This is Cool

JimFiore

Silver Member
Check this out, nothing to do with drumming but this is great stuff.

Here is an interactive graphic involving the European Space Agency's Rosetta spacecraft which currently is closing in on a binary comet: http://sci.esa.int/where_is_rosetta/

Even if you don't care about Rosetta, the interactive graphic is a must try. It's not just a static video. You can zoom in and out, and even more fun, click and drag to move and rotate your orientation.

Here's some background: http://www.esa.int/Our_Activities/Space_Science/Rosetta
 

Anon La Ply

Renegade
Awesome - thanks Jim.

My understanding is that the Earth is travelling through space at over two million kilometres per hour through space by the time you take into account its rotation around the sun, the solar system's rotation around the galaxy and the Milky Way's movement.

Moral of the story: no matter what BPM you think you play, you are moving FAST :)
 

GruntersDad

Administrator - Mayor
Staff member
Glad you made me look that up.

So our "armchair Astronaut" is now moving through 6 different directions and a combined speed of approximately 574,585 MPH
69,361 MPH Spin and Orbit
43,200 MPH Towards Lambda Herculis
15,624 MPH Perpendicular to Galactic Plane
446,400 MPH Orbiting the Galactic Center {or Galactic Spin Rate}
-------------------
574,585 MPH Speed of Earth within Our Galaxy
So for every hour you are away from the solar system, your planet is moving half a million miles, and in several directions…
Now if you want to leave the galaxy add another 1,339,200 MPH to the calculations. This is the speed the galaxy is moving through the universe. But THEN you really get into difficulties pin pointing you reference point. Details can be found here…
So you see… the propulsion unit is the least of your worries….
You better have a REALLY GOOD NAVIGATOR.
 

JimFiore

Silver Member
Nitpicking time. We can't just add those velocities together arithmetically because they're vectors. We need to use a vector addition. Example: Let's say you're on one of those moving sidewalks in the airport and you're going to do a circus trick. The sidewalk is going 2 feet per second. You balance an extension ladder on it and begin climbing straight up with a velocity of 2 feet per second. To an observer on the floor you're not going 4 feet per second, you're going roughly 2.8 meters per second at an angle of 45 degrees to the horizontal. You can only add the magnitudes of vectors if they're all aligned, going in the same direction.

It really complicates the situation but that also makes it more interesting.

If they had graphics like this when I was a kid it's much more likely that I would've become an astrophysicist instead of an electrical engineer. It's like... science geek porn.
 

JimFiore

Silver Member
If you play the animation from the start you can see all of the planetary gravitational assists they used. Planning that out has got to be tons of fun as well.
 

Brian

Gold Member
Nitpicking time. We can't just add those velocities together arithmetically because they're vectors. We need to use a vector addition. Example: Let's say you're on one of those moving sidewalks in the airport and you're going to do a circus trick. The sidewalk is going 2 feet per second. You balance an extension ladder on it and begin climbing straight up with a velocity of 2 feet per second. To an observer on the floor you're not going 4 feet per second, you're going roughly 2.8 meters per second at an angle of 45 degrees to the horizontal. You can only add the magnitudes of vectors if they're all aligned, going in the same direction.

It really complicates the situation but that also makes it more interesting.

If they had graphics like this when I was a kid it's much more likely that I would've become an astrophysicist instead of an electrical engineer. It's like... science geek porn.
Cool link. You are not nit-picking at all, what you said generally sounds correct. Math and physics can be very fascinating. You'd have to calculate all of the components first to find the true vector. I remember studying and analyzing vector mathematics and the coordinate systems back in the day. Most useful in synoptic meteorology.
 

Smoke

Silver Member
It all makes sense now. I've got vectors in my back yard. They transmit and disperse fleas (eventually to my dogs!). My dogs think of them as squirrels.

Cool!

Vectors.
 

JimFiore

Silver Member
Me thinks those are a different kind of vector, Victor, even though those vectors might vector to your pet with victory!


I can't help the vectors thing. AC electrical circuit analysis is nothing but vectors. I have to beat it into some of my students. As I always say, sometimes 5 and 5 is 10, sometimes it's 0, and sometimes it's 7. When you're used to nothing but scalars that sounds like crazy talk. Of course, we don't live in a one dimensional universe even though some people have one-dimensional thoughts.
 

Smoke

Silver Member
AC electrical circuit analysis is nothing but vectors. I have to beat it into some of my students. As I always say, sometimes 5 and 5 is 10, sometimes it's 0, and sometimes it's 7.
Hellllp!!!

Please don't start on S-Parameters, Jim, I gave up on them years ago. It's all smoke and mirrors, and I refuse to believe it. I passed a 2-week long course on RF circuit analysis, then promptly performed an alcohol induced brain dump to relieve the stress. I'm better now.

On a semi-related note, which is correct: hole flow or electron flow?

And how about this teaser - direct voltage. Is it really DC or is it infinite frequency alternating voltage?
 

JimFiore

Silver Member
Hellllp!!!

Please don't start on S-Parameters, Jim, I gave up on them years ago. It's all smoke and mirrors, and I refuse to believe it. I passed a 2-week long course on RF circuit analysis, then promptly performed an alcohol induced brain dump to relieve the stress. I'm better now.
If it related to the topic, I can assure you that I'd find a way to sneak it in. S parameter analysis has a special LaPlace in my heart. (Right. 3 people might get that joke including Smoke and me.)

On a semi-related note, which is correct: hole flow or electron flow?
Answer: Yes.

And how about this teaser - direct voltage. Is it really DC or is it infinite frequency alternating voltage?
Literally the opposite end of the spectrum. DC is not infinite frequency. It's a frequency of 0 Hz. We're talking serious bass here. Infinite octaves below low E. It makes the rate of change of air pressure due to weather systems seem absolutely shrill by comparison.

Seriously though, it works. If you think of DC as the limit of decreasing frequency, you can analyze all kinds of stuff correctly. For example, capacitive reactance approaches infinity and inductive reactance approaches zero, just by using the well known reactance formulas.

I think I may have strayed just a bit. OK, so I wonder- if the two comet nuclei are not in direct contact, do they revolve around each other in a sort of poly-rhythmic fashion?
 

BacteriumFendYoke

Platinum Member
Ever played Kerbal Space Program, Jim? I think you'd like it. It taught me basic orbital mechanics and it's very entertaining.

Those gravity assists are just beautiful. Absolutely ridiculous. The precision in those calculations is absolutely astonishing...
 

Smoke

Silver Member
If it related to the topic, I can assure you that I'd find a way to sneak it in. S parameter analysis has a special LaPlace in my heart. (Right. 3 people might get that joke including Smoke and me.)
For Pete-Simon's sake!! Make it stop. (Recall aforementioned brain dump.) I'm a mechanical/dimensional metrologist. I can barely spell "RF."

µ, Θ, φ and σ are all Greek to me.

I think the two comet nuclei revolve in plain old cut time.
 

JimFiore

Silver Member
Ever played Kerbal Space Program, Jim? I think you'd like it. It taught me basic orbital mechanics and it's very entertaining.

Those gravity assists are just beautiful. Absolutely ridiculous. The precision in those calculations is absolutely astonishing...
Never heard of it but just found the site. Thanks.
 

BacteriumFendYoke

Platinum Member
Hey Jim, Dunc and other eggheads ... would it be fair to say that we are moving through space in fractal vortices?
Not my area of expertise. We are rotating around a point (slightly outside of the Earth's core), that orbits a star that orbits a galactic central point that moves around another point. The local group of galaxies may also orbit or move around another point. Who knows what that rotates around? That's only assuming a four-dimensional Universe. The actual movement in multi-dimensional space is probably much more exotic. Add that to the fact that I'm only assuming a Classical model of physics and discounting quantum motion...

As of now, nobody has discovered any 'clumps' of matter more than 350 million light years across. The Universe also breaks down at the other end with the Planck length - a theoretical construct of the smallest measurable length.

This is only a hobby of mine. I can't pretend to understand the Mathematics of it all.

Jim, KSP is a seriously fun game. You can design and launch rockets and visit planets that are rough analogues of the Solar System, albeit smaller. It uses 'real' orbital mechanics, although the engine they use isn't perfect it's a pretty good approximation. It's also bloody hilarious.
 
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