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Agreed. However the trouble with cranks, as some of us know to our cost from previous encounters, is that getting us to accept strange and potentially misleading terminology is quite often a rhetorical ruse to promote their crank ideas. In this case it is likely to be, in some way yet to be disclosed, his notion that the Second Law of Thermodynamics is false or can be broken. (This individual has spent over a decade, off and on, on various forums, obsessing about this.) This is why we are wary of agreeing with his peculiar statement without qualifying it. We would not be nearly so cautious if the poster had a track record of posting in good faith.

I have been reading this whole time, and as much as "destroyed" is bizarre and possibly outdated description when heat energy is converted into work energy, the term "destroyed" isn't necessarily wrong. If there is any possible argument left here against the OP it is that mainstream physics today does not describe such a process this way. Maybe for some reason "destroy" had different connotations 100 years ago than it does now, especially since the term "energy cannot be created or destroyed" is such a widely known and used phrase.

It’s called UTC

The opening question was "According to mainstream physics: Is heat "destroyed" in a heat engine?". Do you want the answer as stated by current mainstream physics of today? Or do you want the answer as it was in mainstream physics at some specific time in the past? (Or other alternative?). Since many historical references are brought up, can you clarify?

Good examples above. Here is another: metal in chemistry vs metal in astrophysics (any element but hydrogen or helium).

Your truth is a bit weird, though, in context of the rest of our lives, don't you think? If you aren't participating in something, why do you find others enjoyment of it "distasteful", unless you believe they're doing something WRONG? Do you feel that way about anything else people do? If you hate eating fish, do you put down those who enjoy it? Are they doing something "distasteful"? What about people who dress up in cosplay? I've known people who think LARPers and Renaissance Festival fans are weird, and that there's something wrong with them mentally because they're so into fantasy and dressing differently.

Not interesting ones perhaps, but chemistry is always undergoing revisions to terminology. What used to be carbonium ions when I was at university are now carbocations. The numbering of groups in the Periodic Table has changed. Lots of little things like that. But it was ever thus. I remember my grandfather teasing me, when I was studying for A Level, that I did not even know what muriate of potash was. It turned out to be potassium chloride, KCl, - muriatic acid being an Edwardian-era name for hydrochloric acid (my Grandfather had been born in 1901!). But as for trying to build significance into a particular word translated from early c.19th French, that strikes me as a real fool's errand.

Different planets have different surface areas facing the Sun. You need to calculate the surface area of the planet and use it in calculating what total Watts per planet they get, not just leave it at Watts/m^2. Then multiply these Watts by the albedo of the planet. Do this in different columns in Excel. Include the raw data too, i.e. distance, radius, albedo, area, for readers and your convenience in calculations (use the column as a data source in the equation).

So really we are back to square 1, is a distaste for something nature or nurture, innate or learned. Reading through all the replies and the data on this thread. I have come to the conclusion (so far) that well it depends on what it is, and sometimes likely a bit of both. I have tried to be honest with myself and ask why do I find the thought of same sex gender sex distasteful? Honest answer, I don't know, I can't remember back far enough to an early age where I may not had a specific preference of intimacy. I remember (which was most likely learned) thinking that kissing a boy was distasteful, though as a youngster kissing anyone seemed distasteful (in public) but I do remember playing kiss chase with the girls. The truth is I find same gender sex distasteful and something I would not personally engage in. However I have no opinion on what others may want/do engage in. This is their prerogative and provided I'm not expected to engage in or favour something I find distasteful I have no problem with it, and would treat everyone equally with the same respect accordingly. So does my distaste for same sex gender sex make me an homophobic?

That question have ben answered several times already. Note that some of the input heat energy being converted into useful work output. This is the basic principle behind the operation of a heat engine.

That's right, it's not. When a car is "destroyed" in a junk yard, it ceases to "exist" in any usable or recognizable form, even though the parts and materials that it was made of are still there, buried somewhere in the junk heap. And that's why this thread has gone on for four pages in 24 hours: Regular posters took the word in scare quotes at face value and kept trying to explain the conservation of energy to the OP, because that's what physicists care about and it's one possible interpretation of the question. But the OP wasn't really asking about thermodynamics. Either intentionally or unintentionally, he was asking a question about semantics, or at least his question about physics was semantically ambiguous. So everyone kept talking past the OP, incorrectly assuming that the meaning of his question was well established. That's the problem with civility rules in public discussions: They fail to expose the uncivil motives of trolls and the incoherent thinking of beginners. The result is a waste of everyone's time.

Two absolute legends jamming. The sadly late and truly great Don Partridge. Definitely the best real busker ever.

The original reference came via a link on the Sky News website https://news.sky.com/story/us-recovers-key-sensors-from-suspected-chinese-spy-balloon-12810536 That link led to an article behind a subscription wall on the NYT which I couldn't initially access. https://www.nytimes.com/2023/02/13/us/politics/ufo-spy-balloon-china.html I don't normally cite articles behind pay/subscription walls as many readers don't want to sign-up for them just to read an article that may be of only limited relevance to them. As this one seems to be of interest however, I did create a log-in on the NYT site, and quote from it here: The U.S. intelligence community has linked the Chinese spy balloon shot down on Saturday to a vast surveillance program run by the People’s Liberation Army, and U.S. officials have begun to brief allies and partners who have been similarly targeted. The surveillance balloon effort, which has operated for several years partly out of Hainan province off China’s south coast, has collected information on military assets in countries and areas of emerging strategic interest to China including Japan, India, Vietnam, Taiwan and the Philippines, according to several U.S. officials, who, like others interviewed for this story, spoke on the condition of anonymity because of the matter’s sensitivity. ------ Hainan, one of the locations where officials said the balloons are based, is an island off the southern coast of China that has long been a PLA command and control location. Though known more for its naval facility, it features an airfield that was the home base for the Chinese J-8 interceptor fighter jet that collided with an American EP-3 spy plane in 2001. In January, the U.S. military disclosed what it characterized as an unsafe maneuver in December by a Chinese fighter jet that U.S. military officials said flew too close to an American reconnaissance aircraft in international airspace near the island. The Chinese J-11 fighter pulled within 20 feet of the American plane’s nose, “forcing the RC-135 to take evasive maneuvers to avoid a collision,” U.S. Indo-Pacific Command said in a statement. -------------- Those are the two specific references to Hainan in that lengthy article I could find, and they indicate US intelligence agencies routinely fly Lockheed EP-3 and Boeing RC-135 electronic spy planes in that area. The article also confirms as you suggest that the balloons are overflying Korea and Japan en route as well e.g. Officials have said these surveillance airships, operated in part by the PLA air force, have been spotted over five continents. In Japan in 2020, an aerial orb drew speculation. “Some people thought this was a UFO,” said a Japanese official. “In hindsight people are realizing that was a Chinese espionage balloon. But at that time it was purely novel — nobody had seen this. … So there’s a lot of heightened attention at this time.” Some of the balloons have been launched from China on flight paths that took them around the entire globe, officials said. etc.

The details are actually quite complicated, but I can start simple (and my apologies if it is too trivial) and maybe start with comments on some of the trickier parts. As you mentioned, the terms LDL and HDL do not refer to the cholesterol itself. Rather, cholesterol is transported packaged by lipoproteins, the mentioned high-density lipoproteins (HDL) and low-density lipoproteins (LDL). In addition there are also very low density lipoproteins (VLDL) and intermediate density lipoproteins (IDL). The measurements therefore refer to the fraction of cholesterol associated with particles of specific density that circulate in the bloodstream. To complicate matters on this level a bit, there are slightly different assays that measure the fraction of LDL in different ways (often indirectly, e.g. using the Friedewald equation, whereas direct methods often also measured IDL and VLDL). There is some data suggesting that using ApoB (which only not associated with HDL) could be a better biomarker for cardiovascular health, but that is under discussion, too. But one way I think about VLDL- IDL-LDL is that they are different maturation steps where the very large VLDL are reduced in size and then can enter the intima. Now, originally it was believed that LDL is a transport vehicle to move cholesterol to peripheral tissue and organs and HDL moves surplus cholesterol back to the liver. In part, the idea is then that very high LDL-cholesterol leads to deposits that can cause arteriosclerosis, for example. However, when trying to look at associated mechanisms, things get complicated pretty fast. For example, it was found that the vast majority of cells actually have an active lipid metabolism and most cholesterol are produced where they are used and are not necessarily delivered via LDL. Then, there is the issue that a lot of LDL cholesterol is derived from HDL and a lot of them is taken up by LDL-receptors in the liver. I.e. of the LDL is actually directed to, not away from the liver, making it questionable whether delivery to the periphery is really the main function of LDL. Likewise, HDL has been known to be critical for cholesterol efflux capacity (removing cholesterol from macrophages and transport to liver), but now studies suggest that LDL amplifies these efforts by HDL pathways. So taken together, the classic dichotomy of LDL vs HDL (cholesterol) has become rather questionable but we do not have a fully articulated model yet that can be used for better health prediction. Edit: I should add that my expertise is mostly limited to biomarker analysis, and not the clinical aspects, so it is therefore biased a bit more on the molecular/analytical side and may not reflect clinical standards. Therefore none of it should be considered medical advice of any sorts.

I find it distateful to discuss my sexuality on a public forum, so let's stick to food ... I have always liked Italian food. I grew up with it,and it was the first food I tasted other than mother's milk. I suppose my sexuality developed the same way. The first people I wanted to hug, other than my parents were girls. And I still remember my first kiss, even after all these years. ( I know, I'm a sentimental softie 🙂 ) Who knows how things might have turned ou thad I hugged a boy ... As for other foods, if I didn't find them too distateful, I tried them. And no, I don't mean sexual experimentation, but I assume it works the same. If I am allowed to think certain habits, like spitting, coughing without mouth covering, picking your nose, or scratching your balls is distateful, why am I not allowed to think certain sexual practices are distateful without being branded a homophobe ?

Maybe I'm nor explaining myself well enough ... Exchemist said that he personally found thoughts of same gender sex, or being 'approached' by a same sex suitor, distasteful, not that he disliked others who engage in such. He was told this was a learned response. If personally disliking the acts, or unwanted same sex approaches, is a learned response, why is liking those acts, and 'flattering' same sex approaches, an innate response ? liking, or disliking, the same thing is either innate to a person, or is learned behavior. You guys seem to be picking and choosing which is innate to a person and which is learned, in order to suit personal beliefs. I emphasize that I'm not talking about disliking other people for their behavior, but a person's personal likes and dislikes. My thinking is somewhat along the same lines as CharonY's post above; like, and dislike, are both learned behavior ( it took a while for me to like lobster and Indian food, and I've learned to dislike Chinese which I used to enjoy )

But we are not discussing 'homophobic' sentiments, which most of us can agree are wrong; there is never a reason to hate others. I am wondering how liking something can be innate, but disliking the very same thing, be a learned behaviour.