MigL

The direction is uncertain before an interaction and collapse. The spins are always opposite, before or after the collapse. Some observables are always uncertain.

Sometimes the models we build allow for predictions which are non-physical. They are 'weeded out' by inconsistencies that arise ( you should look into some of the absurd properties negative mass would have ), or experimental observations.

Maybe I got it confused with Canada's 36 million. I'm over 65 now; my mind is starting to go. ( or, maybe your immigration system/laws need to change ) At the time that was the definition of 'arms'. Today 'arms' means automatic assault weapons, as well as turbine engined tanks, stealthy fighter jets, aircraft carriers the size of a town, and chemical/biological/ thermonuclear weapons. Do you think that because the American armed forces have them, any rich individual should have access to them also ? ( hate to imagine what that goofball, E Musk, would do with an aircraft carrier )

Com puters are specific to their use. An old Pentium will suffice for Net surfing, as the speed is limited by your internet connection, not computing power. But you might want a Ryzen with 16 cores if you want to edit graphics or videos. Similarly guns have specific purposes. An assault rifle of low caliber has little stopping power and is almost useless for hunting game larger than a rabbit. Its purpose is to incapacitate, as a wounded enemy combatant will tie up two others to care/carry him, while a dead enemy can be left behind. You don't want to have wounded game run off and die somewhere you cannot find it, so assault rifles are bad for hunting. I read statistics that 360 million Americans own 400 million guns, but 3/4 of Americans do not own guns, only 1/4 of them do. At some point, it is simply saying " look, I have more, bigger, guns than you." Nothing more than showing everyone that you have ( are ? ) a bigger dick. And those insecure incels are the ones usually committing the mass killings

Energy and mass are equivalent properties. You cannot have negative mass without negative energy, and the same arguments against their existence apply to both. Only 'exatic' matter is postulated to have negative mass/energy, but it could be just an 'accounting' trick as it is the complement of Hawking Radiation and must be harvested just inside the event horizon of a Black Hole. Good luck with that. The speed a light, c , is reserved for massless particles and nothing having any mass can reach that speed. At one time Tachyons were postulated, which move faster than light and cannot ever slow down to the speed of light, travelling backwards in time. The term Tachyonic has recently gained a new meaning. Particles or quantum fields with imaginary/complex mass are unstable, and said to be tachyonic. see here Tachyon - Wikipedia and here Tachyonic field - Wikipedia

Excellent video, JC. I think you should ... Pay special attention at the end where he explains how neither Republicans or Democrats fixed anything during the years they each controlled all parts of Government. But the blame game works and keeps politicians getting re-elected without ever having to do anything abut it. And the fact that all American politicians are rich enough to have illegal aliens as gardeners, nannies, drivers, etc. ( no sense having to pay Americans real living wages for those 'menial' services )

Sorry. I guess I picked the wrong choice from the auto-correct suggestions.

Going by purely Heisenberg considerations, if at a certain scale translational symmetry ceases to have meaning, can a classical theorem like Noether still say anything about momentum conservation ? If position and momentum are 'fuzzy', or smeared out, translational symmetry and momentum conservation must necessarily be also. Feynman diagrams essentially put a box around an interaction within which all possible series of interaction can happen. The largest series of interactions, with the most nodes are least likely to be realizable as they describe virtual interactions, which are 'off shelf' and don't need to satisfy energy-momentum considerations. I would think that means our current models do not necessarily conserve energy or momentum at small enough scales. The conservation condition is approached, or emerges, when off shelf virtual particle effects become negligible, and you 'zoom back' out of the Feynman box. And it is already exceedingly difficult to keep the few electrons trapped in narrow, shallow potential wells, at current feature size of modern semiconductors in order to define logic levels, but Moore's Law has had a good run, going from a couple of thousand transistors 50 years ago, to over 100 billion in Apple's latest ARM implementation.

Helium ?!?!? Imagine how bad the executioners would feel whrn the condemned person starts talking with a little girl's voice.

very badly posed question. Of course it depends on the properties of the objects in the box. What if they are a lite -weight sponge, and make no noise ? What if they are a compound object, like 'nested' balls, that make multiple sounds on collision ? the hardest part of finding an answer is making sure you ask the right question. And you can call it AI modelling, but it's still a computer, so the old adage still applies; "garbage in, garbage out".

No, not yet. Wachu talkin' bout, Willis. I don't have a clue what that means. You just go on living that drudgery you call life, never venturing out of your mental sandbox. Leave the 'big picture' stuff to those with a sense of wonder and a need to know, who have done the heavy lifting to gain knowledge and expand their horizons.

Your notion of acceleration is not totally valid even for classical systems. Your 'push'/'pull' analogy only works for contact forces; it does not work in the case of gravity, or electromagnetic forces, where the whole body interacts with the force, not just the contact surface. Quantum mechanically things are no different. Contact forces, such as the LHC, are treated the same because the EM part of the interaction is small/weak compared to the collision part. One slight difference is that, classically, most people use Newtonian mechanics, but any 'advanced' treatments, including Quantum mechanical and Relativistic, use Lagrangian or Hamiltonian mechanics ( energy of the system ), as Swansont alluded to previously..

I believe Dim is referring to proper time, tau, ( not co-ordinate time ) which ticks by at exactly one second per second, in everyone's own frame. If so, he is correct.

My mistake. I realized both observer and the light source ahead of him are falling towards the future, but forgot to take into account the light source is ahead of the observer temporally, not spatially. I guess a barefooted observer, falling into a small enough BH, would notice his toenails need trimming, as they may be months ahead of him, in the future.

You're going to have to elaborate, Gemady. I don't see how an observer would be able to see anything ahead of himself upon passing through the Event Horizon, as there are no geodesics for light to follow in the outwards direction. The only available geodesics are forward in time to the center.

I had considered only an outside observer. An infalling observer will see things differently I suppose. But if you fell through the EH of a huge BH, along with a much smaller BH, would you be able to see it ? It it was ahead of you, I don't think you would, and I have my doubts even if the small BH was alongside you. You may be able to see it if it followed you through. And even if we don't consider different observers, how long can the two EHs remain distinct? They are essentially mathematical constructs denoting a region of extremely curved space-time

the word 'paese' can have two meanings. It can mean town, or it can mean country. I imagine this stems from the city-states that were scattered across the Italian peninsula, long before it became the country of Italy.

It was for exactly this reason (food defrosts in a microwave ) that I assumed it was bond stretching and bending, rather than translational and rotational. Thanks for looking into it. No wonder French people drink so much wine; they need the alcohol to cut the fatty foods 😄 .

I don't really understand the proof, but I find some of the approaches interesting.

Not 100% sure, but I would think as soon as the Event Horizons of the two BHs come into contact, they would merge and immediately assume a larger spherical configuration. As to the interior configuration/composition, I don't think we can say much. I'm basing this on Oppenheimer/Wheeler theory, however; I'm sure some computational modelling has been done for merging BHs in relation to gravitational waves.

Here is a ( long ) video illustrating some of the approaches to understand the Collatz Conjecture

Not replying specifically to you; just some general observations. right. And no, nothing stops at the EH; using different co-ordinate systems for a Schwarzschild BH will yield a non-singular EH.

I'm no Chemist, but I do believe you are right.

The geometry of space-time 'starts' at the Big Bang; geodesics extend forward in time, but not backwards. Somewhat like lines of latitude and longitude at the North Pole; they only extend in one direction ( to use Markus' analogy ). A Black Hole is different. The Event Horizon of a Schwarzschild BH ( non-rotating and non-charged ) appears differently to different observers. While an infalling observer may note nothing peculiar falling through the EH ( no time slow-down or tidal forces for large BHs ), a distant observer will note all information transmission from the infalling object slowing on approaching the EH, and finally stopping at the EH. To the outside observer it would appear as if time had stopped at the EH, along with geodesics leading into the EH. The EH is known as a co-ordinate singularity, and this apparent freezing of time does not happen in the proper time of the infalling observer.

Cooking involves applying heat to foodstuffs. Most always externally, as with fire, electrical heating elements, or even infrared radiation. A microwave oven works by pumping microwave radiation ( which is NOT hot ) into the foodstuffs. This microwave radiation is at the right wavelength/frequency to stretch/bend the intramolecular bonds of water ( and few other materials ), thereby heating the water, which then cooks/boils the foodstuffs. IOW, no internal water content ... no cooking. Haven't you ever wondered why the glass tray inside your microwave doesn't heat up ? That would seem very much like 'internal' cooking to me. Hard to dispel a 'myth' that happens to be true.