947 reputation
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bio website ericmenze.com
location Minneapolis, MN
age 30
visits member for 2 years, 11 months
seen 5 hours ago

I'm a Computer (Web) Programmer/Analyst based in Anchorage, AK and Minneapolis, MN. I use (among other things) ASP.NET, C# and SQL Server.

I build things. Bicycles, computers, websites, guitars, cars, motorcycles, sound sytems... lots of things.


14h
revised Are nuclear processes the only processes that release more energy than is input?
added 315 characters in body
14h
answered Are nuclear processes the only processes that release more energy than is input?
2d
comment Why is the sky of the moon always dark?
However, where landings happen the duller dust is stirred up and moved; and the angle of incidence to the camera is not perpendicular to the surface. Check out this page with a reproduction on earth with a soup can: www3.telus.net/summa/moonshot/fillit.htm
2d
comment Why is the sky of the moon always dark?
I can't find many good measurements of lunar surface albedo near landing sites, but it does have an overall average of 0.07% to 0.11% (0.12% including earthshine), comparable to worn asphalt on earth. This would put it quite low compared to snow and deserts, see this chart on the Albedo wiki page.
2d
comment Why is the sky of the moon always dark?
Rovers have, and they have cameras.
Mar
28
answered Why is the sky of the moon always dark?
Mar
19
awarded  Notable Question
Mar
3
answered Is the difference between an event horizon and a singularity merely perspective?
Jan
26
answered Is it possible for the universe to be moving towards something, rather than expanding?
Jan
22
awarded  Popular Question
Jan
20
comment Would cosmological redshift be present in the following situation?
What's a better way? I was hoping to pin it down to this (preposterous) example to nail down specifically what I'm having a hard time understanding; which is the two planets are fully stationary with respect to each other.
Jan
20
comment Would cosmological redshift be present in the following situation?
If it's viewed that way, then the cable stays perfectly taut and doesn't flex during said 'movement'? I'm not sure I'd consider that movement.
Jan
20
comment Would cosmological redshift be present in the following situation?
That last part confused me more. Which is it? If it is actually a property of expansion of space, then why wouldn't the situation pictured above experience redshifted planetary light?
Jan
20
comment Would cosmological redshift be present in the following situation?
Ah - so if we knew true velocities, the entire redshift would be simply due to relativistic doppler effects using said true velocity? I think that answers my question.
Jan
20
comment Would cosmological redshift be present in the following situation?
Why is it initially blueshifted?
Jan
20
comment Would cosmological redshift be present in the following situation?
I guess the fundamental part I'm asking is whether or not the cosmological redshift happens as the light travels through expanding space, or just due to observer velocities, peculiar or proper.
Jan
20
comment Would cosmological redshift be present in the following situation?
But... the universe HAS expanded (even if the planets have not receded), and thus $a(t_0)$ would be != 1, and thus redshift, would it not? Let's say they're REALLY far apart, and the universe has doubled in size since the light was emitted from one planet. Would that not mean $\frac {\lambda} {\lambda_0} = \frac {1} {2} $ ?
Jan
20
comment Would cosmological redshift be present in the following situation?
Why would they have 'peculiar velocity' toward each other, if they are at rest to each other? By the definition of peculiar velocity in the wiki article, would that not mean a peculiar velocity of $0\ m/s$?
Jan
20
comment Would cosmological redshift be present in the following situation?
So according to this, then, the planets would see redshifted light, as the energy density of the space between the planets has diminished from the expansion of the space between them. So - the planets would see somewhat redshifted light from the other?
Jan
20
comment Would cosmological redshift be present in the following situation?
And or the main point, why distinguish between peculiar and non-peculiar velocities, then, and have some distinction between 'doppler redshift' and 'cosmological redshift'? Why not just consider the vector sum of the two velocities as the doppler effect redshift?