How small are we in the scale of the universe? - Alex Hofeldt

TED-Ed
13 Feb 201704:08

Summary

TLDRIn 1995, scientists used the Hubble Telescope to capture an image of over 1,500 galaxies in a seemingly empty part of the sky. This Deep Field image revealed the vastness of the universe, showing galaxies that existed over 13 billion years ago. Later, an updated image, the eXtreme Deep Field (XDF), displayed 10,000 galaxies, many of them incredibly distant. These images provide insight into the universe's infancy and homogeneity, reminding us of how small we are yet capable of exploring and imagining the mysteries of the cosmos.

Takeaways

  • 🔭 Scientists used the Hubble Telescope in 1995 to capture images of a seemingly empty part of the sky near the Big Dipper.
  • 🌌 After ten days and 150 hours of exposure, the telescope revealed over 1,500 galaxies in a tiny portion of the universe.
  • 🖊️ The area captured by the Hubble Telescope is comparable to the size of a ballpoint pen tip held at arm's length.
  • 🌍 The image represented just a small fraction of the night sky, about one two-millionth of it.
  • 🌞 The Milky Way contains 100 to 400 billion stars, including the Sun, while each galaxy in the Deep Field contains billions of stars.
  • 🚀 Apollo 8 astronauts traveled 380,000 kilometers to the Moon, but that distance is minuscule compared to the vastness of space.
  • 🌠 In the 2000s, scientists captured an even deeper image, known as the eXtreme Deep Field (XDF), showing 10,000 galaxies, some over 13 billion years old.
  • ⏳ The Deep Field images act as time machines, allowing scientists to observe galaxies as they were less than a billion years after the Big Bang.
  • 🧪 These images show that the universe is homogeneous, with different regions of the sky appearing similar despite vast distances.
  • 🌌 The script highlights the enormity of the universe and humanity’s ability to wonder, explore, and question the vast unknown beyond our vision.

Q & A

  • What area of the sky did scientists point the Hubble Telescope at in 1995?

    -Scientists pointed the Hubble Telescope at an area near the Big Dipper, a dark spot in the sky free from light pollution.

  • Why was the Hubble Telescope's Deep Field experiment considered risky?

    -The experiment was risky because the telescope was aimed at an apparently empty part of the sky, with no guarantee that anything significant would be captured.

  • What did the Hubble Telescope capture in its first Deep Field image?

    -The Hubble Telescope captured over 1,500 distinct galaxies in a tiny sliver of the universe.

  • How small was the area of the sky observed by the Hubble Telescope compared to the whole sky?

    -The area observed was roughly the size of the tip of a ballpoint pen held at arm’s length, representing about one two-millionth of the night sky.

  • What is the significance of the Deep Field images in terms of understanding the universe?

    -The Deep Field images show a vast number of galaxies in a tiny region, allowing scientists to study the structure and distribution of galaxies across space and time, including those from over 13 billion years ago.

  • How far into the universe and back in time do the Deep Field images allow us to see?

    -The images allow us to see galaxies that existed over 13 billion years ago, less than a billion years after the Big Bang.

  • What did scientists discover when they took a second, longer exposure with the Hubble Telescope?

    -In a second exposure over four months, scientists observed around 10,000 galaxies, with the data contributing to the creation of the eXtreme Deep Field (XDF) image.

  • What is the significance of the eXtreme Deep Field (XDF) image?

    -The XDF combines over ten years of observations, showing galaxies so distant and faint that they are one ten-billionth as bright as what the human eye can see.

  • What does it mean when scientists say the universe is homogeneous?

    -It means that images taken at different parts of the sky look similar, suggesting that the universe has a consistent structure across vast distances.

  • How does the script encourage viewers to reflect on their place in the universe?

    -The script encourages viewers to contemplate the enormity of the universe and our small place within it, but also highlights humanity’s capacity to wonder, explore, and investigate the unknown.

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Related Tags
Hubble TelescopeDeep Fieldgalaxiesspace explorationBig Banguniversecosmologyastronomytime travelextreme deep field