tag:blogger.com,1999:blog-627288822362203855.post8846460980072650913..comments2023-11-14T20:44:36.587-06:00Comments on Cosmic Yarns: Dark Matter - Where is it ???Robert Scherrerhttp://www.blogger.com/profile/17341214577362261827noreply@blogger.comBlogger5125tag:blogger.com,1999:blog-627288822362203855.post-8721012540579571072016-07-27T13:06:04.628-05:002016-07-27T13:06:04.628-05:00Thanks! That the kind of things the lay person doe...Thanks! That the kind of things the lay person doesn't think much about.<br />Kathynoreply@blogger.comtag:blogger.com,1999:blog-627288822362203855.post-38491090965713226312016-07-27T08:57:37.576-05:002016-07-27T08:57:37.576-05:00That's a key point you've raised. Ordinar...That's a key point you've raised. Ordinary matter can dissipate its energy by giving off radiation. That's why all of the gas and stars in our galaxy have collapsed into a disk - it's only the rotational motion prevents further collapse. But dark matter can't radiate energy, so there's no way for it to collapse any further.Robert Scherrerhttps://www.blogger.com/profile/17341214577362261827noreply@blogger.comtag:blogger.com,1999:blog-627288822362203855.post-85221278736197646112016-07-26T15:00:44.845-05:002016-07-26T15:00:44.845-05:00Why would it gather in halos around galaxies, rath...Why would it gather in halos around galaxies, rather then be distributed like normal matter?<br /><br />I suppose that's a hard question to answer when we don't even know what it is. Kathynoreply@blogger.comtag:blogger.com,1999:blog-627288822362203855.post-41989560107568997322016-07-25T10:26:32.183-05:002016-07-25T10:26:32.183-05:00If the dark matter were, for instance, confined to...If the dark matter were, for instance, confined to a sphere the size of Jupiter orbiting the sun, we would easily be able to detect it because of its tug on the other planets. But unfortunately, we don't think that dark matter clusters on small scales. It forms a "halo" surrounding our galaxy, but the average density near us is very low.Robert Scherrerhttps://www.blogger.com/profile/17341214577362261827noreply@blogger.comtag:blogger.com,1999:blog-627288822362203855.post-60505697761198372942016-07-23T11:40:44.180-05:002016-07-23T11:40:44.180-05:00Completely crazy comment from the laity:
What if...Completely crazy comment from the laity: <br /><br />What if gravity from parallel universes seeps through old left-over black holes, making gravitational attraction stronger in those regions that have any, and giving the impression of dark matter?<br /><br />On a more serious note, how non-interactive can non-interactivity get? If gravity were the only way that dark matter interacts with regular matter, does that mean that if we had a Jupiter-mass aggregation dark mater between, say, us and the Sun, we couldn't even see it, only detect it by its gravitational effects?Kathynoreply@blogger.com