109,701 reputation
5167295
bio website ratsauce.co.uk
location Chester, United Kingdom
age 53
visits member for 3 years, 9 months
seen 51 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.


Jul
6
reviewed Close Is there an upper limit to a rocket's size/payload?
Jul
6
reviewed Leave Open How do we know gravity isn't acceleration?
Jul
6
reviewed No Action Needed Is there Phase difference between voltages at end points of a long AC Power line
Jul
6
comment How do we know gravity isn't acceleration?
@integralanomaly5: I've updated my answer to respond to your comment.
Jul
6
revised How do we know gravity isn't acceleration?
Respond to comment
Jul
6
comment About mass defect
@user52153: $k$ can have any value. But whatever value you set $k$ to you have to add that value to both sides of the equation so it cancels out. That's what I said four comments above - I feel we are going round in circles.
Jul
6
answered How do we know gravity isn't acceleration?
Jul
6
reviewed Reject suggested edit on Do all the individual stars that we can see in the night sky belong to Milky Way?
Jul
6
reviewed Looks OK Insulators (also called Dielectrics) which cannot conduct Electricity
Jul
6
reviewed No Action Needed Is the 125 GeV Higgs boson some kind of a “almost-commutative graviton” at the electroweak scale?
Jul
6
reviewed No Action Needed Why is the absolute zero a rational number in Celcius?
Jul
6
comment How does my kitchen scale know I'm holding it?
How are you holding the scales? Are they resting flat on the palm of your hand?
Jul
6
comment About mass defect
@user52153: Any measurement you can make only measures changes in potential energy. We've defined $U$ as potential energy at some position $\vec{r}$ minus the potential energy at infinity, and $E_1$ is then the total energy at $\vec{r}$. $E_1$ is what we would actually measure as we bring the particles from infinity to $\vec{r}$. You can define $E_2 = E_1 + k$, but we can't measure $k$ so we can't measure $E_2$.
Jul
6
comment About mass defect
@user52153: the equation you quote is wrong. If you add some constant potential energy $k$ the equation is $(E_1+k)/c^2 = 2m_0 + (U+k)/c^2$. The $k/c^2$ cancels out and the result is unchanged.
Jul
6
reviewed Looks OK Deriving combined gas law from Boyle's and Charles' laws
Jul
6
answered Absorption cross section and absorption coefficient
Jul
6
answered Why is scattering vector $\vec{q}$ called vector of 'momentum transfer'?
Jul
6
reviewed No Action Needed Is there a limit to acceleration?
Jul
6
reviewed No Action Needed How is the logarithmic correction to the entropy of a non extremal black hole derived?
Jul
6
reviewed Leave Open Why are some surfaces slippery?