SpaceTime with Stuart Gary

The water in your glass may be older than the Sun itself.

Astronomers have traced the story of water from interstellar space to emerging planetary systems by zooming in on the young star V883 Orionis, located about 1,300 light-years away in Orion.

Using the Atacama Large Millimeter/submillimeter Array (ALMA), they detected gaseous water in the star’s protoplanetary disc carrying the same chemical fingerprint seen in comets of our own Solar System.

This strongly suggests that Earth’s water was inherited from ancient interstellar clouds, predating the birth of the Sun.

The key was measuring a heavier form of water, where one hydrogen atom is replaced by deuterium.

Because normal and “heavy” water form under different physical conditions, the ratio between them acts like a chemical time capsule, preserving when and where the water originated.

In V883 Orionis, that ratio closely matches what is measured in Solar System comets and in Earth’s oceans, providing the long-sought missing link between cold star-forming clouds, protoplanetary discs, and icy bodies that later deliver water to planets.

Normally, water in planet-forming discs is frozen as ice and nearly impossible to see, but V883 Orionis is in outburst, heating its disc enough to turn vast amounts of ice into detectable vapor.

ALMA’s sensitivity allowed astronomers to map this water and estimate that the disc contains at least 1,200 times the water found in all Earth’s oceans.

Upcoming facilities like ESO’s Extremely Large Telescope and its METIS instrument will extend this chemical archaeology of water, probing how many other planetary systems may also inherit ancient, life-enabling oceans from the depths of interstellar space.

Time dilation is a prediction of Einstein's Special Relativity that shows time is not absolute.

The main idea is simple: the faster you move through space, the slower you move through time. Its mathematical form is:

Δt = Δt₀ / √(1 − v²/c²) where, Δt₀ is the proper time. v is the relative velocity. c is the speed of light.

As an object's speed approaches the speed of light, time passes more slowly for it relative to a stationary observer.

The Inverse Square Law states that the intensity of a force, light, sound, or radiation decreases in proportion to the square of the distance from its source.

If the distance doubles, the intensity becomes one-fourth.

If the distance triples, it becomes one-ninth.

This happens because the same energy spreads across a larger area as it travels outward.