Jerry Schirmer

Austin, TX

Age: 36

I am a Ph.D. general relativist working as a software engineer. I like to still go and do physics as a hobby, and to keep up my skill and knowledge.

1d
comment Why is it difficult for 2 black holes to merge?
It's hard to answer this directly, but the end answer will be "gravitational radiation is how the black holes fall in, and gravitational radiation is weak, because it couples with $G$ and the leading term is the quadrupole term"
Feb
4
comment Induced metric on a null hypersurface
It's been a long time since I've looked at this stuff, and I"m thinking of it to give you a better answer, but you should look at Sean Hayward's articles on this stuff.
Feb
4
comment Induced metric on a null hypersurface
however, I'm now trying to think through ane example where the statement is false. Note that when particles enter the black hole, the black hole horizon becomes a spacelike, not a null, surface, so this null geometry is no longer valid.
Feb
4
comment Induced metric on a null hypersurface
It's not true in general. Generally, the condition that the horizon is isolated, rather than dynamic, is equivalent to the null tangent vector being a killing field of the induced metric, which gives you the condition you're looking for.
Feb
1
answered Does time symmetry still holds when a particle drops into a black hole?
Jan
27
reviewed Approve suggested edit on Heisenberg Uncertainty Principle scientific proof
Jan
5
awarded Nice Answer
Jan
5
comment What is gravitational energy in general relativity?
@ThomasElliot: it's true about gravitational waves, but definig where the wave is and what they are carrying energy from is a bit subtle.
Dec
28
comment In The Force Awakens, how is it that Finn knows sword combat?
Couldn't Luke learn from the force ghosts of Anakin, Yoda, and Obi-Wan, though? It's not actual dueling, but it wouldn't be nothing, and it would be beyond what we see in episodes IV-VI
Dec
28
comment About the complex nature of the wave function?
@ruskin23: I should have said <i>unphysical</i> time and space dependencies in the wave function. When you solve the Schrödinger equation, and you get an answer that depends on the spatial variables, it's giving you real information about where the particle is. It's different when you multiply by a phase -- that's not giving you information about where the particle is, it's giving you information about how that particle might interfere with other particles.
Dec
11
comment Spark cluster can't assign resources from remote scala application
No effect. The logging says that the worker is trying to attach on a port on that range, irrespectively.
Dec
10
comment If there were infinite many stars
Or, alternately, the stars are receding so quickly that their light has been redshifted to below the visible spectrum.
Dec
8
comment Spark cluster can't assign resources from remote scala application
@RanP: I copied it to my $SPARK_HOME/conf directory with the same result
Dec
7
revised Spark cluster can't assign resources from remote scala application
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Dec
7
comment Spark cluster can't assign resources from remote scala application
OK... I've opened up ports 33290-33296 and added the following to my configuration: conf.set("spark.blockManager.port", "33291") conf.set("spark.executor.port", "33292") conf.set("spark.broadcast.port", "33293") conf.set("spark.fileserver.port", "33294") conf.set("spark.driver.port", "33295") error still persists.
Dec
7
awarded Promoter
Dec
4
revised Spark cluster can't assign resources from remote scala application
added 161 characters in body
Dec
4
revised Spark cluster can't assign resources from remote scala application
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Dec
4
comment Spark cluster can't assign resources from remote scala application
One thing that I've noticed: the local logs are using non-public IPs, and there seems to be no way to force use of public IPs.
Dec
4
asked Spark cluster can't assign resources from remote scala application
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