
How Much More Can We Learn About the Universe? - ernesto95
http://nautil.us/issue/40/learning/how-much-more-can-we-learn-about-the-universe
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agentgt
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).

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

~~~
CoryG89
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
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.

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gregfjohnson
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.

~~~
visarga
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.

~~~
Florin_Andrei
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.

~~~
internaut
It is possible there is a form of understanding that goes over and above what
we'll loosely call reason?

I don't mean woo-like supernatural or mysticism.

Let's use an analogy.

We have instincts and reason. Instincts are quick but flawed, reason is slow
but surer. Reason is to X what Instincts are to reason.

What if there existed X metacognition and above reason itself?

Suppose, for example with the assistance of an AI (capable of seeing larger
pattern a human cannot) in conjunction with brain altering drugs to, crudely,
give you a hit of comprehension/meaning (as a reward) when you successfully
pattern matched with the assistance of the AI. That to me seems like much more
than thinking from 1st principals. It would be something closer to _seeing_
than thinking sequentially.

~~~
Florin_Andrei
It's very hard to even verbalize your intuitions on this topic without veering
into metaphysics. But let me give it a try.

Provided there's a 4th layer on top of the triad matter/energy/information -
then yes, it would be doable.

Our bodies exist in the same way rocks do - just like dead matter.

On top of that, there's the "meta" level of life, which is just matter playing
with energy. It can do things that dead matter alone cannot do.

On top of that, there's the "meta" level of mind, which is just matter/energy
(i.e. life) playing with information. It can do things that the previous two
levels cannot do.

We are organized on 3 successive layers (body / life / mind) because the
universe could be thought of as structured on 3 layers: matter / energy /
information (we have started to figure out the equivalences between these
layers recently).

So mind is what evolution put forward to master the domain of information.
Everything that could be done with information, the mind could probably do,
it's just a question of how fast.

So if there are any limitations to logic (and therefore to reason), it's
likely that these come from the way the information meta-layer of the universe
works.

If you want to see these limitations removed, you better hope there's a 4th
meta-layer (in philosophy I guess you could call it a 4th principle) of the
universe that can do things that the currently known 3 layers cannot do. But
then that 4th meta-layer would have to somehow become embodied, either
naturally (evolution) or artificially (technology).

However, it's hard to figure out how 3-layer beings like us could even begin
to approach building something like that. It would be like a worm trying to
understand quantum electrodynamics.

All of the above is just one giant pile of assumptions floating on thin air.

> _It would be something closer to seeing than thinking sequentially._

Or closer to _being_ what is called _truth_ (that which is), rather than even
"seeing".

Are we getting kicked out of here yet? :)

~~~
nitrogen
The concept of the Technium sounds similar to this 4th layer.

[https://en.m.wikipedia.org/wiki/What_Technology_Wants](https://en.m.wikipedia.org/wiki/What_Technology_Wants)

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

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

~~~
snowwrestler
We don't disagree. The theory is that vacuum energy creates virtual particles,
which are what interact with the plates in the Casimir experiment.

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AnimalMuppet
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
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
... 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!")

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

~~~
tdy721
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
Awesome, thanks!

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user731955373
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