Search results

  1. Dadface

    I Can an electron in the 1s orbital be indefinitely far from the nucleus?

    I think a good reply to your question has been given by ZapperZ in post 17.
  2. Dadface

    I Can an electron in the 1s orbital be indefinitely far from the nucleus?

    Yes I had another look at his post and I see what you mean. It seems that he forgot to take into account the fact that during a transition to the ground state the ionisation energy is radiated to the surroundings.
  3. Dadface

    I Can an electron in the 1s orbital be indefinitely far from the nucleus?

    Of course the choice of convention makes no difference to the calculations. I never said it did. But it can be confusing whatever convention is used. Some people may look at the chosen values and think they are absolute values.
  4. Dadface

    I Can an electron in the 1s orbital be indefinitely far from the nucleus?

    Use a different convention, let the potential energy at infinity be equal to X. We can write energy equations for the particles at infinity and at the ground state. Infinity P.E. = X , K.E = 0 Bohr radius P.E. = X -27.2 ,K.E = +13.6, Energy lost = 13.6 Whatever convention is used...
  5. Dadface

    I Can an electron in the 1s orbital be indefinitely far from the nucleus?

    jaumzaun calculated the kinetic energy to be negative because he thought that the potential energy at infinity really is zero instead of being at a maximum value. When he gets used to the potential energy convention he should calculate that when the atom moves to a ground separation at the Bohr...
  6. Dadface

    I Experimental confirmation of the Born rule

    Yes, but how else can we look at the atom without changing it?
  7. Dadface

    I Experimental confirmation of the Born rule

    Yes. It's details of the latest experiments I'm looking for.
  8. Dadface

    I Experimental confirmation of the Born rule

    https://physicsworld.com/a/quantum-microscope-peers-into-the-hydrogen-atom/
  9. Dadface

    I Can an electron in the 1s orbital be indefinitely far from the nucleus?

    Jaumzaun, Because we can deal with differences in potential energy only, not absolute values, we choose two things: 1. A particle separation 2. A value of potential energy for the chosen separation. Any choices we make would be somewhat arbitrary but the most useful and logical choices, which...
  10. Dadface

    I Experimental confirmation of the Born rule

    Thank you. I found a report from 2013 which summarised the work of a team who used the "photoionisation microscope" to observe some nodal structures of the hydrogen atom. The graphical results displayed seemed to show some agreement between experiment and theory. I'm mainly interested to...
  11. Dadface

    I Experimental confirmation of the Born rule

    Specifically, how would you attempt to detect an electron, at a particular location whilst in the bound state of the hydrogen atom. The particle detector you referred to is no good at the moment. It needs re calibrating.
  12. Dadface

    I Experimental confirmation of the Born rule

    If we assume that a particle can be detected at a particular location, how can we do the detecting?
  13. Dadface

    I Can an electron in the 1s orbital be indefinitely far from the nucleus?

    Of course. I was trying to point out that the way you expressed your comments laid them open to strange interpretations. Take another look at what you wrote.
  14. Dadface

    I Can an electron in the 1s orbital be indefinitely far from the nucleus?

    Thank you but I already have a basic idea of what the Born rule is about. I was trying to point out that some of the comments made were lacking in clarity and my questions were attempts to show how some people might interpret those comments. From your response it seems that my comments in post...
  15. Dadface

    I Can an electron in the 1s orbital be indefinitely far from the nucleus?

    I think some of the answers need clarifying: Does that mean if you have measured where it is, it's meaningful to ask where it is? So it seems that the interpretation is meaningful to Bill, who intends to detect the position but not to Ben who doesn't intend to detect the position. If Bill...
  16. Dadface

    Insights Why We Don’t Discuss Perpetual Motion Machines (PMM)

    It was Professor Sir George Porter who said that when he became a bit of science populariser he got lots of communications from people sending him their designs for PPMs. In the early days, he replied to them all pointing out why their machines wouldn't work but he had to give up doing this...
  17. Dadface

    Inducing electric current in a wire (a comparison)

    The device is commonly known as Newtons cradle. The impulse travels through at the speed of sound in the metal.
  18. Dadface

    Magnetic field lines and magnetic flux density

    Of course the concept, like every other concept in physics, has to be applied with care. It seems to me that some people here don't like my use of the word "flawed" so rather than getting involved in semantics I will refer to the word domain as a summary of the concept of domain of...
  19. Dadface

    Magnetic field lines and magnetic flux density

    It seems to me you are taking things out of context by selecting just certain parts of my posts only. That's very unfair. My criticism of the concept of field lines focuses on one specific area this being where people use the concept to make quantitative predictions. The concept used...
  20. Dadface

    Magnetic field lines and magnetic flux density

    That may be true but I don't see the relevance of the comment. My posts here have been made with reference to the opening post and to one concept only, the concept of field lines. Many people have used that concept to make quantitative definitions that are wrong. Check it for yourself, for...
  21. Dadface

    Magnetic field lines and magnetic flux density

    My posts were reacting to post one where it was pointed out that flux density can be described in terms of concentration of field lines. We have good experimentally based mathematical equations defining terms such as flux density and flux and these make sense. But we read definitions similar to...
  22. Dadface

    Magnetic field lines and magnetic flux density

    It is another way of thinking about the field and if used with care it can be useful. But it can be confusing as well as evidenced by Mr Turings post. If, for example, magnetic flux is described as being proportional to number of field lines, what is that number and what is the constant of...
  23. Dadface

    Magnetic field lines and magnetic flux density

    Mr Turing I think to get an understanding of this you could do the following. Go back to the beginning if necessary: 1. Get a bit of a bit of an understanding of the concept of field lines, which you already have. 2. Get familiar with the magnitude and directions of the forces on current...
  24. Dadface

    Does the resistance of a material vary when introduced into water?

    There are so many variables here but if there is an effect and its very small how will you measure it?
  25. Dadface

    The EMF induced in straight current-carrying conductor

    For a closed loop moving at steady velocity within a uniform B field there will be no internal current but, as predicted by the Lorentz law, there will be a build up of electrons, most concentrated at one end of the loop, and a shortage of electrons, most concentrated at the other end. Hence...
  26. Dadface

    The EMF induced in straight current-carrying conductor

    Faraday's law can be written as: emf = d/dt BAN Assume B is constant and N =1 we can write: emf = B dA/dt In this example dA/dt is the rate of change of area...
  27. Dadface

    Correct statement about a concave mirror

    It's a badly written question as evidenced by the discussion here, but as suggested by jtbell its a question you might come across in an introductory physics course. As such, if it were an exam question the candidate would be expected to reach an answer within less than one minute. The nature of...
  28. Dadface

    Inducing electric current in a wire (a comparison)

    Well if in your opinion the best way to answer the question is by reference to the Poynting vector you could advise the student to look it up. In the coursework component of UK courses students were encouraged to go beyond the syllabus requirements and do some research.
  29. Dadface

    Inducing electric current in a wire (a comparison)

    I think people interpret "B level" in terms of what is taught in the high schools in the country they are living in. In the UK the syllabi have regularly changed over the years but as far as I can recall not one of them has ever required a knowledge of the Poynting vector.
Top