mistermack

It's the sheer lack of education in an obviously intelligent man that makes me wince. Another americanism from the hippy era is "vibrations" , often used in a similar context. Mind you, it's not just America. The English were talking about an "air" of confidence years ago. Although, on second thought's, that's probably down to the French. "De bon air" Debonair.

It really makes me wince when people misuse energy, I'm pretty sure it originated in the US. Probably in the hippy era. Here's what I mean : https://www.youtube.com/watch?v=O_PDcsh3gzk

The most abominable use of English by Americans is their use of the word "energy".

English gets abused everywhere. Like the use of "cool" in america, now spread everywhere. In the west of Ireland, my uncles and aunts never used the word "hot". When talking about the weather, it went from warm, to very warm, then awful warm, (warrum) , and then "shockin warrum". But never hot.

Words and spellings evolve, they don't get handed down. But I agree it would make more sense. Take the word "ass". It can mean a donkey, a pair of buttocks with an anus, an attractive young woman, and a very silly person. But slightly different spellings and variations are evolving on their own, such as asshole, arsehole, arse and piece-of-ass. Once that's sorted out, we can start on "pass".

Heat loss grows faster and faster with temp increase, not linearly. ( can't be bothered to check the details ) So the insulation that works ok for 100 degrees would be no good at all for 500 deg. So you would have to spend a lot more money insulating this battery. 100 tons of sand isn't all that big, really. It would fit in a 4m cube room. But presumably, with the insulation, and pipework for heat extraction, it would be somewhat bigger. I seem to remember I started a thread some time ago, proposing some form of heat/cold storage for new houses, either under the drive, or inbuilt as a cellar. I was proposing using water, but lots of storage mediums could be used. I just looked but didn't see it but found this :

Have you got a link for that, or did you dream it? I've just done some looking up, lacking a link, and the biggest megaliths seem to have been the obelisks, and they did run to hundreds of tons. The Romans moved several of them to Rome on specially made ships. There is no mention of mercury so the good old sleds and winches and levers seem to have done the job. It must have been a phenomenal undertaking to see. such a shame all that work was done for no useful purpose. https://en.wikipedia.org/wiki/Obelisk

Since the majority of stones used in the pyramids were rough cut, uneven in shape, it doesn't seem likely that this method WAS used, otherwise they would have been more carefully trimmed to a standard size fit a trench. Also, having a quick read, the vast majority of the stones were about 2.25 tons in weight. This suggests that they found this size fairly easy to transport, otherwise they would have used smaller ones. Lifting them up each level wouldn't have been too hard, using ramps and levers. Basically, you would just need a lot of manpower. The moving of blocks up to 60 tons would have been a different story, but again, ramps and levers can work wonders, if you have hundreds or even thousands of experienced hands available.

Hazarding a guess, I would say that the 13 hours is more likely to be how long this tank can keep the district heating supplied if nothing else was generating heat. If Berlin already has a well developed district heating network, then it must have a well developed source of heat to supply it, so this storage tank is probably going to be taking heat from the current sources as well. It's likely to be doing the job of a capacitor, evening out the supply levels, rather than acting as a new source of renewable heat as portrayed.

The current gas prices are making all sorts of projects viable, that were previously not. Hot water storage is fine, but you need a distribution network to get it to customers. I'm surprised that Berlin has enough network capacity to make this economic. Unless that is also just at the drawing board stage. The wording of the statement is a bit fuzzy. Fifty million Euros doesn't sound like a major investment. And 10% of Berlin's hot water needs in the winter sounds impressive, but what exactly ARE Berlin's hot water needs? They don't say. The other problem is what happens if gas prices drop back down? Will it cut the legs from under this scheme? It's sure to make a huge difference to the economics if they do drop back. The other thing I find odd is the "up to 13 hours" figure. That strikes me as very poor, for a vast insulated tank. Insulation works better, for bigger tanks, because the surface area increases much slower than the volume for tank size increases. With modern insulating materials, I'm amazed that the figure isn't days, or weeks, rather than hours.

On the practicalities of using this method, it's probably not as work intensive as I first thought. If you are excavating a new gap in front each time, and filling in behind, then you can end up with a trench ready made for the next rock. All you need to do is to use one or two ready cut rocks to fill in at the rear, and keep re-using the same ones as you go along, so you are leaving behind a cut trench to use again. And if you had a good supply of mercury, then you could move forward in reasonable sized steps, rather than inching forwards. Once your trench was cut, you could keep re-using blocking stones at the front, same as at the rear. Not that I'm any closer to thinking that this is what they did. Going uphill would have to be very gradual, you would have to treat it like a system of canal locks. And you would probably have found evidence of mercury production by now, although it would be hard to tell whether it was cinnebar that they were producing, or mercury metal. I believe that mercury evaporates at room temperature so it would be unlikely to find any left over from 5,000 years ago. https://www.livescience.com/earliest-evidence-mercury-poisoning

The physics is remarkably simple. It's only clouded by the meaning of the word "displace". The rock will float purely and simply when the pressure on it's lower surface reaches a certain level P. The pressure in the liquid is purely down to the depth D. If the rock is placed in an open pond, it will float when the bottom is at depth D. Explain how and why the pressure on the bottom is not exactly the same, at depth D, in a close fitting container as described.

No, that's where the mistake is being made. The rock IS displacing a ton of mercury, because if you were to remove the rock, you would need a ton of mercury to fill the void that it left behind. Imagine the mercury was in grain form, like sand. You remove the rock, you need a ton of mercury to fill the hole that it left. Thats how, in the close fitting container, Archimedes principle still applies. Your rock IS displacing it's own weight of mercury.

I'll try a different approach. Imagine the trench is 20 feet long and 2 feet deep. You fill it with mercury to a depth of 1 foot. Your rock slab is just a little narrower than the trench, and it's four foot thick and four feet long. You place it in the trench, and it will float, because it will only sink to a fifth of it's height, as the mercury is five times as dense. So it sinks less than a foot, and doesn't touch the bottom. So there you have your block, floating in the trench. Now, if you block off the trench in front of it, and behind it, do you claim that that will make it sink? Of course it doesn't, it will continue to float. So there you have the block floating in very small amount of mercury, just as in the OP.

You have to get the mercury to the trench. Presumably in ancient times that would be done by carrying it in vessels. (if this method ever was used, which is unlikely). But since the objective is just to raise the stone just enough to clear the floor of the trench, you wouldn't need any pumping power, you would just keep pouring till the mercury was about one fifth of the way up the side of the stone, since it's five times as dense as rock. The only mercury you would need is enough to fill the edge gaps, which could be pretty minimal, and the theorised gap at the front. Then, as I posted earlier, you would pull the rock forward, so that the gap at the front closes, and an equal gap at the rear opens. You would then have to excavate a new gap at the front, and fill in the gap at the rear. It's not really a practical proposition, you would be losing mercury into the air gaps in the soil because of the high pressure at the bottom of the trench. It's just a thing that theoretically would work, but in practice would surely not be viable. The pressure is supplied by the head of mercury, which only has to be one fifth of the way up the side of the rock, because it's five times as dense. It just boils down the the pressure exerted on the bottom surface of the rock, and that is purely down to the depth of mercury. It doesn't matter if it's open or closed, the pressure on the bottom is just a result in the depth of mercury.

No that's wrong. To lift the rock, you just need sufficient pressure on the bottom surface of the rock. In a tight fitting container, you can get that with a smaller amount of mercury. That should be obvious. It appears to contradict Archimedes principle, but it doesn't, because in the tight fitting container, the sunken part of the rock IS displacing the same weight of mercury as it would in an open system. Because it's occupying the same volume as it would in an open system with the same surface level.

I think what the OP is getting at is that it would be theoretically possible to RAISE a rock, in a tight fitting container, with less than it's own weight of mercury, using the head of mercury to exert the required hydraulic pressure on the base of the rock. But the problem is that if it's in a tight fitting container, you can't move it, so lifting it doesn't get you anywhere. So the idea is to have a small gap in front of the rock, and pull the rock into that gap, so the mercury flows to the rear, and then excavate a new gap in front of the rock, and fill in the gap at the rear, hence inching forward bit by bit, constantly excavating in front, and filling in behind. It's a far cry from floating a rock along in a canal of mercury, and of course, you need a flat route. I can't see it being possible in the real world, but I guess you could say it's theoretically possible.

That's ludicrous. Do you get all of your science from Quora ? 😅 To get the rock to float you have to displace it's own weight. If you engineered a PERFECT seal around the rock you might be able to raise it with hydraulic pressure, but then you might as well use water. And you couldn't move it.

I don't get the maths of the OP. 100 litres of mercury weighs about 1 1/3 tons, I just looked it up. So how do you shift ANY megalith with just 1 1/3 tons of mercury, bearing in mind that to float, the rock has to displace it's own weight? If I wanted to shift a stone weighing a ton, I would just rope it up to a few horses and drag it.

Rubbish. If anyone knew anything about depression, it was Spike Milligan. And if you read it a bit more carefully, you'll see that he's advising the WORLD to smile, not offering trying to smile as a cure to those who are depressed. Quote wikipedia : " He had bipolar disorder for most of his life, having several serious mental breakdowns, several lasting over a year.[57][58] He spoke candidly about his condition and its effect on his life: " If Spike said it, it's probably good advice.

I can't imagine how difficult the abortion debate is for Kangaroos. Their fetus comes out, crawles up the mother's fur to the pouch, and carrys on with it's virtual "gestation" inside till it's big enough to leave of it's own accord. The definition of fetus must be really difficult in the marsupial world. As far as I'm concerned, a human fetus is alive as soon as the egg is fertilised. It's alive, but I have no problem with it being killed and removed at that stage, nor when it's developing after several weeks. But somewhere between fertilisation and 40 weeks is a time, after which I would ban aborting a healthy fetus. I don't buy the "it's my body" argument. Or the "it's got a soul" argument. It is what it is, a human fetus, on the way to full term. I don't think people shoud be free to abuse their own bodies anyway. If someone tries to cut their own body parts off, I think we should step in. If they try to jump off a bridge, we stop them if we can. The "freedom" argument has it's limits. I don't believe in inherent rights, it's really just people voicing their instincts, and their life-honed pre-dispostioned. What I would like to see is far more effort being put into preventing unwanted pregnancies, through better education and free provision of contraception methods to all. To be anti-abortion and anti sex education and contraception is just stupid beyond belief.

Even though you dodged the question of aborting 40 week healthy pregnancies, you seem to be advocating it again, if the mother wants it. Any chance of a non-dodge response?

You seem to be arguing for unrestricted abortions right up to AND INCLUDING forty week healthy pregancies that can be born bonnie and bouncing babies. All the mother needs to do is declare it unwelcome, to have the right to have it killed and removed. It's not a great look. Really no difference at all to just killing the baby on delivering it. Probably the safest procedure for the mother at that stage.

There's no conflict. There is just a huge difference. One is an idea, as you said. The other is both an idea and a process that has been verified to be true, hundreds of thousands of times. The idea of creation is on the same level as the idea of the imaginary celestial teapot. A product of the imagination, highly unlikely, and with no evidence to date, and impossible to refute.

Neither can I. That's me dead then. Unless they clone me. Not really. The music's bad enough now. I can't imagine what shite they will be playing in 2242.