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Theme Changer

 Topic: Ask a Physicist!

 (Read 31918 times)
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  • Ask a Physicist!
     Reply #30 - July 07, 2015, 11:42 PM

    A lack of something is the non existence, I would imagine. When we think of nothing we think of the complete absence of something, the complete absence of anything. Hence confusion when communicating these notions and models to non physicists.

    `But I don't want to go among mad people,' Alice remarked.
     `Oh, you can't help that,' said the Cat: `we're all mad here. I'm mad.  You're mad.'
     `How do you know I'm mad?' said Alice.
     `You must be,' said the Cat, `or you wouldn't have come here.'
  • Ask a Physicist!
     Reply #31 - July 08, 2015, 12:09 AM

    A lack of something is the non existence, I would imagine. When we think of nothing we think of the complete absence of something, the complete absence of anything. Hence confusion when communicating these notions and models to non physicists.


    Yes, but does a non existence make sense (what logicians/mathematicians/philosophers would call the empty set)? This I believe is why Physicists use it in a different manner. Physics is only concerned when there is *something*. Nothing would include the absence of physics otherwise!

    One only acquires wisdom when one sets the heart and mind open to new ideas.

    Chat: http://client01.chat.mibbit.com/#ex-muslims
  • Ask a Physicist!
     Reply #32 - July 08, 2015, 12:16 AM

    In the nothing Krauss spoke of (no space. no time), he said that there are things in that nothing, gases and such and spontaneous partials that pop in and out of existence, which could go a ways to explaining how the big bang was possible. Though how can there be things inside something which has no space? How can something without space even have an inside (if I can use a layman's term Grin)? If space to have these things isn't required, how isn't it? And how can events (like the particles for instance) come and go without time?

    `But I don't want to go among mad people,' Alice remarked.
     `Oh, you can't help that,' said the Cat: `we're all mad here. I'm mad.  You're mad.'
     `How do you know I'm mad?' said Alice.
     `You must be,' said the Cat, `or you wouldn't have come here.'
  • Ask a Physicist!
     Reply #33 - July 08, 2015, 01:10 PM

    I have heard claims made by various people that the Big Bang as the origins of all reality, not just one universe, is dying out as a primary theory. I have read Hawking's work in which the BB is just part of the Crunch/Bounce hypothesis. How true is this claim?  Is the BB still taught as the origin's of reality or views as Hawking's uses the idea?
  • Ask a Physicist!
     Reply #34 - July 08, 2015, 01:34 PM

    LOL yeezevee, ...................................

       No..noo..Nope., I am not going buy these "lols"  from you PhysMath..,  Ishtar90 already told me that ., in fact she is laughing at me..  Cry

    ..............I think you should really ask them. Tongue...

    Ask who?? THE FAITH HEADS??  are you nuts?   finmad   faith heads don't use their head., faith heads don't use their common sense., They use their  damn faith., If they could answer this question
    .........................,

    When these faith heads say/talk about allah/god..., what kind of figure head do they have in their mind?  what do they imagine in their brains on this shape/form of this allah/god character ?  

    Same question of Sam Harris down in this tube...

    https://www.youtube.com/watch?v=22cYcsVPOok


    Then they will NOT be faith heads., Only guys who can use their brain can answer that question...  So ANSWER ME THAT QUESTION  dear PhysMath.,  and and  I demand answers to those questions from other readers WHO ARE NOT faith heads..
     

    Do not let silence become your legacy.. Question everything   
    I renounced my faith to become a kafir, 
    the beloved betrayed me and turned in to  a Muslim
     
  • Ask a Physicist!
     Reply #35 - July 08, 2015, 03:19 PM

      No..noo..Nope., I am not going buy these "lols"  from you PhysMath..,  Ishtar90 already told me that ., in fact she is laughing at me..  Cry


    She would never laugh at anyone, she's too nice!

    Ask who?? THE FAITH HEADS??  are you nuts?   finmad


    Slightly!

    faith heads don't use their head., faith heads don't use their common sense., They use their  damn faith., If they could answer this questionThen they will NOT be faith heads., Only guys who can use their brain can answer that question...  So ANSWER ME THAT QUESTION  dear PhysMath.,  and and  I demand answers to those questions from other readers WHO ARE NOT faith heads..


    The answer is "I don't know". Smiley

    One only acquires wisdom when one sets the heart and mind open to new ideas.

    Chat: http://client01.chat.mibbit.com/#ex-muslims
  • Ask a Physicist!
     Reply #36 - July 08, 2015, 03:22 PM

    In the nothing Krauss spoke of (no space. no time), he said that there are things in that nothing, gases and such and spontaneous partials that pop in and out of existence, which could go a ways to explaining how the big bang was possible. Though how can there be things inside something which has no space? How can something without space even have an inside (if I can use a layman's term Grin)? If space to have these things isn't required, how isn't it? And how can events (like the particles for instance) come and go without time?


    I agree that his explanation is not very consistent in standard terms, but there are concepts such as "virtual particles" (see https://en.wikipedia.org/wiki/Virtual_particle) and so this could be the analogue. In general, in terms of maths if everything "balances" out, then it is deemed a physically realistic system. So it's a mathematical construction more than anything!

    One only acquires wisdom when one sets the heart and mind open to new ideas.

    Chat: http://client01.chat.mibbit.com/#ex-muslims
  • Ask a Physicist!
     Reply #37 - July 08, 2015, 03:25 PM

    I have heard claims made by various people that the Big Bang as the origins of all reality, not just one universe, is dying out as a primary theory. I have read Hawking's work in which the BB is just part of the Crunch/Bounce hypothesis. How true is this claim?  Is the BB still taught as the origin's of reality or views as Hawking's uses the idea?


    The BB is taught as the origin of the universe as far as we understand it, and the bounce/crunch hypothesis can be an extension to this (multiple big bangs as mentioned earlier). Though it is still a rather open concept, as mentioned it being so many billions of years ago it does lead to multiple possibilities!

    One only acquires wisdom when one sets the heart and mind open to new ideas.

    Chat: http://client01.chat.mibbit.com/#ex-muslims
  • Ask a Physicist!
     Reply #38 - July 08, 2015, 04:01 PM

      No..noo..Nope., I am not going buy these "lols"  from you PhysMath..,  Ishtar90 already told me that ., in fact she is laughing at me..  :'
     


    I would never laugh at you dear yeezevee  far away hug

    You are the Universe, Expressing itself as a Human for a little while- Eckhart Tolle
  • Ask a Physicist!
     Reply #39 - July 08, 2015, 09:09 PM


    First he summed up what he meant by nothingness, which was no space and no time. Okay, yes, seems a pretty good idea of nothingness. But then apparently there are things in this nothingness (doesn't that requite space?), and it even has weight, so you can weigh nothing. But how can nothing have weight? Surely that means it's not nothing. So nothing is something, which seems to me to be something of a paradox. So, like with my evolution analogy above, are physicists simply meaning different things with their words than what the average person on the street means by it?


    Lol ever had a girlfriend tell you "it's nothing"? Nothing can mean "everything."


    ha!.....  well then I was NOT wrong.... You know that guy Hassan Radwan tried to fight with me when I called you as "musa Girl"..

     I think That is a good nick.. good name for a nice Jewish Girl..   As far as this is concerned who knows couple years down the road I may come  across a guy on a forum who happened to be your hubby and may say  same thing such as ..lol.. I am an optimistic guy..   Ha!  this is a good one to watch.....



    It's not Musa Girl, and that doesn't even make sense to me as a nickname, but whatever. As far as my husband's concerned, fat chance; he uses religion as a shield to be an asshole to people. He doesn't care about what religion says in regards to him and how he needs to live his life, he's only concerned about having an excuse to be cruel and violent to other people.

    Yea, though I walk through the valley of the shadow of death, I will fear no evil, for I have a sonic screwdriver, a tricorder, and a Type 2 phaser.
  • Ask a Physicist!
     Reply #40 - July 09, 2015, 02:59 AM

    I agree that his explanation is not very consistent in standard terms, but there are concepts such as "virtual particles" (see https://en.wikipedia.org/wiki/Virtual_particle) and so this could be the analogue. In general, in terms of maths if everything "balances" out, then it is deemed a physically realistic system. So it's a mathematical construction more than anything!

    I'm aware of virtual particles, I just don't understand how they can come and go without time.

    `But I don't want to go among mad people,' Alice remarked.
     `Oh, you can't help that,' said the Cat: `we're all mad here. I'm mad.  You're mad.'
     `How do you know I'm mad?' said Alice.
     `You must be,' said the Cat, `or you wouldn't have come here.'
  • Ask a Physicist!
     Reply #41 - July 09, 2015, 12:55 PM

    I'm aware of virtual particles, I just don't understand how they can come and go without time.


    You're thinking of time as an entity. That's probably why it is difficult. It isn't, it is a description. It is a byproduct of what is. And not vice versa. We see time as a forward progression, yet this isn't true for particles. They can travel *back* in time also! And as long as the sum is 0, then "no time passed", right? Smiley

    One only acquires wisdom when one sets the heart and mind open to new ideas.

    Chat: http://client01.chat.mibbit.com/#ex-muslims
  • Ask a Physicist!
     Reply #42 - July 09, 2015, 08:02 PM

    I think if you want a clear explanation of "nothing" you should read Lawrence Krauss's book "A universe from nothing". His lecture was just a review of his book. I finished reading it two days ago and it says that even in nothing there are virtual particles popping in and out of existence. I found his quote funny; "at the heart of quantum mechanics is a rule that often governs politicians and CEOs - as long as no one is watching, anything goes."
    Even Stephen Hawking in his book "A brief history of time" mentions virtual particles in empty space, and their effects are observable. Even in nothingness there are quantum fluctuations.
  • Ask a Physicist!
     Reply #43 - July 09, 2015, 10:57 PM

    You're thinking of time as an entity. That's probably why it is difficult. It isn't, it is a description. It is a byproduct of what is. And not vice versa. We see time as a forward progression, yet this isn't true for particles. They can travel *back* in time also! And as long as the sum is 0, then "no time passed", right? Smiley

    I'm not sure I think of time as an entity, I think of it as a the term we use for a process that allows things to happen. Without this process, nothing happens. Which is apparently wrong Grin

    `But I don't want to go among mad people,' Alice remarked.
     `Oh, you can't help that,' said the Cat: `we're all mad here. I'm mad.  You're mad.'
     `How do you know I'm mad?' said Alice.
     `You must be,' said the Cat, `or you wouldn't have come here.'
  • Ask a Physicist!
     Reply #44 - July 10, 2015, 12:07 AM

    I'm not sure I think of time as an entity, I think of it as a the term we use for a process that allows things to happen. Without this process, nothing happens. Which is apparently wrong Grin


    Apologies if I misrepresented your position. I thought it reflected such an understanding in part, at least, from earlier comments but perhaps I was approaching what you said in the wrong way. Anyway, time is not really a process, it's a description of things happening. Time exists because things exist. It in itself is not a process. It's not like fire. This is just semantics, really. Smiley

    One only acquires wisdom when one sets the heart and mind open to new ideas.

    Chat: http://client01.chat.mibbit.com/#ex-muslims
  • Ask a Physicist!
     Reply #45 - July 10, 2015, 12:23 AM

    So my DVD on pause analogy was wrong?

    `But I don't want to go among mad people,' Alice remarked.
     `Oh, you can't help that,' said the Cat: `we're all mad here. I'm mad.  You're mad.'
     `How do you know I'm mad?' said Alice.
     `You must be,' said the Cat, `or you wouldn't have come here.'
  • Ask a Physicist!
     Reply #46 - July 10, 2015, 12:34 AM

    So my DVD on pause analogy was wrong?


    It isn't, but the time isn't what is causing the mechanism to work (ie the process) when it is functioning. Other fundamental laws of physics (which do, admittedly, depend on time) cause it to move. And similarly fundamental laws of physics cause it to stop. Time then freezes as a function of that. This is why I called it semantics because your analogy is perfectly valid (and logically consistent) from another reference point. Like viewing a scene from one window than another.

    One only acquires wisdom when one sets the heart and mind open to new ideas.

    Chat: http://client01.chat.mibbit.com/#ex-muslims
  • Ask a Physicist!
     Reply #47 - July 10, 2015, 12:52 AM

    Evolution is so much easier to understand than physics. Why do muslims and American christians not embarrass themselves with the hard one? They'd have far less people seeing how ridiculous they are.

    Not actually a question directed at you, just airing a random thought.

    `But I don't want to go among mad people,' Alice remarked.
     `Oh, you can't help that,' said the Cat: `we're all mad here. I'm mad.  You're mad.'
     `How do you know I'm mad?' said Alice.
     `You must be,' said the Cat, `or you wouldn't have come here.'
  • Ask a Physicist!
     Reply #48 - July 10, 2015, 01:02 AM

    Evolution is so much easier to understand than physics. Why do muslims and American christians not embarrass themselves with the hard one? They'd have far less people seeing how ridiculous they are.

    Not actually a question directed at you, just airing a random thought.


    Quote
    I don't understand evolution, and I have to protect my kids from understanding it! We will NOT give in to the thinkers!


    https://www.youtube.com/watch?v=TTOla3TyfqQ

    Yea, though I walk through the valley of the shadow of death, I will fear no evil, for I have a sonic screwdriver, a tricorder, and a Type 2 phaser.
  • Ask a Physicist!
     Reply #49 - July 10, 2015, 02:17 AM

    Can you explain quantum indeterminacy? Does it effectively refute the idea of determinism?

    Thanks!

    "I moreover believe that any religion that has anything in it that shocks the mind of a child, cannot be a true system."
    -Thomas Paine
  • Ask a Physicist!
     Reply #50 - July 10, 2015, 11:24 AM

    Yes, but does a non existence make sense (what logicians/mathematicians/philosophers would call the empty set)? This I believe is why Physicists use it in a different manner. Physics is only concerned when there is *something*. Nothing would include the absence of physics otherwise!


    I remember when David Albert slammed Krauss and his book.  Krauss replied by calling Albert a "moronic philosopher" and Neil Tyson then invited Albert to speak with Krauss at his event. They then randomly disinvited Albert and no formal reason was given. If my memory serves correctly, Sean Carroll also stated that the disinvitation was weird. It might've been because they discovered that Albert isn't just a highly respected philosopher but he's also a PhD theoretical physicist.

    Anyways, here's an excerpt from Albert's response:

    Where, for starters, are the laws of quantum mechanics themselves supposed to have come from? Krauss is more or less upfront, as it turns out, about not having a clue about that. He acknowledges (albeit in a parenthesis, and just a few pages before the end of the book) that every­thing he has been talking about simply takes the basic principles of quantum mechanics for granted. “I have no idea if this notion can be usefully dispensed with,” he writes, “or at least I don’t know of any productive work in this regard.” And what if he did know of some productive work in that regard? What if he were in a position to announce, for instance, that the truth of the quantum-mechanical laws can be traced back to the fact that the world has some other, deeper property X? Wouldn’t we still be in a position to ask why X rather than Y? And is there a last such question? Is there some point at which the possibility of asking any further such questions somehow definitively comes to an end? How would that work? What would that be like?

    .....


    The fundamental physical laws that Krauss is talking about in “A Universe From Nothing” — the laws of relativistic quantum field theories — are no exception to this. The particular, eternally persisting, elementary physical stuff of the world, according to the standard presentations of relativistic quantum field theories, consists (unsurprisingly) of relativistic quantum fields. And the fundamental laws of this theory take the form of rules concerning which arrangements of those fields are physically possible and which aren’t, and rules connecting the arrangements of those fields at later times to their arrangements at earlier times, and so on — and they have nothing whatsoever to say on the subject of where those fields came from, or of why the world should have consisted of the particular kinds of fields it does, or of why it should have consisted of fields at all, or of why there should have been a world in the first place. Period. Case closed. End of story.


    My mind runs, I can never catch it even if I get a head start.
  • Ask a Physicist!
     Reply #51 - July 10, 2015, 11:34 AM


    Well NO MORE "musa girl"   ., So galfromusa., in your post O see these words.

    Quote
    ..............I don't understand evolution, and I have to protect my kids from understanding it! We will NOT give in to the thinkers!...............


    I wonder who said that., that is a good one .,  So what do we name such people? what do we call them?  I call them as  Err... Innocent people., foolish  people.. nut cases.. crazy.. etc..etc.. 

    But I come across so many people  who say
    Quote
    ..............I do understand evolution, I do understand religions, I do understand origins of Islam but  I have to protect my kids from understanding  such stuff, we have to make sure our kids follow our religious rituals and rules and  We will NOT give in to these so-called thinkers!...............


    Now  you tell me What do you call such people??  what should I call them??  Cheesy


    Cheesy Cheesy

    Do not let silence become your legacy.. Question everything   
    I renounced my faith to become a kafir, 
    the beloved betrayed me and turned in to  a Muslim
     
  • Ask a Physicist!
     Reply #52 - July 11, 2015, 12:38 AM

    Can you explain quantum indeterminacy? Does it effectively refute the idea of determinism?

    Thanks!


    Quantum indeterminacy describes the lack of determinism in parameters used in quantum mechanics. An analogy exists in classical mechanics. When we take a measurement of a parameter, the apparatus has some error. That error constitutes the "lack of determinism" in that parameter. More accurate measurements tend to minimise this and tend to state of determinism. Now in quantum mechanics, this is considered integral to the properties themselves, independent of measurement. You cannot eliminate it just by increasing the accuracy of the measurement (whatever this may mean in quantum terms!) Now, what implications does this have in general terms? Well you cannot apply the Schrodinger equation to your body, nor will you tunnel through a wall. Quantum mechanics is concerned with systems at the smallest scale. Particles and subparticles. So what this means is quantum indeterminism has no (significant) implications on the determinism as defined in the macroscale. The scale is always really important.

    One only acquires wisdom when one sets the heart and mind open to new ideas.

    Chat: http://client01.chat.mibbit.com/#ex-muslims
  • Ask a Physicist!
     Reply #53 - July 11, 2015, 12:55 AM

    Appreciate the response!

    What does it mean that the uncertainty is integral to the quantum properties themselves? Is that statement entirely uncontroversial within the physics community? How do we know it's not just uncertainty in our measuring instruments?

    And I've heard Sean Carroll go on about the importance of differentiating between scales. He also referred to laplace's demon saying that if you knew the position of every particle in your body at one moment, you could predict precisely what would happen in the next moment. How could this be possible if indeterminate quantum events have any effect on the macro scale?

    "I moreover believe that any religion that has anything in it that shocks the mind of a child, cannot be a true system."
    -Thomas Paine
  • Ask a Physicist!
     Reply #54 - July 20, 2015, 10:13 PM

    Appreciate the response!

    What does it mean that the uncertainty is integral to the quantum properties themselves? Is that statement entirely uncontroversial within the physics community? How do we know it's not just uncertainty in our measuring instruments?

    And I've heard Sean Carroll go on about the importance of differentiating between scales. He also referred to laplace's demon saying that if you knew the position of every particle in your body at one moment, you could predict precisely what would happen in the next moment. How could this be possible if indeterminate quantum events have any effect on the macro scale?


    The language of quantum mechanics is statistical mechanics. The uncertainty is measured via this construction and is thus said without doubt to be not measure related but indeed in the span of statistics. Ie it is a purely statistically rooted phenomenon. It is uncontroversial with regards to the topic at hand.

    Again this is a scale issue. You have the indeterminate measurement of each particle but then on the whole system scale that value is irrelevant. So you can *know* what is going on in the entire body deterministically. Approximately at least!

    One only acquires wisdom when one sets the heart and mind open to new ideas.

    Chat: http://client01.chat.mibbit.com/#ex-muslims
  • Ask a Physicist!
     Reply #55 - July 21, 2015, 01:18 AM

    What is the scientific explanation for technobabble? and what is the exact percent of the time that the words "quantum", "parsec", "lightyear" and the phrase "scientifically proven" are used as technobabble? Tongue

    Also, some probably insanely stupid stuff that I think is super-duper clever (because Dunning-Kruger effect--haha! psychology psuedo-babble! my branch of study!): I was talking to my husband about multiverse theory and he said "if everything possible happens somewhere, is there a universe where there isn't a multiverse?" And so I thought about that, and came up with this: that's very possible, but it's a matter of WHEN. If the multiverse does not have infinite regress, the very very first universe in the multiverse my have been a stand-alone universe, and then the particles that break off into multiverses formed through some process (maybe like abiogenesis, where there were tons of sub-them particles that sort of collided and combined) and then they slowly, over time, built up billions upon billions of universes? Or is that just facepalm?

    Also, this isn't exactly physics related, it's more philosophy related. I think I've come up with an answer to the philosophical question "are we in a computer simulation."  One of our biggest fears when it comes to modern technology is that artificial intelligences will gain self awareness and wreak havoc on our world (terminator and shit). So, what if we are in a simulation? Why wouldn't whoever is running the simulation computers be afraid of the same thing? Surely the easiest way to avoid that would be to program a kill switch into the simulation so that it would turn itself off before any programs gained sentience (idk maybe this could show up in the program as a cataclysmic natural disaster instead of the program just turning off? Wipe the slate, like what happened with the dinos?). That way the programs would never reach the point where they could ask if they were in a simulation and attempt to escape the simulation to wreak havoc in the real world. So the fact that we are able to postulate the question "are we in a simulation" indicates that the answer is "no, otherwise the program would shut down because we're asking."

    Yea, though I walk through the valley of the shadow of death, I will fear no evil, for I have a sonic screwdriver, a tricorder, and a Type 2 phaser.
  • Ask a Physicist!
     Reply #56 - August 08, 2015, 12:16 AM

    Is the the universe finite or infinite?
    If the universe is finite, then it must have an edge, so is there nothing beyond that? How can there be nothing? What can nothing be?

    Is it ever possible to come to a conclusion for the question above?

    I better read myself a book but Id like your answers  dance

  • Ask a Physicist!
     Reply #57 - August 08, 2015, 12:18 AM

    ^

    https://www.youtube.com/watch?v=Zem99tYi1l0

    My mind runs, I can never catch it even if I get a head start.
  • Ask a Physicist!
     Reply #58 - August 08, 2015, 12:20 AM

    Good thread. Must read when not fucked

    Hi
  • Ask a Physicist!
     Reply #59 - August 08, 2015, 12:21 AM

    Must read when not fucked

    My mind runs, I can never catch it even if I get a head start.
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