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condition
In relativistic classical field theories of gravitation, particularly general relativity, an energy condition is a generalization of the statement "the energy density of a region of space cannot be negative" in a relativistically-phrased mathematical formulation. There are multiple possible alternative ways to express such a condition such that can be applied to the matter content of the theory. The hope is then that any reasonable matter theory will satisfy this condition or at least will preserve the condition if it is satisfied by the starting conditions.
Energy conditions are not physical constraints per se, but are rather mathematically imposed boundary conditions that attempt to capture a belief that "energy should be positive". Many energy conditions are known to not correspond to physical reality—for example, the observable effects of dark energy are well-known to violate the strong energy condition.In general relativity, energy conditions are often used (and required) in proofs of various important theorems about black holes, such as the no hair theorem or the laws of black hole thermodynamics.
Hi just joined the forum. Looking forward to getting some experienced opinions here. Really quite desperate to get 2nd opinions etc....
We have a house built in 1934. Our water inlet pipe was changed to the blue plastic about 2 years ago.
We had a disconnected water softer when we moved in and...
I have just taken out a vailliant ecotec plus which is 10yrs old and has nothing wrong with it. The guy had just moved in and wanted everything new. Seems a shame to give it the travellers.
Hi,
I wonder if anyone can tell me if this leftfield idea, would be possible please? It's a bit crazy so please bear with me.
I have a medical condition where I have poor circulation in my feet which is painful. I have to soak my feet in warm / hot water on a daily basis. So I came up with...
If a y plan system shuts down when the last function was central heating power remains on to the motorised valve and maintains the motor in a stalled condition. This means that It can remain in this state overnight . Has anyone found a solution to this situation?
Unregistered
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Hi,
We are having an extension which is going horribly over budget. Our latest obstacle is that our builder has said that he is unable to procure or fit a new extraction flue to our boiler, because:a) it is an old boiler where the necessary parts are now obsolete (a Potterton Suprima, Serial...
Stressed_Dad
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Hi there
I've never posted here before and I'm definitely a layman so apologies if this is posted in the wrong area or I break any forum decorum.
We got a call from the neighbors of the flat we rent out saying there was water leaking into the the wall.
The bathtub (and shower) is right...
If anyone has an open flue boiler strip out coming up in or near kent any time soon and you don't want the boiler for scrap could you let me know it can have failed a cp12 or co readings etc it just needs to be complete ie case and controls and operating
New gas meter ,no pressure drop, 3/4 imperial copper pipe which goes under a concrete floor to a free standing cooker approx 3m pipe run which comes out the floor in 3/4 copper ,pressure and gas rate fine.OAP has bought new free standing cooker and wants it fitted. NO pipe work to any other...
hey all was at the above boiler today done a FGA on it and was getting high CO i cleaned out the primary heat exchanger which was in good condition, i removed/inspected the flue seals which were also in good condition.
There hot water is going cold as the boiler is cutting out when working on...
This is for all you tradesman who work outside of the m25 as this van is not LEZ compliant.
It's done 115k miles (which is nothing for a 10yr old van). Cambelt, water pump done at 100k. Just had an oil and coolant change including filter and thermostat. Plenty of tread left on the tyres. Mot...
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