Q&A 56: Is Everything We See Long Dead? And More...
When we look out into space, are we really just seeing stars, planets and galaxies which are long dead, ghosts from eons ago? Can black holes consume dark matter? Can we repair Kepler and other dead satellites, and more.
Q&A 56: Is Everything We See Long Dead? And More... (YouTube)
Comments (12)
BTW, Fraser, I think I read recently that you guys have the highest gas prices on the continent! Hope you are close to the grocery and other necessary stores!
Yup, I just paid $50 to fill the tank on my Honda... that was a first.
Back to black holes and dark matter. You explanation makes sense -- as far as it goes. But, I am probably missing something here since if the dark matter doesn't "collide" in the traditional sense and bunch up, wouldn't it be possible that the gravitational attraction of the black hole would attract it and it would orbit the black hole UNIMPEDED by collisions and actually enter the black hole, on average, quicker than normal matter? Yeah, as usual, I've probably totally misunderstood your point -- even while I thought I grasped it! ;~)
No, the reason matter can go into black holes is because the tidal forces tear stars apart, for example, and then the material piles up into an accretion disk. With dark matter, each individual particle is going to interact with the black hole as if there was nothing else there. It'll fly near the black hole, orbit around it, and then zip out into deep space again.
Hi Fraser, I know you're a space journalist and it's your job to keep us informed but how do you manage to educate yourself on the cutting edge of space technology? Do you have various scientific contacts that you talk to on a regular basis or are you just plugged into a bunch of different websites that you peruse all day long? And how do you digest the fire hose of information you're exposed to and make it understandable for us common folk?
Thanks Ken, remember that my actual job is to be the publisher of Universe Today, so I'm getting news tips from space agencies, reading journals, and talking to researchers. These videos are kind of a practical way for me to put this to use. :-)
Hello Fraser, do you happen to know exactly how many space observatories are in orbit around the earth or near earth? I can only name few like the Hubble, Gaia, and Swift. I know they all have their own specialised jobs. I would like to know exactly how many are looking beyond our solar system. Also, there must be several space observatories looking at our sun. I try to look up but there are so many different organizations it's hard to know whats who, where, what.
Here's a list of all the space telescopes that have ever been made: <a href="https://en.wikipedia.org/wiki/List_of_space_telescopes" rel="nofollow noopener" target="_blank">https://en.wikipedia.org/wiki/List_of_space_telescopes</a>
Hi Fraser, can you explain how and why we have different size Suns. Surely there is a minimum amount of gases being squeezed together to where we get ignition point. Wouldn't then on ignition of a new star the solar wind would push any further gases away to prevent further fuel being added or does the gravity override this.
Right, the more gas you have, the more massive a star you'll get. The minimum amount is about 15% the mass of our Sun.
Dear Fraser. You are the most practical and logical thinker I know plus your knowledge of astrophysics is impressive. The programs are excellent. I learn something new with every presentation. Thank you.
Thanks a lot!