Delta1212

Whether we can say that the lives of the two stars overlap depends on how far apart they are. Let's say that, in the frame where the stars burn for 7 billion years, they are 3 billion lightyears apart. Light from the first star leaves toward the second star at the beginning of its lifespan. (Event A). Upon arriving at the second star, light from that star heads back to the first star. (Event B). Finally, the light from the second star reaches the first star before it dies. (Event C). Now, no matter what frame you are in, A happened before B, which happened before C. Since the first star was "alive" for the time from event A to event C, and since event B happened between A and C and the second star was alive at B, you can say that both stars were alive at the same time, and every frame will agree that this is true. They will not, however, agree on what points in the lifetime of each star correspond to one another.

Symbiotic bacteria do a variety of things, especially with regard to digestion. It's actually pretty fascinating if you look into. Changing the types of bacteria in your digestive tract can radically alter your metabolism, to the point that obese mice given guy bacteria from thin mice dropped considerable weight, and thin mice given gut bacteria from obese mice out on weight. As far as "policing" goes, the good bacteria mostly occupy space and free resources in the body so that it's unavailable for more harmful bacteria to use. They don't generally attack "bad" bacteria on your behalf, but they do do the job of crowding them out. And yes, especially deadly diseases tend to become less severe over time. Diseases that kill their hosts too quickly don't get a chance to spread, while less severe forms may go undetected or persist well after a more deadly form has killed its host, allowing more opportunities to infect others. The especially deadly diseases are usually a result of species jumping, where a virus or bacteria that is settled in one species mutates in a way that allows it to infect another species that it isn't as well suited to and that it hasn't "learned" how to infect without causing serious damage. The result is often a particularly deadly disease that will blow through a population that doesn't have a strong immunity to it. This creates a selection pressure on the population to become more resistant, and a selection pressure on the disease to become less deadly so it can spread better. It's highly unlikely that a single disease would arise that would be able to wipe out all of humanity because of this settling effect, but several at once can have an incredibly devestating effect because those people with resistance to one disease, who would normally survive and increase the resistance of the general population, may be susceptible to another disease, wiping out immunities from the population. This is actually part of the reason that Native American groups had as high as 90% population loss in some areas in the early years of colonization.

That actually has implicit mathematical exactness. If force equals zero, then acceleration equals zero. I disagree with Bignose on the premise that words can't convey mathematical exactness, but I do agree that any claim must convey mathematical exactness in order to be testable, and any claim that isn't testable isn't scientifically useful.

Let's flip it around. You can't state that two things took place at the same location if they happened at different times, except in a specific frame. Different frames will disagree on the location just as they disagree on the timing. An asteroid passing by the Earth sees itself at rest and the Earth as moving past it. So you might go to bed one night and wake up the next morning in the same bed and say that you fell asleep and woke up in the same location, but at different times. The asteroid, meanwhile, would say that you woke up tens of thousands of kilometers away from where you fell asleep because that's how far the Earth moved in that time. Events that do not take place at the same time in the same place cannot be said to take place at either the same time or the same place, because the distance and time that separate the events will vary with the velocity of the observer.

Simultaneous according to whom? Individuals with different relative velocities will disagree on which events are simultaneous, and since there is no preferred frame of reference, they are all equally correct.

Who is the "we" in this sentence, because I don't call any of your examples science. Also, I'm posting from an iPad and accidentally gave your post negative rep when I meant to hit Quote. If someone wouldn't mind zeroing that out for me, I'd appreciate it.

Why is the universe an electron and not a quark?

Quantum entanglement allows correlations to appear over a distance without respect to timing. It doesn't allow for the transmission of any information over those distances at faster than light speeds, which makes it rather difficult to use as any kind of medium for faster-than-light communication (or thinking).

The amount of resources directed at discovering something new doesn't provide a good metric for figuring out how long it will take to figure it out. Certainly, more resources can make the work on a particular problem go faster than fewer resources applied to the same problem, but comparing different problems doesn't work as well because the complexity of the solutions may be vastly different, or one problem may have no solution and actually be a dead end entirely. You can say that it will take x days to finish a house on y budget with z number of workers, because people have built lots of houses and can say from experience how long it will take and what the relationship to funds and manpower is. You can't then say that applying y funds and z workers to building a warp drive will have it completed in x days, because no one has ever built a warp drive, so we have no idea how much time and money it will take to get one designed and built, or even whether it's physically possible for us to build one at all.

Perhaps rather than "your problem" I should have said "the problem with attempting to define evolution in this particular way." Regardless, the best definition for evolution really is along the lines of "the change in allele frequency in a population over time." Anything that causes that contributes to evolution, but doesn't necessarily encompass evolution. The death of a single individual will (slightly) change the allele frequency of a population because all of that individual's alleles have lost one instance of themselves. The birth of a single individual does the same thing, as each of their alleles now has another instance present in the population. Every birth and death contributes to evolution in this manner, but you can't, for instance, make death a necessary condition for evolution to have taken place, because birth contributes to evolution but doesn't (have to) involve anyone dying.

Ok, let's take this one at a time. New characteristics are caused by mutations in a subsequent generation. Mutation is one element of evolution. The appearance would be an example of a change in allele frequency of the population, since there is an allele that didn't exist before, so that would meet that definition of evolution, although, again, you won't get this new characteristic cropping up without reproduction Any time a change occurs is a mutation. Any new characteristic that pops up would be the result of a mutation, and any environment you set up to select for that mutation and cause a change in the population that would result in the culture evolving. The change would already have been transmitted to a subsequent generation, so you can't really say that you prevented it from being transmitted in one. Part of your problem here is that evolution is a process, not an event. Attempting to define it by required parts is difficult because a lot of things can result in evolution. It's like driving. Is pressing the gas pedal driving? What if the car is off? So the car has to be on. What if you're coasting on the highway? So the car has to be moving? If you're stopped at a red light, are you no longer driving? What if you crash into a wall? Are you still driving while the car hits it? What if you don't have your hands on the wheel or foot on the pedal at that moment? What if you take your hands off the wheel and foot off the pedal while on the highway? What about cars that have a manual transmission? Does the clutch constitute an element of driving? Can you not drive automatic cars then, or is it irrelevant? There are a lot of things that contribute to evolution: reproduction, mutation, and death are major elements. Can you pick out one and say, there, when that happens, is it evolution? Well, in the sense that that event contributes to evolution, yes. In the sense that that event defines evolution, no, because there are other things that can happen which also contribute to evolution taking place.

The thing is, you already have successive generations built into your scenario for both dishes. The MRSA strain is a different generation from the original, non-resistant one, and it's not a change that will instantly take over the population, which means you've already had to go through several "generations" of the bacteria to get the resistant strain. You can then wipe out the culture and that strain will go extinct, but it did evolve to get to that point, and did it generationally.

I've heard some people with the surname Schmaltz pronounce it fairly close to rhyming with false, but as a word it definitely doesn't.

Besides which, by convention, we do treat Earth as the default "rest frame" for most measurements of speed. Scientifically speaking, if you were doing 100mph down the highway and a cop pulled you over, you'd be correct to state that you weren't doing 100mph. In fact, you were at rest and the Earth was zipping by you. Same for the velocities of spacecraft and celestial objects and such. Any time you see anything at all described as moving at any speed other than "at rest" it's generally being given in comparison to either the Earth or, occasionally, the sun. But we also recognize that this is just a convention, that it is arbitrary, that literally any other frame would work just as well, and that sometimes you'll want to calculate results according to a frame other than the conventional one.

You get to read one number off the scale.

Well, since there are only a googol zeroes in the number, that would require writing it a pace just a very tiny fraction faster than one digit per year.

Yes. Because there is a very specific requirement for a new behavior to be considered evolved: it must be biologically rooted. A learned behavior is not genetically heritable and is thus not a result of biological evolution. I'm inclined to think it probably is at least partially, if not wholly, rooted in genetics and vehicular hogslaughter is selecting against the rolling instinct. However, I do not know this for certain. Having a strict definition for what constitutes biological evolution provides us with a framework for how to determine whether the hedgehog's behavior is a result of natural selection, or from an innate ability of hedgehogs to learn new defensive strategies in response to their environment. These are two very different processes, and using a definition of evolution that lumps both of them into the same category is far more restrictive than separating them because it effectively eliminates useful terminology that is used to distinguish between different processes.

That quote has also been attributed to a 19th century patent office worker. I wouldn't take it seriously.

In common parlance, yes. Scientifically, not in the context of biology.

Eugenics largely deals with manipulating the genome towards (someone's idea of) perfection. That is, and was even moreso at the time, defined largely by someone's personal bias as to what represents a "good" quality. And, again especially then but even now, a lot of people would base their idea of a perfect human on racial differences, at least in part. Eugenics is entirely based on subjective criteria for what makes an idealized human, and it is very difficult to remove racial bias from the equation when determining what an ideal human is as a result.

I'm not entirely sure what some of that meant, but I'll try to address what I can. Could you treat the sun's FOR as a preferred frame, calculate everything from the frame of the sun, and get consistent results? Yes. You can also do this with literally any other frame, however, so there is no objective basis for treating any of them as the true "rest frame" for everything. It would be an arbitrary selection with no basis in reality. There simply isn't any way to tell whether something is at rest or in uniform motion except in relation to something else, and it is equally valid to say that that something else is moving. As far as time dilation goes, we've measured a difference in the rate at which time passes depending on how fast an object is moving, as well as how deep in a gravity well it is. I'm not sure how what you've described would negate time dilation as a physical occurrence.

An idea points you in a direction to work. Until you've done the work, you can't really tell how good an idea is. "Light moves at the same speed for all observers regardless of their own motion" is an idea. Until there is a more detailed description of how that even works, and a method laid out for testing whether it is true, it is just an idea. Many people have many ideas, and without testator details, there's very little way to distinguish between the good ideas and the wrong ideas. Metaphor: You and a hundred of your closest friends are all lost in the forest. There are hundreds of different paths branching out from the spot where you're gathered. Everyone thinks a different path is the one that leads out. You each walk down your chosen path for a day, and then walk back. One of your friends picked the right path, so you all follow him down it and out of the forest. But wait, it took three days to get out that way. If everyone had just listened to your friend in the first place, you could have been out of there two days sooner! Wouldn't you agree that one day spent lost is better than three days spent lost? It's easy to say in retrospect which ideas deserved more attention than others. It's extremely difficult to tell what ideas will lead to important discoveries ahead of time. That's why you have everyone work on their own ideas until they have figured out all of the details before presenting it, so that if the idea ultimately takes them nowhere, everyone else hasn't dropped everything they were doing to wander down a dead end. There generally aren't a lot of scientists sitting around thinking "Gee, I wish I had an idea to work on." Most of them have their own ideas to work on. Helping Einstein formulate SR ten years earlier would have taken them away from their own project, and until Einstein had actually gotten the math worked out, there was no way to know whether that was going to be a waste of valuable time or not.

Yeah, this is what I was getting at. Edit: Well, that and the fact that the difference between relative velocity and separation/closing rate is not obvious if you're already having trouble with relativity.

I didn't say it was incompatible with Maxwell's equations. I actually said the opposite, although perhaps that post wasn't as clear as I thought it was.

I think that may be slightly misleading, because I can interpret what you just said in two ways. One of those ways is obviously correct, but seems like it would be misleading given the way you worded it, and the other seems like it would be wrong, although I'm on shaky ground here. If by "traveling at 0.5c relative to Earth" you mean that everyone's measurements agree that the Earth sees the shpaceship moving at 0.5c, then yes obviously. If you mean that everyone measures a 0.5c difference between the velocities of Earth and the spaceship, that doesn't seem like it would be correct. You probably mean the first, but it sort of sounds like you're saying the second, especially in the context of addressing someone who (no offense, michel) has expressed difficulty in grasping certain aspects of how relativity works to begin with. Or, alternatively, I'm wrong to presume that the second case is inaccurate and I have more to learn.