
The Most Important Questions In Science - prateekj
http://www.npr.org/blogs/13.7/2013/09/10/221019045/the-10-most-important-questions-in-science
======
lifeformed
I would replace a couple of the anthropocentric ones with:

1) What is the nature of time, and how/why does our consciousness perceive it
as such?

2) What's inside a black hole?

I also have a philosophical question that maybe has already been explored:

Are the laws of logic always true in every possible universe? Could there
exist a universe where p|^p is not always true? One where the ratio of a
circle's circumference and diameter is not equal to pi? I guess these things
would be impossible to imagine, but is logic just a description of reality, or
is reality an implementation of logical axioms?

~~~
justinpombrio
1) We perceive time as such because the future determines the past but not
vice-versa (H(t|t-1)>0 and H(t-1|t)=0 in terms of entropy) -- thus our brain
can at a given moment contain relatively complete information about past
moments, but necessarily limited information about future moments. I think
relativity gives a pretty good picture of the nature of time; it is a partial
order. Quantum mechanics treats time very differently though, so there is
almost certainly more to say. I think this is a good question to be asking.

2) There's something inside a block hole?

It's funny that you should use those two examples in your last question. The
first one is true or false depending on the logic you use, and the second is
physically false.

The first statement -- that (p or not p) is always true -- is true in Boolean
logic but not always true in Constructive logic; in fact this is what
separates these two forms of logic. My very rough understanding is that
boolean logic best describes situations in which propositions like p are taken
to mean "p is true", whereas in constructive logic p is taken to mean "p is
provable".

The second statement -- that the ratio of a circle's circumference and
diameter is equal to pi -- is false under general relativity. In fact, if you
were to measure the circumference and diameter of a big circle around the sun,
their ratio would be a little off due to the sun's gravity (I forget in which
direction).

You ask whether the laws of logic are true in every possible universe. It
depends entirely on what you mean by every possible universe. To really
consider one possible universe, though (say the one where everything is made
of cheese), we have to be able to reason about it. So if the laws of logic are
not true in it (maybe the cheese is also not cheese), we can't really consider
it to begin with. So yes, the laws of logic are true in every _possible_
universe, though for a rather boring reason.

~~~
eli_gottlieb
Or in other words, every universe we can possibly think of has to have _some_
kind of internal logic, except maybe the Lovecraftian ones.

~~~
lifeformed
But do those internal logics have to be the same across universes?

------
twiceaday
"What makes us human?" has nothing to do with science. It is a strictly
philosophical question.

~~~
Houshalter
I disagree. Questions like how the human brain works and how we can think
abstractly, and how/why humans are so much more intelligent than other
animals. There isn't really anything philosophical about it.

~~~
macspoofing
I have no idea what the heck the author is talking about with that point. The
question is either too simple, in that you can just itemize all the ways we
are different (just so happens that "consciousness" \- #5 - would be a pretty
big bullet point, though we can just generalize and say our DNA makes us
human), or nonsensical. Case in point:

>how/why humans are so much more intelligent than other animals

Because we have three times more neurons than the closest competition. Why do
we have so many neurons? Because there was a selective pressure acting upon
our ancestors.

Furthermore, WE ARE ANIMALS. We have certain special traits unique to us, but
every species has something special about it.

~~~
Houshalter
I get 1.7 to 2 times as many neurons as elephants, a little more for whales,
and they don't seem even half as intelligent. Homo floresiensis had a brain
considered small for a chimpanzee and was capable of making tools and lighting
fires and very likely language. Meanwhile neanderthals had even bigger brains
than us. The number of neurons alone isn't responsible for intelligence.

Even if it _was_ , that doesn't explain _how_ intelligence works or what the
hell the brain is actually doing.

~~~
acqq
Still remember that when the question is formulated as "what makes us humans"
it gets the theological note to it implying that we are special, "divinely
better" or whatever. And that we're not. We're just one specific attempt of
all evolutionary attempts that happened through the billions of years.

~~~
Houshalter
We're not special? We're not better? Are we really being politically correct
for the sake of animals?

~~~
acqq
No, we are not "the chosen ones." We have the brains able to figure out more
than other animals, but it was not predestined. And we are not the only ones
"at the top of the evolution" either. Every animal you see is "at the top of
the evolution" for its branch.

I know it's hard to believe for those who grew up in protestant environment
with the false belief that "God gave us the Earth to use it as we will."

~~~
Houshalter
Humans certainly are "at the top of evolution". Though it depends greatly how
you define "top of evolution". I mean in terms that we might go on to populate
entire galaxies and survive long, long after the Earth has burned to a crisp
and every other species is long dead. Or maybe you could define it in terms
that we are capable of far, far more than any other animal.

If you define it as "merely manages to survive and reproduce in the present"
then yes, everything alive is at "the top of evolution", since that is
actually part of the definition of "alive".

Anyways I'm not sure it matters. How I came to exist doesn't change any of my
goals. I'm still the same person whether I was put here by God or by random
chance or by an evolutionary process.

~~~
acqq
> we might go on to populate entire galaxies and survive long

At the moment, we "might" only in Sci-Fi movies. The reality is completely
different. Better look at how we really handle global warming or control
nuclear weapons. Civilization we know is much more fragile that those who
believe to be "chosen by deity" are able to recognize.

~~~
Houshalter
No country is stupid enough to use nuclear weapons, and it wouldn't make
humans extinct in any case. And global warming couldn't even get as far as
destroying civilization.

We only have to make it 30 or 40 more years anyways.

~~~
eli_gottlieb
Wait, what? Last I heard, another 50 years of global warming and we're the
source of a full-blown mass extinction, one that will probably include us. So
you're saying all we have to do is survive long enough... to die out?

~~~
Houshalter
Full-blown mass extinction? How? As I understand it it's mainly coastal
regions slowly flooding and weather changing. That's not collapsing
civilization.

I'm saying we have 30-40 years until super-human AI. Though short of that
there are still many other advances in technology we could make in that time
that would change things completely.

~~~
eli_gottlieb
> Full-blown mass extinction? How? As I understand it it's mainly coastal
> regions slowly flooding and weather changing. That's not collapsing
> civilization.

Mass extinction of _large sums of the life on this planet_. We might
technically survive, but the ecosystem that supports us is _dying_ , and
_quickly_ , and _we 're_ the ones killing it.

>I'm saying we have 30-40 years until super-human AI.

Ah, ok. Well, if that prediction turns out correct, then you should liquidate
your bank accounts, because then it's 30-40 years until _we all die
screaming_.

(Translation: futurist pls go.)

------
scotty79
I'd like to know if there's some fundamental limit that makes it impossible to
achieve superconductivity at high temperatures in any material.

------
hawkharris
I think #6, the question about sleep and dreams, is especially interesting.

On another NPR broadcast, I heard a researcher talk about how our bodies make
up for sleep we lose. It's not like owing a debt to the bank and paying it
back all at once, he said. If we go days without sleep and then crash, we
won't quite cognitively recover from the lost sleeping time - even if we sleep
for many more hours than usual.

One biological explanation, he said, is that the need to make up for many
hours of lost sleeping time has not been a significant factor in evolution;
modern humans are the first species that intentionally deprives itself of
sleep for long periods of time.

I thought it was fascinating to think about the concept of humans evolving to
go longer periods without sleep and to cognitively recover by "cashing in" on
rest, so to speak.

I'm sorry that I can't remember the author's name to provide more concrete
details; if anyone else also heard the talk, please share a link if possible.

~~~
macspoofing
It's a fascinating question, but I don't see why it is one of the "10 most
important questions in science".

>modern humans are the first species that intentionally deprives itself of
sleep for long periods of time.

Is that correct? It feels wrong. Plenty of species will endure all kinds of
stresses when it comes to survival.

From the article: >Was Freud right about his theory that dreams are some sort
of expression of repressed desires?

This one is easy. No. Dogs dream.

~~~
read
One reason it might be one of the 10 most important questions in science is
that dreaming helps solve problems. When you sleep on a problem the mind
magically presents an answer to the problem the next day. Aside from it's
metaphorical implication that it's important to dream big, dreaming could
literally help answer the other 9 questions.

I find it intriguing HN readers _don 't_ consider it important, actually.

~~~
macspoofing
>I find it intriguing HN readers don't consider it important, actually.

Understanding dreams (and consciousness) is really tied to understanding the
human brain. I would consider that, in general, to be one of _the_ questions
of science, not dreaming specifically.

After all, is the phenomenon of dreams that much more interesting than, say,
the phenomenon of memories and recollection, or emotional experience, or
learning, or anything else brain-related?

~~~
read
It's not clear to me how one can make themselves dream.

You can stimulate memories and recollection, induce emotional experience, and
can initiate learning with known ways that work, even if the understanding of
how they work isn't fully developed.

Are there known ways to stimulate a dream?

------
VanillaCafe
"Why do we dream?" doesn't seem like it ranks in the top 10.

~~~
altoz
more important than "where do we put our carbon". that's an engineering
problem, at best.

~~~
paul_f
It was a decent list until the absurd carbon question.

~~~
huherto
I think it is a very important question that may actually impact our survival
in the planet beyond the other questions that are more to satisfy our own
curiosity.

So I am not sure if you think the question is already solved or is it not
actually a problem.

------
swatkat
_10\. How can we get more energy from the sun?_

I would love to see high efficiency[0] photo-voltaic cells in all sorts of
consumer electronic devices. Imagine solar cells embedded in Gorilla glass on
the back of your phone, camera, laptop etc. :)

[0] [http://sharp-world.com/corporate/news/130614.html](http://sharp-
world.com/corporate/news/130614.html)

------
rob05c
_3\. Are we alone in the universe?_

With regards to this question, I highly recommend
[http://paultyma.blogspot.com/2013/04/why-well-never-meet-
ali...](http://paultyma.blogspot.com/2013/04/why-well-never-meet-aliens.html)

He makes a compelling argument.

~~~
acqq
Still the argument "they have their ships therefore they don't need our Earth"
is more than shaky. I concur with Hawking: we can definitely imagine aliens
who wouldn't blink an eye before they won't care for life of humans, the same
way we _eat_ other animals or simply destroy them as the side effect of doing
something for us more important.

~~~
rob05c
"You're getting warmer. Kip — I think they eat meat." \- Have Spacesuit—Will
Travel

------
m_eiman
There's only one question in science: "How?"

------
rdpi
What is the meaning of Life, Universe and Everything?

------
typon
I would put "Does P = NP?" up there.

------
dnautics
what, no solvolysis of the norbornyl cation??

------
andyl
I wanna know: how/why does the observer change the behavior of quantum
systems?

~~~
hcarvalhoalves
From what I understand, there are two phenomena at play, often mixed together.
The observer might interfere when it tries to measure (the observer effect,
which is true to _any_ system), but there's also an inherent uncertainty on
the way waves are measured (the uncertainty principle).

The observer effect is well-understood, there's nothing magical about it. For
example, a multimeter acts a (very small) resistor, affecting the circuit it's
measuring. Sometimes the error you introduce can be ignored, but get
unmanageable when you try to measure really small systems, where things are
more easily disturbed.

The uncertainty principle, on the other hand, is something else. There's a
video that I think explains the uncertainty principle well, with a practical
example (it's explaining why there's a limit to how many pulses you can send
down a fiber optic and still be able to measure on the other side):
[http://youtu.be/0OOmSyaoAt0?t=7m28s](http://youtu.be/0OOmSyaoAt0?t=7m28s)

~~~
judk
Uncertainty principle is about shape, not measurement. Unless you mean "how
you define the measured aspect of the system" .

Position and momentum are Fourier transforms of each other, and therefore
their waveforms cannot both be confined to small range at the same time.

It is loosely analogous to the concept that a rectangle of area 1 can never
have both side lengths less than 1.

