>I didn't say anthing about nuclear waste. Renewable energy needs non-renewable minerals just like nuclear.

​But the article I brought up did. The claim being made isn't that nuclear needs non-renewable "minerals" while renewables don't. The issue is that "minerals" used in renewables are actually recoverable because they aren't irradiated.

>If you would reduce consentration by 0.01 % (30 years/ 300000 years) you would need to process 7,60076 x 10^6 m3/s of seawater after 30 years. Not 7x10^15 as the study claims.

Please actually read and at least try to comprehend the paper:

>This tells us that, for example, in as little as T ¼ 30 years, a volume of seawater of 7x10^15 m3 would need to be processed - this is clearly impractical as it is over six times larger than the volume of total river outflow in the same time.

This is the total volume of water that needs to be processed at that point, not volume per second. As stated, this would be six times the volume river global river input would be able to provide in the same timeframe, meaning this would be inherently unsustainable.

"Seawater" contains ~3 ppb Uranium, i.e. 3/1000000000, i.e. 0.0000003% of which 0.7% are actually fissile. Your initial concentration isn't 100%, it's 0.0000000021 %.

If we assume that 1 l of seawater has an approx mass of 1 kg (seawater is actually denser but let's ignore that) and assuming that the process was 100% efficient in recovering all the fissile Uranium (it wouldn't be, but let's also ignore that), filtering 7.6*10^6 m³/s of seawater would yield

7.6*10^9 kg/s * 0.0000000021% = 0.1596 kg

The energy contained in 1 kg of U235 (if the conversion was 100% efficient which is isn't but let's ignore that) is 83.15 TJ - ergo the energy you could extract from 0.1596 kg is 13.27074 TJ or ~1.33*10^13 J. Let's just ignore that the thermal efficiency of nuclear plants is ~33% to begin with.

Extraction probably requires pumping all that seawater through a filtration plant, chemical treatment, whatever. Let's assume that all we have is water and U235 - no additional impurities, no uranium compounds that need to be purified and extracted etc. Let's assume we could simply separate water and uranium via reverse osmosis and ignore all the additional steps and energy that would actually be required to use it in a nuclear reactor.

Filtration via reverse osmosis of 1 m³ of water requires 3 - 5.5 kWh. Let's be optimistic and go with 3 kWh/m³ - that's 10800000 J/m³.

Ergo we would need 8.21*10^13 J to filter all of that U235 from the 7600000 m³ we need to process.

Or in other words, extracting uranium from sea water has a negative energy yield, even if we assume that we could somehow seperate it via simple reverse osmosis and the energy conversion was 100% efficient. Which it is not.

>I didn't say anything about the feasibility of using nuclear to replace all fossil fuels, so please do not argue against this strawman.

Even providing global base load would not be feasible let alone economically viable or possible on any meaningful timescale. Given that nuclear isn't a solution for anything, not actually needed and provides no meaningful benefit, what exactely is the point of wasting money and resources on this?

There is a reason why nuclear has been stagnating for the last decades and will play an ever diminishing role in the coming decades:

https://www.iea.org/data-and-statistics/charts/installed-power-generation-capacity-by-source-in-the-stated-policies-scenario-2000-2040

Nuclear is a dead-end for terrestial utility scale power generation. Renewables are the only feasible way to decarbonize our energy sector.

>A benign nuclear solution would be a part.

There is no "benign nuclear solution". Nuclear is hands down the most expensive and impractical way to phase out fossil fuels. It is neither econimically viable nor can it compete with renewables in scalability or the timeframe needed to replace fossil fuels.

>If many of these points were true it would also make renewable energy transition impossible. New sources of uranium and minerals(such as rare earths needed by renewables) are made avalaible if the price increases.

No it wouldn't, given the abundance of the elements involved and the impossibility of recycling irradiated materials on a viable timescale. Renewables ismply don't suffer from the inherent shortcomings nuclear has here. Extracting Uranium from other sources would make nuclear power even more unviable from an economic standpoint.

>How would such tiny a reduction in consetration would make process unfeasible?

Might I suggest reading the actual paper?

https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=6021978

The issue is that the concentration in seawater is measured in ppb to begin with and the amount of water you need to filter to extract meaningful quantities of Uranium rises to infinity as the Uranium is extracted.

>This tells us that, for example, in as little as T = 30 years, a volume of seawater of 7x10^15 m3 would need to be processed - this is clearly impractical as it is over six times larger than the volume of total river outflow in the same time.

Nuclear is already the most expensive option out there. It simply isn't viable as a replacement for fossil fuels on a global scale, and given the growth in energy consumption it is bascially impossible to scale it to meet global base load demands.

>I'm pointing you to real time data from right now

And I have just done the same with reneweables, so your argument is invalid.

Maybe ask yourself why you have opted for a strawman instead of actually adressing any of the points brought up.

No. As per the paper cited in the article:

>In the following section, we will now articulate an important limit to scalability that applies to all forms of nuclear power, whether fusion or fission, uranium or thorium.

The scalability issue is inherent to nuclear technology. Nuclear is many things, but not a solution to terrestial power generation let alone is it gonnasave us from global warming. Renewables are the only source of electricity that is actually scalable.

That is not what the article actually claims though:

>Historical observations show a constant exponential growth of worldwide energy production. A continuation of this trend might be fueled or even amplified by the exploration of new carbon-free energy sources like fusion power.

The problem isn't "fusion", the problem is the exponential growth in energy production which leads to AHF. This is an inherent issue if you use heat engines to generate electricity - which both fission and fusion do. Nuclear power plants have a thermal efficiency ~33%:

https://www.nuclear-power.com/nuclear-engineering/thermodynamics/laws-of-thermodynamics/thermal-efficiency/thermal-efficiency-of-nuclear-power-plants/

while combined cycle gas powerplants can reach about twice of that.

This would be an issue with fission as well as with fusion. Seeing how you can scale neither fission nor fusion to even meet global base load demands that issue is mainly theoretical though. Basically all forms of nuclear power run into massive issues when you try to scale them beyond 1 TW globally.

https://phys.org/news/2011-05-nuclear-power-world-energy.html

You do realize that this doesn't actually adress any of the inherent issues with nuclear - industry as well as technology - that I pointed to, right? Using your logic I can simply point to Iceland to invalidate everything you have asserted so far.

lol, of course somebody has to push the usual "renewables are a conspiracy pushed by the soviets rusians" BS narrative, curtesy of the nuclear industry.

Yeah no, nuclear isn't a solution to anything. Nuclear is an obstacle that isn't needed and a massive waste of money and resources.

https://www.reuters.com/article/us-energy-nuclearpower-idUSKBN1W909J

https://phys.org/news/2011-05-nuclear-power-world-energy.html

https://spectator.clingendael.org/en/publication/nuclear-energy-too-costly-and-too-late

https://en.wikipedia.org/wiki/Levelized_cost_of_electricity

https://www.lazard.com/media/sptlfats/lazards-levelized-cost-of-energy-version-150-vf.pdf

Nuclear wouldn't even be able to provide global baseload capacity, while renewables can easily be scaled to provide for total global capacity. They are basically the only other source that could.

And it's so "safe" that the sector basically wouldn't exist without special legal constructs [see Price-Anderson in the US for exmaple) that absolve the industry from any responsibility regarding these "non-existent" risks:

>The Price-Anderson Act, which limits utility liability in the event of nuclear accidents, is totally out of sync with US energy goals because it places a heavy thumb on the scale of resource acquisition, favoring the wrong type of assets (high risk, high cost) in the current economic environment. In an uncertain environment, financial risk analysis teaches that the investor should preserve options and value flexibility by keeping decisions small and preferring investments with low, more predictable risks and short lead times. With their high risks, large sunk costs, long lead times, and extremely long asset lives, nuclear reactors are the worst type of assets to acquire at present.

https://thebulletin.org/2020/02/the-us-government-insurance-scheme-for-nuclear-power-plant-accidents-no-longer-makes-sense/

https://thebulletin.org/2011/10/nuclear-liability-the-market-based-post-fukushima-case-for-ending-price-anderson/

Oh yeah, "of course" renewables don't work. I guess that's way all the experts point out why going 100% renewable is totally possible?

>Recent studies show that a global transition to 100% renewable energy across all sectors – power, heat, transport and desalination well before 2050 is feasible. According to a review of the 181 peer-reviewed papers on 100% renewable energy that were published until 2018, "[t]he great majority of all publications highlights the technical feasibility and economic viability of 100% RE systems." A review of 97 papers published since 2004 and focusing on islands concluded that across the studies 100% renewable energy was found to be "technically feasible and economically viable." A 2022 review found that the main conclusion of most of the literature in the field is that 100% renewables is feasible worldwide at low cost.

>Existing technologies, including storage, are capable of generating a secure energy supply at every hour throughout the year. The sustainable energy system is more efficient and cost effective than the existing system. The United Nations Intergovernmental Panel on Climate Change (IPCC) stated in their 2011 report that there is little that limits integrating renewable technologies for satisfying the total global energy demand.

https://en.wikipedia.org/wiki/100%25_renewable_energy

😂

>We ran the numbers

Did they though?

>In fact, humans have already begun this process; we have successfully lofted approximately 10,000–20,000 metric tons of material into orbit and beyond (and a good fraction of it has even stayed there). We just have 5,971,999,999,999,999,990,000 metric tons to go and we’re golden.

🧐

>An estimated 25 million meteoroids, micrometeoroids and other space debris enter Earth's atmosphere each day,[8] which results in an estimated 15,000 tonnes of that material entering the atmosphere each year.

https://en.wikipedia.org/wiki/Meteoroid

At the same time, earth loses about 5000 tons of Helium every year. Still, the earth has actually gained mass, not lost it.

Honestly, I don't see all that much evidence in the article of them "running the numbers" regarding Dyson spheres.

>Yes, reuse is absolutely mandatory if you plan to play on the level field with that. Reuse, or learn to build new orbital rocket each week in perpetuity on the cheap, good luck with that.

No it's not. Reuse itself puts a tight limit on your launch capacity, and SpaceX regularely expends boosters. Reuse is entirely optional, and speculating about a "a level playing field" without even knowing how reusability impacts SpaceX financially is pretty misleading.

>But with rise of spacex Ariane model is over and done with, not that it was ever man rated anyway.

It is, actually

>Ariane 5 was originally intended to launch the Hermes spacecraft, and thus it is rated for human space launches.

https://en.wikipedia.org/wiki/Ariane_5

Not that I would expect a SpaceX fan to know that.

I'd also like to remind you that SpaceX was pretty vocal about those Mars colonies and how they would be funded via their satellite internet, none of which has worked out so far, let alone it being profitable. "Reuse" is nice to have, but it is not mandatory.

Nuclear is so "cheap" that is outperformed by every other option on the market:

https://en.wikipedia.org/wiki/Levelized_cost_of_electricity

https://www.lazard.com/media/sptlfats/lazards-levelized-cost-of-energy-version-150-vf.pdf

It is also so "risk free" that the industry wouldn't be able to survive without special legal constructs that absolve it from any actual liability for these "non-existent" risks:

https://thebulletin.org/2020/02/the-us-government-insurance-scheme-for-nuclear-power-plant-accidents-no-longer-makes-sense/

https://thebulletin.org/2011/10/nuclear-liability-the-market-based-post-fukushima-case-for-ending-price-anderson/

>The Price-Anderson Act, which limits utility liability in the event of nuclear accidents, is totally out of sync with US energy goals because it places a heavy thumb on the scale of resource acquisition, favoring the wrong type of assets (high risk, high cost) in the current economic environment. In an uncertain environment, financial risk analysis teaches that the investor should preserve options and value flexibility by keeping decisions small and preferring investments with low, more predictable risks and short lead times. With their high risks, large sunk costs, long lead times, and extremely long asset lives, nuclear reactors are the worst type of assets to acquire at present.

Nuclear is pretty much the worst option and an active hinderance.

>after west killed the industry for 3 decades and made it a niche, low numbers "homemade" enterprise.

The nuclear industry has been the most well funded and subsidized energy industry in history, and this was still the case up to ~2005

https://world-nuclear.org/information-library/economic-aspects/energy-subsidies.aspx

"The west" didn't kill the nuclear industry. The inherent limitations and problems, along with eternal stagnation as far as results are concerned is what "killed" the nuclear industry. And citing "but China" isn't going to change that. Even the chinese have been scaling back their nuclear efforts:

https://www.colorado.edu/cas/2022/04/12/even-china-cannot-rescue-nuclear-power-its-woes

while pretty much every project involving renewables over there overdelivers. Nuclear is a dead end, simply because it's too slow, too expensive and it can't be scaled the way renewables can. Nuclear wouldn'T even be able to provide global base load capacity without running into massive issues.

This isn't really surprising, given the history of outrageous claims that have been used to push and similar "discoveries" in the past in the press.

You'd be surprised by the kind of backlash posting stuff like

https://phys.org/news/2011-05-nuclear-power-world-energy.html

https://spectator.clingendael.org/en/publication/nuclear-energy-too-costly-and-too-late

https://www.reuters.com/article/us-energy-nuclearpower-idUSKBN1W909J

can incur every time somebody drags up nuclear as "the obvious solution".

The nuclear and the fossil fuel industry are often two sides of the same coin.

> when these “environments” don’t suggest it

These what

Also no, nuclear is not the solution, I don't know how often this has to be pointed out. Nuclear is too slow, to expensive and not even scalable:

https://phys.org/news/2011-05-nuclear-power-world-energy.html

https://www.reuters.com/article/us-energy-nuclearpower-idUSKBN1W909J

https://spectator.clingendael.org/en/publication/nuclear-energy-too-costly-and-too-late

https://www.ucsusa.org/resources/nuclear-power-still-not-viable-without-subsidies

while renewables are pretty much the opposite on every one of these points. The nuclear industry - like the fossil fuel lobby - is part of the problem, not part of the solution.

See

https://en.wikipedia.org/wiki/Fermi_paradox

while the chance should be very likely, the evidence we have so far doesn't support this. The question is why. We as a species are currently in the process of answering said question, i.e. rapid decline of our only known biosphere supporting higher forms of life, caused by your cited (rapid) advancement in technology without the ability of dealing with the pitfalls of said technologies.

What you are referring to is known as the Drake equation.

What we are currently experiencing is known as the Great Filter.

> The other is a disturbing, frightening possibility. If we have widespread problems with these kinds of sensors[...]

But basically all of these reports are based on "edge of observability" cases. Which is also why the official report cites a lack of high quality data. These problems are inherent with any kind of sensor system and observations made using said system. Not to mention that as far as I am aware most cases aren't even down to sensor data but simply observers. "Overhauling" of these systems will at best shift the edge of observation, but not address the underlaying problem.

Case in point being the outlandish claims by pilots about "physics breaking" manouvers which are not supported by the actual videos being presented as evidence and observers being unable to correctly identify position lights on aircraft, let alone basic optics.

EDIT:

It seems like CrelbowMannschaft put me on their ignore list in order to prevent me from actually replying to this. I wonder why.

The official reports outright decry the lack of high quality data and that the nature of the employed sensor makes them ill-suited for the task they are put to here. They also list sensor malfunctions, observer misperception, airborne clutter as possible explanations. Given that the Pentagon had to admit that the only actual evidence that has been presented - the videos - show exactely that, and that the plethora of other "UFO" reports made by basically everyone aroudn the globe happen to be down to "edge of observability" issues (distance, speed, focus, etc.) and so far all reports ever made tunred out to be exllainable by mundane means when high quality data was available leads me to believe that this is, in fact, inherent to sensor or observer limitations and not in any way "disturbing" of "frightening" - apart from actual military observers (not combat pilots) being unable to identify collision lights.

Others have already explained out why military pilots make for poor UFO witnesses, and even Hynek pointed that out.

>Avi Loeb

>not peer reviewed

> the paper posits that this is likely more a problem with the sensors recording this data than science’s current understanding of physics

Why are you posting this misleading crap?

>in order to analyze these UFOs, Kirkpatrick and Loeb determined that the recent UAP observations do defy the laws of physics, stating that “the friction of UAP with the surrounding air or water is expected to generate a bright optical fireball, ionization shell and tail—implying radio signatures.” However, many of the UAPs studied show no signs of these signatures

Which "recent UFO observations"? The ones the Pentagon determined they have insufficient data to actually attribute? Or the ones that were identified as observer misconception, sensor malfuctions etc.? The videos that were debunked to hell and back (and which later turned out to be exactely that - observer msiconception, sensor malfunctions etc.)?

Going over the paper they don't actually cite any sources for the UFOs they want to attribute these "properties" to. Avi (or rather the article being linked to) simply claims that because extraterrestrial craft would have to move at such speeds and the fact that we don't observe any indication that they actually do means that they must defy the laws of physics.

Instead of, you know, them not being alien probes made of magic.

The paper itself is simply Avi being Avi and pushing his "but what if Oumuamua was an alien probe" and "what if if space was full of alien probes and civilization which are for some reason invisible" spiel. About half of the citiations in the "paper" is Avi quoting his own works.

>You don’t even need a rocket. You can use a mass driver to fling the material from the moon to earth’s orbit.

That's not how orbital machanics work. You will need some sort of independant propulsion system to actually slow it down and circularize the orbit. You can't just "shoot stuff into orbit".

Oversimplifications like this are exactely why this is basically "a loony idea" and not going to happen in the forseeable future. And neither is there a "$100-billion-plus lunar economy looming" as the article claims, because there is no basis for such an economy.

>Greg Spanjers, program manager for rocket cargo at AFRL, said the military envisions a future when it could be cheaper to send cargo via rocket than by transport aircraft. In a national security or humanitarian crisis, a launch vehicle would fly from Cape Canaveral, for example, and either land on an austere field to deliver cargo or airdrop it.

Seriously, why is this still being pushed? This simply makes no sense from any realistic perspective. Common Sense Skeptic made a quick teardown/debunking explaining this:

https://youtu.be/35AmcnpGVkk

But honestly this should be self-evident. It's simply impractical and a waste of money and resources.