Ask An Astronomer Anything At All About Astronomy (XXXIII)

An extremely busy week for the now quite enormous Q&A page, running at 295 questions ! Don't forget to click the links for the actual answers.

So, here's a question for you : am I crazy to think about trying some sort of hard copy publication, dare I say the word... book ? Obviously with proper editing and expanding some answers so everything would be better self-contained, and due diligence to check for accuracy. Is this a delusion of grandeur or something you'd be prepared to torture your pets just to get a glimpse of a copy ? Or, more usefully, where between those two extremes would you rate this idea and why ?


1) What do you think of this article about generational starships being unworkable ?
It's daft.

2) Why would we bother investing huge resources in generational starships ?
Dude, have you seen how much time we spend making cat memes ?

3) What's your take on this press release about a new law of nature ?
Oh please no not again !

4) Is gravity caused by protons and electrons spinning through space ?
Err, no.

5) Time doesn't exist.
Neither does your face.

6) Is gravity caused by protons and electrons spinning through space and creating a magnetic field which could explain dark matter and dark energy ?
No, dude, let it go.

7) Is there any chance the IAU will adopt a new definition of planet ?
Dunno, but I wish they'd get rid of the current one.

8) Which place in the Solar System do you think is most likely to harbour some form of life ?
Your mum.

9) Extraterrestrials are definitely visiting Earth, you know.
No they're not.

Then we get to a special bonus section. The root question was, "White dwarfs take a very long time to cool to form black dwarfs, but is there a way to speed this up ?". And the final answer is no. But since this involved a very long discussion, I think it's worthwhile to dissect this in some detail.
10) If we increase the density of gas around a white dwarf, could we help cool it down by convection ?
No, this will make it hotter.

11) If we could increase convection inside a white dwarf, could we make it cool down faster to create a black dwarf ?
No, this will make it hotter.

12) Okay, okay ! So why can't we use convection inside a white dwarf to cool it down ?
Because it won't work.

13) Well, what if we shot a black hole through the white dwarf that could force material to mix from the hot core to the cold surface ? Would that help ?
Certainly not, but it would be bloody spectacular and I encourage reader to try this for themselves.

14) What about getting a black hole in orbit of the white dwarf to cancel out its surface gravity so we can build stuff on it ?
No.

15) What about... using lots of black holes to cancel out the surface gravity ?!
No !

16)  What if we filled a white dwarf with teeny-tiny wormholes...
NO !

17) Perhaps some sort of -
I said NO ! STOP IT !

18) But what if -
NO !!!!!


There, that's better.


19) Could we start nuclear fusion on a giant ball of iron ?
Yeah but why bother ? Your mum's so fat she has a higher accretion efficiency...

20) OK, I give up. Is there at least any sort of object that will be like a black dwarf in that it's difficult to detect unless something impacts it ?
Yes there is.