The Largest Black Hole in the Universe - Size Comparison

TL;DR

This video explores the different sizes of black holes, from the smallest primordial black holes to the largest ultramassive black holes.

Transcript

The largest things in the  universe are black holes.   In contrast to things like planets or  stars they have no physical size limit,   and can literally grow endlessly. Although in  reality specific things need to happen to create   different kinds of black holes, from really tiny  ones to the largest single things in the universe.   So how do bla... Read More

Key Insights

• 🌌 Primordial Black Holes: The smallest black holes, if they exist, formed after the big bang and could be the mysterious dark matter holding galaxies together, despite being incredibly difficult to observe.
• 🌟 Stellar Black Holes: These black holes require the collapse of enough matter, such as in the merger of neutron stars or the supernova of a massive star. They can range in size, from 16 km wide (smaller than Paris) to 92 km wide (casting a shadow on Corsica).
• 🔎 Mergers and Discoveries: Black holes can grow larger by devouring stars or merging with other black holes. Exciting discoveries of massive black holes, such as one 142 solar masses and the size of Germany, were made through the detection of gravitational waves.
• ⚓ Supermassive Black Holes: Contrary to popular belief, supermassive black holes, like Sagittarius A Star in the Milky Way, do not act as "anchors" that hold galaxies together. They make up only 0.001% of their galaxy's mass, with dark matter playing a larger role in gravitational effects.
• 💥 Feeding and Activity: Supermassive black holes can release jets of plasma and accretion disks of glowing gas when they devour mass, making them appear much larger than they actually are.
• 🌌 Ultramassive Black Holes: These black holes can reach tens of billions of solar masses, shining as bright as quasars. Examples include an ultramassive black hole at the center of galaxy OJ 287, 18 billion solar masses, and TON 618, with an incredible 66 billion solar masses.
• ❓ Uncertainties in Measurements: Black holes are challenging to study as we cannot directly observe them. Measurements and calculations involve uncertainties and assumptions, contributing to variations in size estimations.
• 📚 Behind the Scenes: Data on black holes is limited, and cataloging them is a relatively recent endeavor. The properties of black holes are derived from their gravitational effects on surrounding matter, adding to uncertainties. Additionally, physics on such scales is not fully understood.

Questions & Answers

Q: How do primordial black holes differ from other black holes?

Primordial black holes, if they exist, would be the smallest black holes and could have formed shortly after the Big Bang, while other black holes are formed from the collapse of massive stars.

Q: How do stellar black holes grow in size?

Stellar black holes grow by accreting matter from their surroundings, such as through the merger of neutron stars or the collapse of massive stars in supernovae.

Q: What is the largest known supermassive black hole?

The supermassive black hole in the galaxy Messier 87 is one of the largest known, with a mass of 6.5 billion solar masses and a size that covers our entire solar system.

Q: Can black holes continue to grow indefinitely?

While black holes can continue to grow through the accretion of matter or by merging with other black holes, there is a gap in scale between black holes up to around 150 solar masses and the largest supermassive black holes, suggesting something else must have happened to form these massive black holes.

Q: How do we observe black holes if we can't see them directly?

Black holes cannot be seen directly, but their presence and properties can be inferred through studying their gravitational effects on surrounding matter, such as the orbit of stars or the emission of electromagnetic radiation from their accretion disks.

Q: What are some uncertainties in our knowledge of black holes?

Due to limited data, there are uncertainties in our knowledge of the sizes and masses of black holes. Calculations are based on approximations and assumptions, and the true sizes of black holes may vary.

Summary & Key Takeaways

• Primordial black holes, if they exist, would be the smallest black holes in the universe, with a mass of a trillion kilograms or less.

• Stellar black holes are formed from the collapse of massive stars and can range in size from 16 km to 92 km in diameter.

• Supermassive black holes are located at the centers of galaxies and can have masses ranging from millions to billions of solar masses.

• Ultramassive black holes are the largest known black holes, with masses of tens of billions of solar masses or more.