General > General Technical Chat
SciFi movies and pathetic misconceptions of tech failing for the story line.
BrianHG:
--- Quote from: rdl on April 18, 2023, 05:34:42 am ---Geostationary orbit is not a "magical" altitude. Orbital speed in geostationary orbit is a bit over 3 km/sec.
--- Quote from: BrianHG on April 17, 2023, 06:28:17 am ---...
To stop your rocket which was stationary relative to the ground from falling, it would have to go 35,786 kilometers above the equator where our geostationary satellites are located. That is the one magic altitude above our equator where you just magically stay stationary above the ground below.
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You are correct that the altitude I mentioned, to maintain that relative stationary position above the Earth's ground way below, because of the Earth's rotation, you would be traveling at your noted ~3km/sec. And like I said it is an orbit.
rdl:
That's probably what you meant, but not exactly what you said. You said that if you shoot a rocket "straight up" to the altitude of the ISS, it will eventually "drop like a rock", but by going farther up to 35,786 kilometers the rocket will "just magically stay stationary above the ground below". You left out the part about also needing to accelerate tangentially to 3.1 kilometers per second.
--- Quote from: BrianHG on April 17, 2023, 06:28:17 am ---It is the same for use here. if we shoot a rocket straight up above the ground to the orbital altitude of our current international space station, once the rocket runs out of fuel, the rocket will decelerate, then begin to drop like a rock as it does not have the angular velocity around the earth to counteract the Earth's gravity.
To stop your rocket which was stationary relative to the ground from falling, it would have to go 35,786 kilometers above the equator where our geostationary satellites are located. That is the one magic altitude above our equator where you just magically stay stationary above the ground below. The altitude of our international space station at 408 kilometers is just way to close and if it were to stay above one point of the Earth relative to the ground, at 408km, it would drop
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newbrain:
--- Quote from: David Hess on April 16, 2023, 01:13:09 am ---Star Wars is not science fiction. It is space opera.
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And, IMO, quite bad space opera.
I still recall in my teens going to watch the original "Star Wars" when it came out with great expectations.
I was coming from dozen of sci-fi books (possibly ~100), and 2001, and Solaris, so I just felt I disappointed that I had watched a bad western.
I have also seen the two following movies, more from social pressure than other reasons, and can't remember having enjoyed them.
You want good space opera? Read the Culture series from Iain M. Banks.
BrianHG:
--- Quote from: rdl on April 18, 2023, 10:06:34 am ---That's probably what you meant, but not exactly what you said. You said that if you shoot a rocket "straight up" to the altitude of the ISS, it will eventually "drop like a rock", but by going farther up to 35,786 kilometers the rocket will "just magically stay stationary above the ground below". You left out the part about also needing to accelerate tangentially to 3.1 kilometers per second.
--- Quote from: BrianHG on April 17, 2023, 06:28:17 am ---It is the same for use here. if we shoot a rocket straight up above the ground to the orbital altitude of our current international space station, once the rocket runs out of fuel, the rocket will decelerate, then begin to drop like a rock as it does not have the angular velocity around the earth to counteract the Earth's gravity.
To stop your rocket which was stationary relative to the ground from falling, it would have to go 35,786 kilometers above the equator where our geostationary satellites are located. That is the one magic altitude above our equator where you just magically stay stationary above the ground below. The altitude of our international space station at 408 kilometers is just way to close and if it were to stay above one point of the Earth relative to the ground, at 408km, it would drop
...
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My meaning 'straight up' as in keeping a relative stationary position above the ground. This means if the ground is rotating, you do have some orbital speed, it's just at low orbits like 408km up, it is not enough to stop you from falling back down like a rock.
David Hess:
--- Quote from: newbrain on April 18, 2023, 11:53:01 am ---
--- Quote from: David Hess on April 16, 2023, 01:13:09 am ---Star Wars is not science fiction. It is space opera.
--- End quote ---
And, IMO, quite bad space opera.
I still recall in my teens going to watch the original "Star Wars" when it came out with great expectations.
I was coming from dozen of sci-fi books (possibly ~100), and 2001, and Solaris, so I just felt I disappointed that I had watched a bad western.
I have also seen the two following movies, more from social pressure than other reasons, and can't remember having enjoyed them.
--- End quote ---
I did not think Star Wars was that bad, for space opera. I had no interest in seeing it but my parents forced me to go. The execution was good.
My list of good science fiction movies and series is awfully short, but there are a few. Most or all never enjoyed general popularity.
--- Quote ---You want good space opera? Read the Culture series from Iain M. Banks.
--- End quote ---
At the time I was reading a lot of Edgar Rice Burrows, but that became a gateway to hard science fiction.
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