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A_A

@ A_A @lemmy.world

Posts
23
Comments
906
Joined
3 yr. ago

This Earth, only home i will ever have had, isn't truly mine. No, i'm just a passerby here ... it might yours if you don't feel how weird, how wrong it is.

  • Israel strikes Iran

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  • Israel strikes Iran

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  • Australian reporter covering Los Angeles immigration protests hit by rubber bullet on live TV

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  • Universe expected to decay in 10⁷⁸ years, much sooner than previously thought

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  • ... Recently we found evidence that spacetime curvature alone without the need for an event horizon leads to black hole evaporation (... this is pair generation !). ...

    Great ! Now tell me : what's the implications of this on cosmological spacetime curvature ?

    original article:https://arxiv.org/abs/2410.14734An upper limit to the lifetime of stellar remnants from gravitational pair production

  • New quantum theory of gravity brings long-sought 'theory of everything' a crucial step closer

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  • Original free access article :https://iopscience.iop.org/article/10.1088/1361-6633/adc82eGravity generated by four one-dimensional unitary gauge symmetries and the Standard Model

    if i get even 0.01% of what this is, then, they really reached a "Theory of Everything" but it can't be experimentally tested until quantum gravity things are detected.

  • A German Experiment Proved That Simple Concrete Spheres Make Fantastic Batteries. Now, California Plans To Submerge A 9-Meter Diameter Sphere In The Ocean And Is Already Planning Versions Of 30 Meters

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  • i agree with all of this except, you know, when they will have to do maintenance ... i guess they will be (they would be) more simply hauling the whole thing out to work at the surface of the sea ... in this scenario the mechanical components would be at the top of the sphere and out of the water.

  • A German Experiment Proved That Simple Concrete Spheres Make Fantastic Batteries. Now, California Plans To Submerge A 9-Meter Diameter Sphere In The Ocean And Is Already Planning Versions Of 30 Meters

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  • Perfect guess ! (afaik) ρ(concrete) ≈ 2.5 tons/m³so full sphere ≈ (2.5 x 382) tons = 955 tonsthey have 400 t so the cavity removes :955 - 400 = 555 t ... so 7.51m diam. cavity... so, yes 3/4m thick wall 😌👍 !

  • A German Experiment Proved That Simple Concrete Spheres Make Fantastic Batteries. Now, California Plans To Submerge A 9-Meter Diameter Sphere In The Ocean And Is Already Planning Versions Of 30 Meters

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  • indeed i made a very simplified calculation not taking into account increase density of salted water nor increased density because of compressibility of water at 500 m deep. Basically i took 1m³(water) is 1 (metric) ton.

  • A German Experiment Proved That Simple Concrete Spheres Make Fantastic Batteries. Now, California Plans To Submerge A 9-Meter Diameter Sphere In The Ocean And Is Already Planning Versions Of 30 Meters

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  • ... a sphere nine metres in diameter and weighing 400 tonnes will be submerged off the coast of California at a depth of 500 to 600 metres. It will have a storage capacity of 0.4 megawatt hours (400 kWh) ...

    i will try a rough calculations : suppose we can have concrete at $100 per ton, then it's a minimum investment of $40,000. Also suppose electricity is stored with a large added value of 10 cents per kilowatt hour, so, for every cycle a rough gain of $40. By these numbers, 1,000 cycles would pay for the concrete ... so, it may look good considering they plan a life of about 50 years for such devices.On the other hand if competitive battery storage cost only one cents per kilowatt hour (temporary in and out storage) and if concrete and fabrication goes up 10 times to $1,000 per ton then it is not economically viable anymore.

    A good calculation of profitability would need to take into account the less than 100% energy efficiency of batteries cycling and of hydraulic energy cycling, ... and so many more parameters which have to be studied.

  • A German Experiment Proved That Simple Concrete Spheres Make Fantastic Batteries. Now, California Plans To Submerge A 9-Meter Diameter Sphere In The Ocean And Is Already Planning Versions Of 30 Meters

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  • ... you’d need some massive ...from the srticle :... a sphere nine metres in diameter and weighing 400 tonnes will be submerged ...

    Can you calculate the weight of a sphere of 9 m of displaced water ?No ? Well, it is 382 tons.So, the concrete sphere is already massive by itself. "You" don't need any complicated anchoring.Same goes with the rest of your mechanical engineering intuitions : you did not work in this domain or study it, did you 😆 ?Also, stress cycling is bad on most material, yes. But here it is compressive stress and the geometry is symmetric. Without further study, i want to believe this thing has good potential and my intuitions tells me it looks nice. Time will tell 😁 !

  • India and Pakistan agree to a ceasefire in US-mediated talks

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  • Congratulation to both sides being mature enough to agree so rapidly to this ceasefire despite (or with the help of 😋 ?) "American mediation".

  • The loons are back. There's something nearly spiritual about listening to them call to each other over a quiet lake.

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  • France accuses Russian military intelligence over cyberattacks

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  • i am irritated about those cyber attacks and really sad about the invasion into Ukraine.

    But i'm glad Europe is taking steps to strengthen its military and i'm puzzle about these stupidly vulnerable infrastructures.

  • Syrians are still surprisingly upbeat. Our pioneering poll reveals much optimism, but also big sectarian divisions

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  • you forgot to put a link to any news article

  • Trump shut down program to end human waste backing into Alabama homes, calling it 'illegal DEI'

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  • it's a basic human right to get rid of waste, including that Trump turd.

  • Israel says airstrikes in Syria are ‘message’ to protect Druze minority

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  • if proportional "messages" were sent by other countries, Israel would shut it's fucking mouth. For good.

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  • Why would the robots doing all the other jobs listen to this delusional human ?

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  • Yes ! hum ... 2 days ago I also wrote

    i think it's this, at :56.10, 38.75

    here :
    .

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    Elevation is Out Now! - Null Signal Games

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  • 😋