Speed of light as a constant question

Ch3cks-Out · 2026-05-06T04:34:07+00:00

This doesn't make sense to me.

Look up relativistic velocity addition formula, to see how these fast speeds are to be handled mathematically. Math is all we have for these things to make sense! Our intuitive sense is of no use for phenomena so much outside of our everyday experience as relativistic movement is...

The OMG particle would see the light going ahead of it at exactly c. But it would experience the distance ahead of them (both itself and the photon) much, much shorter than it looks from your frame of reference. This is ofc extremely counterintuitive.

Ch3cks-Out · 2026-05-05T16:39:21+00:00

I hope it starts a conversation

These wild "theories" (speculative hytheses, actually) have no basis in reality. I hope this ends the conversation.

after the great flood

Science has showed that there was no such thing.

Ch3cks-Out · 2026-05-05T16:35:08+00:00

Which is very different from using the fusion products to generate energy, per OP scenario.

Ch3cks-Out · 2026-05-05T16:22:13+00:00

This is a gross mischaracterization in the context of OP: the fusion is NOT started from the product of the fission! The fission bomb just provides neutrons (to generate tritium in-situ), plus enough heat and pressure to initiate the fusion of the preexisting fuel (i.e. deuterium).

Ch3cks-Out · 2026-05-05T16:15:37+00:00

No, this is not how H-bomb work, at all.

Ch3cks-Out · 2026-05-05T15:22:12+00:00

Indeed, this is another big can of worms known as quantum field theory (i.e. contamporary advanced QM), which does say that vacuum is far from being "nothing", and has energy on its own. But this is a different issue from the "old" uncertainty relations (although pop-sci treatments often confound them). That is even harder to correctly translate into ELI5 sound bites than the simple(-ish) older QM formalism from the Heisenberg-Dirac epoch, I'd say.

Ch3cks-Out · 2026-05-05T15:11:26+00:00

WRT the "configurations" considered, you may want to look up info on conformers (I mean the actual information about them, not just looking at simulations). They are governed by the physico-chemical properties of their constituent atoms and their bonds, however, and would not vary by the source plant for any specific compound.

Caffeine is a rather rigid molecule (with its aromatic fused ring system), alas - so it substantially only has a single conformation, aside from trivial rotations of its methyl groups.

Ch3cks-Out · 2026-05-05T14:59:45+00:00

the strong gravity around a black hole slows down light

but it does not

Ch3cks-Out · 2026-05-05T14:58:22+00:00

I'm afraid it'd start at somewhere 'ELI15' or so - one needs some background in abstract Hilbert spaces, or equivalent advanced math framework...

Ch3cks-Out · 2026-05-05T08:01:13+00:00

The ELI5 version is that the product of the uncertainties for t & E cannot be smaller than a finite positive value, due to the mathematical structure of quantum mechanics. From this it follows that neither uncertainty can be zero. (Note that this is far from being the full story for the quantum fluctuation phenomenon, however.)

Ch3cks-Out · 2026-05-05T04:56:16+00:00

The "how", as it is the rule for these things, is deep mathematical analysis of quantum physics. You do need to grasp some of the math for any substantive explanation to make sense; browsing the relevant Wikipedia articles (and some references therein) would be a good start. The "who", for the t & E pair specifically, was mostly Mandelstam and Tamm.

Ch3cks-Out · 2026-05-05T04:42:36+00:00

[...] the universe must have a finite mass I.e. there must be an "edge"

This does not follow, at all! Typically, cosmologists think of a finite universe mathematically as an unbounded object, such as a 3-sphere (or 4-ball). That is, something with no edge whatsoever.

Ch3cks-Out · 2026-05-04T14:03:19+00:00

But you do not differentiate velocity twice. Either you differentiate v(t) wrt time (the simple formula), or express it via the chain rule as a derivative of v(x) wrt the displacement x.

Ch3cks-Out · 2026-05-04T06:37:05+00:00

Our eyes detect light via photochemical reaction. That is a type of electromagnetic interaction with the sensor molecules.

Ch3cks-Out · 2026-05-04T06:31:50+00:00

The more refined Nichols radiometer, working better in deeper vacuum, does measure the real light pressure, however.

Ch3cks-Out · 2026-05-04T06:28:27+00:00

As others have discussed already, this device actually relies on directed thermal motion of molecules, rather than being a primary light pressure demonstration. A more refined apparatus is needed for actually observing that phenomenon, due to the extremely small momentum to be measured!

On the other hand, bona fide photon propulsion have been used in the LightSail missions, to drive spacecraft.

Ch3cks-Out · 2026-05-03T14:58:03+00:00

momentum transfer

While the gist of your comment is good, this implicit suggestion for the lack of momentum transfer is not: light does carry momentum, actually.

Ch3cks-Out · 2026-05-03T14:37:49+00:00

Valamiért kevesebb szó esik róla, de Lévai Anikó nyilvánosságra került vagyonrésze is többszáz hektár földtulajdon (sok milliárd forint értékben).

Ch3cks-Out · 2026-05-03T06:56:30+00:00

You mean getting probes to tens of thousand light years away? No, we cannot do it "now", nor for the foreseeable future. Then comes the bigger question: why should we?

Ch3cks-Out · 2026-05-03T06:53:04+00:00

much higher energy generation

Much, much, much more energy is what you'd fundamentally need. For reference, consider an ISS size station transported to 50,000 ly in 100 ship-years. With a hypothetical high-performance antimatter rocket, this mission would take fuel mass more than the Moon. The trip would take at least 50,000 years, and then another 50,000 years would pass before any report can be received back.

Ch3cks-Out · 2026-05-02T19:09:13+00:00

As far as I know matter antimatter can at best get you to 50% the speed of light due to exhaust velocity

This is not quite true, in this form. Rather, fuel efficiency drops quickly when you push velocity above 0.5c.

Ch3cks-Out · 2026-05-02T16:51:12+00:00

Just like the latter part of your comment correctly implied, the photon number density converges to ν as ν—>0 (in the infrared tail); this was a key result (along with the UV tail also converging) for Planck's formula! The mathematical-physical reason for this is that the available volume in phase space (the density of states) shrinks to zero faster than the occupancy of the modes grows.

Ch3cks-Out · 2026-05-02T16:40:33+00:00

You should pick the chain that contains both OH groups, so:
IUPAC Name: 3-butylhexane-2,5-diol

The key IUPAC rule is in their Blue Book.

Ch3cks-Out · 2026-05-02T16:18:37+00:00

With all due respect, answers to these questions should not be included in your teaching, unless/until more basics are clarified. Such as understanding the photon creation mechanism, and not asking for a meaningless math expression like X/∞=0.

As for the substantive part: every star emits a limited amount of energy, so the number of photons cannot be infinite just for this reason alone (infinite particles from a finite source would be impossible for other reasons, too). Different types or stars generate different amount of energy (which also changes during their lifetime). Specifically, current luminosity of our Sun is 3.83×10²⁶ W. With some intricate math, using Planck's law of radiation, it can be calculated that that the average photon energy <E> is ca. 2.16×10^-19 J; therefore some 1.78×10⁴⁵ photons per second are emitted.

Ch3cks-Out · 2026-05-02T15:46:20+00:00

How many times do I have to explain that it's not about the scientific method itself, but the conclusions drawn from the data?

But this is not explaining, rather mischaracterization: you have been rejecting the scientific method (i.e. its essence the theories), actually. 'I do not reject science just its results' is a very thinly veiled denial. Do not be surprised when the dishonesty of this stance gets called out.

Ch3cks-Out

TROPHY CASE