Halc

That's really cool. I am hardly qualified to comment, but when has that stopped me? Whacked hard enough to drive the ore down a km, but soft enough to not splatter the stuff all over. Hard sell, that one. The fission takes place on Mars but not the asteroid pre-impact. Seems unlikely since the concentration should be higher before impact. But the ore sits there for a super long time until water does something to what, pull it together? Water does do stuff like that, so maybe. Now it needs to be a bomb, which apparently is triggered by critical mass, and the subsequent boiling off of water. That's not going to happen in a short time since the water has nowhere to go quickly. Geyser maybe, with the overall pressure holding in the rest. Without the water, it goes all bomb on us, much slower than our weapons, but far more pressure keeping it there while it goes on. Eventually the pressure breaks the surface and you get this crater, a lot like Mt St Helens depressurizing in 1980. Where is that? How much does Martian weather erase craters like that? All they have is wind driven dust. So what, it fills in? Look for a deep sand hole? Just vocalizing my naive thoughts. I admit none of it seems to kill the idea. My strongest skepticism is at the top, before all the alchemy takes place. Since we're going off topic (sort of), it turns out they recently found the world's oldest fossilized forest, right by me (bicycle ride away), one old enough to push back the date of the earliest real trees. What they mostly have is a cluster of root systems, really big ones, like with a 15 meter footprint.

Only because it is impossible to know anything at all, like say that the apple is indeed there before you. Such knowledge is a product of induction, not deduction. Similarly, if the universe is finite, there is NO possible way for us to know that either, so your conclusion that mathematics showing the former to be more probable is an indication of a mathematical error, is an unfounded conclusion. There can very much be evidence of infinity, but it isn't a proof, and your comment seems to only deny such a proof, something with which I agree. Is space discreet, where there are two adjacent locations halfway between which there isn't another location? If so, all sorts of funny conclusions can be drawn, perhaps like a preferred reference frame (invalidating all of relativity). If not, there's an infinity for you. Is that infinity observed? I don't think that counts, so no. Is it real? Not if being real is defined as being directly observed by a human. The universe might have an edge a mere 6 GLR away. No light that reaches any human has ever been more than that proper distance away. Clearly the concept of 'visible universe' uses a different notion of what is visible than that 6 GLY limit. For instance, a perfect simulation of everything we see need only process that 6 GLY radius. Anything that happens outside it cannot affect what any human can measure. This line of thinking goes down the rabbit hole of direct vs indirect observation. One concludes the apple is there via induction, not by directly observing the apple, which hasn't a clear way to do. I would have liked to have seen that infinite energy error. I love finding errors in papers making outlandish claims like the one you mention seems to. For entertainment, go to conspiracyoflight.com and find all the proofs that relativity is wrong. Find the flaw in each one. Doesn't take long, but nobody on the site every corrects any of them. Not the purpose of the site, similar to truth being the purpose of any site with the characters 'truth' being part of the website name. George Orwell saw it coming with his ministry of truth. We can say it, but it is trivially falsified. A torrid universe is flat everywhere, and yet has finite volume. One of the oldest examples is the universe of the Asteroids video game (only two dimensions of space, not three). We seem to be digressing. I mostly came into this to point out all the pop-science notions being asserted in this topic, and none of those seem to come from you.

I disagree with the 'possible' part, but I will add that we also do not know that it isn't actually infinite, so by the same logic, it makes no sense to say that "a real infinity shouldn't be possible". I'm actually not talking about phenomena at all. I'm taking about the real universe, not our perception of it, but it seems that your definition of 'real' seems to depend on knowledge, a sort of idealistic stance. But if we take this stance, there is little difference between the abstraction that is mathematics and the abstraction that is the universe. Is time infinite? It's not like the expansion is going to stop and turn around and crunch. So we get to heat death. That happens at some finite time, after which there really isn't time anymore. No visible universe to have a volume. No observation. Not even radiation remains. I have a hard time arguing for infinite time. So it's not that the universe cannot have infinities, it is that you presume an error has been made if one is demonstrated, a sort of denial of evidence. Seems to be a strange stance to take.

The Fermi paradox articles call this the 'great filter', some test that a technological species must pass in order to not get filtered out. It does not look well for humans. Problem is, our current civilization depends on technological continuity to maintain itself. War is one way that ends, but so is the simple exhaustion of non-renewable resources. Once gone, that's it. We cannot advance again and the species reverts to just an animal with an expensive brain that might be more of a hindrance than a help. One has to eat an awful lot of food that other animals don't need, in order to feed the expensive toy. Despite the frequent depiction in fiction ('Aliens' come to mind), nuclear reactors cannot explode. At worst they melt down, arguably a worse fate than a bomb, but not one that is quite as fun to depict on the big screen. The species needs to act for the benefit of the species instead of the individual. I know of almost nobody capable of that. Our core moral code even forbids it. We're quite doomed to fail the Fermi test. I notice that several people might point out the problem (as I am doing here), but nobody posits a solution (including me).

I don't mean to pick on one person, but there seem to be plenty of mistakes. I also realize this topic is a month old. As for 'real infinities', I'm fine with them. The universe is supposedly infinite in size, which doesn't seem to contradict anything. Given that, the universe has infinite mass, but I agree that only finite mass can be contained by any finite volume. I know it is a university site, but the whole page there seems not peer reviewed and flat out wrong. It propagates the popular notion of there being a compressed point in space at the center of a black hole, which is anything but the case. Compression does not go on. Tidal forces tend to pull things apart not compress them. The center of a black hole is singular, which does not mean it's a point, it just means that physics does not describe what goes on there. A coordinate system that isn't signular at the event horizon (Kruskal–Szekeres coordinates, or a Penrose diagram) show the black hole to terminate at a space-like line at the end of time, not a place where all the mass ends up, and all of this is a description of a simple Schwarzschild black hole which by definition is eternal and has nothing falling into it. OK, the Penrose diagram doesn't necessarily show a Schwarzschild solution, but the other does. [Citation needed] Not sure what is being quoted here, but it seems to contain the same mistakes, presuming a sort of Newtonian vision where mass just gets crunched into a point in space. The bit about light (or anything) not escaping is already true at the event horizon (by definition) and is not a property specific to the 'central' singularity. The bit about the ring singularity is correct, but it's a 2D surface, not a 1D circle. It's just hard to draw all four dimensions in a 2D picture. The list doesn't mention a charged black hole, which results in a sort of fuzzy singularity that lacks a neat geometric description. Length contraction is a coordinate effect, not physical compression with proper 'pressure' and all that. I kind of do agree that matter undergoes a sort of coordinate compression as it falls to the end of a black hole. It actually gets pulled apart, but also contracted. At the end of time, it kind of just doesn't exist anymore, but that statement is an assertion of physics at a place where physical law doesn't apply, so nothing officially says that. Coordinate compression cannot contract a the dimensions of a mass down to zero. Such a frame is not a valid one. That's right, which means density (a function of space among other things) is not defined at said singularity.

Yes, i do, by at least two different methods described in my prior post. Yes, countable with natural numbers (not integers). It being countable means there is a 1-1 bijection between the whole numbers and each 'thing'. I can for instance, find one natural number that corresponds to a particular pebble on Pluto. How much time it takes to determine that number is finite, and entirely besides the point of the claim. You seem to suggest that it would take unbounded time to do the work of explicitly assigning a number to each thing, which is true, but it is also true of the integers, unless you're suggesting that the integers are not countable. Not a natural number, agree. The OP seems to presume otherwise, and runs into all sorts of contradictions due to that assumption. The wiki article sort of implies that infinity is a number, but a cardinal number, which can be compared with other cardinal numbers. I'm not sure about infinity being uncountable. I mean I'm not sure if there is a bijection between the natural numbers and the cardinal numbers since one cannot define adjacent numbers. If one is never sure if there is a cardinality between X and Y, then you can't count to Y. You seem to be unfamiliar with the concept of countable infinity vs uncountable infinity. This is what is being referenced when I say that the list of things in the universe falls into the former camp. A set being countable in no way means that it has a finite number of members, but yes, if it has a finite count, then it is a set with finite members by definition.

Not so. A single unique integer is enough to identify any one of those things, and at a specific duration of time. Thus the list of all things in this universe* has the same cardinality as the set of whole numbers. * The whole universe, not just the visible part, but the comment presumes counterfactual definiteness, without which distant and little 'things' don't exist by the usual definition of existence. Numbers can encode those letters, so the letters add no additional utility. In fact, that is one trivial way to describe any 'thing' with just one number. Describe it in text, and the ascii encoding of that text is the single integer in question. There are more mathematically precise ways to do it, but this method suffices. The entire JW bible can be (and is often) expressed with a single integer. More than enough, since infinity is described in multiple finite sources, each of which corresponds to a single number. You are apparently asserting random things which you hope are true, but are demonstrably not and thus are not rational. A region of spacetime (a box of a certain size, for a certain duration) requires 8 coordinates (integers), which can be encoded with a single integer similar to the way the rationals (with integer numerator and denominator each) can be enumerated with a single whole number. They're countable. Similarly, and region of spacetime, of any desired precision, can be expressed with a single integer, and is thus countable. What is impossible is absolute coordinates for any given thing. An origin must be selected, making the coordinate position of any given region relative to that arbitrarily selected origin. So the location of Earth cannot be specified without using a relation of some kind, hence it not having an absolute location. I have no idea why you think the speed of light is relevant to specification of the location of something, except perhaps in the optional effort to utilize natural units. Why does the speed of light not have permission to use any given number more than once? Why would the speed of light need to use a number at all? It isn't an abstracting entity like we are. I.E. what did you mean by that assertion?

There are a great deal of stars with no or very little mass estimates. The Polaris case is important due to it being a Cepheid (the nearest one), and a good mass estimate of those is needed since they're used as cosmic rulers. Anyway, they only recently found something orbiting it, allowing the mass estimate. The earlier estimate was off because only a small portion of the orbit had been observed. It takes 30 years for one orbit, and only now is that more than half complete, allowing the finer calculation. So yes, there are plenty of stars with nothing visibly orbiting it, and it is very difficult to estimate the mass of such a thing.

You didn't read my post. I said it accounts for under half a percent of the heat budget of Earth. That figure wasn't made up. Earth loses internal heat at the rate of about 47 TW. Tidal heating of the mantle/core/crust is under 0.2 TW, well under half a percent of the total figure, small enough that the one article you linked didn't bother to mention it. Sources are linked above.

It does heat the ocean, but internally, tidal stress currently accounts for under half a percent of the internal heat budget of Earth, most of that being near the surface, not contributing even that half percent to the deep internal heat of the planet. The article you chose didn't bother to include sources below some threshold of significance Because radioactive decay accounts for about 100 times the heat compared to tidal heating? It's not a wishful thing. It is the finding of empirical measurements. Half of it is primordial heat leftover from formation, so you omitting that is far more negligent than the one particular article not bothering to include tidal stress energy.

Wider tires do give somewhat better grip. It is not a linear function, so a wider tire has somewhat less load per area, but not in proportion as is suggested by the linear coefficient of friction equation. Wider tires increase weight and drag, so you don't want to go overboard. Less pressure per area decreases wear, and wear is an incredibly important factor in a long race. Wide tires maintain better contact on imperfect tracks, which contain debris and wet/oid spots. The suspension dynamics is more important in the turns where turning grip is more important than thrust, so the suspension is designed to transfer more weight to the front outside wheel in a turn. If turning performance wasn't an issue, the front tires could be far smaller and lighter as they are in drag races. They are not used for acceleration in either case.

Well OK. Some high speed rock hits it, and instead of it all dispersing like a triangle of completely elastic pool balls, it absorbs the energy more like a ball pit, a far more inelastic situation. The rubble pile expands from the new KE, but gravity slowly pulls it all back together and only some little bits might escape. I can buy that. Neither of those objects are rubble piles, although Ceres has quite a bit of ice that holds together at least the outer layers. They both have similar constitution, like that of a typical Kuiper object. I also did not call any asteroid a meteor, but I did suggest that they can be hit by one, just as can any other celestial object. Only way the fragments get ejected is if some other higher-speed object comes in and smacks out a few of them now and then. All the rubble from an object torn apart by Roche forces end up going the same local speed. You don't see Saturn ejecting material of the rings without outside help. Every bit of it is moving pretty much with zero velocity relative to its nearest neighbors. Mars will have some nice rings soon. I wonder how long the whole process takes?

Rubble piles would seem to disperse at even a minor hit from some meteor. How are they stable? Do they simply not get hit due to being such a small target? Things that drift inside the Roche limit of some larger object tend to fall into that larger object in due time. They don't end up escaping the gravity well that created them.

Much of the post would be more understandable with better punctuation and sentence structure. The big bang theory is not a theory about the generation of the universe, so no. This anthropocentric statement presumes humans to be the only or at least first self-aware species on Earth. Given no limit for the eventual age of the universe, any finite specification of a time is closer to the beginning than to the end, so that statement is tautologically true. You don't know this. It seems to presume a form of life that is dependent on the existence of a galaxy, and who knows what might be possible when lifted from the restriction of 'life as we know it'. I can't think of it either, and it would seem more probable in a second-generation star like our own, and not so much the first generation ones in the early stages of any galaxy. Still, our sun was hardly one of the earliest second generation stars to form. The Fermi paradox deals with detecting technological life nearby. The title of the thread asks if we're the first in the universe, and the odds of that are zero, but seemingly they are all so distant and/or so briefly lived that none of them are on (not just in) our local past light cone. And then this devolves into dyson spheres again, the relevance to the topic being left unstated. It will take considerably longer than that to blink out all the black holes. The universe of just radiation and black holes is about as incapable of supporting life as the same one with the black holes gone, but again, that's presuming 'life as we know it' in a way.

This is incredibly hard to parse, but let me attempt something. What does 'different' distance mean? I presume A and B are initially separated by 29 MLY (about 8.9 megaparsecs), but then you indicate that this distance is different from something, but don't say what. If they both have zero peculiar motion, they will be moving apart at a rate of around 600 km/sec due to expansion. This travesty of syntax is baffling. What does 'right' mean at the end there? An 'initial date' is a time, and a date isn't something that reaches a destination or otherwise moves, unless we're talking about the kind of dates that grow on trees. I am guessing that your ray of light emitted from A takes 29 million years to get to B, at which time B will no longer be only 29 MLY away since it is receding at 600 km/sec. B will be over 50,000 light years further away when the light pulse gets there. Now you seem to see a paradox in all this somewhere, but your writing skills fail to convey what you claim is paradoxical. Yes, astronomers looking at something X light years away realize that the object appears in a state and position it was in the past (and not X years in the past if X is large). Nobody is overlooking anything there, but you seem to claim that they're overlooking something. Sorry, cannot help you. You've not in any way identified what you think is being overlooked