomena that are inherently "unabstractable". We may know that a glass of water has a wave function, but we will never know the particular wave function of any glass of water ever. The phenomena in our universe that we can "understand" are those that can be modeled, those for which abstractions can be created that will fit in our brains. There may well be phenomena in the universe (or elsewhere) that are not amenable to modeling in any way that is compatible with human cognitive machinery.

fluxquanta 10y ago
>There may well be phenomena in the universe (or elsewhere) that are not amenable to modeling in any way that is compatible with human cognitive machinery. Could these phenomena collectively be considered a "higher power"?
- udkl 10y ago
  If by "higher power" you mean things that humans can never comprehend, then yes. But us not ever being able to understand it does not mean there is no reasoning behind it. In the end it depends on perspectives & dictionary. You might call it a "higher power" .... I'm contended to end your sentence at 'phenomena'.
  - fluxquanta 10y ago
    >But us not ever being able to understand it does not mean there is no reasoning behind it. I didn't mean to imply that. But honestly, the idea that there exist physical systems in the universe that are too complex for the human brain to ever fully comprehend or model (dashing physicists hopes of a "theory of everything") sounds a lot like a higher power in the more traditional sense. I'm pretty sure that's close to the definition of the Tao, actually.

craigching 10y ago

Anyone know what galaxies are in the "Colliding Galaxies" image?

tdy721 10y ago
Here you go: http://apod.nasa.gov/apod/ap041121.html http://apod.nasa.gov/apod/ap041121.html > Billions of years from now, only one of these two galaxies will remain. Until then, spiral galaxies NGC 2207 and IC 2163 will slowly pull each other apart, creating tides of matter, sheets of shocked gas, lanes of dark dust, bursts of star formation, and streams of cast-away stars. Astronomers predict that NGC 2207, the larger galaxy on the left, will eventually incorporate IC 2163, the smaller galaxy on the right. In the most recent encounter that peaked 40 million years ago, the smaller galaxy is swinging around counter-clockwise, and is now slightly behind the larger galaxy. The space between stars is so vast that when galaxies collide, the stars in them usually do not collide.
- craigching 10y ago
  Awesome, thanks!

user731955373 10y ago

No. [0] [0] https://en.wikipedia.org/wiki/Betteridge%27s_law_of_headlines https://en.wikipedia.org/wiki/Betteridge%27s_law_of_headline...

AnimalMuppet 10y ago

There was a time (just over a hundred years ago) when people thought that there was nothing more to learn about the universe. There were just these two little problems that needed explained... Now, that was because they thought they understood everything there was to know, not because they worried that there were limits beyond which they could not know. But, as the article says, trying to guess how much we will learn (or not learn) in the next, say, 100 years, is a very hazardous business.

Roboprog 10y ago

Glad to hear about testing for gravitational waves. That's really the first observation I have heard about that covers anything older than the cosmic microwave background radiation. Otherwise, who is to say that the universe didn't start out as a somewhat lumpy (not too much, not tool little) blob of gas measured with a few K's (thousands of kilometers across and a few thousand/million degrees Kelvin -- k of Km x k of K)? You can run the numbers back to a geometric point, but what would that even mean without observations of some kind to prove or disprove it?

Roboprog 10y ago
... vs the idea that "inflation" is mentioned as the way to get a mostly, but not quite, smooth universe which (as an article of faith???) MUST have started as a geometric point. How would you rule out "one day there was a blob"? (which is really a crummy hypothesis, but as something to throw out vs inflation -- "for a while, relativity didn't apply, but then it did, because space itself decided to grow, until it didn't, so there!")