What don't we know?

[robnissen]

Below is a partial quote from another thread:

"Why don't we hear of anything "mystery to astronomers" until a theory is produced?"

That thread was about how there was not a good theory about why planets don't spiral into the sun early in their formation, and now a theory has been proposed. I did not know until reading that article that until now there was no theory as to why planets did not spiral into the sun as they were being formed. That got me to thinking about what other things is there currently no good theory for. I am not talking about things that will probably be forever unknown, such as what was before the BB (or how many angels can fit on the head of a pin), but rather things that are part of our every day universe. As a classic example from the past, in the 1800s, scientists knew the mass of the sun and the energy it produced, but they had no theory as to what was the source of that energy. (Another example, why the orbit of Mercury did not match newtonian predictions.)

I am hoping that people will post to this thread so that perhaps there could be a comprehensive lists of current unknowns in science. I am mostly interested in Astronomy/Physics but other unknows would also be welcome. I will start with the most obvious major unknowns from Physics and also a minor unknown from Biology. The ones from Physics are well-known unknowns but hopefully some people here will no other unknowns such as the example that got me thinking about this, what prevented planets from crashing into the sun early in their formation.

1. What is dark matter?

2. What is dark energy?

3. What is causing the expansion of the universe and what is the process for creating additional space between galaxies?

3 (From Biology) What is the origin of sex? (It is my understanding that there is currently no theory on how sex could evolve from non-sexual beings.)

 

[Gravity_Ray]

why did life begin?

why are people and critters sometimes naturally born with more fingers, but never with less fingers?

why is there small deviations from smoothness (anisotopies) in the cosmic microwave background ?

why does my wife insist that I put my shoes in the closet?

:ugeek:

 

[SpaceTas]

To quote approximately an ex vice president "There are known unknowns and unknown unknowns"

You have noticed "unknown unknowns" moving to "known unknowns" caused by the improvement of our knowns ie better observations prompt theorists. Dark energy is a case in point. Before the distant supernova searches revealed an accelerating universe there was no or very little speculation about a dark energy. There was no need.

We still stand on a beach facing a sea of vast unknowns

 

[silylene]

To quote approximately an ex vice president "There are known unknowns and unknown unknowns"

I think that quote was from a certain Sec. of Defense.

 

[centsworth_II]

why are people and critters sometimes naturally born with more fingers, but never with less fingers?

Scratch that off your list.

Cleft Hand

 

[Gravity_Ray]

Thanks Centsworth

I've been reading up on this because a friends child was born with an extra pinky on his hand. Actually I didnt write it well. What I meant to say was why is having more digits more natural than having less digits. For example some cats have 5 toes on front feet but 4 on rear feet as opposed to others that are 4 and 4, there are other animals that have more digits too like some chickens. But its rare for animals to have less digits than their peers.

It was just on my mind when I wrote that post. But I have read up on this subject more. Now I see that both conditions of having extra digits and having less digits in humans congenital.

So thanks, im scratching that one off.

 

[robnissen]

To quote approximately an ex vice president "There are known unknowns and unknown unknowns"

You have noticed "unknown unknowns" moving to "known unknowns" caused by the improvement of our knowns ie better observations prompt theorists. Dark energy is a case in point.

You are right, I am asking for the "known unknowns." The "unknown unknowns" are not worth talking about, seeing as how they are ... uh... unknown. And yes dark energy is a good example of moving from an "unknown unknown" to a "known unknown."

In any event, there haven't been many posts here of "known unknowns," which means either there just aren't that many (which seems unlikely) or people just don't find this topic as interesting as I do (which seems more likely). BTW, because there are two competing theories regarding the lack of posts here, the lack of posts is not now a "known unknown," although if both of the two positied theories are wrong, it would be an "known unknown."

 

[thnkrx]

Hmmm...

...who was the astronomer type a few decades back whose response to a similiar question was (more or less) "Answers? I doubt if we are asking the right questions."

I've done a bit of reading on the history of astronomy and other sciences, likewise there are some past bits and pieces I remember hearing about at the time. For example...

...a few hundred years ago, the astronomers of the day regarded the notion of meteors being rocks in the sky as absurd.

...a hundred odd years ago, continental drift was regarded as absurd.

...when the first good flybies of the Jovian Moons were made, the reaction was one of astonishment and disbelief among the various scientists. None of them had anticipated anything even close to what turned up there. Same story with the initial extra-solar planet discoveries - 'Hot Jupiters' were simply too weird to be considered, as were planets with eccentricities of 50% or more.

...a few decades back, 'String Theory' and 'Dark Matter' were both 'out there' type ideas. These days, they appear to be fairly standard concepts...but I wonder if these are actually 'real' or just 'crutches' because the questions these theories were intended to solve were asked in the wrong way, or were the wrong questions to begin with. The whole 'epicycles within epicycles' thing until a point is reached where you have to stand back and say...'this creates more problems than it solves.'

 

[silylene]

Hmmm...

....I've done a bit of reading on the history of astronomy and other sciences, likewise there are some past bits and pieces I remember hearing about at the time. For example...

Since the times of Pythagoras and Erastrothenes, scientists knew the flat earth theory was absurd. It still is.

Since the times of Newton, scientists knew the hollow earth theory was absurd. It still is.

Since the times of Epicurus, scientists knew that the theory of spontaneous creation of mass from nothing was absurd. It still is.

Since the times of Varro (36 BC), scientists were aware that the theory that spontaneous generation of contageous disease was absurd. It still is.

Since the times if Ib Sina and Descartes, scientist were aware that the theory of 'impetus' was absurd. It still is.

Point is, there are literally thousands of theories which have been discarded long ago, and the (now old) explanation is as valid today as it was when it was first expounded. Finding a handful of theories which were discarded in the last century doesn't mean all the time-proven theories we use as the backbone of science are at risk of being displaced.

 

[robnissen]

Since the times of Epicurus, scientists knew that the theory of spontaneous creation of mass from nothing was absurd. It still is.

I agree with most of your post, but the one I quoted is probably wrong. Pairs of particles and anti-particles regularly form out of the vacuum of space and then instantly combine and go back to nothing. One theory is that perhaps the matter in the universe came about when these particles for some reason didn't recombine. In addition, IIRC Hawking's radiation occurs when a particle and anti-particle form near the event horizon of a BH. Because one is inside and one outside the event horizon they cannot recombine and there is an increase in matter or anti-matter outside of the bh. Finally, even if the particles that pop in and out of existence have no mass, our buddy Albert explained that energy can, in fact, be turned into mass.

 

[bdewoody]

I pretty sure that what we don't know about our universe far exceeds what we do know or think we know.

 

[jgrtmp]

Yes that is correct . It is the basis of the matter anitmatter transform. Its like Entropy. For each amount of matter you have to have an equal amount of antimater created from an event. Once the matter & antimatter come together & annihalate themselves they reconvert into pure energy, with out any residual matter. Kinda like the French Neutron Bomb. I hate having the US blamed for it. Fact is it isn't Star Trek & was physicaly created in a lab in 1936 by Dr. Carl Anderson. The Germans(Nazis) quickly latched on to be basics of it & with the advent of the V2 it became critcal to stop the Nazis/Facists. Nuclear exploits were readily available as both sides had been involved & possibly collaborated in the ideal of progress at the on set of the war. This wasn't a kids dream, this was science becoming reality. What Roddenberry wrote upon was established physics from the 30s. Just how to make a photon torpedo, or an antimatter one, hadn't been publicized. What if they already had a bunker buster that was an antimatter torpedo? 12 stories down & the equal portion of matter gets turned in to Gamma rays---Game over. Phaser banks shooting photon beams??? Why not target a heagy magnetic area of the ship & let the Gamma stream of photons spawl appart & disintegrate any matter it touches within the B field. Or I might add, the spawn of matter particle paint the target for zero accuracy. This was coming out of the 30-60s Tech. What don't we know is how to be honest with ourselves & fight for people to survive. Not for some Fascist movement to say its done it already??? People are starving out there & they are the ones they want to die. You want to live??? Ask the Fascits Nazis how they are going to get away from the Great Attractor or the Super Attractor its bound to...All they know is they are dead & they are taking everyone with them...

 

[emperor_of_localgroup]

Below is a partial quote from another thread:

"Why don't we hear of anything "mystery to astronomers" until a theory is produced?"

That thread was about how there was not a good theory about why planets don't spiral into the sun early in their formation, and now a theory has been proposed. I did not know until reading that article that until now there was no theory as to why planets did not spiral into the sun as they were being formed. That got me to thinking about what other things is there currently no good theory for.

1. What is dark matter?

2. What is dark energy?

3. What is causing the expansion of the universe and what is the process for creating additional space between galaxies?

3 (From Biology) What is the origin of sex? (It is my understanding that there is currently no theory on how sex could evolve from non-sexual beings.)

Here are a couple of questions I think deserve answers.
1) Does an atom have intelligence? If your answer is 'no'. Ask yourself the question 'does cheese have any effect on flavor and taste of a cheesecake?'

2) Do we have all the necessary sensory systems to understand the universe?

Now I must respond to this statement.

Pairs of particles and anti-particles regularly form out of the vacuum of space and then instantly combine and go back to nothing.

If 'something' comes out from 'somewhere', that 'somewhere' is NOT 'nothing'.
3) We still don't know this 'nothing'.