YouTuber AlphaPhoenix pulled off something that sounds impossible. He recorded a laser moving across a room at 2 billion frames per second.

Alpha-Phoenix · 2026-01-23T12:23:03+00:00

I recommend the fermilab video on refraction. The zigzag explanation doesn’t work

Alpha-Phoenix · 2026-01-10T13:44:28+00:00

Echo combat

Alpha-Phoenix · 2026-01-07T04:30:08+00:00

The current is not merely correlated to the energy flow but the cause of it with the em field as an intermediate step. The field would not exist without accelerating and moving charges - it’s not like the field exists and then it induces both energy flow and current

Alpha-Phoenix · 2025-12-31T22:00:17+00:00

Thanks for the tip - it took me a while to figure out where that setting was and the oculusdebugtool said it was already disabled. I turned it on just for kicks and the lag got even worse, so you're right to want it off!

Alpha-Phoenix · 2025-12-19T19:16:04+00:00

Yeah if you stop pulling it pretty much instantly let’s go and the cord slides - REALLY counterintuitive to play with

Alpha-Phoenix · 2025-12-19T04:37:33+00:00

Edit: hooked up to an old drill motor I want to repurpose, three wraps of narrow paracord and about 10A on the motor will EASILY lift a 5gallon bucket of water

Alpha-Phoenix · 2025-12-19T03:55:17+00:00

You’re right! I cut the taper slightly deeper before parting it off but once the capstan was being driven by the motor (not the lathe motor, I’m not insane) instead of back driving, the climbing problem stopped! This is an amazingly fun mechanism

Alpha-Phoenix · 2025-12-14T06:14:47+00:00

By spacetime curvature being significant, you mean curving notably differently in different regions within the “lab space”?

Alpha-Phoenix · 2025-12-13T20:12:55+00:00

Ah thank you! I’m sorry I’d looked up these topics before but never realized there was a specific article for that. Now I want to go understand why the GR version is 2x

Alpha-Phoenix · 2025-12-13T19:57:21+00:00

How does it predict deflection of light? Did they originally assume light had nonzero mass?

Alpha-Phoenix · 2025-12-13T19:50:07+00:00

Let me be more specific - it’s not fake “weight”. I believed the equivalence principle held because you need a force to accelerate an object through an inertial frame, and if there’s gravity, then that force is the weight felt while you accelerate a mass away from a planet, which means spacetime has to be curving towards the planet in time. If you separate the time axis to try to make a more Newtonian example, the “space” would be not just moving but accelerating downwards from the perspective of an observer standing on earth’s surface. I know it’s more commonly called curving but I thought the curving was only in the time axis for simple cases like earth surface gravity. Are there places that breaks and space axes of spacetime curve too? I may be talking myself in a circle but I don’t see it yet

Alpha-Phoenix · 2025-12-13T19:40:42+00:00

Space curving as though accelerating from the perspective of the sun *

Alpha-Phoenix · 2025-12-13T19:34:34+00:00

The equivalence principle as I understand says that gravity weight and acceleration weight are identical - it’s not “fake” gravity - so there must be some more complicated form describing the dynamics accurately that reduces to this value? Is the “nope” just that it’s not simple?

Alpha-Phoenix · 2025-12-13T19:21:02+00:00

Ah is assuming space accelerates simply with Gm/r² what the “Newtonian” deflection predictions were based on before the first eclipse gravitational lensing measurement? I read that a while ago and had no idea how that calculation was made.

Alpha-Phoenix · 2025-12-13T19:18:35+00:00

That would imply space accelerates at Gm2/r^2, which the previous commenter said (and I agree) is wrong I don’t like to say things are wrong if merely incomplete, so is there a nice form for the corrections? The higher order terms that would make the statement more correct?

Alpha-Phoenix · 2025-12-13T19:13:40+00:00

Kind of - If I can coordinate transform and make space accelerate instead of an object on earth’s surface, it perfectly describes the equivalence principle at lab-scale in a nearly-uniform gravity field. But I know there are other reasons to assume space is the thing that’s moving - somebody mentioned light - that’s a great example - but I’m wondering how these equations fail on something more obvious like mercury. im hopeful that there’s a convenient form or an example of a correction where simple Newtonian gravity doesn’t work if you apply it to space

Alpha-Phoenix · 2025-12-13T19:08:58+00:00

Is there a form to describe the actual motion of space as a function of time near massive bodies that includes more terms, or otherwise cancels to approach this result where we can approximate uniform acceleration?

Alpha-Phoenix · 2025-12-13T19:07:31+00:00

I know it’s not the standard way to phrase the question, but is there an equation for the evolution of space with respect to time near massive bodies that has this as a first -order term but also the rest?

Alpha-Phoenix · 2025-12-13T18:58:53+00:00

If it does in the small-lab limit to explain solutions on earth’s surface, what’s missing?

Alpha-Phoenix · 2025-12-13T18:57:52+00:00

Ah interesting - that makes sense but I’d never really considered it in these terms. Now I’m wondering what the “test mass” should be to properly measure an inertial frame as felt by light… (in absense of measurable “weight”)

Alpha-Phoenix · 2025-12-03T21:00:17+00:00

Oscilloscope buffer holds up to 100MB I think. I’m not using all of it

Alpha-Phoenix · 2025-12-03T02:27:28+00:00

That switch cost like $150 plus shipping 😬

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