Understanding Cosmic Expansion

Hubble’s Law

In 1929, Edwin Hubble published his groundbreaking research analyzing the light from distant galaxies. He observed that these galaxies were receding from us at a speed proportional to their distance – this relationship is known as Hubble's Law.

Mathematically, Hubble’s Law can be expressed as: v = H₀d , where *v* is the recession velocity (m/s), *H₀* is the Hubble constant (s/m), and *d* is the distance to the galaxy (m).

v = H₀d

Evidence for Expansion

Hubble’s Law isn't just based on redshift; it’s supported by several other lines of evidence. The Cosmic Microwave Background (CMB) radiation, a relic from the Big Bang, provides strong confirmation.

Furthermore, observations of distant supernovae show that they are dimmer than expected, indicating that they are further away than predicted by a static universe.

The Big Bang Theory

Hubble’s Law is central to the Big Bang theory, which posits that the universe originated from an extremely hot and dense state approximately 13.8 billion years ago.

The expansion explains why we observe galaxies moving away from us – they are literally carried along by the expanding space itself.

Accelerated Expansion

Recent observations have revealed that the universe’s expansion is not only happening but *accelerating*. This acceleration is attributed to a mysterious force called dark energy.

Dark energy comprises approximately 68% of the universe's total energy density, and its nature remains one of the biggest unsolved problems in physics.

Frequently asked questions

Try it live

Everything above runs in your browser — open SPH Fluid and change the parameters while it is running. Nothing is installed, nothing is uploaded, the whole model lives in one tab.