Halc

If the cube is floating (not resting on anything), then it must displace its mass in water (just like a floating boat displaces its mass in water). When it melts, it still displaces its mass in water so no change in water level. All floating ice has about 10% of its volume above the surface since that's the density difference. If it is resting on the bottom of the glass, some of the weight is supported by the glass and not water, so the water level would be low and would rise as the ice melts. This rise ends once the ice stops resting on anything. If the ice is held under the water (by a lid on the glass say), then the water level will lower as it melts until the ice stops touching the lid.

To correct myself, it would depend on if the ice is floating or resting on the bottom or sides of the container. I had assumed floating.

Archimedes says it stays the same. So when the Titanic sinks, does the level of water increase or decrease? At what point in the process does this occur?

There's eternal inflation theory in all its variants which suggest that inflation never ends but forms fractal regions where inflation ceases thus forming bubbles that can be described as 'universes' with varying properties (different physical laws, constants, numbers of dimensions, etc.). In such a model, the universes don't 'disappear' since they're all bounded by inflation still going on. The model does not posit an initial condition for the inflation itself, so an infinite 'past' (if such a word is meaningful there) is not off the table. The 'theory' is an excellent counter to the fine-tuning argument since these bubbles of every conceivable tuning are all inevitable. I put 'theory' in quotes because lacking any empirical predictions (the fine-tuning thing isn't one??), it can be argued that it doesn't meet the definition of a theory.

This seems to imply several unstated premises, without any of which the conclusion does not hold. 1) "Nothing can come from nothing". This seems to assume physical law (that governing the initial conditions for the BB) that disallows uncaused events. Even now, QM allows uncaused events such as the emission of a photon from a lightbulb atom in an excited state which has admittedly a short halflife but is hardly a direct effect of the excitation event putting the atom in that state. 2) "Something always" seems to assume time is unbounded and the universe is contained within it, which contradicts every model I know. Time is part of the structure, not a container for the structure, so talking about time before the BB is like talking about Earth altitude being unbounded, and thus material at altitudes of -13000 km and beyond being required to hold up my house at the top of the pile. I.E., the naive premise can be used as as a proof of the flat Earth with turtles all the way down with Earth sitting atop an unbounded altitude and not having altitude built into the object. 3) "existed" assumes that the universe has the property of existence, despite the fact that existence is not necessarily a property in all views (for instance, it is a relation under RQM), and the fact that no empirical observation would be any different in an objectively existing universe and the same universe without the property of objective existence. I am kind of loosely willing to accept the first premise so long as its status as an unproven premise is acknowledged, but my personal view does not hold to the other two premises which I consider instinctual biases, which is precisely why I favor said personal view. Given the three premises (and perhaps more), the argument is valid, but seemingly not sound. Disclaimer: Have not read the entire thread. Just my comments on the title. Edit: Another one: 4) 'from nothing' contradicts 'always'. If there was nothing before the BB, then there was no time before it. Time is something. So is the state of absence of state. This doesn't invalidate the title statement. It only invalidates a model of "There was once nothing in existence and later on there was something in existence" and I know of no accepted physical model that suggests that.

It only takes one unbounded dimension to have an infinite data set. Our universe appears to have at least four. The location of a single particle is not expressible as a finite size number. Try it. What is your absolute location (not relative to something that doesn't have its own known location)? True, but there is no evidence that space is either finite or discreet. Then it isn’t a Turing machine, which by definition cannot change itself. I’m just wondering why you’ve chosen a Turing machine. It’s only benefit is that it has no limit to its data set. No viable model of the universe expresses an initial state of a point. That’s kind of a pop-science naive view. You can double or square the size of a point all you want and it will remain a point. Likewise, you can double or square the size of a finite size thing all you want and it is going to remain finite in size. Yes, the initial state is expressed as a singularity, but a singularity is just a place where the normal laws of physics don’t apply. It doesn’t mean a point.

A Turing machine runs over a 1D space, not a 3D one. It isn't a binary machine (except for the tape it reads). It is an n-state machine which can in principle run without numbering the states. A Turing machine is also painfully inefficient. It takes trillions of steps (clock cycles) to complete what a modern processor can do in one clock cycle. You seem to have a model of an emulation of a universe, which does not require any particular speed at all, but it does require a finite data set, and our universe does not seem describable with a finite data set.

My parents had an old solar heater that worked exactly that way. No electricity was generated. When it was sunny, water would circulate through the panels which focused sunlight onto the pipes. The water was stored in a tank which fed into the main water heater, reducing the effort to heat it to full temperature. They had a forced-air heating system for the house, so it was never used for winter home heating. As for barrels of rocks, rocks have far higher specific heat than metal, so you'd not want to replace them. I've seen active solar houses, and most of the heat sinks were rocks/concrete.

That was the 'literal interpretation' I was hoping to avoid. We're making only small steps this way. What is the purpose of the inner loop? What is the purpose of the outer loop? What is the purpose of the function (in one sentence)? You have all the information you need to answer that now, and it's only the first question. It's probably best to answer that before considering the other questions. The rest of the questions seem to concern finding potential bugs which is hard to do if you don't know the purpose of the routine.

Right. I don't know MIPS, but I could see that a0 and a1 were the only things referenced without setting them first, and v0 is never used, only written to. So I figured it out that way. Return in v0 is probably a convention, not anything made necessary by the chip hardware. I could be wrong. I've programmed in Z80, IBM 360 (anybody remember Tuggle?), MC6809, 68020, and Pentium. Right. I didn't want to talk about that until you saw it yourself. It helps that the code seems written by a human, giving those obvious label names. A compiler would not have chosen those. Right. Iterate a fixed 32 times through inner loop. Yep sll means that. You're going the wrong way. Right shift divides the number by 2 (or more if by more than 1 bit) No. That would be something like mov $t3 $a0. What do the parentheses mean?": 0($a0) When do we exit the outer loop? In words, not just a literal interpretation of the instruction.

OK so far. It's already practically natural language. What structure do you see? What's the control flow? You give no indication if you see it or not. What are the inputs and outputs? I can see them without know the convention used for passed and return variables. I don't see a stack being set up or utilized as is common with large functions, so this isn't a complex task. I also don't see any other functions or library calls being used.

Without even knowing this particular language, the code seems simple enough to be readable. sltu is not a shift instruction if my guess is correct. It think it is 'set less than unsigned' which just sets condition bits without changing any other register value. srl is a shift instruction To get more help, you need to show what effort you've made to understand it. Translating to java is perhaps not necessary. Try reading it directly.

All orbits are stable unless A) the velocity is small enough that closest approach is less than the radius of the object orbited (collision), or B) the velocity is at least as large as escape veliocity. All velocity is due to forward momentum, by definition. In other words, the velocity vector of an object cannot have a different direction than its momentum. The sun's gravity accelerates Earth downward (towards the sun) always, whether the orbit is eccentric or not. If the Earth is always moving tangentially to the sun, then its orbit is circular (it's not, but close), and there is no 'downward' velocity. The radius remains fixed. There is no other velocity that is the total free fall velocity. There's just the tangential component. For an eccentric orbit, the force on the orbiting thing is typically not perpendicular to its velocity, which results in a change in radius (distance between objects) and orbital speed. One can compute the speed by integrating F=ma over time, or by computing total mechanical energy at any given point in the orbit, which remains fixed for the entire orbit per energy conservation.

~30 km/sec actually, as you seem to be aware. 'Sideways' would seem to mean the velocity vector is approximately perpendicular to a vector pointing at the sun from Earth. This is true of any reasonably circular orbit. So not sure what this UCSB site is referring to. Right now the Earth is almost as close to the sun as it's going to get. It will be closest in a couple weeks. It's orbital distance is not changing at a rate anywhere near 3 km/sec. Around April it might be increasing at a max of under 1 km/sec. If I'm moving thataway, I have no velocity to either side of 'thataway'. 'Sideways velocity' seem to have no meaning out of context. Perhaps if you gave the context of the quote. Edit: I found the quote, and it seems to have been taken unreviewed from a quora thread. The '3 km/sec' is blatantly wrong, as is much on quora. They're talking about orbital velocity (off by an order of magnitude) and talking about why the Earth doesn't fall into the sun.

I was. I was educated for 13 years in a protestant parochial school and was taught that science doesn't conflict with their beliefs. The school placed top in the state in academic contests. Yes, they taught evolution and how it wasn't in conflict with my religion, and although my parents were in denial of it, I wasn't. Later on the church (only partly my denomination) decided to treat science as the enemy, forcing me to choose sides. It forced me to lay aside my assumptions on both sides and actually work it out myself. It was amazing how the pieces fell into place that never quite fit before. I've been in pursuit of such bias-challenging assessments ever since, resulting in my beliefs always being changed and refined. That has started to settle down now that I seem to find minimal self-contradiction in my current stance, but I recognize beliefs for what they are and would never presume to assert that my position is 'the correct one'.

That part isn't very intuitive I'll admint. No, because if I walk away from you, that's also an increase in distance between us, but it's simply not the same thing. Most matter isn't really moving very quickly 'through' space, but rather the space between objects expands over time. Both involve increase of proper distance between objects over time. The differences are more subtle, but to give an example, if Alice is here and Bob (nearby) is moving away from here at 0.7c, then the proper distance between Alice and Bob is increasing at 210,000 km/sec. Ditto for a galaxy ~10BLY away receding from us at 0.7c. But now there's Charlie (also nearby) receding from Bob at 0.7c. Alice and Charlie are now increasing their proper separation at 282,000 km/sec (per relative velocity addition formula). But recession of galaxies isn't that kind of velocity. The galaxy that is twice as distant as the first one (receding at 0.7c) is thus increasing its proper distance from us at a rate of 1.4c (420,000 km/sec). It isn't moving any faster than we are, but the space between us and them is increasing at that rate. The proper distance between Alice and the others can be measured with a tape measure that is stationary relative to Alice, and is whatever Bob or Charlie reads on that tape (with Alice at the 0 reading). The proper distance between the galaxies on the other hand is measured by the count of individual meter sticks of equal cosmological age, each one of which is unaccelerated since the big bang. That means all the meter sticks are moving apart from each other and over time it take more and more of them to fill the gaps. There's nowhere where the big bang did not occur. It happened everywhere, but places that are far apart now where not so far apart then.

Actually it seems very intuitive. If you take any collection of objects in one place and give them all random velocities (different speeds and directions), and assuming none of these pieces accelerates thereafter, they will all recede from each other at a rate proportional to their current separation. A grenade only sort of works this way since they're designed to have pieces that go in different directions but fairly uniform speed relative to the center of gravity, thus forming a 2D shell expanding with the above characteristics. The universe doesn't have a center of gravity and thus no meaningful 'place' where the bang happened, so any random object can be assigned the designation of 'here' and everything must recede uniformly from there at a velocity proportional to its displacement. The big bang wasn't an explosion, but rather the expansion of space itself, but the recession effect is the same as the infinite (no outside boundary) explosion at a location in space, and thus this expansion rate is quite intuitive. That rate is simply 1/time-since-bang, or at least it would be if the expansion rate was always constant, but it's currently pretty close.

Bubble wrap protects the thing from brittle impact, and also scratching. Spring are no better at the former and far worse at the latter. People don't need it since they're already covered effectively with bubble wrap and thus can connect with a hard object (concrete) at slow speeds without damage. Sure, I can break bones with a significant impact, but I would need significant deceleration space/area to prevent that. Car air bags add over 10 cm to my deceleration space and perhaps a quarter square meter to the area. Stunt people put that padding on the thing they hit rather than themselves, else they'd look like Violet in the Wonka factory. If you want to protect against crushing, you need to put a strong cage/box around it. Springs/bubbles are not help.

I have died 3.5 times already (1st three before I was 7), except that in each case science saved me. Sounds like a yes to the question. My wife wasn't first saved by science until her 30's. She's way more fit than I am.

Agree. You say this like I said otherwise. Anyway, it is also arguable that there’s no evidence against it either. MWI doesn’t conclude collapse at all. RQM does, per your quoted bits. Collapse is a relation under RQM. I favor the RQM interpretation, so I’ll likely not give much argument to Rovelli unless he starts claiming he has some kind of evidence against the others. It would have been appropriate to include a description (and not just the diagram) of the experiment along with all these highlights you chose. Is this still going on about RQM? Because if so, there is no ‘the superposition’ to destroy or not. Your statement seems biased towards some interpretation other than RQM, in which case I’m not sure why you brought up RQM in which superposition is relational. Also, I love how Alice, Bob and the friends are depicted as human observers while in the experiment performed, no humans were involved. The symbol just seems to be placed wherever a measurement is taken/recorded by some piece of apparatus, which seem to be these single-photon detector things. It would seem that any interpretation that predicts a different measured outcome would be falsified then. So there’s nothing special about RQM in this respect. Calling something a universal collapse or not is an interpretational assessment. One cannot measure such a thing directly. Copenhagen would simply say that the friends are on the wrong side of the Heisenberg cut, and thus did not cause the universal collapse like the external observers do. Under RQM, collapse happens Wigner becomes correlated with the friend (when decoherence occurs). This may happen whether or not he actually gains knowledge of the measurement result or not. This is why humans are not involved in the experiments since there is no practical way to prevent such correlation. Same with the cat in the box. If you set up the device to not actually base its signal to the outside to be based on the measurement result, then yes, interference (superposition) can still be measured. If it is simply a lie (always invert the result), then Wigner is correlated with the result and will not measure superposition. Wigner will have incorrect knowledge of the result but will know that superposition is gone.

That would indeed be huge, but it doesn't happen. If the friend is capable of calling Wigner, Wigner is effectively in the lab. Decoherence has taken place. Wigner cannot measure interference anymore as the wave function has collapsed. This has nothing to do with what the friend writes or says. This cannot be. If Wigner can measure the system, the lab is not a contained system (not a Schrodinger’s box) and the wave function of the photon is collapsed already due to it already having been measured by the friend. Wigner doesn’t know the result of that measurement (a classic epistemological state), but the photon is not in superposition relative to Wigner. If the lab is a perfect box (zero information coming out), then Wigner has nothing to measure. The friend can lie all he wants. It will have no effect on the outcome of any experiment unless Wigner bases his decisions (what to measure) on the information from the friend.

The real force is from the ground abruptly accelerating the object that was up until that point in freefall.

You need to actually read the post to which you are replying, which gave a fine example of change without speed of change. Another one: Air pressure changes with altitude, which is change without time or 'speed of change'. It has a rate of change which is the first derivative of the atitiude/pressure relationship, but that rate has no time associated with it, and thus cannot be expressed as a 'speed of change'.

Hubble helped provide evidence for the expansion, but did not discover it. He certainly didn't discover the acceleration of the expansion, which wasn't known for over 4 decades after his death. Yes, but that kind of motion (peculiar motion) is caused by local mass distribution, just like Earth's motion is largely effected by nearby masses, notably the sun. With peculiar motion, every change in momentum in one direction must be countered by some other opposite momentum change in the opposite direction. The peculiar motion of the Milky Way is actually more or less away from Andromeda, being largely influenced by the VIrgo supercluster, the Great Attractor, and ultimately the Shapley Attractor, all of which are vaguely in the same direction somewhat away from Andromeda. That will of course change when Andromeda passes us and gets on the other side in its slow dance to eventually consume us. None of this motion has anything to do with accelerated expansion of space. Accleration is observed by noting that Hubble's constant (rate of change in proper distance as a function of comoving distance) is not constant, but has been increasing since a minimum was reached about have the age of the universe ago. Before then it was considerably higher, and decelerating, mostly due to gravity predominating over dark energy during a time when the mass density of the universe was sufficiently high.

It did this from day 1, as do all free standing front load washing machines of which I am aware. The laundromat ones don't do it because they're bolted to the floor and to each other. The imbalance comes from laundry not being perfectly distributed. Nothing I can do stops that since the machine redistributes it, and tries quite hard to do it evenly. My point is that it does it most at a moderate frequency, which is similar to what the OP described. While I'm replying to your posts then: This is a plausible problem. If I take a disk and mount it at a slight angle relative to the axis of rotation, then it will wobble/vibrate as it spins despite not being off center. This is why it takes at least 2 weights to balance a car tire, which in combination yield a static balance (adjust the center of gravity to be on the rotation axis) and a dynamic balance (redistribute the mass of the wheel to a plane perpendicular to the spin axis). Or put it inside. It is a 'washer' after all.