Hornblower, The origin of the highest energy cosmic rays, and why we observe as many as we do despite the expectation that the CMB would apply an important breaking effect to them, is a significant unresolved problem in astrophysics. Dark energy is also pretty darn mysterious, but I'm doubtful that there is any important connection between the two.  

When modeled as a cosmological constant, dark energy is a type of gravitational field (more generally, a correction to the metric of space-time) and so it affects all particles equivalently.

Dark energy also can't accelerate particles in a particular direction.  Intuitively one would think dark energy would expand the universe by "pushing out" on things, but that's actually not how it works -- in cosmology it can't work that way because there is no preferred direction to push from and no walls to push against.  The dark energy is uniform and so it does not apply a net force on anything.   Instead, it affects the expansion of space itself because of its energy density, which changes the metric of space-time.

I was thinking of using both a UV403 filter and an IR720 filter to filter out visible light and see if I can detect the "invisible" parts of the rainbow with the camera.  Not sure if it's possible because cameras have blocking filters on them.  I can do IR photography- but the camera's blocking filter removes about 8 stops of IR light, and on the other end of the spectrum, about 13 stops of UV light.

Yeah, that's a pretty big reduction, but I guess that means the filters are doing their intended job.  There are some guides online for how to modify the camera with taking the filters out, but it's probably not something you want to try unless you are really serious about it and have equipment to spare.  If you're managing to get some results with the filter in place then that's pretty awesome.  I really enjoy looking at B&W infrared photography -- it gives an amazing way to see the world and can produce some really interesting art.  People's faces in particular are very strange in IR, and landscapes and foliage are neat too.

I'd love to see some shots you have made!

Some of the amazing things I found out is that although most of us humans have three types of cones to detect color (thus three primary colors), some lucky people have a fourth type of cone (four primary colors!) so they can actually see more color than normal people can?  And who said that superhumans didn't exist

I've heard of this and it does sound pretty interesting.  And there are other superhuman senses as well.  I had the privilege to meet a "supertaster" who puts that skill to use as the blendmaster of a tea company.  People also generally have a broader range of hearing when they are young, and lose the sensitivity to high frequencies as they age.  I used to be very sensitive to higher frequencies than normal, and have a vivid memory of walking through a neighbors yard with some friends and was suddenly incapacitated by a soul-piercing sound that nobody else could hear.  Turns out we had walked in front of a motion-sensitive deer deterrent that throws out ultrasound.

This gets more into the realm of neuroscience than color theory, but have you ever heard of a condition called hemineglect?  I think it's one of the weirdest things about how people can perceive the world differently.

Hornblower, The origin of the highest energy cosmic rays, and why we observe as many as we do despite the expectation that the CMB would apply an important breaking effect to them, is a significant unresolved problem in astrophysics. Dark energy is also pretty darn mysterious, but I'm doubtful that there is any important connection between the two.  

When modeled as a cosmological constant, dark energy is a type of gravitational field (more generally, a correction to the metric of space-time) and so it affects all particles equivalently.

Dark energy also can't accelerate particles in a particular direction.  Intuitively one would think dark energy would expand the universe by "pushing out" on things, but that's actually not how it works -- in cosmology it can't work that way because there is no preferred direction to push from and no walls to push against.  The dark energy is uniform and so it does not apply a net force on anything.   Instead, it affects the expansion of space itself because of its energy density, which changes the metric of space-time.

Hemineglect? Never heard of it- but just breaking down the term, does it have to do with some senses atrophying because we don't use them as much when we get older?  Just a shot in the dark lol.

There is also the "Great Attractor" and why do superstructures in the universe resemble the structure of neural networks of our own brains?

Traversable acausal retrograde domains in space-time

Ah, I see.  And I found that there is in fact a linear combination of functions that will work:

The series expansion x^2/2 + x^4/4 + x^6/8 + x^8/16 + ... will approximate the curvature of the circle.  And the function x^(very large even number) is virtually flat between -1 and 1 but very steep outside, so if you add them together they will approach the shape you want in a single analytical function.  For example,

y = x^2/2 + x^4/8 + x^6/16 + x^8/32 + x^10/64 + x^100

Hemineglect? Never heard of it- but just breaking down the term, does it have to do with some senses atrophying because we don't use them as much when we get older?  Just a shot in the dark lol.

No, it's way weirder, and usually is a result of damage to the brain.  A person with hemineglect "neglects" half of space.  Not because they cannot see it (their eyes work just fine), but because their brain is unable to process or even contemplate it.  For example, you might ask a person with this condition to draw a clock, and they will cram the numbers all on one side, neglecting the other half.  It's as if the other half of the clock does not exist.

There is also the "Great Attractor" and why do superstructures in the universe resemble the structure of neural networks of our own brains?

A funny coincidence.  The structure that evolution developed which optimizes the storage and transmission of information in brains happens to look similar to the 3D structure formed by gravitational collapse of a fluid with small initial density fluctuations.  We can model the formation of the cosmic web this way using just gravitational forces in the Lambda-CDM model and it reproduces the observed structure amazingly well.

Traversable acausal retrograde domains in space-time

Cute!  Essentially identical to doing this, but with math and general relativistic rigor.