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Showing content with the highest reputation on 12/06/17 in all areas

  1. 2 points
    Do you mean the interpretation of what they perceive based on what they have seen? I don't know why, but I don't like the idea of assigning laws to things that are subjective or not well defined. Why does perception even need laws? Law 3 seems odd... why can't it be effected by anything else... or is 'anything else' covered by 'the limits of the perceiver'. No offence - and I could be wrong as I often am - but don't see the need to assign laws to what we call perception.... the dictionary definition seems to do a fine job imo. It reminded me of this: https://imgur.com/gallery/pleGM
  2. 1 point
    Been there, did the experiment, got the eyestrain. The OP seems to be smushing together two different "ways of looking" at the light. First off, you have a burning sample (or a gas sample in capsule with high voltage). That glows and you see a single color. Purple is the one I most remember, hydrogen or one of the noble gases. That color is all the wavelengths the sample is emitting, mixed together. So that's "look one". Now, let's put a prism between you and the glow. You now see a set of bright lines, each line being a single wavelength., and so a single color (it is possible that you will still see a line the same color in part one, but I think that is only if the purple spectral line is much much brighter than any others) Oh, and a word of warning with that page of spectra. If you do the experiment, you do not see "dim background full spectrum with bright lines". You see only the lines. So those images are a little misleading. The main page doesn't mention it, but if you click on a spectra it includes the disclaimer...
  3. 1 point
    I am not quite as positive about that. Certain groups, including the Hamas are fueling their power by declaring that the peace negotiations are biased against Palestinians. Often, they were forced to the negotiation table in order to demonstrate they themselves were not acting in bad faith. This step pretty much confirms to the Arab world that the negotiations were biased from the get go. My take is that this move is likely to empower the radicals while diminishing the influence of moderating forces.
  4. 1 point
    +1 Yes most likely sulphuric (car battery acid). However hydrochloric is put into "limescale removers" for toilets, by bleach manufacturers. It comes in black rather than blue bottles in the UK, but is easy to mistake. The acid and tha alkali remove different componeents of a blockage. As already described, caustic alkali (yes it is caustic so use rubber gloves) attacks the grease componenent which sticks things together. But cellulose fibres in paper and cloth and other fibres such as hair and roots can be mechanically trapped in the drain. That is where you should use the acid to dissolve them out, as the alkali will not touch that situation. Always remove as much as possible mechanically first, since that will reduce the need for chemical action and is cheaper. If you do use the acid, a bucket of washing soda (sodium carbonate) will flush it away safely afterwards. The build up your referred to creates a highly nutrient soup for plants so they try to break into the drain with their roots. This can be quite a nuisance with old drains. Finally you should keep monitoring the situation and clearing before it gets to bad in future.
  5. 1 point
    I'd echo this. I am a chemist and would say that you are going the right way in treating it with respect. I use it as a last resort to unblock drains. Some people do suffer burns from the chemical when using it this way, but this can be avoided by treating it with respect - wear gloves (rubber) and eye protection. I would also advise, if it doesn't unblock the drain, NOT to go back to pressure washers and things for some time afterwards... you don't want to splash the solution back out of the pipe onto your self. Regarding the heat generated during the dissolution of the NaOH I would say that this probably actually helps clear the blockage. Last resort though... I usually get good results from Mr Muscle's drainage un-blocker products and the 2 pack gels that react and gas to build pressure in the pipes to help unblock them. NaOH has always worked as a last resort for me. I have heard it said NEVER to put it down the toilet.... I have never had the need thankfully and probably would not just in case. I read somewhere once (years back) of a guy burning his, er, self with NaOH that he'd used in the loo to clear a blockage. The toilet water was still alkali some time after and splashes caused burns on his... er, body.
  6. 1 point
    As one of the parties involved has called it a "kiss of death", I think the answer is yes. I just don't understand what the reason is for doing this. It certainly ins't going to help anything. Unless Trump thinks he can solve the Middle East problem simply by siding with Israel and telling everyone else to get lost. So much for the "great negotiator".
  7. 1 point
    It'll be sulphuric acid. Hydrochloric acid is cement cleaner/mortar stain remover and the fumes of the concentrated stuff are very strong.
  8. 1 point
    Almost certainly. The question with which I'm wrestling is how many new deaths and threats this will create, and also whether or not this sort of "disruption" may actually help in the long-term... Decades of negotiations have failed and perhaps this is the type of crazy step which is needed to get us out of the horrible status quo. I don't know. As I prefaced, I'm wrestling with the question quite a bit.
  9. 1 point
    They originally thought they couldn't obtain the information themselves, which is why they went to Apple. So it was, at least in part, a technical issue. But a brute force solution just shows ignorance of the details.
  10. 1 point
    It is a simplification of E^2=p^2c^2 +m^2c^4 Which is derived in special relativity. Also, E=mc must be wrong as it fails dimensional analysis.
  11. 1 point
    Irrelevant, this could not serve as evidence in court, data has to be obtained according to the law, this is not a technical issue.
  12. 1 point
    You overlooked one small detail: limited retries.
  13. 1 point
    I found out what Re means Reynolds number we were both wrong found it on a equation picture.
  14. 1 point
    It gave 1 on my calculator..
  15. 1 point
    What is it that makes "matter"? We consider a table as being made of matter. I can touch it and it feels solid. But what is really happening I "touch" the table. My hand, and the table is made up of atoms with electrons in shells around a nucleus and these electrons have electric fields. So what is happening is that my the electric fields of the electrons of the outer layer of my hand interact with the electric fields of the outer layer electrons of the table. It is just an interaction of fields and nothing is really "touching" anything in the way we commonly think about it. The matter of the table is made of atom bound together by electromagnetic forces. Are the atoms themselves matter? We generally say that they are. Atoms are made up of electrons, protons and neutrons. Are they matter? Again, we tend to say that they are. Protons and neutrons going further are made from quarks. Quarks and electrons are considered fundamental particles, They are also considered matter particles. So, what are these fundamental particles made of? are they little balls of "something" that is imbued with the properties we measure the particle as having, or are they just the some total of the properties they exhibit? Thinking of them in the first way seems like trying to extend the analogy of how the macroscopic world appears to be down to where it doesn't hold. It seems much more likely that the second view is better, a fundamental particle is just "made up" of its combined properties. It has a mass and maybe a charge, etc. and fields associated with them, and the only way to interact with them is through these properties. They are just entities with a collection of properties. If this is the case, Is there a single property that defines its "matterness". If it can't interact through the electromagnetic force, is it not matter? Is the Neutrino matter? it has mass, but no charge, it also interacts with other matter rarely and only under certain conditions. A neutrino could pass through light years of lead without having one interaction. Would you call a neutrino "matterless mass". The WIMP model for dark matter just assumes that is is made up of particles like the neutrino, and which share like properties in some respects.
  16. 1 point
    So your saying that Star ship trooper's aliens are real. Maybe there is no reason to think that intelligence could not evolve that way given the diversity of life on earth, like ant colonies and such along with how much more diverse the Universe would be then that. Given that there are more stars systems in the Universe then every grain of sand of every beach in the world within the Universe.
  17. 1 point
    Not quite, Physics is never about defining reality. We leave that task to philosophers lol. One thing I always stress is a field is an abstract device. A field is precisely a treatment under geometric basis, where every coordinate is assigned a function. That function will provide either a scalar or vector/spinor quantity. Now that is clarified onto particle themselves. Its no mystery that everyday objects are comprised of particles. The coupling strength of the EM force provides us our sense of solid. Everyone pretty much understands this. However most people run into difficulty letting this "solid thinking" go when it comes to the quantum realm. They look for that solidity in particles. The wave particle duality teaches us that a particle has both wavelike and pointlike characteristics. However they tend to confuse two key aspects. The wavelike characteristic in this instance is not the probability waves. The probability waves simply provide the probability of locating said particle in point of detail the probability wave can have any number of particles. The particle excitation defined by the Compton wavelength for force particles and the Debroglie wavelength for the matter particles. For the matter particles when the pointlike characteristic becomes meaningful, the region of said particle is DeBroglie wavelength. Now each of these two waveforms have distinctive cutoff points except the HUP makes it tricky to pin down as it will always be inherently fuzzy due to the HUP. These two wave are akin to physical waves not probability So lets ask some questions. 1) the electron is a fundamental particle, it is not made of smaller particles. Yet has no internal structure. So lets think about that for a minute. How can a solid electron not be made up of smaller particles if it is solid ? 2) How does a solid particle pop in and out of existence, from where and how ? the novice tends to think quantum tunneling but that is wrong. 3) if you supercool an electron to a Bose Einstein state, why does it no longer appear spherical but becomes squiggly lines ? 4) How can a neutrino pass through a 1000 lightyears of lead without being deflected. It should hit another solid particle at some point. Simple statistics tells is that. Now lets borrow a passage from a condensate state article. "When this happens, the sample undergoes a phase transition: a Bose Einstein condensate forms. Because the particles in the BEC are all in a single quantum state (i.e. the ground state), they can be described by a single wavefunction. The constituent particles in a BEC can thus be likened to a ‘superatom,’ a system in which thousands or even millions of atoms behave like a single particle. The phase transition can be understood in terms of the particles’ thermal de Broglie wavelength." Now this indicates that particles can and do alter their waveforms and become indistinguishable from one another. This condition is thermal equilibrium. How would that be possible if different particle types are solid? When you start examining the body of evidence it becomes more and more clear that particles are precisely that "Excitations" and not solid. With excitations particle production answers all the above questions. The pointlike characteristic is indeed the DeBroglie wavelength. This is what any QM related field teaches us and experiments reflect. Nor are they made of Strings, that is not what String theory teaches. Here is the random grab BEC paper I borrowed that quote from. https://www.google.ca/url?sa=t&source=web&rct=j&url=http://massey.dur.ac.uk/resources/mlharris/Chapter2.pdf&ved=0ahUKEwiVt4vUw_HXAhUQyWMKHQ91DtMQFggkMAE&usg=AOvVaw1DHUh-BTAMS7yr-2lNfTFf A little sidenote you will be amazed how much easier physics becomes to understand when you can discard looking for "solid" or a fundamental cause where everything starts. Though by understanding potential differences between regions (anistropy is an immense help). As well as thinking of charge (attraction/repulsion) of any type as vectors.
  18. 1 point
    I'm against making everyone drive on the same side of the road because it impinges on peoples freedom.
  19. 1 point
  20. 1 point
    The scale factor time derivitaves are simple ratios. The scale factor today is 1 you compare the radius at the time you wish to examine and compare it to the radius today. If for example the radius then is 1/2 the radius today. Then [math] \ddot{a}(t)=0.5[/math] it is as simple as that. If you have 3 dots then you compare to two dots. If two dots compare to 1 dot. They are just ways to keep track of the sequence of time comparisons
  21. 1 point
    It is impossible to disprove any ideas like that (see also solipsism). As such, you can't actually prove any of the things you stated before. All you can do is confirm that they appear to be real to you.
  22. 1 point
    Yes, I do remember writing that, and this is a very fair criticism. I wrote the qualifier “to a large extent” in anticipation of exactly this response, and (also to a large extent) language itself fails me here. I acknowledge the seeming contradiction in my point. We call it “control” and we frame our will as “free,” but I cannot escape the importance of the copious evidence to the contrary. Hold a warm cup in your hands and you perceive others more kindly. Skip a meal and you react to a harmless passing comment viciously. Sleep a bit more or a bit less and all of your responses and capabilities are affected. Add to this our problem with blind spots and illusions and also the massive impact of the gut microbiome and we see that the point only gets further reinforced and entrenched. We look to the scans and monitor the electrical signals, the blood flow, the action potentials... No matter how carefully we design the study or how many different methods we use to explore this, the results are every time the same. Our decisions are already made well before the other areas of our brain responsible for sense of self, awareness, consciousness, and executive function ever show any activation whatsoever. We assert control when instead it’s the concentration of ions and the conductivity of nerve cells or thickness of myelin sheathing and density of the dendrites that drive it all. We are like boats in the ocean claiming to control the weather as we simultaneously get swept along passively by the currents, waves, and winds. Theres no avoiding the conclusion that free will is an illusion once you study the underlying dynamics and neuroscience, and this IMO remains true even if I do still sometimes get tripped up with language and word choices.
  23. 1 point
    I also am disappointed about how often students at university are shouting down and protesting any speakers that they don’t agree with 100%. It’s as if there are purity tests being imposed, and not just at this school, either. It’s happening at schools across the nation and beyond, and I see the same thing happening on social media where people are being blocked and unfriended and even outright harassed or threatened for thinking differently or not falling in line. It’s a very real problem. This is a huge mistake. Very shortsighted. Very immature. Detrimental to our wellbeing in a liberal democracy. Fascistic, even There are a few problems with your approach, though... First, it was a small group of students who shutdown the talk, not the university. You may as well blame Starbucks as a company for vandalism when two of their customers knock down a trash can or blame the site manager for littering when those same customers leave a cup on the table. It’s a failure of logic, a breakdown in mental engineering. Second, you blame BLM as a whole for the comments of a handful of individuals. Third, you generalize about all liberals and liberalism. The fallacies you use to make your points are almost too numerous to count. There’s merit in the underlying point you’re making, but it’s so often drowned out by this ridiculous desire to poke people and agitate others and laugh, as if you need to feel superior to compensate for feelings of inferiority. You’re not a chimp throwing feces and should stop acting like one. Fourth, free speech is not the guaranteed right to speak anywhere about anything you please. Instead, it’s about whether or not the government can punish or prevent you from speaking. However, if you start acting and speaking foolishly in my home, I can kick you out. In my restaurant, I can have you removed. At my university, I can block you from entering, etc. That said, you’re right about this blocking of speakers being a bigger problem, this desire to silence others instead of addressing their horrible ideas openly. I say this as someone you’d likely dismiss as being liberal (as you have in the past), and I say this as someone who could be an ally to you... someone who wants to partner with you in standing up for important principles like these. But you make it really hard with your pubescent attitude, persistent trolling, incessant need to split discussions into us/them, right/left, conservative/liberal, good/evil, and also your fundamental misunderstanding of what the first amendment and what free speech actually are. Because it’s not this. Their first amendment rights were in no way infringed since it wasn’t government doing the infringing.
  24. 1 point
    The ACLU speaker, and students who wished to hear her, should have designated that venue a 'safe space'; Then BLM protesters wouldn't have been able to intimidate them.
  25. 1 point
  26. 1 point
    I think the operative word is 'particular', which I don't think we here disagree with. The problem and concern is that we are entering into a new phase where the governments want free access to everything, on a whim. The notion that if you aren't doing anything wrong you have nothing to fear is complete bollocks. There are elements of people's lives that I think they have a fundamental right to keep private from routine governmental surveillance
  27. 1 point
    You need to read Apple's statement - if you have already looked at it read it again critically This is the meat of their argument - 1. They have cooperated in the San Bernadino case 2. The Powers that be have decided to use this scare of internal terrorism to get what they had before mobiles and hate the fact that they have lost - access. They have been pressurizing the large tech companies in USA to grant them access to your data / contacts / photos / email / browsing whenever they fancy it It is easier and more palatable for Apple to couch the argument in terms of someone else getting hold of the back-door key - but in reality it is worse that the government might have it. And whilst everyone would surely agree the Government would only use this ability once...hang one a sec - no they would use it all the time String - Look at any freedom of expression website in the UK and see who the government has now admitted to wire-tapping, spying on, intercepting mail ... "back in the bad old days". Well they are still at it - but the current stuff is still hidden and won't be released for years - and I for one do not want my government to have an immediate unfettered access to my personal communications.
  28. 0 points
    Yes, that was my point. The statement “I am lying” must refer to what they’re lying about to have meaning.. Otherwise it’s an invalid statement as in its not a meaningful statement. It may look kind of like a natural thing to say because such statements typically refer to something in the previous sentence but there’s nothing in the previous sentance to refer to. Maybe you can think of it like using reference frames If you dont provide an observer in their own reference frame and what their observing in the context of it’s reference frame. then the problem doesnt make sense. “I am lying” is implying a referal to something that isnt there. so it doesnt make sense.
  29. -1 points
    Nonsense. You were just condemning me for my opinions of liberals. Yet when BLM equates liberalism, the core of political liberal ideology, with white supremacy you equivocate. Do you support the liberal positions of the ACLU on free speech or not? If you do, don't you think you should condemn this chant of BLM? Don't you wonder why the BLM movement has go so far astray?
  30. -1 points
    As for what happens when a geometric object becomes a point, I think it fails to exist. According to Euclid: "A point is that which has no part."