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  1. Dear All, I am going to take a hiatus from the forum from today. As some of you might know, the natural sciences are not my only area of interest; in particular, I am committed to a form of spiritual practice as well, and have been living in a Buddhist monastery as a lay person for the past few years. I have made the decision to deepen this practice further by ordaining as a monk in the Theravadin Thai Forest tradition, and for various logistical and monastic-political reasons this should ideally happen at a traditional training monastery in Thailand. So tomorrow I will be departing for Thailand to seek ordination there. I think it doesn’t need pointing out that forest monks generally don’t spend a lot of time on Internet forums, so chances are that I will only get to check in here very occasionally, if at all. That being said, there are a lot of question marks and uncertainties, particular in terms of immigration formalities, so it is possible that I need to come back here to Europe in a few weeks once my initial entry permit runs out, and make alternative arrangements from here (meaning I’ll have to find another place to ordain). I will only know once I get to the monastery and start dealing with the local immigration authorities (I see frustration and nightmares on the horizon!), but I’m willing to take that risk. I have been debating whether it is useful to present my reasons for going this path - you have seen me here being on about physics and equations all the time, so this might appear strange to some of you. But I’ve decided not to, because when it comes down to it, I can’t really present a convincing rational argument - this decision simply didn’t come about as the result of reason. I will say only that I’ve seen and understood enough in the spiritual practice that I have already done in the last few years, to know that this is the right path for me. The argument is a phenomenological one, not the result of rationality, so it cannot be easily conveyed in a written post. Spirituality ultimately expresses itself in the kind of person you become by engaging in it, and that’s not something you can fake or wear as a mask. You also cannot reason yourself into the monastic life - that is far too weak a basis for anyone to be at peace with that form of life, never even mind to be able to derive any benefit from it. It needs to be a true conviction that arises somewhere deep within, and that cannot be verbally communicated to others. I will add here that for me there has never been any contradiction between scientific endeavours, spiritual practice, and philosophical enquiry. Not only is there no contradiction, for me these are just aspects of the same underlying motivation to better understand the human condition; hence, if engaged with in the right way, they are complementary and inform each other. I have always felt strongly that it is necessary to achieve some kind of synthesis of these three things for us as a species to make any kind of real long-term progress, since each one in isolation can be misused for harmful and even destructive purposes, as history has sadly shown us all too often. So anyway, thank you everyone for sharing in these discussions, and I hope I have been able to make some kind of contribution - no matter how small - to this forum. In case I’m not back here for a while, I wish all of you the very best, and hopefully we’ll cross paths again. Keep my account open, just in case
    12 points
  2. I got a major award today (plaque, not a sexy leg-lamp) for my "staunch defense of USNO's interests" in a project I'm working on
    8 points
  3. I was reading through Mordred's long standing thread on space and I came across some posts from Mike in the early part. Members may wish to know that Mike passed away earlier this month after a long standing degenerative illness (not covid). Mike was an interesting character, an artist with a degree in Physics and the founder of a successful manufacturing business before retirement to Cornwall. His artistic (dreamy) side gave him an unusual and sometimes frustrating perspective on Physics, especially later in life when we knew him. But he was a genuine character and sometimes offered suprising insights as well.
    8 points
  4. Staff have decided to update the forum rules to include the following: This is in response to a number of threads and certain members who have made threads here under the premise of 'just asking a question,' only to reveal that they are in fact trying to peddle conspiratorial or otherwise nonsense ideas. While covered to some extent by pre-existing rules, we have decided to make it explicit that we will not be hosting these sorts of threads, if for no other reason than the fact that they are a waste of everyone's time.
    8 points
  5. OK let's clarify something here. First consider the following definitions. Mass is resistance to inertia change Energy the ability to perform work. Spacetime a geometric model system with 3 spatial dimensions with 1 time dimension. In physics dimension is an independent variable or value that can change without affecting any other mathematical object. So how does mass curve spacetime. Well GR models bodies in free fall that is without any force applied. Time is given units of length and can be called an interval. This is done by setting c which is constant to all observers and adding a unit of time. So the time coordinate is given units of length by ct. [latex] (t,x,y,z)=(ct,x,y,z)=(x^1,x^2x^3x,x^4)[/latex] the last is in four momentum form for convenience as its useful to model a particle trajectory along the x axis. Now what is spacetime curvature. Well space is just volume... (Very important ) it isn't a stretchable bendable fabric... Those are just analogy descriptive. What spacetime truly means by curvature is the worldline paths for light it us the null geodesic. If you shoot two laser beams in flat spacetime those beams stay parallel. If spacetime is curved then the beams converge for positive curvature and spread apart for negative curvature. This is a consequence of how the mass term affects the time it takes for a particle to go from emitter to observer. That whole resistance to inertia. So let's drop two objects toward a planet. You have the usual Centre of mass. As the objects free fall they do not stay parallel. They will converge upon one another as they approach the center of mass. That what is really meant by curvature the free fall paths are curved. Not the volume of space.
    8 points
  6. So looking at the image below, it appears that Galagidae have recognizable soles, but Cynocephalidae do not : and when we look at a primate phylogeny, we see the split between these two groups is around 65 million years ago: So soles originated about 65 million years ago, give or take. You meant soles as in soles of the feet, right?
    8 points
  7. So if I change the charge of one plate, somebody can measure an instantaneous change at the other plate. Wouldn't that be a violation of special relativity? @Menan You show that you do not understand entanglement. Let's go one step at a time. First a classical example. I have a bag of balls, they are all red or green. Without looking I pick two balls, and I put them in separate boxes. I keep one, and send the other far away. Then I open my box, and see it is a green ball. What can I conclude about the colour of the ball in the remote box? Right, nothing. And why? Because there was nothing special with my picks. It could have been two reds, two greens, or one red and green. Now I pick, looking of course, one red and one green, and put them in two separate boxes. So what I did here is 'entangle' the balls. Now I shuffle the two boxes, so that I do not know which one is which. If I open one, and see that it is red, I immediately know that the ball in the other box is green. And of course, this is independent on the distance. If I send the second box lightyears away, and only then open my box, I still know immediately what some alien sees when he opens his box. I know it because the observations are correlated. And the correlation already happened at the moment of my picks. That is the moment of entanglement. It is not when the boxes are opened. Now in quantum physics, there are processes where two particles pop out, which have e.g in one aspect always opposite values. Say the direction of spin. So if I measure the spin e.g. in a vertical direction, say it is 'up', then I immediately know that the other one will measure spin 'down', when also measured in the vertical direction. But as with the balls, the 'moment of entanglement' is when these particles popped into existence. But in quantum physics a few things are different: first, it is impossible to say which particle has which spin without measuring (it is as if I created the green and red balls, including their boxes, without knowing which ball is in which box). But as the two particles are entangled, if I measure both, the measurements will always be correlated. And there is nothing special with correlation: if I send one particle far away, and then measure my particle in the vertical direction, and the alien measures his particle in the same direction, I will always know what he measures: the opposite of my measurement. The 'spooky' aspect comes in when we do not know from each other in which direction we measure the spin. It can be vertical, horizontal, 30o, 45o, 55.3977o. What we find is that the correlation is stronger than one would expect if we would assume that the particles already had a definite spin from the beginning. But it still is correlation, not causation. As with the red and green balls, there is no direct causal relationship between my and the alien's observation. The causal relationship goes back to the moment of 'entanglement'. Everything afterwards is just correlation, and therefore cannot be used to transfer information. And because there is no causal relationship between my measurement of the spin of my particle, and the alien's measurement, I cannot use entanglement for sending information. And all this is very well understood by all quantum physicists, and is no secret at all.
    8 points
  8. You can label it Political Correctness, or whatever you wish. The fact is that our Western societies are now almost at a point where the individual right nt to be offended, trumps society's right to free speech. And where your own personal, subjective reality can be forced, under threat of law, on the rest of society. If it was someone in authority doing this to society, you would all label him a despot, or dictator, or fascist. When it is anyone with a gripe against the rest of society, or a pretentious, virtue signalling university student, who has no clue what being underpriviliged really is, you guys all stand and cheer, while disparaging those who stand up against the nonsense, claiming they are out of their area of expertise, or just in it for popularity and money. You guys need to give your collective heads a shake !
    7 points
  9. Well, since Markus has expressed his desire to join a Monastery, I think that definitely answers the OP question. But, some words to Markus... ( no offence meant, just trying to lighten the mood ) A young monk arrives at the monastery. He is assigned to helping the other monks in copying the old laws of the church by hand. He notices, however, that all of the monks are copying from copies, not from the original manuscript. So, the new monk goes to the head monk to question this, pointing out that if someone made even a small error in the first copy, it would never be picked up! In fact, that error would be continued in all of the subsequent copies. The head monk, says, “You make a good point, my son.” He goes down into the dark caves underneath the monastery where the original manuscripts are held in a locked vault. Hours go by and nobody sees the head monk. The young monk gets worried and goes down to look for him. He sees him banging his head against the wall and wailing. “We missed the R! We missed the R! We missed the R!” “Father!” cries the young monk. “What’s wrong?” The head monk with tears in his eyes replies, “The word is CELEBRATE!"
    7 points
  10. I am unsure why you would think that - you have never upset me in the slightest with anything you have said, so no apology is necessary at all. But just to set the record straight anyway: it is highly unlikely that I know more about GR than you do I am merely an interested amateur, and everything I post here - without exception - is entirely self-taught. Unlike Mordred, I have no academic credentials in any area of science; truth be told, I never even went to university at all. My understanding of GR and physics in general is cobbled together from a variety of textbooks over the years. I am on the autism spectrum, and one of the defining characteristics of people on the spectrum is that we tend to get totally absorbed by narrow areas of interest (this is called monotropism) - for me that just happened to be physics, specifically GR, at least in the beginning; so I did a lot of reading and self-study in that area. In recent years my interests have diversified somewhat, and I also got involved with certain areas of philosophy and spirituality. Also, understanding GR is natural and intuitive to me, in a way that does not seem to be the case for most neurotypical people; perhaps people on the spectrum find it easier to step outside established paradigms (in this case Newtonian physics) and look at things from a different angle. We tend to have difficulties with other aspects of life, though. I can only speak for myself here. I have no interest whatsoever in anything to do with politics; I stay as far away from it as I can. Anytime in the past when I needed to get involved in politics (workplace, family, etc) it ended badly for me in some way or another. The main reason would be that, as being on the autism spectrum, I am unable to read social cues and guess at peoples’ social intentions. Social interactions between neurotypical people are a complete mystery to me, I cannot understand them. I function reasonably well in daily life, but that is only because I have learned to mask a lot; it’s not the same thing. To me, politics is a bunch of people with strong opinions, who do not recognise them as being opinions, and mistake them for some kind of reality. So they get terribly agitated when others don’t share them; there is a lot of suffering it it, really, and no one seems to even see that. I have plenty of views and opinions as well, but I tend to be able to recognise them as such (or so I hope), and see how they are changing with time, so I don’t try to push them on other people. They are just constructs of my mind, so ultimately they say more about my mind than they do about the world at large. As for religion and ethics, they are areas of interest to me - but I personally don’t see them as something to be debated or discussed on social media, which is why I don’t participate in those threads. Religion - or rather: spirituality - in particular is something you do, not just some passive view on the world. I see lots of people who call themselves “Christian” or “Muslim” or “Buddhist”, but these are just labels - those same people may speak and act in ways that reveal complete ignorance of the nature of human suffering. And conversely, some of those people I have met who were most at peace with themselves and the world did not label themselves in any way; they just lived a truth that existed within them on a visceral, intuitive level. So religion and spirituality are never external things, they come from the inside; they are lived, not debated. That’s all I can really share with regards to this. Ethics, to me, is the art of finding the path of least suffering, for myself and everyone else who is involved, in any given situation. There is no such thing as “right” or “wrong”, there is only cause and effect. One can write down general principles for this that may hold true in most cultural backgrounds, but ultimately it is again something intuitive and visceral, something that happens inside. Intention has a lot to do with it - if we act from a place that understands the suffering inherent in all sentient life, and consciously choose to act in ways that minimises it to the best of our limited abilities, then the seeds of our actions will generally be wholesome ones. Again, I think it has a lot to do with one’s reasons for being here. I am on this forum for two reasons only - to expand my own knowledge and understanding, and to help others do the same; and very often, these two things are mutually co-dependent, and happen simultaneously. It is no longer about getting anyone else to adopt my own views on things. Ultimately you cannot force someone to understand something; you can only offer them the tools that might enable them to put the causes and conditions in place for such understanding to arise eventually. But different people come from different backgrounds, and they are at different stages of their own journeys when they arrive here on this forum; it does happen that someone just isn’t ready to listen, and then it won’t matter what you say to them, regardless of how rational and scientific it is. They will be unable to see the merit in it. It’s not even their “fault” really, it’s just that the conditions are not right yet for understanding to arise. Getting upset or offended will never help in these situations - most often it is best to simply disengage and walk away. After all, it is their journey, so I don’t need to loose my own balance over it.
    7 points
  11. Just did not want to let this pass without a party (Dutch treat...). You are all invited at the lakeside! (Just Click on the picture to see it full size.) Thank you to all from who I learned a lot, and also thank you all who understand less than I do about certain subjects, but force me me to rethink, or make my viewpoint clearer, or force me to read some book or article (again). I noticed that much of what I read is influenced by topics here in these fora. And thanks to those who make this forum possible, moderators, administrators, sponsors, etc. Up for the next 1000!
    7 points
  12. SR does not claim that such an observer will always see the Earth clock run slow, if by see, you mean what his eyes or instruments directly record. In this usage of see, he will see it run at a rate of T = To ((1-v/c))(1+v/c))1/2 where v is positive if Earth and the Observer are receding from each other and negative if they are approaching each other. A factor contributing to this observation is the the distance and thus the propagation time for signals is constantly changing, getting longer when receding and getting shorter when approaching. This factor works out to be c/(c+v) When you factor this out of the first equation you are left with the time dilation equation. This means that there are two things to consider: what you see happening to the Earth clock, and what is happening to the Earth clock. So while while receding from the Earth, the observer will see the the 1000 Hz signal as being 500 hz and the Earth clock as ticking 1/2 as fast as his own,. Taking into account the effect of the increasing distance, he will determine that the Earth clock is ticking 0.8 as fast as his own. He will meet up with the object when his own clock reads 1.01.2022 (as the distance between Earth will be only 1.2 ly as measured by him and this is how long it takes to traverse this distance at 0.6c.) He will see the Earth clock reading 1.01.2021, but determine that it is 8.07.2021 on the Earth at that moment. Now at first, you might be tempted to think " But wait, if he sees 1.01.2021 on the Earth clock, and the Earth is, according to him, 1.2 ly away, wouldn't that mean that it should be 3.15.2022 on the Earth by his reckoning?" This is not the case. The light he is seeing at that moment left Earth at a time when the distance between them was less than 1.2 ly, so the time it took the light he is seeing took less than 1.2 years to reach him from the Earth. Now he accelerates in order to come start the trip back towards Earth. We will assume a minimal acceleration period. Now this is the part where people tend to get tripped up. After he is done and is now approaching the Earth and not receding, we will assume that he still reads 1.01.2021 on the Earth clock by visual means. However, he will no longer conclude from this that it is 8.07.2021 on the Earth. Instead he will conclude that it is 6.05.23. During the return trip he will see a frequency of 2000 hz from the signal and the Earth clock tick twice as fast as his own. But again, taking into account the decreasing distance effect, he will conclude that the Earth clock is ticking at a rate 0.8 as fast as his own. Thus he will see the Earth clock tick from 1.01.2021 to 1.01.2025, but conclude that it ticked from 6.05.23 to 1.01.2025 during his return leg. (see will see it tick off 4 years, but conclude that it ticked off 1.6 years. Again, it all come back to what happens during that acceleration period. As far as anyone at rest with respect to the Earth is concerned, nothing special beyond the standard SR effects take place. But for the observer actually undergoing the acceleration, things aren't this simple. For him, the rate at which clocks run depend on which direction they are from him relative to the acceleration he is undergoing and the distance from him in that direction. Clocks in the direction of the acceleration run fast, and those in the opposite direction run slow (beyond what he sees. This even effects clocks that share his acceleration. A clock in the nose of the Ship will run fast and one in the tail will run slow. ( in this case, since there is no changing distance between himself and the clocks, what he sees, will be in perfect agreement with what is happening to the clocks. While this may seem to be at odds with common sense, it is how a Relativistic universe works. A problem with your questions is that they only deal with particular points of the whole scenario without taking in the whole picture. It like comparing two men walking and only considering where they end up. Below we have the paths of two men, Red and Blue, over the same interval. If you just look at where they end up, you would conclude that Blue walked a shorter distance because he ends up closer to the starting point than Red does. But when you consider the whole interval, it is clear that Blue walked a further distance. The same thing is true with SR, if you only consider the end results, you are missing what is really going on.
    7 points
  13. Putin dies and goes to hell, but after a while, he is given a day off for good behavior. So he goes to Moscow, enters a bar, orders a drink, and asks the bartender: -Is Crimea ours? -Yes, it is. -And the Donbas? -Also ours. -And Kyiv? -We got that too. Satisfied, Putin drinks, and asks: -Thanks, how much do I owe you? -5 euros.
    6 points
  14. Despite a month of promises, on Thursday the 24th at night, conviniently while the Putin shitstorm started he reinstalled a prosecutor in the disciplinairy chamber who tormented a pregnant woman resulting in her death becuase of religious BS. The disiplinairy chamber is an illegal entity and a private tool of Kaczyński and Ziobro (minister of justice and prosecutor general in one person) and is the main reason which prevents us from receiving the 150 bln euro form the EU post Covid fund and results in us paying around 1mln euro in fines. Daily. The president is not autonomous, he's a tool and a clown, unfortunately. Just came back home from a day of trips, dropping people off at shelters and getting food and supplies.
    6 points
  15. There are several parallel issues here. One is that wealth acquired by the ultra wealthy tends to get put into tax shelters and nebulous investments so it grows (but remains outside the system), whereas that same money in the hands of the less fortunate goes IMMEDIATELY into the community around them. They spend it on groceries and vehicle repairs and school clothes for kids and paying the electricity bill so it’s not dark in their apartment anymore at night and their kids can read. The providers of those goods and services in that community where this money is being spent ALSO spend the money once received for THEIR groceries and THEIR service needs and on THEIR kids. Dollar for dollar / unit for unit… the money in the hands of the less fortunate does more net good than money in the hands of the already fortunate. Yes, spending from the wealthy also creates jobs and injects money back into the system, but very little relative to money used in “trickle up” stimulation packages. Also, a bit of extra money in the hands of someone who already has a bunch of it doesn’t tend to change their behavior or encourage extra spending. Getting $1,000 tax break when you’re sitting on $50M isn’t going to suddenly result in them finally making a call to a plumber or the purchasing a new dishwasher… but for the person living paycheck to paycheck that money literally changes lives, gets spent and injected back into the system quickly, and results in lasting reductions in poverty and suffering. When you’re living at the margins, every dollar counts. It also costs a lot to be poor. When the washing machine breaks, you can’t afford a new one but you can afford to pump quarters into the machine at the laundromat… but that ends up being more expensive on net. When the car breaks down, you don’t get to work on time and you get fired. The rich, however, have tax protected ways of growing their wealth and can afford tax attorneys to hide it. Paying more tax has more impact on their ego than on their lived experience. The anger at the rich is out of hand, though. We need better policies and enforcement mechanisms, not more hate and vitriol directed at those doing better than us. Sadly, the anger is probably in large part intentionally being amplified by the very people on the receiving end. If they can keep everyone mad and focused on the wrong things, then the status quo remains stable and no progress or change gets made. Like most issues in economics, we make a huge mistake by treating it as a moral failure when at its core it’s a policy failure. Fixing the policy is just super hard because the people with the power to change the laws tend to be the same ones benefiting the most from them… and also because focusing on wonky policy details is hard for a public who’s often just trying to survive through to tomorrow and who’d much prefer throwing stones and being distracted with us/them tribalism. Perhaps this thread could try focusing on wonky policy details instead of distractions like yachts and steel boats… or not.
    6 points
  16. Throughout the COVID-19 pandemic there have been key findings that have altered our understanding or required responses to this disease. For example, the realization that pre- or asymptomatic persons might be infectious has required a different approach to masking and social distancing. While we have several threads discussing the pandemic, I feel that recent developments justify a new topic, especially as it could be used to clarify potential misunderstandings. With the delta variant (B.1.617.2) gaining dominance we are seeing yet another change that requires us to re-think the trajectory of the pandemic. First of all, the transmission rate of this variant is much higher than estimates for the original strain. The CDC has compared it to chicken pox, which has a basic reproduction number (R0) of >10. What does it mean? First of all, this might indicate that vaccine-based herd immunity is entirely out of the picture. With a R0 of 10 you would need to have a total protection of >92% of the population. Since the effectiveness of the best vaccines against the delta variant are a bit lower than 90%, it means that even with no vaccine hesitation and even if we could vaccinate children with it, we won't hit the required target for herd immunity. This has been assumed to happen for a while now, and might be the least surprising bit of news. However, there are a few recent findings that have prompted changes in messaging, for example with regard to masking. The key issue here are the finding that folks with breakthrough infections have similar viral loads as unvaccinated folks. What does it mean? Fundamentally there some vaccinated folks that get infected with SARS-CoV-2. That in itself is not surprising. Historically, breakthrough infections happen for most vaccinations at low frequencies. Most of the time the focus is on illness, i.e. symptomatic manifestations of infections. However, as mentioned, the possibility of asymptomatic spread has changed that. The fact that vaccinated folks still have high titers means that folks with breakthrough infections could infect others and especially unvaccinated folks are at risk of becoming seriously ill. Vaccinated folks, for the most part do not seem to develop serious symptoms anymore, but it means that vaccinated folks could unwittingly infect and endanger un-or undervaccinated folks. This has prompted a reversal in the masking recommendation. Moreover, it has made many infectious disease experts nervous as in many countries mask mandates are being lifted. Unknowns: There are still many open questions. For example, in the US, the delta variant is causing more illness in younger folks, including children. It is not clear whether this is really a property of the virus, or just because younger folks tend not to be vaccinated. It is not certain whether the vaccine effectively protect from long-haul COVID symptoms. The rate of breakthrough infections is unclear, we know the lower end of the estimate based on detected cases, but since folks without symptoms typically do not get tested, we do not know exact numbers. Even in a highly vaccinated community it is possible that there is a large enough reservoir to allow new variants to develop. https://www.cdc.gov/mmwr/volumes/70/wr/mm7031e2.htm?s_cid=mm7031e2_w https://www.medrxiv.org/content/10.1101/2021.07.31.21261387v1 Discussion points: As a whole it means that we are heading into new territory during fall and winter. The big question is whether the current vaccination rates are good enough to prevent mass hospitalization or will easing of restrictions make folks forget that the disease is still there and cause a new surge. Vaccine hesitancy will add fuel to this potential fire. The communication in many countries/states/provinces have been confusing to say the least and quite a few folks I have talked to seem under the impression that there is little danger left, despite the fact that even in highly vaccinated countries, especially younger folks are barely hitting 50% of full vaccinations. Moreover, most folks in the world are still unvaccinated, meaning that we will need to prepare for more variants. Everyone is being sick and tired of the situation, yet undoubtedly the world has changed yet again (and will continue to do so). A big decision at some point is to establish how many deaths we are comfortable with. With regard to flue, for example, the number is surprisingly high across countries and by any estimate, COVID-19 is going to eclipse it, unless very high vaccination rates are maintained, which is notoriously difficult. Edit Aug, 19, 2021: A new preprint has come out indicating that with the Delta variant Pfizer might only be 42% effective at preventing infections (not disease!) and Moderna was about 76%. https://www.medrxiv.org/content/10.1101/2021.08.06.21261707v1 This seem to highlight that behavioral prevention is still going to be important.
    6 points
  17. I’m on the autism spectrum myself. The problem here is that we can’t isolate a specific sensory stimulus at the exclusion of everything else. So in this particular example, the stimuli coming from eye contact and his spoken words are both present, and both equally prominent simultaneously, which makes it difficult to focus on the actual content of either one of them. Averting eye contact simply makes it easier to focus on the person’s speech, so a lot of autistics will do this unconsciously and automatically. A better example would be a room full of people all talking to each other; it is very hard for me to just focus on what the person in front of me is saying, since I am forced to equally register all the other conversations in the room at the same time. There is no functioning filter there to limit and focus sensory stimuli - which is why we get sensory overload in certain stimuli-rich environments. Note that this is a matter of degree - different environments affect different autistic people in different ways and degrees.
    6 points
  18. A question about a sign convention that leads to a lot of confusion. This is not the only instance multiple sign conventions in Science. In this case it is a result of History. Thermodynamics was originally developed by physical scientists and engineers. They were concerned with making machines (steam engines) for the industrial revolution. Steam engines are heat engines. That is they thought in terms of input (heat in the form of fuel) and output (work). Both of these were thought of as 'naturally being' positive quantities. So they wrote their version of the Law of Conservation of Energy (The First Law of Thermodynamics) as ΔU = q - w. Chemists came to the scene from a different point of view. They wanted all forms of energy to have the same sign, whichever side of the conservation appearance they appeared so they could present the equation as a sum on both sides of the equation. So they wrote their equation as ΔU = q + w. By then it was also realised that, although all the terms are energies, there is a difference between ΔU , which is a state variable of the system, and q and w which are exchange variables of the energies crossing the system boundary. So they tidied up by stating that all energies crossing the boundary from the system to the surroundings are negative and all energies passing from the surroundings to the system are positive. Now they could add them up, move them about in equations and between equations in other parts of Science in a consistent manner. It is an improved system But it shows the importance of knowing the sign convention in use and the equations that go with it. This last remark also applies to other such instances of multiple conventions such as those in Electricity, Elasticity and elsewhere.
    6 points
  19. This is my 1000th post! Time to celebrate, This is a fine moment to open the Islay Single Malt I got for Christmas. Cheers from Ghideon, to all new and old form members!
    6 points
  20. It might help, if you @Angelo would first, in an objective tone, lay out exactly what you believe Tyson's argument to be, and the steps in his reasoning (as far as they are provided and assuming they are truthful). As far as I understand the simulation hypothesis, is that it is based on chance and likelihoods coupled with some very specific assumptions; however the things you say, and the way you ask your questions and/or comment on other peoples posts, to me seems to indicate that you (at best) don't know the full reasoning behind the simulation hypothesis (or you do understand it, but are wilfully creating strawmens). Additionally, it would be great to present the strongest argument(s) for the simulation hypothesis, and not immediately assume that Tyson and other people agree on everything. If he has some illogical reasoning or assumptions you don't agree with, then it may be good to find a better version of the argument, instead of immediately disregarding the entire hypothesis. If you are really interested in understanding Tyson's and other people's point of view on this, it would help to start with a detailed summary/explanation of the hypothesis, because I could explain it (as far as I understand it), but I doubt the explanation is similar to what you think it is. And if you aren't sure on WHAT people belief, then it is very strange to already think of it as nonsense, therefore (assuming you have good reason to think of it as nonsense) it should be easy for you to explain it (in your own words, please don't just link something, that doesn't test your current understanding). Kind regards, Dagl
    6 points
  21. My son holding my grand daughter!
    6 points
  22. Implicit here is a false suggestion of equivalence. That’s not the case. If a kid walks down the hallway in school and gets punched in the face and has his lunch money stolen, is it his fault for carrying lunch money or walking freely down a public hallway? No, of course not, but if you think “both sides” need to compromise here then that’s precisely what you’re saying... that the kid is equally guilty as the bully. Trump last year said send a bill to my desk and I’ll sign it. Republicans were in control so drafted their version. Democrats agreed to vote for it and provide billions of dollars for this wall last year, and the compromise was that dreamers would get status. Trump backed out. He moved the goalposts. He said I want more. Funding ran out in December and Democrats said, fine... we’ll sign the republican bill yet again... we’ll compromise... but want money allocated to smarter enforcement options. A wall is not smart, and even countless republicans across the nation and some on Fox News itself agree. Trump said no. Eff you, a wall or nothing. Democrats said, Republicans still control all 3 branches of government. Since they’re in control, they need to get their president onboard. They couldn’t. President had a tantrum. Paper tiger in the Oval Office. Said he wants a shutdown. Shutdown began. Democrats took control of the house in January and on Day 1 passed a bill to reopen the government. Senate leader McConnell would not even bring it to the floor. Democrats later said they’d give more money for border protection, just not a wall. They compromised. President still refused. Wall or nothing. Eff the workers. Democrats passed multiple other bills to reopen parts of the government and agreed to negotiate terms on border security. They AGAIN voted for the previously passed republican funding bill from December. McConnel AGAIN wouldn’t bring it to the floor. Today Democrat senators continued to pressure McConnell to bring the bills up for a vote. He refused. He said it was pointless because the president won’t sign. Democratic Senators reminded him that they had the votes to override a presidential veto... that they are a co-equal branch of government and need to act like it. McConnell left. He just walked off the floor. Still no vote. Democrats will again pass a bill tomorrow to reopen the government. The bill will be the one drafted and previously agreed to by republicans. I agree there’s a lack of compromise here, but to say it’s equal across the aisle is absurd. The bully is trying to steal the lunch money. The other side has already offered to share their sandwich with him and are not at fault merely for having lunch money in their pocket.
    6 points
  23. Right, he is saying that the speed of light in both directions is the same with respect to any inertial frame as measured from that frame. So in the following example we have two observers. One standing along the tracks and the other traveling along the tracks in a railway car. Two flashes are emitted from two points along the tracks that are equal distance from the track observer. the light from these flashes arrive at the midpoint observer at the same moment as the railway observer is passing him. Thus both observers detect the light from the flashes at the same time. Like this: For the midpoint observer ( or anyone at rest with respect to the tracks) these flashes were emitted simultaneously, as shown by the expanding circles: However, for the railway car observer, events have to occur differently. He still detects the light from both flashes simultaneously, and they arrive when he is adjacent to the track observer. But unlike the track observer he has not remained halfway between the emission points the entire time. He is not an equal distance from the emission points when either of the flashes was emitted. But he must also measure the speed of light for each of the flashes as being the same relative to himself. But since the distances each of these flashes travel relative to him are not the same, in order for the light of the flashes to reach him simultaneously, they must have left at different times. And the sequence of the events for him occur like this: For the track observer, the flashes are emitted simultaneously, but for the railway observer they are not. This is the relativity of simultaneity: Events that are simultaneous in one inertial frame are not so according to another which in relative motion with respect to the first frame.
    6 points
  24. I am pleased to now add CharonY and Strange to the list of gullible fools wonderful people willing to sacrifice their time for the greater good here at SFN. Congratulations!
    6 points
  25. As I said in my previous post. Relativity makes no such claim when it comes to what an observer will visually see. This is a straw-man argument based on a misrepresentation of Relativity. To explain the difference between what the observer would visually see vs. what he is conclude is happening, we'll use some space-time diagrams. First consider two clocks separated by some distance and stationary with respect to each other. The blue line is our "observed" clock and the green line is our "observing" clock. The scale is such that light, shown as the yellow lines, is drawn at a 45 degree angle. Thus our observer will see light that left the blue clock when it read 1 arrive when his clock reads sometime after 3, and he will see the blue clock read 1 at that time. He also will see the light that left the blue clock when it read 2 arrive sometime after his clock reads 4. However, this does not mean that he will think or conclude that what he sees actually represents what time it is for the blue clock at those moments. That would be shown by the black horizontal lines, which shows that when the green observer sees the blue clock read 1, he knows that it actually reads the same as his own, or somewhat after 3, and when he sees the blue clock read 2, it actually at that moment reads somewhat after 4. Now let's add a third clock, one that is moving at 0.6c relative to the both clocks so that it and the blue clock are closing in on each other. This will be the red line in the following diagram. The light that left the red clock when it read 1 still arrives at the blue clock when the blue clock reads somewhat after 3. But the light that left when it read 2, arrives before the blue clock reads 4. The blue clock observer will in fact see the red clock ticking at a rate twice as fast as his own. But again he will not conclude that this means that this represents what time it actually is at the blue clock. When he sees the blue clock read 1 he will conclude that it reads a bit before 3 at that moment and when he sees it read 2, he will conclude that reads something before 3.5 at that moment, as shown by the black lines. He knows that the light carrying the image of the blue clock reading 2 left the blue clock when it was closer to him than the light carrying the image of it reading 1 left the blue clock. His has to account for this when determining when exactly that light left according to his own clock. As the black line from his clock reading 2 shows, the red clock didn't actually read 2 until sometime after his clock read 2. Thus after accounting for the time it took for the light from the red clock to reach him, he will conclude that the red clock is ticking slower than his own. This is time dilation. Now add yet another clock, this time so that it and the observer are receding from each other, as shown by the light blue line. Again the light leaving when it reads 1 arrives at the green observer when the green clock reads after 3. But the light leaving it when it reads 2 doesn't arrive until the green clock read after 5. The green observer will see the blue clock ticking at 1/2 the rate of his own. But this time, the light blue clock is further from the green when it reads 2 than it was when it read 1, and when the green observer takes this into account, it will turn out that when compared to his own clock, the light blue clock is ticking slower than his own, and by the same rate as he concluded that the red clock is ticking slow. The light blue clock exhibits the same time dilation as the red clock. This is what Relativity says is happening in the real universe, and this is not you you are trying to claim it says ( that an observer will always see a clock as running slow). If you are going to argue against a theory, you have to argue against the actual theory rather than some imagined version of your own creation.
    6 points
  26. Stephen Hawking has passed away at the age of 76 on Pi day, 3/14/2018. http://www.bbc.com/news/uk-43396008 https://www.theguardian.com/science/2018/mar/14/stephen-hawking-professor-dies-aged-76?CMP=fb_us
    6 points
  27. This is the rhetoric pushed by billionaires who don't need the government the way most of us do. Isn't it pretty obvious that the billionaires in politics today are only interested in removing restrictions on themselves, and limiting the money spent on the rest of us? These folks have been hammering this message of "bad government" and "sleazy politicians" for decades, while actively being the representatives with the sleaziest behavior, doing everything they can to make the government bad. They don't care if you have access to libraries, museums, parks, swimming pools, or healthcare. They have all those things taken care of due to their massive wealth, and object to taxes that make these things available to the rest of us. They've chosen to ignore our efforts that brought them great wealth, and instead spend money convincing folks that government needs to be dismantled for OUR good. And now they have this blatant racist sexual assaulter-in-chief who is morally and economically corrupt, and happens to have a deluded following all chanting about bringing down the Fed. Working class folks who think this billionaire has their backs while he whittles away at the very thing that has the best chance of making all their lives a lot better. The wolves have tricked the sheep into removing restrictive fences, and the sheep are all praising the freedom.
    6 points
  28. Puerto Rico agrees. Black athletes agree. The anti-fascist movement agrees.
    6 points
  29. Why do you limit your options to 'god did it' or 'everything popped out of nothing'? What about it didn't start, i.e. it's always existed? What about 'we don't know'? Also, as i understand it physicists have found that things do simply pop into existence. And yes, i'm frequently astonished by existence. Why does that imply god? I like this question. Many people seem to question that the universe could either just pop into existence or that it has always existed - but are happy to ascribe these exact same properties to something they call 'god'. Either way something has this property - why not discard the middleman and simply ascribe it to the universe. Depends how god is defined. A god that set up the conditions for the big bang but does not intervene at all thereafter would be impossible to detect, at least with our current capabilities. A personal god that answers prayers and parts seas has been pretty well debunked. Such a god would be easy to detect - we would just look for instances where the laws of physics contradict themselves (i.e. the rules change) - seas start to part, lakes turn into wine, whatever other crazy stuff you think a god might do. There is no sign of such a god.
    6 points
  30. Just want to alert you to someone hacking your account and posting analogies so awful a five year old could see through them. Hope you can fix this breach soon! Good luck!
    5 points
  31. Yes @joigus, I lurk in the shadows and follow proceedings here whenever I get the opportunity At present I live in the jungles of Thailand, having recently been ordained as a monk, and do not have access to anything other than an old mobile phone with spotty and slow internet access, so I’m not really in a position to participate in discussions. It’s just too slow and painful to type this way. I will return once I get access to better infrastructure - perhaps some time next year. Satellites in orbit are in free fall - place an accelerometer into them, and it will show exactly zero at all times. No proper acceleration -> no force acting on them. And yet they don’t fly off into space, but remain gravitationally bound into their elliptical orbits. Clocks in them are also dilated wrt to far-away reference clocks, which is also a gravitational effect. Thus, no force, but still gravity. Newtonian forces are simply bookkeeping devices, and as such they often work well - but only in the right context. Their nature is descriptive, but not ontological. They are not very physical either, given that they are assumed to act instantaneously across arbitrary distances. The strong, weak, and EM interactions aren’t ‘forces’ in that sense at all, since they work in very different ways. They are only sometimes called ‘forces’ by convention, for historical reasons. They ultimately arise through the breaking of symmetries, with the particles involved being irreducible representations of symmetry groups. Finally, it should be noted that physics makes models, that’s what it sets out to do - and as such it is always descriptive rather than ontologically irreducible. So, asking whether gravity “really is” A or B, or whether A or B are “true” is fairly meaningless, since both A and B are descriptions of reality, but not reality itself. Like maps of a territory. The correct question is thus whether models A and/or B are useful in describing gravity, and in what ways and under what circumstances they are useful. So - Newtonian gravity is sometimes useful, but GR is more generally useful, as it gives more accurate predictions for a larger domain. So for now the best answer to “what is gravity” that we have is a purely descriptive one: it’s geodesic deviation, and thus a geometric property of space time. To put it flippantly, it’s the failure of events to be causally related in a trivial manner. Future advancements may upend this picture in the high-energy domain, perhaps radically. We’ll see. I’m sorry I can’t contribute much at the moment, but I’ll leave you with the above thoughts. I could have written much more, but it’s too much of a pain on a small mobile phone screen.
    5 points
  32. 5 points
  33. Volcanic lightning is hard to beat. https://en.m.wikipedia.org/wiki/Volcanic_lightning Calbuco, The Awakening.” ... Calbuco Volcano is located in the lakes region south of Santiago, Chile’s capital city and is one of the 10 most dangerous volcanoes in the country. After more than 40 years of inactivity, the day April 23 the volcano erupts, spewing more than 200 million tons of ash https://www.dailytelegraph.com.au/news/photos/national-geographic-photo-contest-2015/image-gallery/a2afa2087ecd4f4d62475d231b129e31
    5 points
  34. As swansont has already stated, dark matter is matter that is hypothesized to exist due to the apparent gravitational effects we see, but which doesn't interact electromagnetically like the regular matter we are used to dealing with. This means it does not emit, reflect, or absorb light either, thus the description "dark". And as he said, we don't really know just what it is made up of yet. There are a couple of possibilities. Massive Compact Halo Objects (MACHOs) would be objects like neutron stars and black holes. These are object formed from "normal" matter (or at least a far as black holes go initially from it), but compact so much mass into a small area that they are just to small and dim to see individually. However, we need quite a bit of dark matter to explain observations, and there are reasons why we don't think the universe could have this much mass in the form of MACHOs, as it would have effected how the universe evolved, resulting in one that looks a bit different from what we see. Another possibility is Weakly Interacting Massive Particles (WIMPs) These are sub-atomic particles that have a rest mass, but just don't interact via the electromagnetic interaction. (And pretty much everything having to do with how we interact with regular matter, from touching it or seeing it, to chemical reactions involves electromagnetic interaction) These "ghost-like" particles would pass right through you like you weren't even there. While this this seems bizarre, we actually already know of a particle that behaves like this, the neutrino; Billions of them pass through you every day with your ever noticing it. Neutrinos ( or at least the type we know of) don't work for dark matter for various reasons, so the WIMPs of dark matter would be something like, but not identical to neutrinos. It is also possible that both of the above play a role in making up the total effect we see. swansont also mentioned attempts to explain things by a modified theory of gravity. The problem with this is that a number of observations are not compatible with such an explanation. An example would be galaxies that appear to be identical but exhibit different gravity profiles. Even if the rule of gravity were different than what we presently think they are, they would still need to be consistent from galaxy to galaxy. So while its perfectly possible for different galaxies to contain different amounts of dark matter and thus as a whole act differently in terms of gravity, it is hard to explain why the actual rules governing gravity would change between galaxies. Having said this, it is still possible for a modified gravity theory to play some role, if combined with dark matter. A new theory of gravity which also incorporates a mix of MACHOs and WIMPs could end up being the final answer. Right now we are at the stage of continuing to make observations in order to narrow the playing field. We have eliminated some possibilities, but there are more to explore.
    5 points
  35. Fake news! It was a perfect renewal! Absolutely perfect. In a world where even my fridge can give me reminders, I still managed to forget. Luckily Capn was able to social engineer his way through my answering service who sent a page out to me stating "CAPN REFSMMAT - RE: WEBSITE". They even listed a hospital he was calling from 😂. I wasn't on call today so when I heard my answering service text me I about lost my mind until I saw who it was.
    5 points
  36. Glad to be back had some RL issues which are done with now
    5 points
  37. Join a science forum and post once...
    5 points
  38. It seems you have to know an awful lot these days not to offend people, other than not saying anything. Good manners, adherence to tolerant principles, and absence of mal-intent does not seem to be enough.
    5 points
  39. It's pretty easy, and it's been done to death. Most of their arguments are strawmen, in that they make a false or misunderstood claim to attack, instead of a more difficult, legitimate claim. For instance, that the creation of proteins is astronomically improbable, therefore it couldn't have happened. Since they mistakenly think the universe is only a few thousand years old, they can't accept that evolution had millions of years to miss before it finally hit. Many of the arguments are nitpicking Darwin, as if the theory began and ended with him. They ignore what every scientist knows, that theories are dynamic, changing as new evidence shapes them into better and more accurate predictions. And they keep repeating arguments that have been refuted, which is seriously dishonest from an intellectual perspective. I still hear "If we descended from monkeys, why do we still have monkeys?" being spread to ignorant audiences. They study evolution only enough to cherry-pick the parts many don't understand, and then ask questions they don't want answers to. If they really studied evolution sincerely, with an open mind, they would come to the obvious conclusion that there's no other way it could work. Evolution is a fact, and the Theory of Evolution describes how it works, with observational accuracy backed up by more evidence than almost any other theory.
    5 points
  40. Accusations of deliberate, widespread bias and falsification of results, across every major institution (in several different nations) doing climate science and climate modelling really does require evidence. Evidence of which, if this misconduct was really going on, would leave a much clearer trail than a couple of questionable phrases in one email exchange. There is no such evidence, just accusations or it would have come to light a long time ago. Does anyone really think successive governments across the developed world, many with demonstrated hostility to climate science's reports and studies, could not uncover that extent of deliberate bias and collusion? Or that level of incompetence not be noticed within long running non-secret institutions where high standards - with everything on the record - are essential to everything they do? The claims of bias and incompetence are all accusation and no evidence. We have agencies that can pick out guarded exchanges between anonymous terrorist conspirators but they can't catch out hundreds (thousands?) of published working scientists conspiring within and between legitimate government agencies? They haven't exposed this alleged conspiracy of incompetent science and world subjugation because it doesn't exist. Making casual accusations against ordinary people doing their job (better than some people like) is, itself, a serious kind of wrongdoing (slander), besides being very insulting to people who, so far as evidence goes, have been doing their jobs with all the appropriate care and attention and honesty. All that professional effort to work out how our climate system really works, only to be casually accused of being everything from colluding in incompetence to engaging in a global conspiracy! What upsets me almost more than anything else, is that climate scientists have given us an extraordinary gift in the forewarning and foresight they have given. The window of time to transform the way we do energy has been precious beyond price; that we have been squandering it is not the fault of climate scientists failing to communicate. The persistent counter-messaging by opponents and obstructors is indicative of a far more insidious conspiracy of biased incompetence than even their made up version of conspiratorial climate scientists and green-socialist-globalists. In the face of that kind of politicking, and given the seriousness of the climate problem it is climate scientist who do not resort to advocacy that I find questionable. Mistermack - I think you are too gullible and that you have been gulled. I don't expect you to believe anything from me even if you did give it due consideration. Or from Al Gore or from Greenpeace or whoever; however, I do think you should consider taking the Royal Society and National Academy of Sciences, the NOAA, NSIDC, NASA, CSIRO, Hadley CRU and so on, seriously.
    5 points
  41. In previous threads, staff have mentioned that we have on occasion curtailed or removed the ability for people to use the reputation system. In previous versions of the forum software we were able to limit positive or negative reputation limits separately. This meant that the impact of people who wished to use the reputation system to target specific members was always low, and staff could easily reverse it. This no longer being the case means that the system is more open to being abused by people wishing to use it as a form of personal attack. Thankfully, we have had very few cases where staff have had to intervene. For those cases where we have had to do something, admin have created two new member groups with reputation point limits set to either 0 or 2, which limits the use of both positive and negative rep points.
    5 points
  42. Here we finally have it! Proof of the existence of a creator? Best evidence yet!
    5 points
  43. Because I am a philosopher, not a scientist, and this is a science forum, I did not feel any obligation to vote on the issue. Most people, who have read my posts already know my view on the "click-it squad". I would also like to say that I do not see much value in the vote, as the people who are in the forum are reasonably happy with the way the system works, and the people who are not happy with the system have mostly left. So I predict that the vote will be self-confirming and retain the system. The one point that was brought up in this thread, about people arguing with accepted Science, makes sense to me. I can see that it would be frustrating to have to repeat over and over something that has been well established in Science. In my recent thread, Consciousness and Evolution, I worked through seven pages, seven full pages, before I could get the other members to understand that all life is conscious. There are different levels of consciousness, sentience, awareness, sensing, perceiving, whatever, but it is all consciousness. Even after repeatedly telling them that Science confirms this, and explaining that a biologist, a micro-biologist, and a neurologist all confirmed this, there were still arguments. One might wonder why I bothered to work so hard on this. It's simple -- I can not demonstrate the possible connection between consciousness and evolution if the other members do not know WTF consciousness actually is, as they tend to confuse it with the rational aspect of mind. The new ideas don't start until page eight and go through to page ten. A ten page thread that, at most, has only three pages of worth. So I do sympathize with the arguing problem. On the other hand, in Philosophy, it is necessary to know how to make an argument. Telling a philosopher that they must work Philosophy without making an argument is like telling a scientist that they must work Science without using experiments. Absurd. A lot of people in this forum know how to argue, but few know how to make an argument -- with the exception of mathematical arguments. Would it help to post some instructions on how to make a philosophical argument? You did ask for opinions, and philosophers always have lots of opinions, so please consider. There are a lot of posts about new members having problems in the forum. The perception seems to be that new members do not know enough about Science, so they make mistakes until they learn, then their problems with down votes cease. Nonsense. This thinking assumes that new members are uneducated, that they are not professors, scientists, teachers, philosophers, or other educated people. It assumes that new members have nothing to contribute. It also assumes that the old members know more than the new members. I am pretty certain that I know more about consciousness than most members and did when I joined. There may be a few members, who know as much as I do, but I have seen no one who knows more. Of course, you could say that consciousness is not studied in Science as that topic is covered by Philosophy, but there are a surprising number of titles in the Science section with the word "consciousness" in them. It hasn't been that long since I was a new member, so I will tell you what I remember. Notes To Gee: 1. It is OK to insult Religion, Philosophy is just fluff, but do not say anything against Science or you get a down vote. 2. It is always important to be respectful, well mannered and proof your work, but in this forum be very careful how you word things because if it is possible to twist your meaning, someone will and you get a down vote. 3. Tell everyone that you are a scientist, not a philosopher, and deny any belief in "God". (I couldn't do this and got a lot of flack for being a philosopher.) 4. Never complain to a Moderator about a member who has a high rep -- no matter how they are acting. It will backfire. 5. Always agree with the popular opinion -- or DON'T POST. Posting opinions that are unpopular will earn you a down vote. 6. If you ever get three down votes on a post -- GET OUT OF THE THREAD. Tar never learned this one, got about 40 down votes in one thread and left the forum. I will miss him. 7. Avoid the Religion forum as they are all fanatics. Some hate religion, some love religion -- but they are all fanatical about it. 8. Avoid Ethics as that forum can be summed up as "If you would just think like me, act like me, or be like me, you would be ethical." (chuckle) I don't know what maggot in my brain caused me to recently write a thread there, but it didn't work out. I wrote a thread about power and entitled it Powerful Men, Beautiful Women, and Sex. Apparently I did not know that the Powerful Men were being mean to the Beautiful Women Sexually, so it was a thread about sexual harassment. By the bottom of the second page, I apparently was the cause of this harassment. Who knew? 9. Stay away from Politics unless you can think of it as a newspaper and not post. 10. If you ever need a few up votes, go to the Science section, look around for something that interests you, and then profusely thank whoever answered your questions. Sucking up in Science is always good for an up vote. 11. If you found Swansont in a thread in Philosophy, you could often be more open and honest in that thread because people tended to behave when he was around. In this thread, I learned why they behaved. (chuckle) One thing I will say is that Swansont apparently had a lot of power, but I never saw him abuse it and believe he possesses integrity. He is not the only one, and I don't mean to single him out as I see integrity in many members. I just noted early on that people behaved themselves around him. 12. Do not start your own thread. It is suicidal. It is OK to question, but if you start a thread with an idea in mind, you are going to be attacked. For some reason, members in this forum take an original idea as an assault on their authority, so they attack. If I followed these rules, my rep points went up. It did not have a damned thing to do with learning Science. Gee
    5 points
  44. I'm told that when naked mole rats sit around shooting the breeze, they discuss how they are a clear aberration. Apparently domestic cats hold much the same viewpoint. Not to mention African Greys. It seems its a tendency of any reflective species to view itself as unique and special. You can probably eliminate any single species from the planet and the biosphere will continue pretty much as it was apart from some small, local readjustments. So you can replace the word "humans" in your statement with the name of any species . If you don't feel a Great White is not a super-fish would you like to take one on in unarmed combat. I suggest it won't be long before you are truly unarmed. Moontanman has mentioned examples of intelligence and tool use, etc. There are plenty of examples of animals that are faster than us, or anything else,have better vision than us, or anything else, can endure lower temperatures than us, or anything else. And so on. If we insist on comparisons that focus on our strengths and ignore our weaknesses it is difficult to not to consider us super, but that seems a biased approach. Overgrazing is common. Predators sometimes kill too many of their prey. The Great Barrier Reef is being destroyed by one of its inhabitants. There are, I think, numerous examples of this. We are better at it than most, but I don't think most of us want to boast about that.
    5 points
  45. It is difficult to explain why you are wrong because you don't understand the subject and so you just reject the explanations (this has been true in all of your threads). And yet you are the one who constantly quotes the words of others but ignores the science. For example: Dalo: I don't believe X Others: Here is a simple explanation why you are wrong ... D: That's a bit vague, can you be more specific? O: <detailed explanation with evidence and a mathematical analysis> D: I don't need all that maths and what about [irrelevant sidetrack] O: What exactly are you asking? D: How dare you! O: I'm just trying to clarify D: I don't believe Y, as I have been saying all along O: So you have changed the subject D: No, you keep introducing P and Q, but I want to talk about Z O: OK. Do you understand <basic schoolboy physics>? D: Why should I have to? If you can't prove me wrong ... O: <collective sigh>
    5 points
  46. First off, dark matter and dark energy are two different things and the reasons for expecting their existence are completely unrelated. The only thing they have in common is that they have "dark" in their names. The initial evidence for dark matter came from observations of how stars move in galaxies. Galaxies are formed from stars that are mutually orbiting each other. If we look at a galaxy, and estimate its mass by the matter we can see, we find that there does not appear to be enough to hold the galaxy together. At the speed the stars are orbiting, they should fly apart. We also know how these stars should orbit if the mass is contained to the shape we see it as having. Not only does the galaxy have more mass than that we can see, but the unseen mass must be distributed a lot differently than the part we do not see. For example, in a typical spiral galaxy, a good deal of the mass must be located above and below the disk-like shape we see. If it was made of normal matter, we should see it, if not in the visible spectrum, it should be visible at some other spectrum. This leads us to believe that whatever is causing that extra mass is not made of normal matter, but a type of matter that does not emit or interact with light or any part of the electromagnetic spectrum. Thus the term "dark matter. There have been attempts to explain the discrepancy through developing different models for how gravity behaves, but to date, none have been consistent with all the observations we have made. Dark energy concerns itself with the expansion of the universe. We have known for a long time that the universe is expanding and that distant galaxies are moving away from us. But until couple of decades ago, we assumed that the mutual gravity between the different parts of the universe was slowing this expansion down over time. What we did not know was whether this was enough to eventual stop the expansion all together. In the 1990's a study was made to try to determine if this was the case or not. Basically it worked because as we look at distant galaxies, we are seeing them as they were when the light left them. Thus as we look further away we are looking further into the past. Thus, to explain it simply, by comparing various galaxies' distances to how fast they appear to be receding from us, you can work out how the expansion of the universe has change over time. The surprise came when it was discovered that the universe's expansion was not slowing down, but was speeding up. Not only was it mutual gravity not enough to stop its expansion, but something was overcoming the gravity and pushing the universe apart. They decided to call this unknown influence "dark energy" (mainly because they had already coined the term "dark matter") . We really know very little about dark energy, and the term really just is a place holder for whatever it turns out to be. (Much in the way the terms "X-rays" was coined before we learned that they were just a certain part of the electromagnetic spectrum.)
    5 points
  47. This would be very cool. Unfortunately, here in the USA, I don't see that happening any decade soon since there would be parental concern about the radioactivity as well as (unreasonable) religious concerns. * The discussion reminds me of a point I read once that if Darwin had been wrong, the discovery of DNA and how it works would have destroyed his theory and we would have been seeking an alternate mechanism. Instead the discovery of DNA lead to a refinement of Darwin's theory into the even more robust Evolutionary Theory. It is humbling to think of how Darwin, through observation and deduction, derived the process of natural selection and developed his theory and that we have only needed to refine it a bit in spite of more than a century of amazing discoveries. I used to believe in evolution but I no longer do after studying it – now I understand and accept it. I also now see three groups: those who believe in evolution, those who don't believe in evolution – but neither of those groups understand it – and those who understand and accept evolution. I have never met someone who understands evolution but doesn't accept it – all who claim to be such people show that they don't actually understand evolution and really they just don't believe in evolution.
    5 points
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