This is an interesting article about jhana stuff. From my experience I can concur with the analysis and recommendations provided.
Source:http://notesonthedhamma.blogspot.com/2023/02/the-physics-of-jhana-from-jhanic.html?m=1
The Physics of Jhāna: from jhānic impotence, to jhānic omnipotence
What I wrote already
Jhāna-constipation ⛜🌊: A condition where one is practicing the method of attaining Jhāna correctly, but energy channels are partially blocked.
jhāna force, and equation: quantitative analysis of jhānic force.
J.A.S.I. ('Jazzy') effect: ”Jhānic Automatic Spinal Inflation”: this is what you feel when the jhāna force is propogating through the space of the entire physical body.
🌟PIE: 🌟PIE = (P)recious (I)nternal (E)nergy.
If you maintain genuine celibacy (not even thoughts of lust), mostly dwell in noble silence (2nd jhāna or better), minimizing talking and other activities that drain PIE,
then your jhāna battery charges and fills with PIE, and the jhānic force gets stronger.
Adding a few more explanations to tie things all together.
Sexual impotence and jhānic impotence share a root cause.
Too much sexual activities that drain the PIE, causing a PIE deficit.
People can also drain PIE enormously with recreational drugs and intoxicants, alcohol, staying up all night and playing video games, partying, singing, etc.
jhānic impotence:
This is a state far worse than jhāna constipation. With Jhāna constipation, jhāna force is strong but energy blockages are not dissolved yet, and you feel tight knots and various kinds of discomfort and even sharp pain when you're doing jhāna meditation properly.
With jhāna impotence, the jhāna force is weak, PIE is weak, like when a battery has weak voltage and low current. Vital functions of the body don't work properly.
If one does jhāna meditation correctly while in jhāna impotent state with low jhāna force, PIE deficit, you're likely to experience various physical pains, psychosis, mental illness.
Even young kids who are overly sexually active can get into this state. It's probably a lot more common now a days with high speed internet, easy access to rich media porn, dating apps to hook up with other promiscuous kids.
When you hear about really disastrous cases of meditation causing extremely negative effects (like psychosis) in people meditating correctly, odds are high they are in a state of jhānic impotence, low energy state with a PIE deficit.
Of course modern medical "experts" would disagree, saying that regular sexual activity (including daily masturbation) is healthy and not a cause of psychosis.
Then they blame the meditation as the cause of the psychosis.
If you want to get out of sexual impotence or jhāna impotence, then go celibate. Eat healthy, get at least an hour or two a day of moderate to moderately vigorous physical exercise, and you will recover from this eventually.
If you listen to modern medical "experts", you'll take medications that may alleviate some symptoms of psychosis, you will never get truly better.
The real problems in most cases are a PIE deficit and a weak jhānic force that can't distribute the PIE everywhere in the body.
the physics of jhāna
The optimal posture to maximize jhānic force is sitting in full lotus.
But you get a fraction of full jhānic force in any posture with proper training.
As a rough estimate, if full lotus gets you 100% of jhānic force,
standing could get you 70%
lying down could get you 70-100%,
walking, taiji quan can get you 50%,
As long as the jhānic force is running at a level beyond a normal non-jhāna meditator doing ordinary physical activities, you'll get a net gain in PIE accumulating daily, and gradual increase in jhānic force leading to increasing higher states of jhāna, better health, better immune system, increasingly sharper mind, better memory, better mental faculties.
When you're in jhāna, you feel tangible forces coarsing through every cell of your physical body.
Jhānic force is trying to constantly course through all the interconnected loops of energy in the body, dissolving any blockages along the way gradually.
jhāna equilibrium
The jhānic force running everywhere is balancing the 4 elements of the body (solidity, heat, liquidity, wind force). When it's in proper balance, it's fourth jhāna, a state of jhāna equilibrium.
How are the first three jhānas not in equilibrium?
first jhāna
The first jhāna is more dominant in solidity, hardness, like ice (solid form of water).
You get surges of heat and jhānic force melting the hard ice into water, but the surges are both interrupted and triggered by vitakka and vicāra, thinking and evaluation with mental talk, verbal thoughts unspoken.
In other words, V&V used skillfully is what drives first jhāna, but the extraneous energy expenditure of first jhāna V&V prevents the strong force of second jhāna.
second jhāna
second jhāna, you've learned to keep the foot on the pedal to the metal, the jhānic force is unadulterdated, not surging on and off interrupted by V&V.
The feeling of liquidity is more dominant here of the four elements.
Wind force (jhānic force) and heat have melted most of the ice in your body into water, the runs up from the base of your spine up your back to the top of your head, and feels just like the jhāna simile says, like you're sitting in a lake with your butt on the spring that forcefully feeds jets of hot water from the bottom of the lake.
It feels like a jacuzzi where you're sitting on the jets.
If you got a full second jhāna going, and your microcosmic orbit opened up, from the top of the head the river of gushing spring water goes down your face, chest, feeding into the belly area.
third jhāna
Third jhāna marks a stage much closer to jhānic equilibrium for 4 elements in balanced harmony.
What's calmer here, compared to second jhāna?
Physically, second jhāna force and heat melted all the ice and liquified the body, strong currents of hydraulic force distributing the liquified state everywhere.
So now the physical mostly cuts off, the force that remains just gives you subtle vibrations of physical pleasure, as opposed to the strong hydraulic raging rivers from second jhāna.
The body is all water, the water is calm and still.
Mentally there is more pacification because Pīti, mental joy, is dropped. That is, any extraneous energy needed to cause mental joy is dropped. For example as an analogy, you hear a funny joke, second jhāna is like you're laughing out loud body shaking, third jhāna is you're just smiling, body is calm but you have warm fuzzy sensations.
As jhānic force is sublimating four elements into a higher energetic state of PIE,
this manifests as heat element evaporating water into empty space and visible light.
If you have enough PIE, you perceive visible light maybe like the size of a button around the middle of your head, white color, or blue color, or red, or grey.
That is what the white, blue, red lotus are alluding to in the pond with still clear water in third jhāna.
fourth jhāna
From second jhāna on, once you know how to get mental and physical tension out of the way, it's like you're flooring the pedal to the metal on your car accelerator, and someone with no jhāna or anti-jhāna has their foot stomping on the brakes instead of the accelerator.
Once you know how to do second jhāna, you automatically will gradually move to third and fourth jhāna if you stay with the program being celibate, noble silence, keeping wasteful usage of PIE to absolute minimum.
Fourth jhāna, as jhānic force continues to improve the equilibrium and harmony of the 4 elements, visible light and space (feeling of emptiness of hardness element) continue to increase.
This is why the fourth jhāna simile is a man covered completely with a white cloth.
It literally is like that.
Try it out.
Cover yourself with a large white cotton cloth.
Look through the cross patterns of the threads of the white cloth, it's like transparent white that you can see through.
The small button of light from third jhāna? If you keep doing the work of jhāna, letting the jhānic force increase and PIE accumulate day by day, the light gets bigger, stronger, brighter.
Your body gets lighter (weight, not visible light), even you step on the scale you still weigh the same as you did before (in force pounds, kilos), you somehow feel much lighter weight, and you feel levitation is possible someday.
As you get more and brighter light, your mind gets sharper and more clear, your memory gets better.
Your bullshit detector is mighty.
You can discern corrupted dhamma from proper dhamma.
You're not fooled by charismatic teachers who talk eloquently but don't teach or do the genuine Buddha's jhāna.
And you're definitely not impressed by smart people with impressive credentials and published works but no actual jhāna experience.
