Recent content by Leo.Ki

Thank you so much, Ben. I think I see clearer now. The waves being very probably calculated as part of the whole very dynamic gravitational environment, what I described naively as the gravitational redshift would already be included in the package and would not be something that can be clipped...

The cosmological redshift of GW150914 was estimated, but what about its gravitational redshift due to it having been produced so close to the merging black holes? I am expecting varying redshifts depending on where in the vicinity of the phenomenon each stretch of wave was created, and when...

I was just reading about squeezing on this paper: https://dcc.ligo.org/public/0089/P1200041/019/P1200041_v19.pdf It triggered a question though: With all the 90° reflections that the laser goes through before entering the arms (see fig 1 on pg 6), isn't the phase compromised?

Martin, I don't think the LIGO team tries to compensate for the motion of the Solar system or our galaxy. We observe the gravitational waves in our own frame of reference - even if it is not really inertial - and the waves move at the speed of light (as far as we know) in our frame of reference...

Thank you Orodruin. The 250 Hz peak frequency is very small indeed - even if, for the way back in the case study I described, it is double that - or the arm is very short. But on theoretical grounds, how important is the Shapiro effect compared to the other effects causing the interference...

I am trying to understand how the photons in the LIGO beams behave when going along the "slopes" of the gravitational waves, in particular how the Shapiro delay gets factored into the resulting interference. To simplify the situation, suppose that a LIGO photon starts orthogonally to a wave...

Thanks, Schrödinger's Dog. The problem is that the frequency of the incident photon is constant only for an inertial frame. Unless the acceleration of the atom is caused by gravity, the atom is not likely to accelerate as a whole block. Moreover any acceleration is quantized in tiny jerks if I...

I'm wondering whether QM considers photon absorption by an accelerating atom as an instantaneous event, or the change in velocity (and proper time) of the atom affects the perceived distribution of the wave packet and the outcome of the process. In other words, is there a "Doppler gradient"...

Thank you to everybody who replied. I lack the knowledge to understand some things, but I do understand the link you draw between the TI and GR spacetime, AnssiH. In such a case the whole notion of causality has to be revised - the notion that the future evolves in the transactions seems a...

While trying to wrap my head around the Transactional Interpretation, I wondered why we need signals from the future. For the electron about to be ejected, the surrounding space is already filled with information about everything around, and if the momentum conditions assign it to strike beyond...

Thank you Rach3, I like this idea of a smooth transition between two sets of particles/fields. The photons look a bit like the energy of the fields gone free to zip away in a concentrated form. Is it possible to swap the time and space axes and have an electron hit a gamma ray of equal energy...

Thank you Carl and Careful, Your replies raise even more questions in my mind. I understand that annihilation and creation are actually misnomers for "mere" transformations, even if we don't work out what is transformed exactly. I even read once that an electron-positron pair isn't annihilated...

When an electron and a positron, for instance, annihilate, do their fields disappear away at c from the point of the annihilation, letting their former influence still apply beyond the vanishing line? If the energy of these particles is entirely in their fields, as I sometimes read, how can...

Thanks Larry Yes, it is really problematic, but it was some kind of thought experiment.:smile: Maybe we could discover some kind of universe-wide equilibrium in the age of the particles, classically or quantically, since everything seems linked up by way of various symmetries. If the universe...

Thanks for your explanations, pibomb. Of course one should pick a preferred frame before one attempts to calculate the age of any particle. In spite of the practical impossibility, I wondered what kind of result we could expect for the average age of all particles in the universe. I suppose...