The notion that we can utilize a weak, inefficient, short-lived, non-renewable resource like solar power is complete nonsense. Solar power requires vast amounts of energy and mineral resources to build the collection machines and power distribution systems. Sunlight is renewable: lithium, cobalt, germanium, and copper damn sure are not. The vast economic damage sustained by the UK, Germany, Spain, and California are proof positive that this entire concept is nonsense.
This article is a familiar example of climate and renewable energy denial rhetoric, mixing factual statements with distortions, omissions, and loaded language. Here’s a breakdown and rebuttal of the key claims:
1. Yes, the sun powers the planet — but so what?
“Our star, the Sun, is basically the engine which drives all life and movement on the planet… Peltan employs this… to dishonestly plug solar panels…”
Rebuttal:
• Acknowledging the sun as the dominant energy source isn’t a “gotcha” — it’s the entire point of solar power. Solar panels are a way to directly tap the sun’s energy without waiting millions of years for it to become fossil fuels.
• Saying that invoking the sun to promote solar is “dishonest” is bizarre. It’s simply recognizing where the energy comes from and using current technology to capture it more cleanly and efficiently.
2. Misleading claim about energy density and land use
“Solar is orders of magnitude less [energy dense] than nuclear or fossil fuels… you have to build thousands of acres on farmland or wild spaces…”
Rebuttal:
• Solar’s low energy density is true per unit area, but deployment can be optimized:
• Rooftops, parking lots, highway medians, reservoirs (floatovoltaics), and already disturbed land are prime solar locations that don’t require new land use.
• Agrivoltaics (solar panels above crops or pasture) enables dual use of farmland.
• The land impact of solar is vastly smaller than fossil fuels when you count mining, drilling, pipelines, spills, and climate impacts.
• Nuclear has higher energy density, but is slower to deploy, far more expensive, and has security and waste issues.
3. Basic intermittency talking points
“Not available at night… varies by season… varies by weather…”
Rebuttal:
• These are well-known engineering constraints, not fatal flaws:
• Storage (batteries, pumped hydro, thermal, and emerging tech)
• Demand management (using more power when supply is high)
• Other sources (e.g. hydro, geothermal, and yes, even nuclear)
• All energy systems have vulnerabilities. Fossil fuel plants also fail in extreme weather (as seen in Texas 2021).
• Resilience comes from system design, not from pretending only 24/7 generation counts.
4. Romanticizing fossil fuels as “condensed solar”
“Fossil fuels are… prehistoric solar energy… packaged into a neat, convenient, usable form beneath our feet!”
Rebuttal:
• Yes, fossil fuels come from ancient biomass — but burning them releases CO₂ trapped for millions of years in a matter of decades, radically destabilizing the climate.
• This is not a poetic “recycling” of solar energy. It’s a geologic carbon bomb.
• The idea that climate science is “pseudoscientific, unverified and unverifiable” is an egregious denialist lie. The greenhouse effect is 150+ years old, and climate models have been validated repeatedly.
5. Token gesture to nuclear
“If you want to be a zero carbon purist, go for nuclear fission… before humanity cracks fusion…”
Rebuttal:
• Nuclear can play a role in decarbonization, especially in high-demand areas, but:
• New nuclear is slow and expensive (10–20 years typical build time)
• Waste, safety, and cost issues remain
• No serious energy transition plan excludes solar and wind, because nuclear alone cannot scale fast enough
• Claiming that any pro-solar stance means you’re against nuclear is a false dichotomy.
6. Appeal to fear: “Chinese-made,” “kill switches,” etc.
“Environmentally unfriendly Chinese-made solar panels… with kill switches…”
Rebuttal:
• The U.S. and Europe are rapidly scaling domestic solar production.
• Solar panel components don’t contain “kill switches.” This is unfounded conspiracy rhetoric.
• If China dominates solar manufacturing, it’s because they invested early and heavily. The answer is domestic policy and innovation, not abandoning solar.
7. Ad hominem attacks on Peltan and Musk
“Solar energy spivs… Communist China apologists… The X Emperor should stick to rockets…”
Rebuttal:
• When someone resorts to insults and name-calling, it’s often because their substantive arguments are weak.
• Peltan’s credentials (presumably Dr. Daniel Peltan, a physicist and clean energy advocate) stand on their own.
• Musk’s support for solar isn’t new — he co-founded SolarCity and merged it with Tesla years ago.
Final Thoughts
This article blends factoids with ideological framing, attempting to undermine clean energy by:
• Presenting well-known limitations as fatal flaws
• Romanticizing fossil fuels without addressing climate consequences
• Using rhetorical attacks instead of engaging with actual energy system analysis
It reflects reactionary denialism rather than a serious critique.
"Solar panels are a way to directly tap the sun’s energy without waiting millions of years for it to become fossil fuels."
My point is that we have ancient sunlight, condensed into a highly efficient, usable form called coal, oil or gas, right there, waiting, beneath our feet. We don't have to wait millions of years for it to become available - Nature has already completed the process. You think instead that we should be harvesting modern sunlight, a far more rarefied source of energy, using vast arrays of solar panels which only work during the day and hardly work at all during winter in high latitudes. Coal, oil and gas (prehistoric solar energy) can be burnt 24/7, 365 days per year, using far less land/surface area.
"Saying that invoking the sun to promote solar is “dishonest” is bizarre. It’s simply recognizing where the energy comes from and using current technology to capture it more cleanly and efficiently."
Solar panels are at best, just over 20% efficient, which means that they can only convert a fifth of the solar energy which strikes them into electrical energy. By no stretch of the imagination can that be called 'efficient'. By contrast, a modern CCGT operates at an efficiency of around 64%. Solar panels are not 'clean' either, especially if they are sited on cleared natural habitat or farmland. They also require significant quantities of rare earth materials, which have to be mined. I quote:
"The extraction and processing of rare earth materials have significant environmental implications. The mining of these materials often involves harmful practices such as deforestation, water pollution, and the release of toxic byproducts."
"Rooftops, parking lots, highway medians, reservoirs (floatovoltaics), and already disturbed land are prime solar locations that don’t require new land use."
But this is not happening in practice. huge areas of prime farmland and former wild spaces are being converted to solar 'farms' because developers can maximise profits by doing this, rather than siting their panels on geographically dispersed rooftops, parking lots, highways, etc. Connections to the grid are also a lot simpler for these larger purpose-built installations.
"Yes, fossil fuels come from ancient biomass — but burning them releases CO₂ trapped for millions of years in a matter of decades, radically destabilizing the climate.
This is not a poetic “recycling” of solar energy. It’s a geologic carbon bomb."
Your 'rebuttal' consists of two pseudoscientific hysterical statements regarding atmospheric carbon dioxide and its alleged 'catastrophic' effect upon earth's climate, where the atmospheric CO2 concentration today is 420ppm but has been 2000-5000ppm regularly throughout geological history, during which periods, life has thrived on planet earth and where there is virtually no evidence to suggest that that the CO2 concentration caused warmer global mean temperature, in fact the opposite appears to be the case: warmer global mean surface temperature resulted in higher atmospheric CO2 from outgassing oceans and intensification of the carbon cycle.
"The idea that climate science is “pseudoscientific, unverified and unverifiable” is an egregious denialist lie. The greenhouse effect is 150+ years old, and climate models have been validated repeatedly."
Dangerous/catastrophic anthropogenic GHG global warming is a THEORY which has NOT been verified by experiment/direct observation. Climate models (with all their inherent biases, approximations and parametrizations of highly complex physical processes) have to be tweaked radically in order to accurately hindcast temperatures and their supposed accurate forecasts consist of a huge spread of possible futures where even the ensemble mean fails to coincide with observations, despite the efforts of some scientists (like Hausfather for instance) to demonstrate otherwise.
"When someone resorts to insults and name-calling, it’s often because their substantive arguments are weak . . . . . . . an egregious denialist lie . . . . . . It reflects reactionary denialism rather than a serious critique."
Your arguments are weak and you resort to name calling. I resort to name calling and my arguments are robust.
Your reply is a defense of fossil fuels dressed up as pragmatism, but it relies on outdated talking points and misleading comparisons.
Yes, fossil fuels are “ancient sunlight” — but burning them dumps millions of years of carbon into the atmosphere in mere decades, destabilizing the climate we rely on. That’s not efficient, it’s reckless.
Solar doesn’t need to match gas plants in thermal efficiency — sunlight is free. And no, most solar panels don’t use rare earths, and yes, rooftop and disturbed-land solar is expanding fast globally. The “solar destroys nature” line ignores the actual footprint of fossil fuel extraction and pollution.
CO₂ has been higher in the distant past — but at much slower rates, in worlds without 8 billion people, coastlines, and modern agriculture. Today’s CO₂ spike is geologically abrupt, and yes, it is warming the planet — just as physics predicted over a century ago.
You dismiss all this with rhetoric and ridicule. But the evidence is clear: modern solar, wind, storage, and nuclear are cleaner, safer, and increasingly cheaper.
We’re not stuck with the 19th-century playbook. We can build better — and we must.
Oh Jeez, I haven't got time to dismantle your 'rebuttals' at the moment, but I thank you for your valued and highly illustrative contribution from Renewables Cult Land and rest assured, I will respond, in detail, as soon as time allows.
I am looking forward to that rebuttal, as I would be unable myself, and at this point wouldn't feel confident to bring up your points in any conversation. I didn't know for example that most solar panels don't use rare earth minerals (if this is true).
It looks AI generated, with turns of phrase, punctuation and structure familiar from ChatGPT. Some AI detectors don't identify it as AI, but they are probably thrown off by the quotes from your piece. It might be interesting to ask grok for a rebuttal to the rebuttal :D
No human-written Substack comment has a "Final Thoughts" heading :) The second comment also uses AI. This time the style has been changed to make it look somewhat more like it's been human-written, but for example it still makes extensive use of em dashes, which don't exist on human keyboards. And nobody changes their writing style that drastically between comments. AIs are comically biassed in favour of wind and solar; if you ask them to name a country where wind and solar have reduced the cost of electric power, they tie themselves in all sorts of knots.
I definitely think you're right. Is this a case of somebody getting AI to challenge my article and then merely parroting its response on this site, or has AI been programmed to 'seek and destroy' renewables critical articles and is therefore acting independent of human agency by generating such replies? The former seems the more likely, but you never know.
It's a human pasting the AI output; the first comment was in generic ChatGPT/DeepSeek format, which just isn't how you would implement an autonomous AI troll, unless for comic effect. No doubt the autonomous trolls are on their way. Just charge them to comment! :D
God, that was fantastic. Every person who is capable of sort of objective thinking should have to watch Feynman speaking simply about the process of carbon storage in trees from sunlight and it's expenditure in burning wood.
Look to Australia we have a moratorium on nuclear, the greens are no longer environmentalists plus we have a relatively new breed called the Aquas - funded by a billionaire heavily invested in “ green “ energy, and a few weeks back the sheep elected a socialist government with an overwhelming majority. We will become the first country in the world to go back to third world status. The labor party prime minister is totally devoted to Trotsky. Cry my beloved country.
I love that there already is a whole ecosystem that uses solar called “satellites in orbit” and we also see what happens when you are completely reliant on solar incidence angle otherwise known as “Philae Lander problem”.
Musk is probably supporting solar because he owns a solar company. Unfortunately for him, and I’m sure he knows this, his solar and EV businesses are dependent on the climate change hoax which is collapsing all round the world including in Trump’s USA, looney EU and shackled UK excluded.
As usual with supporters of wind and solar, they disregard the problem of wind/solar (and interconnector) lack of inertia which our legacy grids are designed for (ref. the recent total blackout in Iberia) and they disregard the problem of no wind and no sun on national and even continental scale for potentially days or weeks on end, particularly in winter when power is needed most.
Interesting to note that since the nationwide blackout, Spain has reverted to using much less solar and wind and much more gas and nuclear in their grid fuel mix. This should be a lesson to Miliband that similar events are bound to happen in the UK well before his fabled 95% grid decarbonisation is reached (it won’t be). In other words, Net Zero is impossible due to engineering constraints, which most sensible people understood many years ago: https://principia-scientific.com/spain-quietly-boosts-nuclear-and-gas-after-blackout-it-still-wont-explain/.
The notion that we can utilize a weak, inefficient, short-lived, non-renewable resource like solar power is complete nonsense. Solar power requires vast amounts of energy and mineral resources to build the collection machines and power distribution systems. Sunlight is renewable: lithium, cobalt, germanium, and copper damn sure are not. The vast economic damage sustained by the UK, Germany, Spain, and California are proof positive that this entire concept is nonsense.
This article is a familiar example of climate and renewable energy denial rhetoric, mixing factual statements with distortions, omissions, and loaded language. Here’s a breakdown and rebuttal of the key claims:
1. Yes, the sun powers the planet — but so what?
“Our star, the Sun, is basically the engine which drives all life and movement on the planet… Peltan employs this… to dishonestly plug solar panels…”
Rebuttal:
• Acknowledging the sun as the dominant energy source isn’t a “gotcha” — it’s the entire point of solar power. Solar panels are a way to directly tap the sun’s energy without waiting millions of years for it to become fossil fuels.
• Saying that invoking the sun to promote solar is “dishonest” is bizarre. It’s simply recognizing where the energy comes from and using current technology to capture it more cleanly and efficiently.
2. Misleading claim about energy density and land use
“Solar is orders of magnitude less [energy dense] than nuclear or fossil fuels… you have to build thousands of acres on farmland or wild spaces…”
Rebuttal:
• Solar’s low energy density is true per unit area, but deployment can be optimized:
• Rooftops, parking lots, highway medians, reservoirs (floatovoltaics), and already disturbed land are prime solar locations that don’t require new land use.
• Agrivoltaics (solar panels above crops or pasture) enables dual use of farmland.
• The land impact of solar is vastly smaller than fossil fuels when you count mining, drilling, pipelines, spills, and climate impacts.
• Nuclear has higher energy density, but is slower to deploy, far more expensive, and has security and waste issues.
3. Basic intermittency talking points
“Not available at night… varies by season… varies by weather…”
Rebuttal:
• These are well-known engineering constraints, not fatal flaws:
• Grid diversity (geographically dispersed solar/wind)
• Storage (batteries, pumped hydro, thermal, and emerging tech)
• Demand management (using more power when supply is high)
• Other sources (e.g. hydro, geothermal, and yes, even nuclear)
• All energy systems have vulnerabilities. Fossil fuel plants also fail in extreme weather (as seen in Texas 2021).
• Resilience comes from system design, not from pretending only 24/7 generation counts.
4. Romanticizing fossil fuels as “condensed solar”
“Fossil fuels are… prehistoric solar energy… packaged into a neat, convenient, usable form beneath our feet!”
Rebuttal:
• Yes, fossil fuels come from ancient biomass — but burning them releases CO₂ trapped for millions of years in a matter of decades, radically destabilizing the climate.
• This is not a poetic “recycling” of solar energy. It’s a geologic carbon bomb.
• The idea that climate science is “pseudoscientific, unverified and unverifiable” is an egregious denialist lie. The greenhouse effect is 150+ years old, and climate models have been validated repeatedly.
5. Token gesture to nuclear
“If you want to be a zero carbon purist, go for nuclear fission… before humanity cracks fusion…”
Rebuttal:
• Nuclear can play a role in decarbonization, especially in high-demand areas, but:
• New nuclear is slow and expensive (10–20 years typical build time)
• Waste, safety, and cost issues remain
• No serious energy transition plan excludes solar and wind, because nuclear alone cannot scale fast enough
• Claiming that any pro-solar stance means you’re against nuclear is a false dichotomy.
6. Appeal to fear: “Chinese-made,” “kill switches,” etc.
“Environmentally unfriendly Chinese-made solar panels… with kill switches…”
Rebuttal:
• The U.S. and Europe are rapidly scaling domestic solar production.
• Solar panel components don’t contain “kill switches.” This is unfounded conspiracy rhetoric.
• If China dominates solar manufacturing, it’s because they invested early and heavily. The answer is domestic policy and innovation, not abandoning solar.
7. Ad hominem attacks on Peltan and Musk
“Solar energy spivs… Communist China apologists… The X Emperor should stick to rockets…”
Rebuttal:
• When someone resorts to insults and name-calling, it’s often because their substantive arguments are weak.
• Peltan’s credentials (presumably Dr. Daniel Peltan, a physicist and clean energy advocate) stand on their own.
• Musk’s support for solar isn’t new — he co-founded SolarCity and merged it with Tesla years ago.
Final Thoughts
This article blends factoids with ideological framing, attempting to undermine clean energy by:
• Presenting well-known limitations as fatal flaws
• Romanticizing fossil fuels without addressing climate consequences
• Using rhetorical attacks instead of engaging with actual energy system analysis
It reflects reactionary denialism rather than a serious critique.
"Solar panels are a way to directly tap the sun’s energy without waiting millions of years for it to become fossil fuels."
My point is that we have ancient sunlight, condensed into a highly efficient, usable form called coal, oil or gas, right there, waiting, beneath our feet. We don't have to wait millions of years for it to become available - Nature has already completed the process. You think instead that we should be harvesting modern sunlight, a far more rarefied source of energy, using vast arrays of solar panels which only work during the day and hardly work at all during winter in high latitudes. Coal, oil and gas (prehistoric solar energy) can be burnt 24/7, 365 days per year, using far less land/surface area.
"Saying that invoking the sun to promote solar is “dishonest” is bizarre. It’s simply recognizing where the energy comes from and using current technology to capture it more cleanly and efficiently."
Solar panels are at best, just over 20% efficient, which means that they can only convert a fifth of the solar energy which strikes them into electrical energy. By no stretch of the imagination can that be called 'efficient'. By contrast, a modern CCGT operates at an efficiency of around 64%. Solar panels are not 'clean' either, especially if they are sited on cleared natural habitat or farmland. They also require significant quantities of rare earth materials, which have to be mined. I quote:
"The extraction and processing of rare earth materials have significant environmental implications. The mining of these materials often involves harmful practices such as deforestation, water pollution, and the release of toxic byproducts."
https://green.org/2024/01/30/solar-energys-dependence-on-rare-earth-materials/
Not 'clean'. Not efficient.
"Rooftops, parking lots, highway medians, reservoirs (floatovoltaics), and already disturbed land are prime solar locations that don’t require new land use."
But this is not happening in practice. huge areas of prime farmland and former wild spaces are being converted to solar 'farms' because developers can maximise profits by doing this, rather than siting their panels on geographically dispersed rooftops, parking lots, highways, etc. Connections to the grid are also a lot simpler for these larger purpose-built installations.
"Yes, fossil fuels come from ancient biomass — but burning them releases CO₂ trapped for millions of years in a matter of decades, radically destabilizing the climate.
This is not a poetic “recycling” of solar energy. It’s a geologic carbon bomb."
Your 'rebuttal' consists of two pseudoscientific hysterical statements regarding atmospheric carbon dioxide and its alleged 'catastrophic' effect upon earth's climate, where the atmospheric CO2 concentration today is 420ppm but has been 2000-5000ppm regularly throughout geological history, during which periods, life has thrived on planet earth and where there is virtually no evidence to suggest that that the CO2 concentration caused warmer global mean temperature, in fact the opposite appears to be the case: warmer global mean surface temperature resulted in higher atmospheric CO2 from outgassing oceans and intensification of the carbon cycle.
"The idea that climate science is “pseudoscientific, unverified and unverifiable” is an egregious denialist lie. The greenhouse effect is 150+ years old, and climate models have been validated repeatedly."
Dangerous/catastrophic anthropogenic GHG global warming is a THEORY which has NOT been verified by experiment/direct observation. Climate models (with all their inherent biases, approximations and parametrizations of highly complex physical processes) have to be tweaked radically in order to accurately hindcast temperatures and their supposed accurate forecasts consist of a huge spread of possible futures where even the ensemble mean fails to coincide with observations, despite the efforts of some scientists (like Hausfather for instance) to demonstrate otherwise.
"When someone resorts to insults and name-calling, it’s often because their substantive arguments are weak . . . . . . . an egregious denialist lie . . . . . . It reflects reactionary denialism rather than a serious critique."
Your arguments are weak and you resort to name calling. I resort to name calling and my arguments are robust.
Your reply is a defense of fossil fuels dressed up as pragmatism, but it relies on outdated talking points and misleading comparisons.
Yes, fossil fuels are “ancient sunlight” — but burning them dumps millions of years of carbon into the atmosphere in mere decades, destabilizing the climate we rely on. That’s not efficient, it’s reckless.
Solar doesn’t need to match gas plants in thermal efficiency — sunlight is free. And no, most solar panels don’t use rare earths, and yes, rooftop and disturbed-land solar is expanding fast globally. The “solar destroys nature” line ignores the actual footprint of fossil fuel extraction and pollution.
CO₂ has been higher in the distant past — but at much slower rates, in worlds without 8 billion people, coastlines, and modern agriculture. Today’s CO₂ spike is geologically abrupt, and yes, it is warming the planet — just as physics predicted over a century ago.
You dismiss all this with rhetoric and ridicule. But the evidence is clear: modern solar, wind, storage, and nuclear are cleaner, safer, and increasingly cheaper.
We’re not stuck with the 19th-century playbook. We can build better — and we must.
Oh Jeez, I haven't got time to dismantle your 'rebuttals' at the moment, but I thank you for your valued and highly illustrative contribution from Renewables Cult Land and rest assured, I will respond, in detail, as soon as time allows.
I am looking forward to that rebuttal, as I would be unable myself, and at this point wouldn't feel confident to bring up your points in any conversation. I didn't know for example that most solar panels don't use rare earth minerals (if this is true).
It looks AI generated, with turns of phrase, punctuation and structure familiar from ChatGPT. Some AI detectors don't identify it as AI, but they are probably thrown off by the quotes from your piece. It might be interesting to ask grok for a rebuttal to the rebuttal :D
You could be right.
No human-written Substack comment has a "Final Thoughts" heading :) The second comment also uses AI. This time the style has been changed to make it look somewhat more like it's been human-written, but for example it still makes extensive use of em dashes, which don't exist on human keyboards. And nobody changes their writing style that drastically between comments. AIs are comically biassed in favour of wind and solar; if you ask them to name a country where wind and solar have reduced the cost of electric power, they tie themselves in all sorts of knots.
I definitely think you're right. Is this a case of somebody getting AI to challenge my article and then merely parroting its response on this site, or has AI been programmed to 'seek and destroy' renewables critical articles and is therefore acting independent of human agency by generating such replies? The former seems the more likely, but you never know.
It's a human pasting the AI output; the first comment was in generic ChatGPT/DeepSeek format, which just isn't how you would implement an autonomous AI troll, unless for comic effect. No doubt the autonomous trolls are on their way. Just charge them to comment! :D
God, that was fantastic. Every person who is capable of sort of objective thinking should have to watch Feynman speaking simply about the process of carbon storage in trees from sunlight and it's expenditure in burning wood.
The heat within the Earth’s crust, mantle, and core is from radioactive decay of atomic nuclei. It’s from naturally occurring nuclear fission.
Look to Australia we have a moratorium on nuclear, the greens are no longer environmentalists plus we have a relatively new breed called the Aquas - funded by a billionaire heavily invested in “ green “ energy, and a few weeks back the sheep elected a socialist government with an overwhelming majority. We will become the first country in the world to go back to third world status. The labor party prime minister is totally devoted to Trotsky. Cry my beloved country.
I can't 'like' this comment - it's too sad.
I live in the UK.
Race you to the bottom!
Ditto above.
I love that there already is a whole ecosystem that uses solar called “satellites in orbit” and we also see what happens when you are completely reliant on solar incidence angle otherwise known as “Philae Lander problem”.
Musk is probably supporting solar because he owns a solar company. Unfortunately for him, and I’m sure he knows this, his solar and EV businesses are dependent on the climate change hoax which is collapsing all round the world including in Trump’s USA, looney EU and shackled UK excluded.
As usual with supporters of wind and solar, they disregard the problem of wind/solar (and interconnector) lack of inertia which our legacy grids are designed for (ref. the recent total blackout in Iberia) and they disregard the problem of no wind and no sun on national and even continental scale for potentially days or weeks on end, particularly in winter when power is needed most.
Interesting to note that since the nationwide blackout, Spain has reverted to using much less solar and wind and much more gas and nuclear in their grid fuel mix. This should be a lesson to Miliband that similar events are bound to happen in the UK well before his fabled 95% grid decarbonisation is reached (it won’t be). In other words, Net Zero is impossible due to engineering constraints, which most sensible people understood many years ago: https://principia-scientific.com/spain-quietly-boosts-nuclear-and-gas-after-blackout-it-still-wont-explain/.
Miliband wants triple the supply of solar power by 2030 but what use would that be in another “year without a summer” as happened after the eruption of Mount Tambora in 1815? https://scied.ucar.edu/learning-zone/how-climate-works/mount-tambora-and-year-without-summer
Perhaps Elton would like to visit the Sun in one of his rocket ships. Perfectly safe if he goes at night.