116,962 reputation
5182312
bio website ratsauce.co.uk
location Chester, United Kingdom
age 53
visits member for 3 years, 11 months
seen 16 mins 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.


1h
answered Gravitational time dilation, does time of the observer at a lower gravitational potential looked slowed down in the frame of the higher one
1h
comment Positivity of Bulk modulus and shear modulus in isotropic materials
Wouldn't a negative bulk modulus mean the more you tried to compress the body the more it expanded?
2h
comment Period of oscillations for hanging and standing spheres
Try it! You can easily assemble a system like this. Just tie thead to one end of a stick, hold the stick horizontal with the thread vertical then let the stick go.
2h
comment What happens to an orbiting body moving with the Earth's angular speed at various altitudes?
@JoshuaLin: a hyperbolic orbit starts at infinity and ends at infinity i.e. in a hyperbolic orbit the velocity of the object is everywhere greater than the escape velocity. For $r < r_e$ the object has a velocity less than the escape velocity so it's orbit can never be hyperbolic no matter how small $r$ becomes.
2h
comment How can a 360 Degree Rainbow be formed?
possible duplicate of Is it possible to witness a circular rainbow?
7h
comment Is light emitted in zitterbewegung?
Larara, the link I've suggested is a duplicate in the sense that it answers your question. Zitterbewegung doesn't really exist.
8h
comment Why (and how) do foods stick to a pan?
This question appears to be off-topic because it belongs on the Chemistry Stack Exchange
8h
comment Could the universe really be a hologram?
This question appears to be off-topic because it is nonsensical
9h
reviewed Approve How light speeds up after coming out of a glass slab?
9h
reviewed No Action Needed Does quantum entanglement arise from quantum theory or is it merely an experimental observation?
10h
comment Momentum in the frame of reference of the center of mass
The second part of your question contravenes our homework policy, and I'd guess that's why your question got closed. Your first sentence is a fair question though. You could try editing your question to have just the first sentence. I would vote to reopen if you did that.
10h
reviewed Approve Why don't we have a theory of everything?
10h
reviewed Leave Closed Critical engine failure just after rotation: what percent of accelerated slipstream lift does the wing loose?
10h
reviewed Leave Closed Momentum in the frame of reference of the center of mass
10h
reviewed No Action Needed Does quantum entanglement arise from quantum theory or is it merely an experimental observation?
10h
comment Does quantum entanglement arise from quantum theory or is it merely an experimental observation?
@CuriousOne: you're a devil for giving good answers as comments. Can't you expand this to an answer as a Christmas special? :-)
10h
reviewed Reviewed How to calculate the solid-liquid interface energy knowing the surface free energy and liquid contact angle?
10h
comment How to calculate the solid-liquid interface energy knowing the surface free energy and liquid contact angle?
Do you really mean free energy? I suspect ypu actually mean surface tension. If you know $\gamma_{SA}$ (20mN/m), $\gamma_{LA}$ (73mN/m) and the contact angle just draw the forces acting at the edge of the drop. The three forces must sum to zero so you can calculate $\gamma_{SL}$. This is exactly what Young's equation does.
11h
reviewed Reject Prove the relation between relative velocity ,momentum and energy
11h
reviewed Reopen Force of a Train