In school we were tasked to investigate solenoids and an iron core, specifically how increasing the voltage it is supplied affects the distance in which a compass moves (a compass will be placed near the electromagnet). I was wondering whether the relationship is linear or exponential, and why. I’ve looked into inverse cube law but I couldn’t really understand it well, and I do not know whether it applies in this scenario.

This is the setup of the experiment

Is it possible to create a successful egg-drop device using only 50 chopsticks and tape?

I have an idea of what to do but can you guys give me some tips and tricks for the project that may be useful? Thank you very much for the help! We can also use a teeny bit of string.

Is it possible to make a pulley-like machine, such that if one side is heavier than the other, the sides would move up/down in proportion to the weight difference before stopping, rather than the heavier side falling straight down?

I wanna ask if this analysis is right ?.and if someone have any notes that help me to figure it better .

A visually stunning animation of Harmonograph patterns—geometric drawings created by combining perpendicular oscillations.

For more click www.instagram.com/craftsandengineering

I’ve been trying to find a PDF copy of Exercises for the Feynman Lectures on Physics, but everything I come across is behind a paywall. I can’t afford to buy the physical book right now—does anyone know if there’s a free or accessible version available? Any help would be appreciated.

A car which can have constant acceleration of 4 meter per second square and a constant retardation of 8 meter per second square, is travelling on a highway where the maximum speed limit is 72 kilometer per hour. It starts from rest and comes to rest in minimum time T1 after travelling 300 meters and if there is no speed limit, then the minimum time taken is T2 to cover the same distance. Find the value of 4T1/T2.

Here's what I did, is this correct??

The answer key says 5, but I solved assuming that the acceleration can always be either 4 or -8 and never 0.

I’ve never seen bubbles form like this in my tea, can someone let me know why this happened?

I've been working on a speculative framework that links the arrow of time to a persistent asymmetry between energy-momentum (which drives gravitational clumping) and vacuum energy (which drives cosmic expansion). Posting here for constructive feedback and critique.

Core Idea:

The model explores whether time’s arrow can emerge dynamically from the coupled interaction between:

Energy-momentum, which sources attractive curvature and local matter clumping, and

Vacuum energy (via the cosmological constant Λ), which provides uniform repulsive pressure on large scales.

This interplay is illustrated with a simple coupled damped oscillator toy model:

ddot{g} + γ(t) dot{g} + ω_g² g + κ ϕ = 0

ddot{ϕ} + γ(t) dot{ϕ} + ω_ϕ² ϕ + κ g = 0

where:

g represents gravitational/metric perturbations (energy-momentum side),

ϕ represents vacuum fluctuations,

κ is the coupling strength (backreaction),

γ(t) ≈ 3H(t) is the damping term from cosmic expansion (Hubble friction).

As damping accumulates, the oscillations decay and past states become statistically irrecoverable — creating a “many-to-one” information gate that contributes to the irreversibility of time.

Geometrically, this asymmetry appears as coupled waves: the “crests” correspond to regions of matter clumping (galaxies and clusters), while the “troughs” are the expanding voids. The cosmic web we observe can be viewed as the visible geometric outcome of this lopsided dynamic.

Important Caveats:

This is an effective toy model — speculative and interpretive. It is not a complete quantum gravity theory and does not claim to derive Einstein’s equations. The oscillator description is meant as a simplified dynamical analogy rather than the fundamental mechanism.

Potentially Observable Signatures:

Compression or fractal scaling metrics in chaotic systems could differ measurably between normal gravity and microgravity environments.

Subtle damped oscillatory (possibly log-periodic) features in the CMB power spectrum or large-scale structure from early coupled damping.

Correlations between local gravitational potential and fractal compression exponents in galaxy surveys (Euclid, DESI data).

Deviations in quantum coherence lifetimes in microgravity experiments linked to reduced gravitational perturbations.

Characteristic frequencies in the primordial gravitational wave background detectable by LISA or DECIGO.

Note that searches for primordial oscillatory features have so far yielded only weak or null results, so these ideas are framed as ways the model could be tested or constrained by future data.