usenet weirdness

Can that be done with e-field spherical symmetry? How would the H field know which direction to point?

Why are physics types so often insulting and obnoxious?

I've been to physics meetings that shocked me with their brutality. That mentality is terrible for brainstorming and inventing things.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

Sorry, it's _symmetric_, of course --

(T_00 T_01 T_02 T_03) (T_00 T_01 T_02 T_03) (T_10 T_11 T_12 T_13) = (T_01 T_11 T_12 T_13). (T_20 T_21 T_22 T_23) (T_02 T_12 T_22 T_23) (T_30 T_31 T_32 T_33) (T_03 T_12 T_23 T_33)

Physicists are particulary careful to prove that they are NOT inventing things.

john larkin snipped-for-privacy@glen--canyon.com wrote or quoted:

The E field of a charging or discharging spherical capacitor should be a spherically symmetrical E field that is changing.

We assume that a symmetrical setup does not suddenly create forces that break this symmetry (as long as we are not dealing with interactions with the weak force).

If there would be a magnetic field, it can't have a transversal direction anywhere one a sphere with the same center as the capacitor for that symmetry reason. It also cannot have a radial component because for symmetry such a radial component must be the same everyone and by Gauss' law the magnetic flux through any closed surface must be zero.

(The above used a 2024 text by Ján Lalinský.)

I (Stefan) think each changing electric field line creates a rotating magnetic field and at every point there are as many such fields in one direction as in the other, so they all cancel.

LPZ gave a kind of abstract answer: Due to symmetry, the problem is essentially one-dimensional, and 1-D electrodynamics does not have magnetic fields . . .

Newsgroups: sci.electronics.design

Like Isaac Newton for example? (but he denied to much)

Jan

Their big big problem is their inability to suffer fools gladly.

They are professionals amongst themselves. They can take it. Brutality is what keeps the brainstorming in check,

Jan

Barbarian.

Linked to their enthusiasm to call people fools.

For sure.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

Indeed - although it can look rather cruel to onlookers.

I'm curious though is the Demon brand still existent in demon.nl ? Or is your handle a throwback to times past? Ping says domain not found. It was exorcised in the UK soon after Vodaphone got their hands on it.

When the cap fits... You are arguing out of ignorance and unwilling to learn.

Physicists have heard all of the deranged objections to Einsteins theory of relativity and general relativity so many times before that they are not inclined to give any quarter to hand waving wannabes like you.

The mathematics is a precise detailed description of how things work - natural language is far too ambiguous to make meaningful progress.

Or a spade a spade.

Sure,

Jan

Au contraire, the barbarians are at the gate. It is the way science is financed, and careers are made, that force people being blunt.

With time and money always in short supply wastage must be kept to the minimum, (so no time for fools with hobby horses)

Jan

Bull, it is just an approximation of the observed. I does NOT explain Annie Sing

Why babble here then? QED!

Einstein's thinking was already proven wrong By Alain Aspect many years ago

About as stupid as the current main stream thinking about how the universe came about and how it works

Maybe after the next nuke war some fresh thinking will get rid of all that As well as get rid of the 'power from nuclear fusion' crap.

Just projects to keep Albert's parrots busy at taxpayer cost never creating anything.

Every day new things are found, theorized:

Wrong.

^^^^^^^^^^^^^ Nonsense.

Wrong.

Wrong. Since the postulation and confirmation of general relativity we know that gravitational effects are not (solely) based on mass, but rather more generally on the density of stress, energy, and momentum:

The Einstein Field Equations are in units where c = 1

G_ab + Lambda g_ab = 8pi G T_ab,

where

G_ab = R_ab - 1/2 R g_ab

is (a component of) the Einstein tensor, R_ab is the Ricci curvature tensor, g_ab is the metric tensor, R = g^ab R_ab is the Ricci curvature scalar, Lambda is the cosmological constant, and T_ab is the (stress--)energy--momentum tensor.

Gravitional effects are understood (in GR) as a consequence of the curvature of spacetime which is described by the quantities on the left-hand side of the equations.

The energy--momentum tensor of a 1+3-dimensional spacetime has 16 components, but it is antisymmetric so only 10 of them are unique. Anyhow, the time--time component is proportional to the energy density which is at relative rest is proportional to the mass density:

T_00 ~ rho_E ~ dE_0/dV = c^2 dm/dV = c^2 rho_m.

It does not.

IOW: This is way over your head.

As an engineer, though, you should appreciate the requirement to agree and conform to standards. That includes network standards which you keep violating by your address munging:

It is not. You are arguing from your ignorance.

It is possible, just very difficult:

The total energy of both photons has at least to be equal to the sum of the rest energies of the particle and antiparticle.

You would have to separate the particle and the antiparticle to prevent them from annihilating again, which means that the total energy of both photons has to be much larger than the sum of the rest energies of the particle and the antiparticle. You need energy for the magnetic fields that keep them separated.

A single electron is not very useful, indeed, and you need more energy to produce it this way than it could do usable work because it needs kinetic energy *and* rest energy E_0 = m_e c^2.

No, the total electric charge is conserved. What happens in "charging" is that electric charge is added from or removed to somewhere else.

Electric charge can also be "induced" by bringing an electrically charge in the vicinity of an electrically neutral object. Then the carriers of electric charge in the formerly neutral object arrange themselves such that the distribution of electric charge is no longer uniform:

.---------. ,---------. : (+) (-) : : (+) (-) : : (-) (+) : : (+) (-) : : (+) (-) : : (+) (-) : : (-) (+) : : (+) (-) : : (+) (-) : : (+) (-) : : (-) (+) : : (+) (-) : : (+) (-) : : (+) (-) : : (-) (+) : : (+) (-) : : (+) (-) : : (+) (-) : : (-) (+) : : (+) (-) : '---------' '---------'

Some time later:

.---------. ,---------. : (+) (-) : : (+) (-) : : (+) (-) : : (+) (-) : : (+) (-) : : (+) (-) : : (+) (-) : : (+) (-) : : (+) (-) : : (+) (-) : : (+) (-) : : (+) (-) : : (+) (-) : : (+) (-) : : (+) (-) : : (+) (-) : : (+) (-) : : (+) (-) : : (+) (-) : : (+) (-) : '---------' '---------'

Nonsense. A changing electric field induces a magnetic field, and a changing magnetic field induces an electric field:

Sorry, it's _symmetric_, of course --

(T_00 T_01 T_02 T_03) (T_00 T_01 T_02 T_03) (T_10 T_11 T_12 T_13) = (T_01 T_11 T_12 T_13). (T_20 T_21 T_22 T_23) (T_02 T_12 T_22 T_23) (T_30 T_31 T_32 T_33) (T_03 T_13 T_23 T_33)

Of course not.

Not a throwback, I never changed it. It was valid, once, despite saying 'nospam'. There is also a Reply-To: header for serious replies, if really needed.

Eh, you are replying to several people at once.

Eh, I guess that 'john larkin' is an innocent bystander from <sci.electronics.design> who got a bit lost.

As already noted, SPR is a reserve for the care and feeding of relativity nutters, and for people who like to do some careing and feeding. Some moments of observation will tell you who is what.

Since there are some competent people there you may still learn something new, occasionally,

Jan

You must be a physicist to dispense insuts so eagerly in a discussion group.

My opinions about the brutality of the physics world were acquired first-hand.

I did find the scientists in a few places to be collegial and happy to brainstorm. LANL and LLNL come to mind.

I'm just trying to visualize a time-varying spherically symmetric gravitational or electric field.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

Do photons have the same gravitational effects as their mass equivalents?

Are people stupid for asking questions?

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

CERN people weren't as nice.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

john larkin snipped-for-privacy@glen--canyon.com wrote or quoted:

The electromagnetic stress-energy tensor bends spacetime. To see the Hilbert stress-energy tensor T of a source-free electromagnetic field F, please see the section "Electromagnetic stress-energy tensor" on the Wikipedia page "Stress-energy tensor". (I think this also is equation 4.2.27 in "General Relativity" (1984) - Robert M. Wald.)

A single photon does not have mass, while a pair or gas of photons can have mass.

Usually, the space-time curvature generated by realistic light is small and therefore rarely has an observable effect. However, in the early universe it once dominated over matter.