183 reputation
6
bio website stevenlu.net
location Burlington, MA
age 25
visits member for 2 years, 6 months
seen Aug 27 '13 at 1:07

Apr
24
comment Orbital mechanics and rocketry: Is it ever a good idea to intentionally lower periapsis?
@DeerHunter I see. so plane changes should be performed at apoapsis? That makes sense (lower delta-v at lower orbital speed to perform the same plane change)... So i'd want to adjust the position of the apoapsis to coincide with one of the rising or descending nodes? Because it's too difficult to know where or how to get that apoapsis in the right spot that ahead of time (before entering an orbit)
Apr
24
comment Orbital mechanics and rocketry: Is it ever a good idea to intentionally lower periapsis?
You're awesome, thanks!
Apr
24
comment Orbital mechanics and rocketry: Is it ever a good idea to intentionally lower periapsis?
@DeerHunter you're probably right. My background isn't in this field
Dec
2
comment With Newton's third law, why are things capable of moving?
This answer is completely awesome. My question to you is how on earth did you decide it that it was better to write in an entire warning label instead of removing the word "match"?
Jun
28
comment Does diffraction contribute to the Black Drop effect?
Right. I remember now from my class on Physics of Sound that the diffraction effect of structures depends on the pitch of the sound. I'm sure if I work out the expressions and factor in the distances the attenuation factor due to diffraction will work out to an infinitesimal quantity. This quantum effect would probably affect the measurement of light intensity there for a nanosecond.
Dec
20
comment Calculating stress without strain
Well of course you get the accept. Not gonna hold out on ya.
Dec
20
comment Calculating stress without strain
Well... I think I still need a bit more direction in the way of how to get it done though.
Dec
17
comment Calculating stress without strain
I think the actual crack geometry can be faked pretty convincingly. I'll post back with results from my code when I get it finished.
Dec
17
comment Calculating stress without strain
I'd also like to point out something I hadn't considered up to this point. Consider the L-shape again but this time it is spinning. Due to inertia alone, at some particular speed a real structure of that shape would break due to internal tensile forces. How to go about calculating something like that?
Dec
17
comment Calculating stress without strain
Can anybody come up with a partial differential equation which may have something to do with planar stress?
Dec
16
comment Calculating stress without strain
Thanks for commenting. These links and directions will help me a lot.
Dec
16
comment Calculating stress without strain
This is great. I need to do a bit of studying up to find out what particular PDE's I want to come up with FEA solvers for, then see how far I can get. I'm going after real-time speed and you are showing me that it is definitely possible. Accuracy is not paramount either, but the more variables I can tweak for different effects, the better. Got a long road ahead of me but this will be spectacular if I can pull it off.
Dec
10
comment What is escape velocity? In reality, how can something no longer be under the gravitational influence of something else?
I would say the important bit is that the velocity will tend toward some constant value as t->infinity. Like an asymptote. It doesn't need to go to zero.
Dec
6
comment What happens to a rotating rod that breaks in two?
Sorry. I think I was meaning to say Conservation of Rotational Kinetic Energy. I do understand the notion of measuring Angular Momentum from a point outside an object. Even if it travels straight while not spinning it is a nonzero value so long as it is offset from the path
Dec
6
comment What happens to a rotating rod that breaks in two?
okay. the notion of conservation of angular momentum is silly because it is the total energy which is conserved. It can change into different forms freely (as it often does in the typical roller coaster examples).
Dec
6
comment What happens to a rotating rod that breaks in two?
Thanks for editing tags and title. Much better. :)
Oct
6
comment Effects of high frequency lighting on human vision?
I think a lot of my questions could be completely answered if I just had the proper equipment for performing some scientific testing. An oscilloscope would allow me to figure out the duty cycle, and light power meters too for finding out intensity.
Oct
6
comment Effects of high frequency lighting on human vision?
That is definitely a good idea because it would take into account actual cognitive performance based on vision rather than relying purely on how it "feels".
Oct
5
comment Effects of high frequency lighting on human vision?
Yes I am aware of that. The variable I'm concerned with isnt the logarithmic response, it's the relationship between high (well, 120hz isn't that high) frequency modulations which contain the same average energy.