ESOcast 194: Cutting Edge of Contemporary Astronomy
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- čas přidán 17. 02. 2019
- In this ESOcast, six astronomers tell us about the hottest topics in contemporary astronomy. Covering topics ranging from dark matter to exoplanets, these astronomers make the case for why these cutting-edge fields deserve time at ESO's telescopes.
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Credit:
ESO.
Directed by: Herbert Zodet.
Editing: Herbert Zodet.
Web and technical support: Mathias André and Raquel Yumi Shida.
Written by: Stephen Molyneux and Calum Turner.
Narration: Sara Mendes da Costa.
Music: Tomaz Vital (trilhavital.com) - Horizontes and
Nuclearmetal/New Horizons - Planetarium.
Footage and photos: ESO, M. Kornmesser, L. Calçada, spaceengine.org, S. Brunier, ESA, Hubble, NASA, G. Bacon, L. Frattare, Z. Levay, J. Anderson (STScI), P. Horálek, D. Elbaz, Hubble Heritage Team (STScI/AURA), A. Nota (ESA/STScI), Westerlund 2 Science Team, F. Ferraro (University of Bologna), T. Matsopoulos, Daniele Gasparri, F. Kamphues, Frank Summers, Space Telescope Science Institute, Martin White, UC Berkeley, Lars Hernquist, Harvard University, C. Malin (christophmalin.com), B. Tafreshi (twanight.org), Gianluca Lombardi (glphoto.it) and The Illustris Project (visualization by Dylan Nelson).
Scientific consultant: Paola Amico.
Executive producer: Lars Lindberg Christensen. - Věda a technologie
I am very much thankful to you all for working hard on such topics and explaining us in a very simple laymen language. Thank you for once again and keep uploading videos. It helps us especially me who can't even afford telescope for my own observations. Thank you
Feel your pain, brother. I've been in your place. :/
Extraordinary work！Understanding how universe works means most to intelligent cretures like us.
Fantastic
I wanna see more videos about superclusters
Sara Mendes da Costa is an excellent narrator and her voice can make anything sound interesting.
Go get 'em Euronerds
we missed the narrator :) thanks
Adoro perspectiva em 3D das nebulosas e galáxias
Thank you for your work. Very interesting video. It tells us that we basically don't know much about the universe and the driving forces of this fantastic big clockwork. Even Supernova we don't fully understand yet we have known them since 1604 and they have had a name since 1931. My question now is since there that kind of order in the universe and that intelligent human beings don't understand much of it how can so many people believe it came by coincidence, and not creation? I don't blame any, I just don't understand it. I certainly believe this beauty are made by a loving and living God who's powers are beyond imagination. The Bible even says God know every one of the stars. We could ask ourselves another question. Before Big Bang there was a immense energy (E=mc2). From where came this energy? Have it always been there? Or is it a God who used his energy to start the universe? Again thank you for all the exciting news here. I really look forward to see the results from James Webb telescope along with, ELT, TMT, and GMT. Again thanks for showing us this beauty, study it and tells us in a great way what you find and are working on.
Does dark matter have to consist of a new particle?
t. gobold What's the theory that you'd be pointing towards? What were you thinking?
@@WingofTech there are already studies that hypothesize DM consisting of tiny black holes. Or in the extreme case some people propose an alternative version of general relativity that could explain the rotation curves of stars in their residing galaxies
@@tatjanagobold2810 Evidence gathered so far appears to contradict those theories : "tiny" primordial black holes would be expected to leave a number of signatures depending on their mass (runaway hawking evaporation, micro-lensing events, etc...).
Searches for such signatures have so far come back negative. It doesn't mean they don't exist, but if they do, they're too rare to be a significant contribution to dark matter.
As to the MOND (Modified Newtonian Dynamics) theory and the likes, it appears to be invalidated by two things:
-The dark matter to visible matter ratio observed in galaxies appears to be quite variable. Modified versions of gravity should apply the same to all galaxies, and therefore do not explain those discrepancies.
-The "bullet cluster" (1E 0657-558) is an ongoing collision between two clusters of galaxies. Imaging in the X-ray by the Chandra space telescope shows the distribution of hot gases in the cluster, and imaging in the visible by Hubble shows not only the position of galaxies, but also the distorted images of background galaxies, gravitationally lensed by the cluster's mass.
From this, it is possible to map the distribution of both visible matter (gas and galaxies) and dark matter (mass). And the result is that both got segregated during the collision, more dark matter being present on the outside of the cluster, and more visible matter in the center. Again, if dark matter was in fact due to modified versions of relativity, the distribution of regular matter and dark matter should still match.
This does however match quite well the predictions for WIMPS (weakly interacting massive particles) : as the clusters collide, their gases slam into each other, stopping each other, and visible matter gathers in the center. But since dark matter particles would interact so weakly, they would pass right through each other and continue further, matching the observed distribution.
(That would also be true for primordial black holes, but I've already explained why we can exclude them).
So, that's why new particles are currently by far our best hypothesis as to what constitutes dark matter.
We may have no observational evidence for them, but they're the only explanation left so far that seems to match the (indirectly) observed properties of dark matter.
Very interesting, thanks for that. I don't see why it wouldn't be possible for there to be various miniature black holes being a driving force in the universe.
@@WingofTech yes me neither but several scientists proposed and worked out this idea!
First! 🙋♂️