March 29, 2018 Zimmerman/Batchelor podcast

Please consider donating to Behind the Black, by giving either a one-time contribution or a regular subscription, as outlined in the tip jar to the right or below. Your support will allow me to continue covering science and culture as I have for the past twenty years, independent and free from any outside influence.

Embedded below the fold in two parts. The first segment was a detailed discussion of Soviet-style nature of China’s space program, while the second segment delved into dark matter and the uncertainty of science.



  • Localfluff

    The fact that dark mass is individual to each galaxy, as in this extreme case, actually speaks for dark matter as the explanation. Since it varies from galaxy to galaxy it rather has something to do with that object’s peculiar history in the lumpy world of hot dark matter. And that is just one out of millions studied, so there will be odd balls out there after a few billion years.

    Astronomers have found the most bright things first, only now are they zooming in on dim galaxies. 90 years since Edwin Hubble discovered intergalactic space and the expansion of space (i.e. dark Energy with today’s glossary). Prepare for more and more dim stuff nearby to be discovered.

  • Brendan

    Except that the only proof of dark matter is as a fitting constant. Despite billions being spent, it stubbornly refuses to be found – except among the equations that keep galaxies from spinning apart.

  • Localfluff

    @Brendan, Galactic rotation curves was the way “dunkle Materia” was discovered by Fritz Zwicky in the 1930s (who also foresaw neutron stars, also of utmost interest today, a very successful astronomer of the last century). Dark matter is seen on larger scales in galaxy clusters that have collided and thus separated ordinary matter from dark matter. And the large scale structure of galaxy cluster locations. And the missing mass is also somehow revealed in the temperature variations in the microwave background radiation, the image of the entire universe. So it is present in all cosmological scales.

    It is not yet observed, I think, on sub-galaxy scales. But tiny galaxies, especially those streams from colliding dwarf galaxies that are surrounding the Milky Way, might be a step towards mapping dark matter more and more locally. I would think that Gaia’s extreme precision astrometry might be capable of revealing any dark matter interfering with the stars’ movements in our quarter or so of the Milky Way. But the expectation is that dark matter is too diffuse and widespread (“hot”) throughout the galactic halo for any local effects to be observed.

  • Localfluff

    Developments in astronomy in the 20th century was about adding unexpected things not predicted by RT or QM or anyone’s imagination. Like big bang, inflation, intergalactic space, dark matter. And there’s room for more surprises. The more they look the more they find and the telescope evolution is awesome.

Leave a Reply

Your email address will not be published. Required fields are marked *