Um, have you read the post you quoted from? ( https://www.physicsforums.com/threads/photon-states-should-not-evolve.925675/page-4#post-5847397 )
Carrock: Saying that 'the concept of "time" does not apply to them' also often leads to incorrect inferences.
PeterDonis: How So?
Carrock: Hard to...
Hard to find a reference, but I've seen claims that photons experience change in some way, but time does not pass for them. It's usually harder to understand when time is implicitly avoided but a vaguely similar concept is used.
Often isn't necessarily. There's no problem e.g. in moving a clock...
'Saying that the concept of "time" does not apply to them' also often leads to incorrect inferences; I subjectively find the latter more annoying.
I was simply trying to indicate that it's never necessary to have photons' energy, momentum etc change.
It's often useful to think the photon is...
The general view, I think, is that time isn't an applicable concept for a photon, since a reference frame 'moving with' a photon isn't possible.
To go from this to saying that photons are timeless (i.e. without defined time) is OK IMO. Whether or not their 'time' 'stands still' is semantics...
I'm wondering if you want the LED power or (LED + dropping resistor) power.
I plugged some values into https://www.vishay.com/resistors/pulse-energy-calculator/
Pulse width 0.04 sec
Voltage 2V
Current 0.005A
and got Pulse Energy = 0.4mJ
Then cycle time = 2S gave 0.2mW
I'm guessing you had a...
Seems like ~9W during the pulse - very high for one LED. You need to give the voltage drop across the LED, and whether the voltage during each pulse varies for a useful answer. Also I presume you want the energy used during the ten hours.
There do seem to be some elements where electron capture and presumably electric fields are significant.
"Around the elements in the middle of the periodic table, isotopes that are lighter than stable isotopes of the same element tend to decay through electron capture, while isotopes heavier...
I made a rather careless late night post.
I should have confined myself to saying "N (or N+1) does not converge on a limit as N goes to infinity. lim N and lim (N+1) are not defined and can't be compared.
You're referring to ##\infty## which has been described as "not a cardinal number, but a description for going to as large a number as we like."
In the limit N goes to ##\infty##, lim N < lim (N+1). Although "lim N = lim N+1" is often written, it is clear that the LHS is one smaller than the...
There's another fuel which I read about in a reprint of a 1950's comic - isospin monatomic hydrogen.
It's got the best specific impulse of any chemical fuel, with no worries about radioactivity or toxicity.
It does have a few drawbacks...
I believe it's only been made in microscopic amounts...
A problem here is the use of ##\infty## without clearly distinguishing it from the real numbers, which have a cardinality equal to ##\aleph_1##, assuming the continuum hypothesis.
##\infty## is defined here as "an abstract concept describing something without any bound or larger than any...
You're assuming the energy of a photon must be defined by a comoving inertial frame.
Unless you can justify that, then you can choose a local frame where the photon has not lost energy or evolved.
In special relativity, you can make the the frequency or momentum etc of a photon any arbitrary finite value you want, by choosing an appropriate reference inertial frame from which to measure it.
Similarly, in GR, any apparent bending, doppler shift etc is a result of curved space etc and...
I would find it difficult to do this; as it is not the question asked I won't try.This is correct.
From #2
$${V^2/R_1 \over 76} = {V^2/R_2 \over 24 }\ . $$
You can work out from this the numeric ratio ##{R_1 \over R_2}##.
WRONG! or English error... the voltage across each resistor in series...
You know the power with V across each resistor.
With the resistors in series and their ratios known, you can calculate the voltage across each in terms of V e.g. V-x,x.
You can then calculate the power with V-x or x across each resistor compared to V.
You can't calculate and don't need the...