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2:37 AM
Q: How do neutron star binaries form?

WillGDo neutron star binary systems come from previously active-star binaries, where where both stars have gone supernova and left behind neutron stars that are still in orbit? Or do they form when two previously unbound neutron stars approach each other and fall into orbit?

11 hours later…
1:32 PM
Q: Vacuum collapse -- why do strong metals implode but glass doesn't?

Akash ChandraThis question has been puzzling me lately. I'm sure you've seen demonstrations of metal containers imploding when evacuated. Here, for example, are two videos of vacuum collapse: Experiment 1, starts at 1:58, Experiment 2 However, when the same experiment is conducted with a material as fragile...

2 hours later…
3:51 PM
Q: Total force on upper block in two block system

user75659If a block $m$ is placed on another block $M$ and a force $F$ is applied on bolck $M$. Then how many forces are acting on block $m$.(Friction is non zero) https://learnscreen.files.wordpress.com/2011/10/image1.jpg Is pseudo force acting on block $m$ or not?

4:50 PM
Q: Nuclear decay triggers

Chris KrauseI am not a physicist but I have been wondering about this: I understand that the decay of a nucleus is a random event and one cannot predict exactly when it will happen for a particular nucleus. What I would like to know is what triggers this event to happen?

7 hours later…
11:46 PM
Q: What fuel is J005311 burning?

RickJ005311 is two white dwarf stars that have merged in such a way, that, well they merged instead of exploding. (Only 7 or so such mergers have been found.) Its stellar wind is blowing at 16,000 km per second and has reached a surface temperature of 200,000 C. The weird thing is it emits no ligh...


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