Recent content by black hole 123

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    Temperature inside an enclosed space

    ok, i didn't know about the reradiate in IR wavelength. i have another question. if i put the same aluminium foil on a thermal conductor and a thermal insulator, and place both under the sun, suspended above ground with aluminium facing upwards, after many hours will the air beneath the thermal...
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    Temperature inside an enclosed space

    its summer where i live and the ceiling space gets extremely hot, much hotter than ambient outdoor. under a shade outdoor, the air temp beneath shade will be colder than air temp in sunlight. yet in a space with no air flow, the temp is always hotter from my experience. why is this? this isn't...
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    B Julius Caesar Problem from a SpaceTime Physics book

    hi i just read this question, and have a question of my own. for me, no matter how fast i travel or in what direction, i will never see the murder right? because the murder has a time like interval with me, and simultaneous events have spacelike interval, and interval length is the same to all...
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    B Universe Becoming a Black Hole: What Would It Look Like?

    this kind of answers my question, what i was thinking is if all the matter in the universe suddenly started gravitating towards some point (i know this won't happen in our universe but let's assume magic happens), and a person outside this sphere of shrinking matter would see a black hole...
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    Tensor Products and Maps Factoring Through

    i don't really understand ur question. what do u mean what theorem is need? this is an elementary result that u use for non trivial theorems, u don't prove elementary properties with other theorems. the tensor product V(x)W is the "freest" way of having formal sums (v1,w1)+(v2,w2)+...(vn,wn)...
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    B Universe Becoming a Black Hole: What Would It Look Like?

    suppose the universe started shrinking. because the density vs mass is a 1/M^2 factor, density can be made arbitrarily small given high enough mass. so it's not hard for all the mass in the universe to quickly reach black hole density. when critical density of the universal is reached, what...
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    B Rod Dipping in a Black Hole: Exploring Tidal Forces and Event Horizon Impact

    thanks for the answer. i forgot its the pull of rocket not tidal force. pervect is that for a small black hole? a human can fall into a supermassive black hole and not be torn, and (most) humans are over 1 meter in length. also about the inside of the black hole, can it be thought of as simply...
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    B Rod Dipping in a Black Hole: Exploring Tidal Forces and Event Horizon Impact

    if there's a really good rocket hovering just above a super massive black hole with very low tidal force, and it dips a rod just inside the event horizon, will the rod break? it seems a certainly but the tidal forces are very weak. is it like dipping ur feet into piranha infested water? so when...
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    A Vector space (no topology) basis

    yes I am pretty sure there's a theorem saying existence of hamel basis is equivalent to AC so if someone managed to write down explicit basis then that can only mean trouble... this is like the issue with ultrafilters and well ordering of reals and many other things.
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    I Prove that if T is injective, T*T is invertible

    im pretty rusty on this so double check for mistakes... to show T*T is injective u just need to show if T*Tu=0, then u=0. 0=<T*Tu,u>=<Tu,Tu>, so Tu=0. since T is injective, u=0 T*T is linear and injective and goes from V->V, so range of T*T must have same dimension as V, i.e. range of T*T is V...
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    B Does a field with 0 value "exist"?

    this has bugged me for quite a while. i was listen to chalmers talk about consciousness and making comparison consciousness to the field generated by a mass/charged particle. i know this is slightly philosophical question, but does a field with uniformly 0 value exist in the sense we mean...
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    B Doesn't the choice of measurement prove free will

    hi, this is slightly off topic, but can someone clarify wat free will is? obviously determinism means no free will, but non determinism doesn't imply free will. u might then say free will is behaviour that's not deterministic nor conforming to the calculated probability distributions of the...
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    B Quantum eraser and time travel

    hi, it seems i misunderstood the experiment. i thought if the first 2 detectors of the idler photon (to determine the slit the idler came through) were shut off, then the TOTAL pattern would show banding, and if the detectors were turned on, then the total pattern would not show banding...
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    A Is QM Foundations Facing a Crisis?

    i don't know any advanced quantum theory but i don't think interpretations of QM has anything to do with "axioms" of QM, because axioms are only a calculational/epistemological thing. also the math side and how things settled seemed very arbitrary to me, the CH is obviously false and people just...
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    I Human eyes can detect single photons?

    i disagree with the consciousness/collapse thing. even if somehow u need a human eye to see the photons to cause collapse, the eye is a mechanical device, consciousness whatever it is, is only observing the electrical pattern in the brain not what the eye sees. Nugatory put it succintly, the eye...
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