mistermack

What deal would that be?

There's a load of old bull spoken and written about what we voted for in the referendum. Remainers bang on that we didn't vote for "no deal". I actually was right on the fence on the day of the referendum. I simply couldn't pick a side, it was too close, so I abstained. But I know fully well what we were voting for. The ballot paper said, to paraphrase " do you want to leave the EU, or remain in it? " And that was it. There was nothing about deals. Basically, everybody who voted knew full well what that meant. If we vote leave, we leave, and it's understood by all that the terms of leaving are the best that can be negotiated at the time, by the government of the time. If no deal is the best we can get, that's what we voted for. If some deal acceptable to parliament is negotiated, THAT'S what we voted for. We simply voted to leave, and the conditions are whatever deal can be done. Right now, there is NO DEAL on offer that parliament will accept, so no deal it is. The referendum vote covered that scenario. The duty of any current government is to leave, and it should never have taken this long. That's the real disgrace of it. Deals don't take years, unless one or both parties don't want a deal. In this case, the EU don't want our deal, and Parliament doesn't want the EU's deal. So no deal it is.

That should be obvious, from a basic reading of the composition of the atmosphere. The air contains 20.95% oxygen, and 0.04% carbon dioxide. If you were to DOUBLE the current carbon dioxide, you would only need the tiniest fraction of the available oxygen to achieve it. It doesn't need a prof. of Atmospheric Science to work that one out. In addition, the raising of CO2 levels would aid photosynthesis in the ocean, pumping more oxygen back into the atmosphere.

The way I'm picturing it at the moment, is that massive bodies have an effect on inertial reference frames in their vicinity. At any point in space, an inertial reference frame is one in which an object that is experiencing no force is at rest, or moving at a constant velocity. At the surface of the Earth, an object that experiences no force, accelerates downwards at 32 ft/sec/sec, or 9.8 m/s2. So inertial reference frames have to be accelerating downwards at that rate. The Equivalence principle of General Relativity sheds light on it for me : https://en.wikipedia.org/wiki/Equivalence_principle First paragraph : In the theory of general relativity, the equivalence principle is the equivalence of gravitational and inertial mass, and Albert Einstein's observation that the gravitational "force" as experienced locally while standing on a massive body (such as the Earth) is the same as the pseudo-force experienced by an observer in a non-inertial (accelerated) frame of reference. So the force on you, as you stand on the Earth's surface, is the pseudo-force caused by being in an accelerating inertial frame of reference, that's accelerating downwards at 9.8 m/s2.

I'm not sure that's right, or a gas would just collapse down in a puddle. You have pressure, which is the combined effect of collisions of the gas molecules. I think, if you picture yourself as a molecule, getting hit from side to side, and above and below, you will be scoring more hits from below than above, because it's denser below. So the extra hits from below force you upwards. Would that be a fair picture?

You often hear of people moaning about subsidies being given to this or that technology, but in the case of nuclear or fossil fuel, they are becoming essential. If you install large quantities of wind and solar, it makes sense to use them to the max, as they don't consume fuel, and they chalk up political brownie points by increasing the renewable statistics. But since backup is essential, it's obvious that the backup will supply less power as the wind and sun supply more. The backups still have to be paid for, whether they are used or not. Nobody's going to build or run that plant, or finance it, without covering their costs and making a profit. So how do you pay for it ? If their generation figures are shrinking, then you have to raise the price that they get per unit. Or pay them in big chunks of grants. Either way, they can then be portrayed as being subsidised, when in fact, they are being paid to support the wind and solar. So as I've said numerous times, this subsidy is paid to support the shortcomings of wind and solar, not to support expensive nuclear or fossil plants.

Since you give no link, I looked myself. I'm assuming that you mean this : https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/812626/Press_Notice_June_19.pdf And the relevant paragraph says : • Renewables’ share of electricity generation (wind, solar, hydro and other renewables) increased to 35.8 per cent in 2019 Q1, compared to 30.5 per cent in 2018 Q1, mostly due to increased capacity and higher wind speeds in March 2019. Wind and solar combined accounted for a record high of 23.6 per cent of electricity generation in 2019 Q1. So the figure for wind and solar is below the 25%

Viable doesn't really mean much. In the real world, the word they are looking for is economic. Or competitive. If you invent something that's one of those, you could make yourself a billionaire. I would like to see it. I do like the idea of wind power and solar taking over. It's just frustrating that it's so limited. I'm just pointing to the real-world problems, I'm not happy that it's that way. By the way, wikipedia has the UK percentage renewable at 28 percent. All of the countries with a high percentage seem to have very high proportions of Hydro. https://en.wikipedia.org/wiki/List_of_countries_by_electricity_production_from_renewable_sources The figures that they give for overall energy use show how far we have to go in the UK : In 2017 renewable production generated:[4] 27.9% of total electricity 7.7% of total heat energy 4.6% of total transport energy

Well, I make that three quarters of our electricity that we don't get from renewables. And that means that in the UK, we have cover for windless nights, with fossil fuel and nuclear generation three time that of renewable. The UK illustrates the point I'm making. And importing power doesn't really address the question, you just export the problems abroad. France is 70% nuclear for electricity, so if we import some of their surplus, the chances are it's nuclear. If the UK governments keep their promises about electric vehicles, it's going to be hard to supply the juice, with people wanting to charge them up overnight, or on days and nights with little or no wind. It would be a bit weird to have most cars electric, but powering them with electricity generated by fossil fuel. I'm in favour of the current policy, from what I'm reading. Diversification is wise, a buffer against unforeseen problems. But nuclear is a great base-load provider, and it's only politics that is holding it back. Part of the politics is the extra costs that politicians are imposing to upgrade the systems so that a Fukushima type incident is covered. As if France and the UK stood the same risk as Japan of a major earthquake or sunami.

Once you leave the Earth's magnetic shield, you would need to provide some all-round shielding for a spinning craft, against the worst solar storms. If it's not spinning, then you could presumably concentrate the protection on one side and turn that towards the Sun till the worst is over. According to wiki : "A solar flare on January 20, 2005 released the highest concentration of protons ever directly measured,[14] giving astronauts as little as 15 minutes to reach shelter." and " Anyone who had been on the Moon's surface during a particularly violent solar eruption in 2005 would have received a lethal dose." [24]

I'm sorry. 😭 I hadn't noticed.

I haven't said a word against Hydro as a renewable. It's in a totally different class and my comments don't apply to it because it's generally reliable, 24 hrs a day, 365 days a year. Under very rare circumstances, it becomes unreliable, I believe New Zealand recently had a problem with a totally unexpected period of drought, ( I'm not going to check that, so it may be wrong ), but in general, Hydro is a special renewable, and I'm only addressing wind and solar. The countries that that you refer to, that generate a high proportion of their electricity with renewables are nearly all the lucky ones blessed with a lot of Hydro. They are a special case, but there is no prospect of increasing Hydro, it's generally maxed out wherever it's viable. Countries that do have a lot of Hydro generation can afford to go a bit on wind and/or solar, because they have that backup that other less lucky countries have to provide using nuclear or fossil fuel. If you have no hydro, then you still have to provide full cover for windless nights. That problem simply doesn't go away.

I think what we do is change the new environments to what suits us best. Even at the south pole, we've created a mini environment that's more like the tropics. The same could be said for the space station, except for the 1g of gravity that's missing. Presumably if we ever live on the Moon or Mars, it will be in little bubbles of Earth-type tropical environment. Edit : In a way, the invention of clothing is where it all started. Your clothes create a mini-environment around your skin, that is more acceptable than fresh air.

Thanks. That's a pretty stunning picture, even if it is the logical consequence of not interacting. Presumably the same can't happen with a black hole, or can it? Once inside the event horizon there is no path out so I'm guessing it would be trapped inside.

If countries were actually serious about eliminating carbon emissions, then nuclear is the only serious way to go. Wind and solar are trendy but pretty pointless, until they can provide 24 hour power. If you chose nuclear to provide the cover for wind and solar shortcomings, then you would be carbon free. But the point is that you wouldn't actually need the wind and solar at all. You could just keep the nuclear installations running 24 hours, which is actually how they operate best anyway. Modern nuclear is much cleaner and safer than old designs, but it's held back by the failure of a few old units. Fukushima was old and very outdated, Chernobyl was an old Soviet design run by Ukrainians, and yet they have been used to drastically hold back the entire industry. It's like grounding all commercial jets, because of a couple of crashes. But like jet planes, nuclear is incredibly safe compared to most of the competition. Anyway, there is the option of Thorium nuclear, which is fundamentally safer than current technologies, and also less useful for building weapons.

I find the concept of dark matter quite fascinating. It prompts so many questions. If it only reacts with visible matter through gravity, that kicks up some questions for me. One question is how much dark matter is sitting inside the Sun, unaffected by all the heat and turmoil, just held in place by gravity. If you look up the composition of the Sun, it's given as Hydrogen 75% , Helium 24% and Oxygen 1% approximately. So, after four and a half billion years, it's accumulated zero mass of dark matter. Common sense says that there must be some lurking in there, but maybe it's such a tiny amount that it doesn't show up in measurements.

I'm not up on that concept at all. I'm speculating about how the genetic makeup of the population might change in the future. I don't think it's going to change much at all, until we start tinkering with the genes, and then all bets are off.

I think you're being incredibly selective, ignoring millions of good things that humans have achieved, in favour of the few well known problems. Just off the cuff, I can point out the increase in life expectation, the improvement in infant mortality figures, the progress in cancer treatment, the cars that don't break down or rust like they used to, Oil of Olay, and the sex change operation. It's a wonderful world and you know it, unless you suffer from a pessimism disorder.

Good point. Maybe equipment is specially packed to survive launching, but even so it would need to be more robust than I was imagining.

Nothing on the ISS is designed to operate at 1g, so they would have to start again, to design a station that could spin safely. There's nothing impossible about spinning space stations, I'm sure that they are the way to go in the future, but they are going to cost a lot more if you have to lift all of the materials off the Earth. One limiting factor, as already mentioned, is the feeling of sickness caused by the Coriolis effect. The minimum diameter for a spinning station producing 1g that doesn't cause sickness in the average person is about 200 metres, so there never was the slightest temptation to spin the ISS. You can compromise, by going for less than 1g, and so spinning a smaller station. But obviously you lose something by compromising. It's possible to spin two modules, connected by a 200m tether, rather than a cylindrical station but you might get stability problems with that. With a cylindrical station, you could have the docking point in the centre, so that you would just have to give your approaching craft a very slow spin to make docking no problem. And, you could have the solar array connected to the centre via a cable, so you would just need a mechanism with a bearing to transfer the power to the spinning station. In the distant future, it's likely that people will be mining the Moon for raw materials, at a much lower cost than lifting off from the Earth, and then you could make space stations much bigger and more substantial, so a 200m diameter space station wouldn't be prohibitively expensive.

So an accretion disk acts like a spider's web, capturing matter that would otherwise float by? I can picture that, but I'm not sure it would increase the intake of the black hole substantially. Once stuff gets orbiting, it can stay there for billions of years, unless the density of objects is high. If you regard the Milky Way as an accretion disk, around the Supermassive black hole at the centre, it's taken fourteen billion years and we're still not sucked in. If ordinary matter is moving at a reasonable velocity relative to a massive body like the Earth or Sun or a black hole, it can easily whizz by like a comet round the Sun. But if dark matter is moving slowly, it wouldn't have that escape mechanism. Which prompts an interesting question. Does the dark matter of the Milky Way rotate around the centre with the normal matter? Or is that an unknown as well?

If there is six or seven times as much dark matter as observable matter in the Universe, it must surely have an effect on black holes. If they are sucking in six tons of dark matter, for every ton of the usual stuff, it's going to affect the calculation for whether a black hole is liable to be shrinking or growing. According to wikipedia : " A black hole of one solar mass (M☉) has a temperature of only 60 nanokelvins (60 billionths of a kelvin); in fact, such a black hole would absorb far more cosmic microwave background radiation than it emits. A black hole of 4.5×1022 kg (about the mass of the Moon, or about 133 μm across) would be in equilibrium at 2.7 K, absorbing as much radiation as it emits. Yet smaller primordial black holes would emit more than they absorb and thereby lose mass." I wonder if the calculation of that allows for the constant flow of dark matter into the black hole? Maybe you could detect the dark matter by how black holes behave.

I was just musing on from this paragraph in the article that you linked : " It must have been born cold (i.e., it was moving slowly compared to the speed of light even at early times), and it must not collide or interact (above a certain constrained threshold) with itself or any of the Standard Model particles. " If it started out moving slowly, and hasn't interacted since, it seemed like it's highly probable that it's still moving slowly. I'm sure that all of this has been thoroughly gone into, I'm just mulling over what I've read.

Ah, that's what I was getting at. If dark matter is so unlikely to interact with other matter, maybe there is no mechanism available that can speed it up to a speed that it can be detected at.