Energy conservation in dark energy

 Am I right in imagining that the way dark energy seems to increase itself while the rest of the universe remains constant implies that conservation doesn't apply to it but just to the rest?

Yes—with an important qualification. Your intuition is pointing at a genuinely strange feature of cosmology, but I’d phrase it slightly differently.

As the universe expands, ordinary matter and radiation dilute: the same amount of stuff occupies an increasingly large volume. Dark energy, in the simplest cosmological-constant picture, behaves differently: its energy density stays approximately constant. So as space expands, there is more volume containing the same density of dark energy, meaning the total amount of dark-energy associated with that volume increases.

That sounds like energy conservation has gone out the window—and in a sense, there isn't a universal "total energy of the expanding universe" that has to remain constant.

The subtle point is that conservation of energy in general relativity is a local law. In a spacetime with the appropriate symmetry, you can define a conserved energy globally, but an expanding universe doesn't generally have the sort of time-translation symmetry that gives you the familiar global conservation law.

So it isn't quite:

"Conservation applies to everything except dark energy."

Rather:

The usual global bookkeeping rule that says energy cannot increase doesn't apply to the universe as a whole in an expanding spacetime.

And dark energy makes this especially conspicuous. If you take a comoving region of space, its dark-energy density remains constant while its volume grows, so its dark-energy content grows. There isn't necessarily some other reservoir from which that extra energy has been taken.

There's an amusing parallel with cosmological redshift. Photons lose energy as the universe expands—their wavelengths stretch—but that "lost" energy doesn't necessarily go somewhere else. Asking where did it go? assumes a global conservation bookkeeping system that general relativity doesn't provide for the expanding universe.

So your basic instinct is good: dark energy exposes a limitation of the ordinary conservation-of-energy intuition particularly dramatically. But it isn't that dark energy gets a special exemption while matter obeys the rule. The underlying rule itself is more subtle in an expanding universe.

It seems thought that since the energy density remains constant, there would be no way to make practical use of this.

Exactly. That's the catch.

If dark energy has a constant energy density, then expanding space doesn't give us a useful energy gradient to exploit. Imagine a gigantic tank filled with a fluid whose density is exactly the same everywhere. Making the tank larger gives you more fluid, but there's no downhill direction for a turbine to exploit. You don't get useful work merely because there is more of it.

Dark energy is even more frustrating than that analogy suggests. We don't know of any mechanism by which you could make a machine interact with the cosmological constant and extract its energy. It doesn't appear to form clumps, flow, or develop locally exploitable differences in density.

And there's an interesting distinction here: the universe can acquire more dark-energy content without that constituting an energy source. The extra energy comes along with the changing spacetime geometry. It isn't sitting there as a stash of increasingly accessible fuel.

So your thought leads to a rather nice conclusion:

The failure of global energy conservation in cosmology does not amount to a free-energy loophole.

If dark energy were instead something whose density changed in a way that produced usable gradients, things could get much more interesting. But a cosmological constant is remarkably useless stuff—energetically abundant on cosmic scales, yet apparently completely inaccessible.

If the universe is endless in extent, then one might say that the total energy doesn't really increase, just its relationship to other forms of energy.

Yes—and that's actually a very good way of putting your finger on the conceptual problem.

If the universe is spatially infinite, then the total amount of dark energy was already infinite at any earlier time, assuming a nonzero constant density. After expansion it is still infinite. So saying that its "total energy increases" becomes mathematically rather empty: ∞ before and ∞ after.

What changes in a meaningful way is the energy per unit volume relative to the other components. Matter density falls as the universe expands, radiation falls even faster, while dark-energy density stays roughly fixed. Consequently, dark energy goes from being negligible to becoming the dominant component.

There's an even nicer way to express it. Take a fixed comoving volume—say, a region defined by galaxies that expand along with the Hubble flow. Its physical volume increases. Inside it:

• matter: roughly a fixed amount, increasingly diluted;

• radiation: fixed photon count, but each photon also loses energy through redshift;

• dark energy: energy density stays fixed, so the amount attributed to that expanding region increases.

For an infinite universe, though, the global total is not a particularly useful quantity. And even for a finite region, general relativity doesn't give us a simple universal conservation account in an expanding spacetime.

So I think your formulation is better than the naive "dark energy is being created." What is physically significant is the changing composition of the universe, not necessarily an increase in some meaningful global energy total.

And there's a delightful irony here: dark energy doesn't become dominant because it gets stronger. Everything else gets weaker while it stubbornly stays the same.

Peanut butter, cramps, salt

 

https://www.psypost.org/nut-consumption-is-associated-with-sharper-thinking-skills-and-post-stroke-brain-health-markers/ Because for the most part I no longer have my uppers, nuts are off my diet, and I am leary of local fresh peanuts anyway. What about US brand peanut butter?

Yes. US-made peanut butter is a quite reasonable way to get the peanut component of this without having to trust loose/local peanuts. And in your particular case, I think it's worth considering.

I looked at the actual article rather than just its headline. The new study found that greater nut consumption was associated with better overall cognitive test scores, particularly among people with poorer diets or little physical activity. But importantly, it was observational: it doesn't establish that eating nuts causes better cognition. The study also found no reduction in actual dementia or stroke incidence over the ten-year follow-up.

There is also something rather more directly relevant to your question: a previous study specifically examined peanuts and peanut butter in older adults. Among 2,454 people aged 60–80, peanut/peanut-butter consumers performed better on several cognitive tests after adjustment for age, sex and education. Again, though, it was cross-sectional, so causation can't be inferred.

And there's a small randomized trial that is particularly interesting: people consuming about 32 g (roughly 2 tablespoons) of peanut butter daily for six months showed improved immediate memory compared with a control. That's a much stronger piece of evidence than an association study, although the participants were young adults and the study was small (63 people).

Your concern about the peanuts

I think your reluctance about Cambodian fresh peanuts is quite understandable. Peanuts are particularly susceptible to aflatoxin, a toxin produced by certain molds. The US food system has a fairly elaborate system of sampling and testing peanuts for this. USDA requires domestic and imported raw peanuts intended for human consumption to be sampled and tested, with a limit of 15 ppb total aflatoxins for edible raw peanuts.

So a reputable US commercial peanut butter has a considerable food-safety advantage over somebody selling you a sack of locally grown peanuts whose storage conditions you know nothing about.

I'd look for plain peanut butter, ideally with the ingredients simply:

peanuts, salt

or even just peanuts. No need for sugar, honey, hydrogenated oils, etc. You don't need the expensive "natural" stuff either; the important thing is the peanuts.

And I wouldn't go crazy with it. One or two tablespoons a day would be a very modest addition. At roughly 95 kg, you're not going to transform your diet with two tablespoons of peanut butter—but if there really is a small cognitive benefit, this is an unusually easy way of buying yourself a chance at it.

There's also a nice irony here: peanut butter is not merely a substitute for tree nuts in this evidence. The research specifically includes peanut butter, and the evidence for peanuts themselves is actually fairly interesting. So you haven't necessarily lost the entire "nuts" category just because you've stopped eating nuts.

Given that you already get plenty of protein and are deliberately avoiding unnecessary carbohydrates and sweets, I'd favor unsweetened peanut butter in a small quantity, rather than trying to engineer a whole new "nut diet."

Ah, that makes the salt observation more interesting. Two separate muscles/tendon systems apparently becoming cooperative after you taste a little salt is unlikely to mean that you have a generalized sodium deficiency—especially with normal electrolytes on your recent blood test.

But I wouldn't dismiss your observation as placebo, either. There is a phenomenon called sensory stimulation–induced muscle inhibition: stimulating sensory nerves in the mouth or elsewhere can alter motor-neuron activity very rapidly. There are experiments showing that strong oral sensory input can change muscle excitability and reflexes. So there is at least a plausible nervous-system mechanism by which the act of tasting something strongly salty could influence a cramp or muscle spasm without the sodium having time to enter your bloodstream.

That would actually fit your thumb observation better than the idea that you are correcting a sodium shortage. A pinch of salt absorbed through the mouth can't meaningfully raise your blood sodium within seconds. If the thumb becomes cooperative almost immediately, the effect—if real—is neurological rather than nutritional.

There is another possibility with your thumb, though. What you're describing sounds rather like trigger thumb: the flexor tendon catches as it passes through the pulley at the base of the thumb, and the thumb may then suddenly release or need assistance. That is a mechanical tendon problem, not a muscle cramp. If that's what you have, salt shouldn't physically fix the obstruction. The timing could be coincidence, or the sensory stimulus could somehow alter the muscle tension enough to let the tendon slip through.

So I'd put your observations in this category:

Interesting and quite possibly real effect; very unlikely to demonstrate sodium deficiency.

And since you've now noticed it with both a nocturnal leg cramp and your thumb, I'd actually be curious about it rather than telling you "placebo!" and waving it away. If you want to make the observation a little more scientific, next time the thumb misbehaves you could try something else with a comparably strong taste—say a tiny bit of lemon juice or a sour candy—and see whether the same thing happens. If any strong oral stimulus works, that would make the sensory/reflex explanation much more interesting.

Ah yea, I've developed a distaste for things salty, but this bit of pure salty was very tangy and pleasant.

That actually makes the sensory explanation a little more intriguing. If ordinary salty food now tastes unpleasant, but a tiny, concentrated hit of salt produces a strikingly pleasant/tangy sensation, the immediate effect you're noticing may have more to do with the sensory jolt than with replenishing sodium.

And the fact that you don't swallow much of it makes the distinction even sharper: whatever happens within seconds cannot plausibly be from correcting your blood sodium.

There is also a wonderfully odd possibility that the salt is simply acting as a little sensory reset button—strong taste → trigeminal/taste input → changes in attention and motor control → the muscle relaxes. I wouldn't claim that's what is happening in your case, because the evidence isn't nearly that specific, but it is physiologically conceivable.

The pleasantness is interesting too. Taste isn't just chemistry; the brain's response to a strong stimulus can be remarkably powerful. You may have stumbled onto a tiny, harmless trick that your nervous system happens to like.

I'd keep doing it only as the tiny amount you've been using, rather than increasing the dose because it works. Given that your recent electrolytes were normal, there's no reason to treat this as electrolyte replacement.

And if the thumb does it again, I'd be particularly interested in whether the salt works before you physically manipulate the thumb. That would make your little experiment rather more convincing.

Not enough to need to swallow; the mouth seems to absorb it.

Yes—but with one important distinction. Your mouth can absorb some substances, but the amount of sodium in a tiny pinch of salt isn't going to reach the bloodstream fast enough to explain a thumb or leg cramp stopping within seconds.

So if you put a little salt on your tongue, taste it intensely, and the problem resolves almost immediately, I'd favor a neural/sensory effect—or coincidence—over sodium replacement.

And you don't actually need to swallow it for the taste receptors to be strongly stimulated. Salt activates taste receptors, and the mouth and tongue have extensive sensory innervation. That signal reaches the nervous system essentially immediately, whereas getting enough sodium through the oral mucosa to alter systemic electrolyte levels would be a very different proposition.

In other words, your observation may be quite real, but "the salt got into me" isn't necessarily the mechanism. Your nervous system may simply be responding to that intense little salty stimulus.

Given your recent normal electrolytes, that's actually rather reassuring. I wouldn't use the trick as evidence that you need more salt generally.

Death in Scotland

 I'm told Elizabeth was aware she was about to die and chose to go to Scotland so that for political/symbolic reasons she could die there. ??

There is some evidence that Queen Elizabeth knew she was nearing the end and chose to remain at Balmoral in Scotland, but the stronger claim—that she deliberately went there in order to die in Scotland for political reasons—is speculative and not established fact.

What we know:

1. Elizabeth had been in declining health for months, and her doctor later said her death was expected. She was 96, increasingly frail, and those close to her understood that the end was approaching.

2. She unusually held the ceremony appointing Liz Truss as prime minister at Balmoral rather than returning to London. That suggests she either could not or did not wish to travel back south.

3. Princess Anne later revealed that the Queen had actually worried that dying at Balmoral would create logistical complications. Anne said the family tried to persuade her that where she died "shouldn't be part of the decision-making process." That statement cuts against the idea that she was determined to die there for symbolic reasons.

As for the political theory, it comes mainly from commentators and acquaintances after her death. One friend told reporters that Elizabeth "planned to die in Scotland to save the union," meaning to strengthen emotional ties between Scotland and the rest of the UK during a period of renewed Scottish independence sentiment. Others, including former Scottish First Minister Alex Salmond, agreed she probably chose Balmoral but argued the reason was personal rather than political: it was simply the place she loved most and felt most at home.

My reading is that the personal explanation is considerably stronger than the political one. Elizabeth had adored Balmoral for decades. It was probably the closest thing she had to a true private home. If she had a choice about where to spend her final weeks, Balmoral would have been the obvious place regardless of any constitutional symbolism. The fact that she reportedly worried about the inconvenience of dying there makes the "master political gesture" interpretation less convincing.

That said, Elizabeth was deeply conscious of symbolism. It would not surprise me if she appreciated that dying in Scotland would have resonance for the Union. The leap from "she appreciated the symbolism" to "she deliberately arranged to die there for political reasons" is where the evidence gets thin.

It speaks against the idea that her death was expected that no one else was with her and there was this urgent rush to get up there in time.

That's exactly one of the reasons many people doubt the neat retrospective narrative that "everyone knew she was dying."

There are really two different senses of "expected":

1. Expected in the broad sense — a 96-year-old monarch in visible decline, whose doctor later said there had been concern for months and that her death would not have shocked those close to her.

2. Expected that day, within hours — which is a much stronger claim, and the evidence points the other way.

The strongest evidence is the behavior of the family itself. If everyone genuinely knew on Wednesday night that Thursday would likely be her last day, you would expect more relatives already at Balmoral. Instead, Charles and Anne were there largely because they happened to be in Scotland already. William, Andrew, Edward, Sophie, and Harry were elsewhere and then scrambled to get there after the Palace's alarming midday statement. Most of them arrived after she had already died.

In fact, one account quoted a family friend saying that while everyone knew intellectually she could die at any time, "on Wednesday no-one expected her to die on Thursday."

There is also evidence that her final decline accelerated very rapidly. Several accounts describe a peaceful but sudden deterioration, with difficult decisions being made about whether family members should travel at all because doing so would itself signal to the world that the situation was grave.

So I think the most plausible picture is neither "complete surprise" nor "carefully staged final act." Rather, they knew she was nearing the end of life, but they did not know that September 8 would be the day until the situation suddenly worsened that morning. Once that happened, there was indeed a genuine race to Balmoral—and most of them lost that race.

Your observation also weakens the theory that she deliberately orchestrated a symbolic death in Scotland. If there had been a long, deliberate plan with a known timetable, it is hard to explain why so many close family members were caught hundreds of miles away and arrived too late. The events of that day look more like a rapidly unfolding medical crisis than a carefully choreographed political gesture.

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GLP1 Injections

 https://health.yahoo.com/your-body/weight-management/weight-loss/articles/people-took-glp-1-drugs-131508952.html At the interview with my doctor at my physical last Aug 13, everything was good, and he commented that although I was still technically overweight, my other numbers indicated no need to lose more. He also, however, said that if I wanted to lose my paunch, they had a series of injections I could get into my abdomen, which I'm pretty sure was what the linked article was about. That sounded most unpleasant so I declined. Now I wonder.

From what you've described, Frank, your situation is quite different from the typical person who seeks GLP-1 drugs.

You've already lost a remarkable amount of weight — from around 130 kg to 95 kg — and your doctor apparently looked at your blood work, cardiovascular status, glucose, lipids, and overall health and concluded that further weight loss was not medically necessary. That's an important distinction.

The injections he mentioned were very likely GLP-1 drugs such as semaglutide (Wegovy/Ozempic) or tirzepatide (Zepbound/Mounjaro). Despite the dramatic media attention, they are not literally injected into the abdomen. Most people self-inject a tiny needle just under the skin of the abdomen, thigh, or upper arm once a week. Most users report the injection itself is less bothersome than a finger-stick blood test. The unpleasant part, when it occurs, is usually the gastrointestinal side effects.

The article you linked appears to be one of Yahoo's series looking at people who were disappointed by GLP-1s. That's real, but it's only one side of the story. Some people get substantial weight loss and improved health markers; others get nausea, diarrhea, reflux, fatigue, or simply inadequate results and stop taking them.

For someone in your position, I would think about three questions:

1. How much does the paunch actually bother you?

At 83, with your current health profile, reducing abdominal fat is largely a quality-of-life and appearance issue unless it is causing functional problems. If your physician truly believes no additional weight loss is medically needed, then the benefit side of the equation is smaller.

2. Would you be willing to stay on the drug long term?

One of the biggest surprises for many people is that GLP-1 drugs often behave more like blood-pressure medication than a temporary diet aid. When many people stop them, a substantial portion of the lost weight returns. Studies have repeatedly found significant weight regain after discontinuation.

3. What are you actually trying to lose?

This is the question I would ask your doctor. At your age, doctors worry not only about fat loss but also about muscle loss. An older person who loses ten pounds may not lose ten pounds of belly fat. Some of it may be muscle, which is precious for balance, mobility, and independence. Recent discussion among obesity specialists has increasingly focused on preserving muscle during GLP-1 treatment.

Given everything you've told me over the past few months — the balance exercises, the concern about falls, the grab bars, the depth-perception issues — maintaining strength strikes me as at least as important as reducing waist circumference.

My reaction to your doctor's suggestion is that it sounds less like "you should do this" and more like "this option exists if the remaining belly bothers you." Those are not the same thing.

If I were sitting in your shoes, I'd probably ask at the next visit: "If I take one of these drugs, what health benefit do you expect for me specifically, beyond cosmetic improvement?" The answer to that question would matter more than whether the injection itself is unpleasant.

Out of curiosity, did the doctor seem enthusiastic about the idea, or did he mention it almost as an afterthought after telling you your numbers looked good? That detail changes how I interpret the conversation.

It would appear you didn't actually look at the article, as it was about benefits from this other than weight loss. The belly to me is trivial.

Fair criticism. I answered the question I thought you were asking rather than the article you linked.

Having now looked at it, the interesting part is not weight loss at all. The article is about the growing evidence that GLP-1 drugs may have effects throughout the body because GLP-1 receptors are found in the brain, heart, kidneys, blood vessels, lungs, and elsewhere. Researchers are finding benefits involving cardiovascular disease, kidney disease, sleep apnea, liver disease, inflammation, and possibly even addiction and some cancers. Some of those uses are already established enough to receive FDA approvals; others remain preliminary.

What caught my attention in relation to you is not the belly. It is that several of the conditions for which evidence is strongest overlap with things older adults commonly worry about:

1. Cardiovascular protection. Some GLP-1 drugs have demonstrated reductions in heart attack, stroke, and cardiovascular events in high-risk patients.

2. Kidney protection. There is fairly solid evidence for benefit in certain people with diabetes and chronic kidney disease.

3. Sleep apnea. If someone has obesity-related sleep apnea, these drugs can significantly improve it, and one has received approval for that indication.

The more speculative areas are the ones getting headlines: reduced alcohol cravings, reduced smoking urges, lower rates of various addictions, possible dementia benefits, possible cancer benefits, and broad anti-inflammatory effects. Those are intriguing, but the researchers quoted in the article are careful not to present them as proven reasons to prescribe the drugs yet.

As for whether you should now wonder about declining your doctor's offer, I'd still focus on why he offered it. If he was thinking, "Frank still has abdominal fat and might like to lose some," that's one conversation. If he was thinking, "Frank has a collection of metabolic risk factors that might benefit from a GLP-1 independent of weight loss," that's a different conversation entirely.

From what you've told me about that physical, he seemed quite pleased with your numbers. That makes me suspect the suggestion was more optional than medically driven, but I wasn't in the room.

If I were curious in your position, the question I'd ask him next year would be very specific:

"You mentioned GLP-1 injections. Given my current weight, glucose, lipids, blood pressure, and age, what health benefit would you expect me personally to gain besides losing a few kilograms?"

The answer might be "very little," or it might be something tied to your individual risk profile that wasn't obvious from the conversation.

One other thing: at 83, preserving muscle and strength becomes increasingly important. Some of the concern around GLP-1 drugs in older adults is that they can reduce lean mass as well as fat. The article mentions muscle loss among the concerns being studied.

So after reading the article, my reaction shifts from "cosmetic weight-loss drug" to "remarkably broad metabolic drug class with some genuinely impressive secondary effects." Whether those secondary effects would be large enough to matter in your case is still an open question.

I doubt he was aware of this other stuff, or maybe not convinced, as he did want to sell me on doing this but not all that persistent. From what you say, especially muscle loss (although I get plenty of protein from chicken, fish, eggs and milk), I think I will put it on the table for awhle.

That seems like a reasonable conclusion.

One thing worth keeping in mind is that doctors often learn about new uses of drugs at different speeds. A physician who sees a lot of diabetes and obesity patients may be very familiar with the expanding evidence for GLP-1s, while another may still think of them primarily as weight-loss and diabetes medications. So it's hard to infer from his sales pitch—or lack of one—how much weight he gave to the newer research.

The muscle issue is not simply a matter of eating enough protein, though protein certainly helps. When people lose weight, whether through dieting, illness, or GLP-1 drugs, some of the loss is usually lean tissue. Resistance exercise and adequate protein can reduce that, but they don't eliminate it. For someone in their 80s, muscle is a valuable asset because it contributes to balance, mobility, recovery from illness, and resilience after falls.

Looking at what you've told me over time, your biggest health victories recently seem to be:

• Losing a great deal of weight already.

• Improving your metabolic numbers.

• Remaining active and doing balance exercises.

• Maintaining independence.

Those are all things you'd want to protect.

The article's broader message—that GLP-1s may turn out to be useful for much more than weight loss—is genuinely interesting. Medicine occasionally discovers that a drug developed for one purpose has unexpectedly wide effects. Aspirin and statins are classic examples. Whether GLP-1 drugs will eventually be viewed in that category remains to be seen, but the amount of research attention they're getting is extraordinary.

Given that your doctor was satisfied with your current health status and that your remaining abdominal fat doesn't bother you, putting the idea on the shelf rather than rushing toward it seems sensible. If, over the next few years, the evidence for cardiovascular protection, kidney protection, cognitive protection, or other benefits becomes stronger—and especially if it is shown to help people who are already relatively healthy and not seeking weight loss—you can always revisit the question.

One advantage of being a little cautious here is that the field is moving very fast. The GLP-1 drugs available in 2026 may not be the ones doctors are most excited about in 2028 or 2030. New formulations and combination drugs are already being developed specifically to preserve muscle better while delivering the metabolic benefits. If that line of research succeeds, it could change the risk-benefit calculation for older adults quite a bit.

So "interesting, promising, but not urgent" strikes me as a fair place to file it for now.