Ask an astrophysicist anything.
>>7970768
What's it like being jobless?
>>7970768
Why kind of math do you use to model rotating stars?
Opinions on orbital phase curves as a method for exoplanet detection?
How many foodstamps do you get
This girl is into me and laughs at all my stupid jokes, what should I do to ask her out?
>>7970768
How much do you have to do with the maintenance or repair of the telescope you use?
What kind of telescope do you use?
Does software generally control the telescope (like automatically mapping and tracking distant galaxies) or do you specifically take the controls and look at shit you want to look at?
Or are you some kinda unemployed theoretical astrophysicist in Indiana or some shit?
Or did I mistake 'astronomer' for 'astrophysicist?
Where does your funding for your work come from? Is it all research grants for very specific research or are there more enduring, general funds available?
>>7970773
>>7970773
KEK
>tfw thats my dream job but thats so true
>>7970768
Whats ur sign?
>>7970768
>astrophysicist
when's the last time you had a warm meal?
>>7970952
rekt
>>7970768
n my class my prof talked about finding the solution to Einstein's equation for a spherically symmetric body in vacuum. He then said that the ricci tensor vanishes.
I am a little confused about this point. Since we're in vacuum T_uv vanishes, but why does that necessarily mean that Ruv vanishes as well. Couldn't it be that Ruv - 1/2 guv R also happens to vanish for all components? Or is that simply impossible?
In summary, why does vacuum imply vanishing Ricci tensor?
Yo what's the best atom
>>7971034
Not OP, but I can help. If you take the trace of the EFE's (multiply by g^(uv) on both sides and sum over indices) you get:
R - 4R/2 = -R = kT
where T=g^uv T_uv. Substituting this relation into the original EFE's we have:
R_uv + (k/2) g_uv T = k T_uv
or:
R_uv = k(T_uv - (1/2) g_uv T)
These are called the "trace-reversed" field equations. If we have T_uv=0 then we also know T=0, therefore R_uv=0.
>>7970768
The guy who teaches Astrophysics at my uni(we petitioned to have it offered) teaches high school physics as his fulltime job.
What are you doing to make sure you aren't in his place?
>>7970768
How do you reconcile that the Einstein action isn't quantizable and produces conformal anomalies that fucks any chances of quantizing gravity? They don't go away unless you have some other defects like cosmic strings or vortices that can cancel out the anomaly, but all of your theories are basically fucked since they can't be quantized.
t. grad student in TQFT
>>7971303
If he knew the answer to that he'd be famous, no?
>>7970768
In the expansion of the Universe, what is being displaced by a created space? How can u create space in a space?
>>7971885
Well I'm not asking him to solve the problem, just how he deals with the fact that his cosmological models are by and large unquantizable bullshit.
