Dark Energy - 15b - Intro to Astronomy Sessions
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- Опубликовано: 12 ноя 2023
- When astronomers measured how the expansion rate of the Universe has changed over time, against all expectations, it was found to be accelerating. All known types of matter and energy should cause the expansion of the Universe to slow down. There seems to be some other form of "dark energy" driving the acceleration of the Universe. Here we briefly discuss some of its apparent properties and the associated lines of evidence.
Full Series Playlist: • Intro to Astronomy Ses...
Please note that this was designed as an introductory survey of astronomy course, mostly for non-science majors, and does simplify many of the topics accordingly. I encourage people who are just getting into astronomy to use this as a jumping off point for more in depth studies. I've tried to edit out specific references to my course (regarding assignments, tests, etc.) but I might have missed some. Finally, scientific fields are constantly advancing, with new data and studies resulting in our ideas being continually improved. This means some of the ideas presented here may soon be out of date, so I again encourage people to continue to investigate whichever topics are of particular interest to you.
Opening Image Credit: www.nasa.gov/feature/goddard/...
This is really priceless content. Thank you for your hard work.
Hopefully more exciting times ahead when it comes to this topic.
Some thoughts:
1. Is it safe to say that the rate of change of Universe's expansion needs to be *monotonous* according to known laws of physics? Its highly unlikely that the expansion speeds up and then slows down... right ?
2. Early in the video you laid out the different possibilities of the Universe's fate with respect to the density of matter-energy. Taking into account dark energy (and its uncertain nature), is it possible for *a* universe to accelerate in the reverse way, collapsing faster and faster?
3. If the energy contained in space itself made it expand (and therefore increased its own quantity), would that imply the violation of energy conservation at the largest scale? Could this somehow trickle down to our scale?
4. Can the ratio ( matter & dark matter/dark energy ) itself change as the universe evolves?
5. To match our observations, is it necessary for the density of dark energy to be exactly constant everywhere? If its higher and lower in small enough patches of space would the universe "notice"?
6. This last one is more of an exercise in imagination, but it _might_ look like the quantites of dark energy and dark matter somehow "conspire" to keep the universe flat. Not a scientific theory whatsoever.
Thank you.
Would you be interested in making a video about ADS-CFT correspondence ?
Dark energy an't accelerate universe expansion forever at increasing speed. That would mean it constantly increase its own energy forever. It's acting as kind of vacuum for space-time universe itself in all directions🤔