Recent content by andrew s 1905

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    I Help identifying this Tumbling object in a night sky photo from Namibia

    Which would make me think it is relatively close. However, from a single observation it is most likely impossible to identify unless a candidate can be found. A rocket launch with a discarded "tumbling" stage for example. Regards Andrew
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    Stargazing How can we be sure that Leavitt’s law works?

    All quite true but not what you originally posted. "Just giant balls of hydrogen and helium". Not realy the type of helpful input one would expect of a MS in Astronomy. Why not include what you did in your second post. Your propensity to prefer put downs rather than explanations is sad...
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    Stargazing How can we be sure that Leavitt’s law works?

    Because different populations of stars have different constituents in different proportions and are not just balls of hydrogen and helium. Our understanding of stars is not as well defined as you imply.
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    I Cosmological red shift and cosmic time dilation

    Thanks, please close this thread. Regards Andrew
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    I Cosmological red shift and cosmic time dilation

    Thanks sorry I missed it. Andrew
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    I Cosmological red shift and cosmic time dilation

    This https://www.frontiersin.org/articles/10.3389/fphy.2022.826188/full#h14 paper makes the claim as in the summary. I don't have the experience to judge the merit of the claim. I would value any views on it is correct or not and if incorrect where the error(s) is (are). I do have some...
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    Our Beautiful Universe - Photos and Videos

    Software Bisque Paramount mounts have had Protrack or many years. It uses feed forward control based on a pointing model. This is implemented in The Sky X pro software. It was developed by Patrick Wallace who has worked on many major telescopes pointing and tracking. See here for so e of his...
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    I In a closed loop system with a pump, how can we control the pressure?

    The classic solution is a kickback loop (value outlet to inlet) with a control valve in the loop. By changing the flow rate (through the kickback loop) you control the outlet pressure via the pump curve. Regards Andrew
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    I Any evidence of white holes in the Universe?

    On reflection the big difference between black and white holes was that there was/is a theoretical way to created a black hole from what had already been observed or near extrapolation while none exists (as far as I know) for white holes. Regards Andrew
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    I Any evidence of white holes in the Universe?

    The same could have be said of black holes. In advance of what? Certainly, not the discussion of if they existed or not. You are reflecting the polished hindsight view of the reality of the the road to the acceptance of the reality of black holes and that they had been observed conclusively...
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    I Any evidence of white holes in the Universe?

    Well I imagine you would calculate the expected spectrum (thermal ?) and compare it with observation. You would look to eliminate other possibilities like black hole accreation disks massive stars etc. One could of course have made such disparaging remarks about black holes in my life time...
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    I How to interpret this new Keck spectrum picture of Jupiter?

    I maybe missing something but won't the spectrum be of reflected sun light? So it will show the solar spectrum with some modifications due to the refective properties of Jupiter's atmosphere. Regards Andrew
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    Diffraction Effects and Artifacts in Telescopes like the JWST

    Two stars in the image have been manipulated to have equal lengths but other stars in the field show none at all! Regards Andrew
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    Diffraction Effects and Artifacts in Telescopes like the JWST

    My apologies it is was not my intention to shout. It is used a lot on this forum, which is where I came across it, so did not spell it out. Again sorry for the confusion. Regards Andrew
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    Diffraction Effects and Artifacts in Telescopes like the JWST

    I am saying it is For All Practical Purposes not possible. I don't recall saying it was impossible in principle but given the finite life of stars I am inclined to think it is. In your calculation there will come a point along the diffraction spike where the diffraction pattern will fall below...
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