Recent content by RobbyQ

So can a particle of, say, spin 0 decay into two particles of spin +1/2 & -1/2 but still obey the conservation laws where the total spin is still 0 ?

Thanks Parok So in the quantum world, measuring just about any property is a probabilistic process eg spin ?

If the creation of entangled photons is a probabalistic process and bosons are indistinguishable, how do you know if two photons are entangled and related? For example, in the double slit WPD experiment where a signal and idler entangled photon pair are created. How do you relate them

I agree . Very informative. Also what's interesting (about 5mins into video) is that they keep it slightly Earth side of L2 so it has tendency to fall Earth wards and so the thrust burners to correct it back towards L2 are always Sun facing so as not to have to turn it around and get burnt up.

Thanks. This video I found very interesting too as it discusses the component forces leading up to the JWST orbit around L2. And even this is simplified.

Wow that's crazy. It actually orbits the L2

I often wonder what the accuracy is when dealing with spacecraft and wondered how accurate a craft needs to be positioned into the Lagrange (L1,L2,L3) positions. Are we talking plus or minus 1km/100km/1000km etc. It's just that the system is so vast and what instruments are used to achieve a...

I always understood that a photon of correct wavelength would raise the energy level of an electron (which is the case) But reading about lasers and stimulated emission I read the following where the electron drops a level upon absorption:- "A photon with the correct wavelength to be absorbed by...

What experimental setup do we use to measure PE loss in Hydrogen atom formation. Or, in fact, the PE needed to separate the electron and proton until they reach their rest mass. Is it an implementation of the Einstein's Box (which I understand was a thought experiment)?

And the mass deficit is the binding energy? So I cannot think of the spring system in this way?

Yes understandable PeroK. Hence why I wondered if this could be measured even. But from a mass/energy equivalence is it conceptually correct i.e if I were to convert both the uncompressed and compressed systems into pure energy would I observe the added PE difference?

If I take a spring with clamps and I weight that system accurately. Then I compress the spring and clamp it thus giving it potential energy. If I now weigh the clamped spring I should see an increase in mass because of the added energy. Is this the case and something that could be proved in the...

Thanks. But how do you associate 2 entangled photons out of the whole bucket load of entangled photons. And how do they measure the shared quantum state of 2 entangled photons and put it to practical use once there is a state collapse from observation?

In this video how are the entangled photons later used and actually identified as an entangled pair amongst billions of others. Also does he really mean the photon is split or is the quantised energy split with half frequencies?

In this video Dirac talks about the Fine Structure Constant 1/137. Can we now explain why this is?