Imagine yourself in a boat on a large ocean, the water stretches to the distant horizon, with the weakest fields…
Imagine yourself in a boat on a large ocean, the water stretches to the distant horizon, with the weakest fields just outside it. It is morning, just before dawn, and a dense fog has settled along the coast. When the chill grabs you on your early watch, you take a guy out of the corner of your eye, lightly blinks through fog.
And – yes – there! Another guy closer, the light is a bit stronger. As you scan the horizon, more fires show the dangers of the remote coast.
A newly formed star illuminates the surrounding cosmic clouds in the image of the ESO La Silla Observatory in Chile. Damask articles in the big clouds surrounding the star HD 97300 diffuse their light like a candle in a fog and create the reflection bubble IC 2631. Although the HD 97300 is in the headlight for now, it’s a lot of dust that makes it so hard to miss herald’s birth of further, potentially destructive, future stars. Imsge: ESO
You know this coastline, which returns to the same port year after year. You know that the lighthouses are all the same brightness, made of the same manufacture and kept in good condition over the years.
And so pass the time you play a small game. Consult your maps, you know the distance of each guy, and how far has the light traveled to reach your salty eyes. But their light, bright and sharp on a clear evening, is shaded and shaded by the persistent fog. You know how light they should be and you can compare the brightness of what you see, peering through the layers and the dimmed layers to estimate the amount of fog that hugs the coast.
It’s not like you have anything better to do.
This is just the procedure astronomers used recently to measure the total sum of starlight in the universe – minus, of course the fog and the lighthouses and salty sailors.
Our cosmic lighthouses are the active galaxies, the most powerful engines in the universe, where matter that flows into giant black holes compresses and warms and ignites in a ray of radiation before swallowing by the event horizon. In its fires, these whirling chaotic lumps of energy give more energy than millions of galaxies and can pump their light through the universe.
When ignited in the young cosmos, they look like lighthouses, shining but
Between these lighthouses and our telescopes are all things