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Kinda Curious Teckie Q?

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Comments

  • #32
    seamus
    Registered Users Posts: 68,317 ✭✭✭✭seamus


    [Deleted User] wrote: »
    Should the wording be changed to "Energy cannot be created or destroyed, except in a Big Bang"? Cause if you want to go that route, I imagine a lot of things would have to be changed so as to not confuse those of limited ability.
    No. Even in the big bang nothing was created. All of the energy in the universe was concentrated into a single point and then released.


  • #33
    dxhound2005
    Registered Users Posts: 20,479 ✭✭✭✭dxhound2005


    Deleted User wrote: »
    Basically, the person who breaks the laws of physics and creates this will be the richest man the world has ever known.

    Fusion is as good as it gets if we ever make it that far. That would change everything.

    Change some things in our use of electricity and in transport. But it would not change human nature. There would still be wars and famines.

    Nuclear fusion will not be needed if renewables gradually replace fossil fuels. Australia could produce enough energy from solar to power the world four time over. They are working on ways to make ammonia from solar, which can then be used to power hydrogen fuels cells. Hydrogen fuel cells could be the way to non polluting cars.

    https://www.sciencemag.org/news/2018/07/ammonia-renewable-fuel-made-sun-air-and-water-could-power-globe-without-carbon


  • #34
    The Rape of Lucretia
    Closed Accounts Posts: 7,440 ✭✭✭The Rape of Lucretia


    seamus wrote: »
    No. Even in the big bang nothing was created. All of the energy in the universe was concentrated into a single point and then released.

    Exactly. So the energy was created before the big bang.


  • #35
    biko
    Registered Users Posts: 81,223 ✭✭✭✭biko


    Because mass is a kind of energy


  • #36
    [Deleted User]
    Posts: 17,381 ✭ [Deleted User]


    seamus wrote: »
    No. Even in the big bang nothing was created. All of the energy in the universe was concentrated into a single point and then released.

    Which is mad to think about. But my point is that it shouldn't need an addendum saying that at some point, this energy sprung to life.
    dxhound2005 wrote: »
    Change some things in our use of electricity and in transport. But it would not change human nature. There would still be wars and famines.

    Nuclear fusion will not be needed if renewables gradually replace fossil fuels. Australia could produce enough energy from solar to power the world four time over. They are working on ways to make ammonia from solar, which can then be used to power hydrogen fuels cells. Hydrogen fuel cells could be the way to non polluting cars.

    https://www.sciencemag.org/news/2018/07/ammonia-renewable-fuel-made-sun-air-and-water-could-power-globe-without-carbon

    I think it would be an enormous change in the future. In 2019, it may be hard to see where all this electricity could go, but imo it will be a big thing when it's available.

    This is based on the whole Dyson Sphere idea.
    The Rape of Lucretia wrote: »
    Exactly. So the energy was created before the big bang.

    Which is irrelevant. What you called that poster out on was semantic at best. You called out someone for stating what is accepted in all of science. Since the Big Bang, it can't be created or destroyed.


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  • #37
    seamus
    Registered Users Posts: 68,317 ✭✭✭✭seamus


    [Deleted User] wrote: »
    Which is irrelevant. What you called that poster out on was semantic at best. You called out someone for stating what is accepted in all of science. Since the Big Bang, it can't be created or destroyed.
    It's not even semantics, it's just wrong. No energy was created in the big bang.


  • #38
    endacl
    Registered Users Posts: 22,231 ✭✭✭✭endacl


    biko wrote: »
    Because mass is a kind of energy

    I always found it energy sapping. Stopped going when I wa 11.


  • #39
    Franz Von Peppercorn
    Closed Accounts Posts: 7,070 ✭✭✭Franz Von Peppercorn


    seamus wrote: »
    It's not even semantics, it's just wrong. No energy was created in the big bang.

    Just before it, then.

    It’s best to say that energy cannot be created or destroyed since the Big Bang.


  • #40
    seamus
    Registered Users Posts: 68,317 ✭✭✭✭seamus


    Franz Von Peppercorn wrote: »
    Just before it, then.

    It’s best to say that energy cannot be created or destroyed since the Big Bang.
    There is no "before" the big bang. It's meaningless. Time didn't exist until the big bang.


  • #41
    recedite
    Closed Accounts Posts: 13,993 ✭✭✭✭recedite


    While we are waiting for fusion power, there's a couple of cool techs out there providing free energy. All new houses have either solar pv cells on the roof (free electricity) or a heat pump. A heat pump heats the house using a magic box which spews out 3 or 4 units of power for every 1 unit you put in.
    I'll leave any further explanation for the honours class ;)


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  • #42
    Franz Von Peppercorn
    Closed Accounts Posts: 7,070 ✭✭✭Franz Von Peppercorn


    seamus wrote: »
    There is no "before" the big bang. It's meaningless. Time didn't exist until the big bang.

    That’s actually a non explanation, in fact theologians have argued similarly about the time before creation. God apparently lived outside of time. So stop asking questions.

    It’s also not fully accepted. There’s also a multiverse theory.

    Nevertheless it clearly has no explanatory power as to where the energy for the creation of the universe came from.


  • #43
    seamus
    Registered Users Posts: 68,317 ✭✭✭✭seamus


    Franz Von Peppercorn wrote: »
    That’s actually a non explanation
    Yes, that's exactly what it is. There is no explanation for the energy of the universe. It is folly to assert a "before".
    Nevertheless it clearly has no explanatory power as to where the energy for the creation of the universe came from.
    There is no reason for us to believe the energy "came from" anywhere. Before we can answer that question we need to determine if the questions exists in the first place.

    We have no model of physics to explain it, so at present there is no requirement for the energy of the big bang to have been created or to have an origin. For all intents and purposes it has always existed.


  • #44
    Franz Von Peppercorn
    Closed Accounts Posts: 7,070 ✭✭✭Franz Von Peppercorn


    seamus wrote: »
    Yes, that's exactly what it is. There is no explanation for the energy of the universe. It is folly to assert a "before".

    There is no reason for us to believe the energy "came from" anywhere. Before we can answer that question we need to determine if the questions exists in the first place.

    The question definitely exists. I just asked it.
    We have no model of physics to explain it, so at present there is no requirement for the energy of the big bang to have been created or to have an origin. For all intents and purposes it has always existed.

    There’s definitely a logical requirement for the energy to have been been there and physics not explaining it doesn’t seem to make that logic disappear. “Always been there” is also not much in the way of an explanation.

    St Augustine used tricks like this to argue that the angels weren’t co-eternal with God although the bible says they were (he says they were eternal in time but god was eternal before time), that God didn’t tarry in the creation of the universe and that we couldn’t even talk about what God was doing pre universe as there was no time prior to the creation of the earth. God was also always there. Doing nothing but not doing nothing as there was no time. Then the universe and time happened. Caused by God.

    So the “nothing to explain before there was time” has a not very good pedigree as an explanation.

    As it turns out that’s not the only physics solution these days


    Big bounce.

    https://en.m.wikipedia.org/wiki/Big_Bounce

    Multiverse.

    https://en.m.wikipedia.org/wiki/Multiverse

    And a general overview here including theories on string theory and colliding “branes”.

    In String theory the multiverse is a higher dimensional space in which branes (=universes) float around and sometime 2 branes collide in big fiery explosion (=big bang) and create a new brane.


    https://en.m.wikipedia.org/wiki/Initial_singularity


  • #45
    Fourier
    Registered Users Posts: 10,558 ✭✭✭✭Fourier


    Actually energy can be created and destroyed. In Newtonian Mechanics it can't which of course is what describes most motions of energy we see everyday.


  • #46
    Fourier
    Registered Users Posts: 10,558 ✭✭✭✭Fourier


    seamus wrote: »
    There is no "before" the big bang. It's meaningless. Time didn't exist until the big bang.
    That's a pop science notion found in many books unfortunately. In truth there may have been trillions of years prior to the hot dense state described by the Big Bang theory. The 13.7 billion year age is the limit of what current theories can track.


  • #47
    The Rape of Lucretia
    Closed Accounts Posts: 7,440 ✭✭✭The Rape of Lucretia


    OK, so what we can probably all agree on then is that :
    - energy can indeed be created.
    - admittedly, we dont know how it was created, nor when.
    - that it exists, proves it can be created, and that it is probably sloppy science to declare that because we dont know the how or the when, to declare that it is a law that it cannot be created
    - while we have the evidence it was created, we dont have evidence it can be destroyed, so the jury is out on that bit for the moment
    - in the OP's proposition, as they state it, and assuming normal batteries, motors, and alternators, we know that in the real world, inefficiencies mean his machine will not run forever
    - but, if one of those components were to include an energy creating process, then, his machine would indeed keep running


  • #48
    Fourier
    Registered Users Posts: 10,558 ✭✭✭✭Fourier


    The Rape of Lucretia wrote: »
    OK, so what we can probably all agree on then is that :
    - energy can indeed be created.
    - admittedly, we dont know how it was created, nor when.
    - that it exists, proves it can be created, and that it is probably sloppy science to declare that because we dont know the how or the when, to declare that it is a law that it cannot be created
    - while we have the evidence it was created, we dont have evidence it can be destroyed, so the jury is out on that bit for the moment
    We know it can be both created and destroyed, it occurs all the time in cosmology and subatomic reactions.


  • #49
    Capt'n Midnight
    Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 90,684 Mod ✭✭✭✭Capt'n Midnight


    Deleted User wrote: »
    Basically, the person who breaks the laws of physics and creates this will be the richest man the world has ever known.

    Fusion is as good as it gets if we ever make it that far. That would change everything.
    No it wouldn't.

    To get energy there are costs for fuel , for generating equipment and maintenance and financing until it comes online, for storage, for transmission, and for decommissioning.

    for wind and hydro and fusion the fuel cost is zero
    for fossil fuel and nuclear it's the opposite

    for dispatchable power like hydro and fossil fuel and biomass the storage costs are zero
    for nuclear and renewables it's not

    for locally generated power the transmission costs tend to zero
    for wind and nuclear not so much

    nuclear is in a class of it's own when it comes to the insane financing and decommissioning costs

    Solar is dirt cheap to install and maintain, but high storage costs.



    So even if you could generate electricity at Zero cost you would still have to factor in all the other costs too.


    You can get nuclear batteries. They are small, last for decades, provide power 24/7 365. But gold is way cheaper.


  • #50
    Wtf ?
    Banned (with Prison Access) Posts: 343 ✭✭Wtf ?


    We should go the nuclear way then. Too much ''What if's over nuclear power. A Nuclear sub or ship needs re powering after 20 or 30 years. The only thing stopping a Nuclear machine staying at sea, On or under the sea for an unlimited time is food for the crew. Human's are the weak link.


  • #51
    [Deleted User]
    Posts: 17,381 ✭ [Deleted User]


    Capt'n Midnight wrote: »
    No it wouldn't.

    To get energy there are costs for fuel , for generating equipment and maintenance and financing until it comes online, for storage, for transmission, and for decommissioning.

    for wind and hydro and fusion the fuel cost is zero
    for fossil fuel and nuclear it's the opposite

    for dispatchable power like hydro and fossil fuel and biomass the storage costs are zero
    for nuclear and renewables it's not

    for locally generated power the transmission costs tend to zero
    for wind and nuclear not so much

    nuclear is in a class of it's own when it comes to the insane financing and decommissioning costs

    Solar is dirt cheap to install and maintain, but high storage costs.



    So even if you could generate electricity at Zero cost you would still have to factor in all the other costs too.


    You can get nuclear batteries. They are small, last for decades, provide power 24/7 365. But gold is way cheaper.

    This was a weirdly formatted post so I don't really know how to reply. All I'm saying is that fusion is a totally different thing to what we think of when we think nuclear. Expensive to get running but if we ever do it, we don't even need renewables anymore. There isn't even any nuclear waste from it.


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  • #52
    Capt'n Midnight
    Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 90,684 Mod ✭✭✭✭Capt'n Midnight


    Deleted User wrote: »
    This was a weirdly formatted post so I don't really know how to reply. All I'm saying is that fusion is a totally different thing to what we think of when we think nuclear. Expensive to get running but if we ever do it, we don't even need renewables anymore. There isn't even any nuclear waste from it.
    Fusion is the future. Always was, always will be.

    ITER will cost €20 Bn. First plasma isn't due till 2025 at the earliest. Years of research then. Then if it's viable there's the costs of commercialising it and the time to get planning permission and construction.

    Fusion isn't going to be a major power source any time soon. There'll be a whole life cycle of fossil, wind and solar by then.


    At a 4% interest rate the interest payments alone on the ITER would be €800m a year. ITER will produce 500MW less 50MW, and that's heat rather than power so maybe closer to 250MW of electricity. Carbon capture would be cheaper.

    ITER is a research rector so costs should come down, in time.


  • #53
    Capt'n Midnight
    Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 90,684 Mod ✭✭✭✭Capt'n Midnight


    Wtf ? wrote: »
    We should go the nuclear way then. Too much ''What if's over nuclear power. A Nuclear sub or ship needs re powering after 20 or 30 years. The only thing stopping a Nuclear machine staying at sea, On or under the sea for an unlimited time is food for the crew. Human's are the weak link.
    Nuclear has some niche applications.

    Naval reactors tick most of the boxes, except for the insane costs.




    It's going to cost $1.5Bn to decommission the reactors on the Aircraft Carrier USS Enterprise. And by decommission they mean store the reactors in a trench like this for a hundreds of years. That's a billion dollars more than then initial estimate.




    An interesting question would be to compare whole life cycle nuclear costs , including the overhead of projects that were shut down early and factoring in the known cost overruns, with the costs of deep geothermal. Or the costs of insulating every home in the country.


  • #54
    Skylinehead
    Registered Users Posts: 11,690 ✭✭✭✭Skylinehead


    Capt'n Midnight wrote: »
    Nuclear has some niche applications.

    Naval reactors tick most of the boxes, except for the insane costs.




    It's going to cost $1.5Bn to decommission the reactors on the Aircraft Carrier USS Enterprise. And by decommission they mean store the reactors in a trench like this for a hundreds of years. That's a billion dollars more than then initial estimate.




    An interesting question would be to compare whole life cycle nuclear costs , including the overhead of projects that were shut down early and factoring in the known cost overruns, with the costs of deep geothermal. Or the costs of insulating every home in the country.

    Enterprise is quite special though, they built it with 8 (!) reactors. I think all the rest have 2 bigger ones, should be easier for decommissioning.


  • #55
    Capt'n Midnight
    Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 90,684 Mod ✭✭✭✭Capt'n Midnight


    Nixonbot wrote: »
    Enterprise is quite special though, they built it with 8 (!) reactors. I think all the rest have 2 bigger ones, should be easier for decommissioning.
    Smaller reactors should be easier to move.

    Either way they've had over 60 years to plan for this, it's been done already on dozens of subs and cruisers so there shouldn't be any surprises, and it's now going to cost three times as much as they thought it would ? This is normal nuclear economics.

    Again decommissioning just means bury it as is, no fancy stuff.


    The Enterprise produced 210MW using 4 reactors.
    Turlough Hill can pump out 292MW , it cost £22m back in the day
    The €650m Silvermines project would be 360MW and potentially be worth €80 million a year. ( payback in under a decade)



    If you have cheap energy storage then renewables have a tiny capital cost compared to nuclear.



    Back to the original question frictional and heating losses will drain the energy out of the system very quickly. So no perpetual motion there.

    But if you want nearly free power solar , wind tidal , wave will give you that, but you have to store it or back it up with something.

    Hydro or geothermal will give you free power, but it's very expensive to build as all the low hanging fruit was snapped up a long time ago.


  • #56
    Skylinehead
    Registered Users Posts: 11,690 ✭✭✭✭Skylinehead


    Capt'n Midnight wrote: »
    Smaller reactors should be easier to move.

    Either way they've had over 60 years to plan for this, it's been done already on dozens of subs and cruisers so there shouldn't be any surprises, and it's now going to cost three times as much as they thought it would ? This is normal nuclear economics.

    Again decommissioning just means bury it as is, no fancy stuff.
    Did they think about it when building it in the 50s? Probably not. I'm not privy to the details so I assume there's some difficulty there.

    The article above spells it out pretty clearly:
    Nobody has ever disposed of a nuclear-powered aircraft carrier before. Turns out it's not easy.

    Carriers are not submarines, they're way bigger and more complex. I think it takes 2 years just to refuel the things.


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