116,972 reputation
5183312
bio website ratsauce.co.uk
location Chester, United Kingdom
age 53
visits member for 3 years, 11 months
seen 4 hours ago

Semi retired old time computer nerd who started programming on a Commodore Pet.

Since I'm also active in the Physics forum I should add that I started as a theoretical chemist, moved into solid state photochemistry and finally worked in industry as a colloid scientist. I only became a full time computer nerd in 1997.


Dec
14
comment Could the explanation for this simple electric train be attributed to Lenz's Law?
I can't see how Lenz's law is involved. The motion is just due to the force a (permanent) magnet feels in a diverging magnetic field.
Dec
14
comment What does observation mean in two-slit electron diffraction experiment?
possible duplicate of What is an observer in quantum mechanics?
Dec
14
comment Period of a pendulum in a lift going up
possible duplicate of Period of pendulum in falling lift
Dec
14
comment How do you define the resonance frequency of a forced damped oscillator?
I've heard the terms pure resonance and practical resonance used to describe $\omega_0$ and the frequency maximum of the amplitude respectively. A quick Google suggests these terms are widely used.
Dec
14
comment Why spin-$\frac{1}{2}$ nuclei have zero electric quadrupole moment?
I'm pretty certain you can show that $\langle\tfrac{1}{2}|Q|\tfrac{1}{2}\rangle = 0$, where $Q$ is the quadrupole operator. However the details have slipped from what I laughingly refer to as my memory. This might give you enough clues to Google the answer.
Dec
14
comment Period of oscillations for hanging and standing spheres
In (a) the sphere will swing to and fro, like a pendulum, as well as rotate.
Dec
13
comment Which of the following minerals has the highest PEF reading?
A quick Google tells me it's the average atomic number per unit volume. Iron carbonate wins because iron has the highest $Z$ of all the elements in your list, plus $FeCO_3$ is the densest of all the minerals listed.
Dec
13
comment Classical Mechanics contradicts Conservation of energy?
@Chris: you're quite correct that I assume energy is conserved, but then if it wasn't all of modern physics would come tumbling down around our ears. Energy can't not be conserved without violating some pretty fundamental symmetries of the universe. The point of my answer is to show how the energy is moving around your system and explain why the initial impression that energy isn't conserved is wrong. If you want to start from the position that energy isn't conserved then, well, you're on your own because for a start we couldn't use Newtonian mechanics to analyse the system.
Dec
13
comment Can quantum physics be compatible with materialism?
This question appears to be off-topic because it is about philosophy not physics
Dec
12
comment Where can I buy LEDs with an accompanying spectrum document?
This question appears to be off-topic because it is about suppliers of electronic components
Dec
12
comment What's the Cause of Quantum Entanglement?
Shubham, searching this site for quantum entanglement will find you lots and lots of related questions. We expect that people will make at least this token effort to look for an answer before they post a new question.
Dec
12
comment What's the Cause of Quantum Entanglement?
possible duplicate of What is quantum entanglement?
Dec
12
comment Fluids and pseudo force
What does Archimedes tell you about the upthrust on the block? Suppose the lift was accelerating downwards at $9.81$m/sec (i.e. $g$) what would happen then? Hint: there are three possibilities not just the two you mention in your question.
Dec
12
comment Why is stress a tensor quantity?
@user166748: the introduction to the Wikipedia article on tensors does a fair job of summarising what a tensor is.
Dec
12
comment Why is stress a tensor quantity?
Though a scalar is a tensor of course - it's a rank 0 tensor.
Dec
12
comment String Theory Landscape
Damon, the accepted answer to the question I've linked explains how the $10^{500}$ is calculated, though it's in a comment to the answer not the answer itself. The source article (also written by Urs Schreiber) is here, and the calculation is discussed in the section Models in type II string theory / F-theory.
Dec
12
comment String Theory Landscape
possible duplicate of Why does string theory have such a huge landscape?
Dec
11
comment Is there a field for which neutral particle and antiparticle, can be considered as positive and negative charge?
Sofia, neutrons are bound states of three quarks and they have no net electrical charge because the quark charges balance out. It's like asking if hydrogen atoms could be the source of some field because they have no net charge either.
Dec
11
comment Do the fields exist without electric charges?
@Sofia: the $\pi_0$ is not an elementary particle. It consists of a pair of charged quarks - either $u\bar{u}$ or $d\bar{d}$. It decays to photons because the charged quarks annihilate each other. I suspect you will find in all apparently neutral particles that decay to photons charged particles will be involved somewhere.
Dec
11
comment Length contraction, front middle or back
Note that acceleration of a rigid raises all sorts of interesting issues. See this paper on the Arxiv a discussion. If you're only interested in steady speeds that simplifies things. If so can you adjust your question accordingly.