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Physics lists four fundamental forces, yet a school textbook finds a dozen.
Most of the ones you feel are a single force in disguise. A table pushing back, friction, a rope pulling and a spring resisting are all atoms pushing on atoms through electromagnetism. Newton wrote down gravity in 1687, and Charles Coulomb measured the electric force with a twisting wire in 1785. The weak and strong forces were only found in the twentieth century, because they act across distances smaller than an atom.
That is why the last two have no everyday feeling. Without the strong force no nucleus would hold together, and without the weak force the Sun would not shine.
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Four equations that turned invisible forces into light.
Maxwell unified electricity and magnetism into a single framework. A changing electric field creates a magnetic field, and a changing magnetic field creates an electric field. Together they sustain each other, racing outward as electromagnetic waves at the speed of light.
Gauss’s laws fix the sources: charge produces electric field lines, while magnetic field lines never begin or end. Faraday and Ampère (with Maxwell’s correction) show how the fields continually generate one another.
From these four lines, radio, light, and the entire modern world quietly emerge.
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A TV news anchor expresses frustration after 20 boxes of HokBen she received were stolen during Gibran’s resignation announcement.
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Stop idolizing politicians. They’re our employees, and when they don’t do their jobs, we need to fucking fire them.
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Vector calculus rests on one operator, ∇ = (∂/∂x, ∂/∂y, ∂/∂z), used in three ways. The gradient ∇φ maps a scalar field to a vector field, the divergence ∇ · F maps a vector field to a scalar, and the curl ∇ × F maps a vector field to a vector field.
Two integral theorems connect these local derivatives to global quantities. Gauss's divergence theorem says the outward flux through a closed surface equals the total divergence inside: ∯ F · dA = ∭ ∇ · F dV. Stokes' theorem says the circulation around a closed curve equals the flux of the curl through any surface it bounds: ∮ F · dl = ∬ (∇ × F) · dA.
Applied to electric and magnetic fields, these two theorems turn Maxwell's equations from their integral form into their differential form.
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John Archibald Wheeler famously summarized General Relativity as matter tells spacetime how to curve, and curved spacetime tells matter how to move.
Newton described gravity as an attractive force between masses. Einstein changed the picture: gravity is connected to the geometry of four-dimensional spacetime, where space and time are inseparable.
The Einstein field equations express this relationship:
Gᵤᵥ = (8πG/c⁴)Tᵤᵥ
Matter and energy determine spacetime curvature, while freely falling objects follow paths called geodesics:
d²xᵘ/dτ² + Γᵘₐᵦ(dxᵃ/dτ)(dxᵇ/dτ) = 0
This geometry explains phenomena such as Mercury's orbital precession, gravitational time dilation, the bending of starlight and gravitational waves.
Newton's gravity remains an excellent approximation in weak gravitational fields and at low velocities. Einstein's theory reveals the deeper geometry behind it.
Gravity is not simply a force acting through space. It is a manifestation of spacetime geometry.
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Kaderisasi di ITS tidak mengajarkan politik, pergerakan, ataupun aktivisme. Itulah kesalahan dan dosa terbesarnya. Edukasi dan peran politik sepenuhnya jd kewajiban lembaga pusat (BEM ITS).
Bahwa memang mhswa ITS cenderung apatis tapi terlalu mencintai hmd nya, itu benar,
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Akhirnya aku tahu cara pakai GIF
Ternyata gampang banget😂
Singkatnya
1- Tekan lama pada GIF
2- Tekan "Salin tautan video" dan tempel di mana saja
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plis ini dia lucu bgt woyy anteng😭. kucing aja kalo stress diajak nightride sudirman🌝💃🏻
Besok² pake helm ya meng 😭🤣
