An angiogram uses X-rays and a special dye (contrast) to take pictures of the arteries in your brain, heart, and kidneys. The dye is injected into a small tube or catheter into an artery in your groin or (sometimes) your arm.
As the cloud collapses the force of gravity drawing the cloud inward gradually becomes stronger because the strength of gravity follows an inverse square law with distance. hoâ¦pe that helps.
In addition to the hydrogen, these clouds are seeded with heavier elements from the stars that lived and died long ago. Theyâre held in balance between their inward force of gravity and the outward pressure of the molecules. Eventually some kick overcomes this balance and causes the cloud to begin collapsing.