mistermack

First impressions are that you need sunlight for the photosynthetic reaction, and there's a limit to the amount of energy in each square metre. So no matter how efficient your plant becomes, it can't acquire any more solar energy without getting much much bigger. And of course, you would die if it turned cloudy. Or in the shade, or if you dived too deep.

Maintaining a plasma is an extremely difficult operation. It has to be kept in shape with phenomenally powerful magnets, and the hotter it gets, the more unstable it gets. It's very impressive that they kept it going for ten seconds. We have a Tokamak in Oxford called JET and there's one in the USA called TFTR. They are all research Tokamaks, they are nowhere near sustainability. The JET and TFTR found that as energies and densities of the plasma increased, stability got worse, and couldn't be improved with machines of their size. That's what led to the ITER project. Interestingly, JET have recorded temperatures of 200 million C, according to this : https://www.bbc.co.uk/news/science-environment-27138087 and they did set the record for Q . To break even on energy in/out you need Q of 1 and they managed 0.67. The break even point is a bit misleading. You need five to ten times energy in/out ratio to be economic, because the energy in is expensive electricity, and the energy out is low value heat. Some of the problems to be overcome to enable a continuous run are stability at higher energies, materials for shielding and heat collection that can withstand the constant bombardment from neutrons, and robots to remotely handle materials in a harsh environment. I'm amazed that with the joint effort being made, the budged is less than twenty billion, for something that's potentially world changing. Bill Gates could have funded ITER three times over. I think I read somewhere that the USA spends more on pet grooming, than it does on fusion research. It shows how seriously government actually take climate change. ITER is pin money to them. There are other approaches to fusion being followed, using high-powered lasers to heat pellets of fuel, but they don't seem to be as optimistic about those at present. I'd like to see the money going into ITER and it's successor DEMO doubled or trebled, to speed it along. There must be a profit in it at the end, looking at what the world spends on electricity, and how it's forecast to rise.

I did clarify it especially for you. I know it's confusing, that was 1948. Have you tried using a calculator?

That's a point, but String Junky didn't specify what the 1 degree referred to. As the overall average temperature of the ocean is only 4 degrees C, a rise of 1 degree seemed an unlikely scenario. If the whole ocean DID warm by a whole degree, I would have thought that Greenland and Antarctica would be in floods of meltwater by then. To warm the entire ocean a whole degree would probably take thousands of years of high atmospheric temperatures. (that's a guess on my part ) This page claims that the oceans started warming 135 years ago, 70 years before CO2 levels showed any significant rise. That was about the time the little ice age ended, so it makes sense. They claim a 1.1 C rise in surface temps since then, but it takes an awful lot longer for the entire ocean to warm. https://www.livescience.com/19414-oceans-warming-135-years.html

And yet wikipedia has sea level rise from 1897 to 1997 of 18cm. Bit of a discrepancy between 18cm and 80 cm. "At least since 1880, the average global sea level has been rising, with about an 18 cm (7.1 in) rise from 1897 to 1997.[1]" https://en.wikipedia.org/wiki/Sea_level_rise Hindsight might see it rather differently though. We are at present in a warm interglacial period, and these don't last. The consequences of going back into the full glacial condition of the current ice-age would make a bit of global warming look like heaven. The next glaciation is already overdue according to many projections, and it might be that it's only raised CO2 that is holding back the onset. We don't know, but it WILL happen at some point, without human intervention. Maybe in the future, there will be the ability to create a stable climate, who knows? It's never happened before. But global freezing has been far more prevalent than global warming in the recent past.

Everyone in Britain today will escape the extremes of global warming. Just by dying. Ken Fabian, you're graph shows CO2 in the atmosphere peaking at 2,000 parts per million in the year 2300. That's just the kind of crazy wild guess that makes me a sceptic. Anything goes in climate science. It's a world of activists, not scientists. There is no critical restraint. There's no way anybody can forecast CO2 levels that far ahead. There are so many unknowns around the corner, as well as all the knowns, like wind power and solar and nuclear. If the world was REALLY worried about CO2, they could cut emissions drastically tomorrow. The reason that they don't is that governments don't buy it, they just pay lip-service to it for election purposes. Speculating about the year 2300 is just crazy talk. The first fusion reactors will probably go on stream around the year 2050. Who knows what low carbon technology will be like in the year 2070? All of these fantastical projections are based on nothing changing or all trends getting worse. Who in the year 1840 could have forecast carbon levels in the year 2020? That's the sort of thing that's being bandied about. Ludicrous.

I'm not sure what is the point behind your mentioning it. The problem is historical, it's being dealt with, and it's a consequence of growth of a city, and paving over of land. Anyway, climate change isn't done either, is it? Half a degree in my lifetime can hardly be called change. Tiny fluctuation would be closer.

Citation DEFINITELY needed. It's being done as we type.

This is historical, and there's a huge project underway to improve the sewage system : https://en.wikipedia.org/wiki/Thames_Tideway_Scheme

Is that right? According to this they get refracted : http://www.x-ray-optics.de/index.php/en/physics/refraction Interestingly, according to that page, X rays are refracted in the opposite direction to visible light. So focusing lenses for X rays would spread optical light. I'm a bit mystified by that, as visible light refracts more as the wavelength gets shorter, so I expected X rays to follow that pattern. But logically it would mean that there must be a certain wavelength in the ultraviolet that gets zero refraction by glass.

Meanwhile, here in the UK, we've had a nice spring, lovely sunny summer, and the autumn is nice too. So it's not all bad news. No water shortages, no floods. Thanks, climate change.

I didn't say it wasn't. You don't seem to understand what you reply to. I'm sure fifth graders know what excess means. You should try asking one of them.

What we have done to soils has added huge quantities of carbon to the atmosphere and oceans. Overgrazing and firewood and fuel gathering has turned huge areas into desert and semi-desert, and there is now practically no carbon in the soils. It can be reversed by managing grazing, but a lot of the countries are so poor that it's not feasible without outside help. Excess means the CO2 that's NOT absorbed by plants etc. How do YOU not know this?

If you are counting every gram of CO2 we release as waste, then you need to count every gram we cause to be fixed in the minus column. Soil erosion due to overgrazing leaves bare rock exposed to the elements. The weathering of the rock takes out CO2. In the Himalayas, mountains are being denuded due to firewood cutting, with the same result. Farmers spread lime on their fields, in areas of acidic soil. That takes carbon out of the water and fixes it, in a similar way to weathering of rocks. There are lots of ways that we remove CO2, as well as adding to it. The use of timber in buildings takes it out of the bio cycle, at least for a while. More carbon fixed. Maybe more could be done to re-use timber at the end of it's life, or to use it for power generation. I'd like to see a ban on just burning it away on bonfires. On the minus side, the cutting down of forests to grow palm oil or for cattle ranching is adding hugely to the CO2 in the air, both by burning the spoil, and impoverishing the soil.

A friend of mine got legionnaires disease, it nearly killed him. It was a one-off, there was no local outbreak at the time. The authorities thoroughly checked out his house and found no source. Some time later, he was telling me about pressure washing cars, (he's a dealer) taking water from a pool of standing water. I said to him, "there's your legionnaire's source". Pressure washers can easily produce droplets that you can breathe in, and standing water is of course a breeding ground for Legionella bacteria. I think they were using two stroke high powered pressure washers. Pretty dangerous I think. I wouldn't dream of using anything other than mains water in one.

Even when the birth rates level off in the countries that are growing rapidly, ( or IF they level off, there's no guarantee ), there is a big population blip on the way because their life expectancy will rise. That's likely to be a one off but it's still substantial. On the difference in carbon use, some of the biggest emitters are big countries, where people fly a lot, and drive long distances, and goods come from far away. Countries like the UK are more compact and are able to use less because of that. And having a mild climate helps too, on heating and AC.

That's probably accurate, but it's misleading. Half the world's countries doesn't mean half the world's population. In reality, more than five billion (two thirds) of the world's population are increasing their numbers at a high rate. The other third are going the other way, it's true, but they are also receiving immigration from the 2/3 that is growing. (which tends to push their birth rates up again)

Teach them about condoms and other contraceptives, and how much children cost to raise. That might do some good.

I can't picture why air conditioning should be a factor in a virus infection. Legionnaires is bacterial, and breeds in cooling towers. It's not spread in car AC. It could be a rare complication from a flu-like virus, or even a midge carrying a virus or similar. Lucky it's rare, it sounds nasty.

I think all of our global warming problems would go away. We might have to turn up the boiler a bit though. But on the plus side, I could drive to France without paying for the tunnel.

You can hardly have a debate without some disagreement. Disagreement and intolerance aren't the same thing. I think you'll find I'm the most tolerant person you'll ever encounter. Apart from Donald Trump maybe.

So whatever suits your story is literal, and what doesn't is symbolic, or describing a vision????? Enjoy your cherries.

Well said. In 1917, it was widely thought that the Milky Way was all there is, the entire universe. The "Great Debate" didn't happen till 1920. Einstein was working in the dark, compared to today. Anyway, the title to the thread is COMPLETELY wrong, in saying that Einstein was COMPLETELY wrong. It was Einstein's own theory that was used to prove him wrong on the steady state Universe. That's even more impressive than him getting it right first time. It's because Einstein got General Relativity right, that we know he got something wrong.

I'm with Carrock as to the "final answer". You may well keep going back until you find a gap in science. It's well acknowledged by all that we don't have all of the answers, and it's probable that some things ARE going to turn out unknowable. But to imagine that "there must be a creator" is an answer is just wishful thinking. It's no answer at all. You've just moved the mystery along a bit, to an imaginary being. If a gigantic god appeared in the sky tomorrow, and said in an almighty voice " I did it all !! " you still wouldn't be any the wiser, unless you found out what caused HIM, and what caused THAT. etc etc. Religious "philosophers" claim that there must be an "uncaused" cause to start it all off. But that's a nonsense. If you can have an uncaused cause, then you can have an uncaused Universe. It's no answer at all. Just the good old God-of-the-gaps, shoved in to put something in place of a mystery. Doesn't matter if it's true or not. Just shove it in there. People have been doing it for thousands or even millions of years.

I think there ARE, but in still air they are perfectly balanced by the surrounding pressure, so there is no NET horizontal pressure. As for the downward force, if you picture it as a really simplified column of ten molecules, (each of weight M) stacked one on top of another like bricks, then each molecule has a different force at the top than the bottom. The top one has zero at the top, and M at the bottom. The second has M at the top, and 2M at the bottom. The third has 2M at the top, and 3M at the bottom. In each case, the resultant force on the molecule is M upwards, and it's balanced by it's own weight of M downwards. At the bottom, there's a force between the last molecule and the Earth of 10 M. And that's the reason for the Atmospheric pressure at sea level. Because of the constant movement of molecules, the pressure at the bottom operates in all directions, but all lateral pressure is balanced by the equal and opposite pressure of the surrounding air.