How Much More Can We Learn About the Universe?

http://nautil.us/issue/40/learning/how-much-more-can-we-learn-about-the-universe

by ernesto95 • 10 years ago

116 69 10 years ago

agentgt2• 10 years 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• 10 years 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• 10 years 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 :)

chriswarbo2• 10 years 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.

pc863• 10 years ago

How is someone thinking about the universe for half an hour before bed any more meaningful than someone thinking about the Denver Broncos?

mindcrime2• 10 years ago

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.).

Likewise. I sometimes feel bad that what I do doesn't have a more immediate impact on people's lives somehow, in terms of things like poverty, health-care, clean water/food, etc.

OTOH, the skills I have can be put to use in those areas, but the only outlet I really have to do that is to volunteer with non-profits of some sort, which is something I do a bit of (but probably not enough).

CoryG892• 10 years 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?

mindcrime2• 10 years 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• 10 years ago

Most people think about it, it's just that most people process these ideas through the filter of religion.

enrmarc• 10 years 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.

AnimalMuppet2• 10 years ago

Seems to me that the data is stored in the positions of the particles that make up the planet.

logfromblammo2• 10 years 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.

calgoo• 10 years 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• 10 years 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• 10 years ago

I spent this past weekend reading about Heat Death Of The Universe and Black Dwarf stars.

csn• 10 years 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.

no1youknowz• 10 years 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

udkl2• 10 years 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• 10 years 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• 10 years 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• 10 years ago

Black matter and finiteness come back on a regular basis in my mind.

unexistance• 10 years 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-Ma...

hashmp• 10 years 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.

snowwrestler2• 10 years ago

I believe the Casimir Effect is usually taken as proof that virtual particles physically exist.

cygx• 10 years ago

No, it's generally taken as a proof of vacuum energy. However, it's arguably just the van der Waals force in disguise.

criddell2• 10 years ago

If you keep reducing, I think you end up a Tegmark's mathematical universe.

dTal2• 10 years 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_physici...

gregfjohnson• 10 years 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.

fluxquanta3• 10 years 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"?

udkl2• 10 years 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'.

visarga2• 10 years ago

Not just an abstraction barrier, but also a working memory limit of maximum 7-8 objects at a time. We're limited in more than one way in how much we can understand.

If we ever discover AGI, I think we will begin a new discipline, called "AGI studies" where humans try to understand what it discovers, to keep up. But the hard part would be to develop the most efficient concepts in order to understand even what it has to teach us. How do you communicate with an intelligence vastly superior to yours? Maybe the AGI will also develop the concepts and language necessary to communicate its findings to us.

ori_b• 10 years ago

Maybe the AGI will also develop the concepts and language necessary to communicate its findings to us.

It will, because without that, humans will just shut down the "machine that only speaks gibberish". Effectively communication with humans is a survival requirement.

Florin_Andrei2• 10 years ago

The question is whether the limits mentioned above are due to constraints in the processing power of the "human CPU", or are limits inherent to any approach based on logic. In other words, does reason itself, no matter how fast or large, have limits?

Results such as the incompleteness theorem, Godel's work, etc seem to suggest that logic itself has limits, along with everything derived from it and/or built on top of it. In other words, even an ASI, even if you converted the whole known universe to "computronium" - it would not do better against those limits than evolution-shaped human brains. Reason itself seems to have an event horizon.

The fact that the human brain has very clear and obvious processing power limitations is a separate issue.

trhway• 10 years 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.

these are internal limits of the models they are confined to - reminds about the Achilles and the tortoise paradox before availability of the limit/differentiation/integration tools.

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.

once the model of wave functions gets obsolete, the question itself wouldn't make sense. Such inability to brute force the calculation of such wave functions is one of the reason driving the more deep thinking in science.

dredmorbius2• 10 years ago

Several other limits as well:

Extending to the 19th century and you'll find a few more limits to knowledge and capabilities.

1. Einstein, general reletivity, and the speed of light as an absolute limit.

2. Thermodynamics, and the limits imposed by entropy.

3. Rankine and Carnot expressing the limits of efficiency of heat engines.

4. Claude Shannon and the limits of information density over a communications channel.

5. Hubbel's expansion constant and the size of the observable Universe.

6. Moore and Wright with (empirically-derived) principles of production efficiencies.

7. M. King Hubbert, and limits to the total amount of petroleum in the US and world.

8. Meadows, et al, and the potential limits to human growth. Somewhat rough, but clearly finite.

9. Keeling and limits to atmospheric absorption of CO2 without producing significant climate change.

(Not all of these limits are fully accepted, though I've strong reasons to believe they're well founded.)

selestify• 10 years ago

Very cool, thanks for the list

careersuicide• 10 years ago

10. The Chandrasekhar limit (and also the TOV limit), you could argue this is a subset of the limits imposed by relativity, but I think it's interesting and important enough to warrant being listed separately.

craigching2• 10 years ago

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

tdy721• 10 years ago

Here you go: 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.

craigching2• 10 years ago

Awesome, thanks!

user731955373• 10 years ago

No. [0]

[0] https://en.wikipedia.org/wiki/Betteridge%27s_law_of_headline...

AnimalMuppet2• 10 years 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.

Roboprog2• 10 years 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?

Roboprog2• 10 years 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!")

How Much More Can We Learn About the Universe?

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