Free planetarium

 
User avatar
Starlight Glimmer
Explorer
Explorer
Posts: 240
Joined: 02 Nov 2016
Location: Somewhere

Science and Astronomy Questions

30 Aug 2017 19:40

Watsisname wrote:
Bit more accurate representation for how big it would look on the sky, in the sense that the Moon is like a pea held at arms length, and you can't quite see the craters on it.  But you could still (barely) spot the bands on Jupiter.

Image

Other interesting thing to remark on is its magnitude.  Jupiter appears about magnitude -2.7 at its brightest.  If we brought it 10 times closer to Earth, it would be 102 = 100 times brighter just by being larger on the sky.  But its surface brightness would also increase by a factor of 13, by being 3.6 times closer to the Sun.  So together this would change its magnitude by -2.5log10(100*13) = -7.8 magnitudes, or down to about -10.5 magnitude at its brightest.  That's pretty bright -- brighter than any Iridium flare and approaching that of the full moon! (Jupiter's clouds make it more reflective than the Moon which is why it is still so bright despite being apparently smaller and farther from the Sun).  

It would be a commanding presence in the night sky when the Moon isn't around, and plainly visible in broad daylight as well.

Thats quite impressive! 
How about if it was Saturn? Venus? 
 
User avatar
Salvo
Explorer
Explorer
Posts: 231
Joined: 03 Nov 2016
Location: Veneto, Italy
Contact:

Science and Astronomy Questions

30 Aug 2017 23:45

You can easily do that with Space Engine  8-)
The universe is not required to be in perfect harmony with human ambition.

CPU: Intel Core i7 4770 GPU: ASUS Radeon R9 270 RAM: 8 GBs
 
User avatar
PlutonianEmpire
Explorer
Explorer
Posts: 245
Joined: 02 Nov 2016
Location: MinneSNOWta
Contact:

Science and Astronomy Questions

30 Aug 2017 23:49

Adding to the Jupiter thing, with Jupiter in Mars' orbit, why not make it one of its' moons? In Europa's orbit, for example? How different might Mars be then?
Specs: Dell Inspiron 5547 (Laptop); 8 gigabytes of RAM; Processor: Intel® Core™ i5-4210U CPU @ 1.70GHz (4 CPUs), ~2.4GHz; Operating System: Windows 7 Home Premium 64-bit; Graphics: Intel® HD Graphics 4400 (That's all there is :( )
 
User avatar
Marko S.
Explorer
Explorer
Posts: 169
Joined: 02 Jul 2017
Location: Serbia

Science and Astronomy Questions

31 Aug 2017 01:10

Salvo wrote:
Source of the post You can easily do that with Space Engine 

Yes, thing is almost the same as Jupiter except that it has rings and would maybe look more pretty. It is better to do it in SE indeed. I even recommended that for first question about Jupiter.
And I was thinking also how would Mars look from the distance of Jupiter? Probably wouldn't even be visible that much. You would need better telescope for it. Much better. maybe Hubble would be enough, maybe something less powerful. Even at this distance it is now. We see just one small point in the sky using amateur telescope. And not to mention it's moons.
Specs: Ram: 8gb | Vram: 1gb | Graphics card: AMD Radeon | Hard-drive: 1tb | Processor: AMD Athlon X4 750 Quad Core Processor | CPU: 3.40 GHz | OS: Win 10 and XP (lol) |
We use time just to orientate through space.
 
User avatar
JackDole
Pioneer
Pioneer
Posts: 598
Joined: 02 Nov 2016
Location: Terra

Science and Astronomy Questions

31 Aug 2017 01:21

I give this question further on this thread.
Julian wrote:
Source of the post What would happen if a ship with an Alcubierre warp drive collided with a planet at FTL speeds? Or a star?

Perhaps Watsisname  can answer this question better than I do.
JackDole wrote:
Source of the post As far as I understand, this is not possible because a ship in a warp bubble is not in our universe, but in its own space-time bubble, in its own mini-universe. But I can be wrong.
 
User avatar
midtskogen
Pioneer
Pioneer
Posts: 395
Joined: 11 Dec 2016
Location: Oslo, Norway
Contact:

Science and Astronomy Questions

31 Aug 2017 04:00

This is in the realm of science fiction.  When travelling through hyperspace there is no interaction with our universe, apart from the start and endpoints.  This is not the case for warp travel, like with the Alcubierre drive.  It changes the geometry locally in our universe, but does not detach from it, so a traveller can still collide with a planet or star or for that matter a dust particle.
NIL DIFFICILE VOLENTI
 
User avatar
DoctorOfSpace
World Builder
World Builder
Posts: 920
Joined: 22 Aug 2016
Location: SpaceX Mars Colony
Contact:

Science and Astronomy Questions

31 Aug 2017 09:08

midtskogen wrote:
Source of the post collide with a planet or star


Which is death in all the best ways

midtskogen wrote:
Source of the post for that matter a dust particle.


Which is death if only locally in the bubble their original velocity was something pretty high.

If I recall correctly there are horizons within a warp bubble so to some extent it is separated from the universe, however it is not cut off completely. The ship inside is just unable to transmit information out the front of the craft, and us unable to receive information from behind the craft.

This doesn't mean an object in the path of the ship won't be able to interact, in fact depending on the strength of the bubble the object will be displaced, crushed or ripped apart, or move right through the bubble and potentially collide with the ship.
CPU: Intel Core i7-5820K 4.2GHz 6-Core Processor - RAM: G.Skill Ripjaws V Series 32GB (4 x 8GB) DDR4-2400 - GPU: EVGA GeForce GTX 1080 Ti SC Black Edition
Quando omni flunkus, moritati
 
User avatar
midtskogen
Pioneer
Pioneer
Posts: 395
Joined: 11 Dec 2016
Location: Oslo, Norway
Contact:

Science and Astronomy Questions

31 Aug 2017 10:59

DoctorOfSpace wrote:
Source of the post The ship inside is just unable to transmit information out the front of the craft

Which may not be just a "just".  Assuming that the ship has all the energy needed, how is it supposed to supply the energy to sustain the bubble if nothing can reach the front horizon?
NIL DIFFICILE VOLENTI
 
User avatar
An'shur
Space Tourist
Space Tourist
Posts: 33
Joined: 26 Dec 2016
Location: Universe

Science and Astronomy Questions

31 Aug 2017 11:08

Watsisname wrote:
It would be a commanding presence in the night sky when the Moon isn't around, and plainly visible in broad daylight as well.

I know it is possible to see Venus in daylight without any optical aid, provided that you know it's exact presence. I've seen it many times. I also managed to get Venus and Jupiter into a single field of view of my 114mm Bresser Pluto reflecting telescope, still way before sunset, during their conjunction in summer, 2015. Jupiter looked like if you cut a circular area of sky and painted it brown. It was not really much brighter than the background and unlike Venus, it was not visible without the telescope.

The question is: Could I somehow see Jupiter or Mars (Both can have nearly the same maximum brightness) in daylight with unaided eyes?

Edit:

midtskogen wrote:
It changes the geometry locally in our universe, but does not detach from it, so a traveller can still collide with a planet or star or for that matter a dust particle.

There is gas in interstellar and intergalactic space. On earth, an object in free fall cannot exceed terminal velocity, because the air creates drag. Would interstellar gas create drag if the warp ship moved at extremely high velocities? Would it somehow limit the maximum speed of said ship? (Assuming that Alcubierre drive is possible)
 
A-L-E-X
World Builder
World Builder
Posts: 804
Joined: 06 Mar 2017

Science and Astronomy Questions

31 Aug 2017 11:53

JackDole wrote:
A-L-E-X wrote:
Source of the post does this apply to the patch "e" too?  I couldn't get it to recognize the LandTo function and with the patch installed all my saved locations are off :-( I need to redo the lat/long.  What is "Time"? and I assume "Height" is elevation above the surface in meters?

Is the FOV function changed too?  What about the single key functions like pressing <END> to straighten the horizon?

For me, LandTo and Fov work exactly as in SE 0.980. The END button also.

Thanks, I got it to work!  I was using commas earlier to separate the fields, I think that's what it was.
Are versions later than this going to use the new format?  Any ideas why they switched to a more complicated format for the future, Jack?
 
A-L-E-X
World Builder
World Builder
Posts: 804
Joined: 06 Mar 2017

Science and Astronomy Questions

31 Aug 2017 11:55

DoctorOfSpace wrote:
midtskogen wrote:
Source of the post collide with a planet or star


Which is death in all the best ways

midtskogen wrote:
Source of the post for that matter a dust particle.


Which is death if only locally in the bubble their original velocity was something pretty high.

If I recall correctly there are horizons within a warp bubble so to some extent it is separated from the universe, however it is not cut off completely.  The ship inside is just unable to transmit information out the front of the craft, and us unable to receive information from behind the craft.

This doesn't mean an object in the path of the ship won't be able to interact, in fact depending on the strength of the bubble the object will be displaced, crushed or ripped apart, or move right through the bubble and potentially collide with the ship.

I like that idea, Doc- it fits in with how I believe other universes exist, on the other end of a warp bubble, with their own arrows of time and dimensions.
 
A-L-E-X
World Builder
World Builder
Posts: 804
Joined: 06 Mar 2017

Science and Astronomy Questions

31 Aug 2017 11:57

midtskogen wrote:
This is in the realm of science fiction.  When travelling through hyperspace there is no interaction with our universe, apart from the start and endpoints.  This is not the case for warp travel, like with the Alcubierre drive.  It changes the geometry locally in our universe, but does not detach from it, so a traveller can still collide with a planet or star or for that matter a dust particle.

well to be fair theoretical physics is often the realm of science fiction, but I find science fiction the best kind of fiction, it makes you more curious about how things work, much better than the trash fiction that's out there in everyday life.
 
User avatar
DoctorOfSpace
World Builder
World Builder
Posts: 920
Joined: 22 Aug 2016
Location: SpaceX Mars Colony
Contact:

Science and Astronomy Questions

31 Aug 2017 12:14

midtskogen wrote:
Source of the post Assuming that the ship has all the energy needed, how is it supposed to supply the energy to sustain the bubble if nothing can reach the front horizon?


The ship is carried with the wave, the distance from the ship to the front of the bubble is directly linked with the ring around the craft.  There is no need for any FTL signals to be transmitted.  

The ring is what generates the field and that is what acts on space, nothing is directly interacting with either end of the bubble.  The ship and ring within the bubble are carried along, locally never exceeding the speed of light, but directly between both regions.
CPU: Intel Core i7-5820K 4.2GHz 6-Core Processor - RAM: G.Skill Ripjaws V Series 32GB (4 x 8GB) DDR4-2400 - GPU: EVGA GeForce GTX 1080 Ti SC Black Edition
Quando omni flunkus, moritati
 
User avatar
spaceguy
Explorer
Explorer
Posts: 181
Joined: 30 Dec 2016

Science and Astronomy Questions

31 Aug 2017 14:09

What's the type of fluid flow in Jupiter's atmosphere that creates these clouds formations? The same process looks similar to Earth as well. 
Attachments
pia21377-1041.jpg
 
User avatar
Watsisname
Science Officer
Science Officer
Posts: 928
Joined: 06 Sep 2016
Location: Bellingham, WA

Science and Astronomy Questions

31 Aug 2017 14:56

midtskogen wrote:
Source of the post Assuming that the ship has all the energy needed, how is it supposed to supply the energy to sustain the bubble if nothing can reach the front horizon?

Consider a related question: "how is a black hole able to sustain an event horizon around itself if nothing can reach the horizon from within -- or even leave the singularity in the first place?"

That's a common way to answer this question and make it seem like it isn't an issue, but there's actually a lot of subtlety to it.  In fact, according to the outside universe, the inside of a black hole doesn't exist.  All events at the horizon take place infinitely far in the future, and events in the interior are never observed.

If we're outside, the properties of the event horizon and external gravitational field appear because to us there is a spherical shell of mass frozen on the horizon, and the field from a spherical shell is the same on the outside as if it were a singularity instead.  Only when we shift into the reference frame which is falling into it do we discover that the mass has collapsed to singularity and the space-time extends into that region.

So the black hole isn't really "sustaining" its event horizon from a singularity at all.  There is no contact between the two.  It just turns out that the gravitational field according to observers inside and outside happen to exactly match up, even though they have totally different ideas of where the mass is located.

General relativity suggests in this case to take a shortcut.  Say that the mass "really is" at the central singularity, and then use the field equations to determine the geometry of the surrounding space-time.  The equations insist that you'll get a black hole with an event horizon.  To not have the horizon would violate the equations.
 
So with the Alcubierre drive, we could similarly say that the equations demand that this particular mass-energy distribution must create this space-time geometry with horizons around it.  But we must also remember that the Alcubierre solution was found by solving the equations backward.  It started with the space-time geometry that has this FTL behavior, and then worked backward to find the mass-energy distribution that causes it.  But it does not tell us how that distribution could actually be created, or how that Alcubierre space-time could be generated out of an initially typical space-time.  

We know the mass-energy that yields this solution is exotic and violates some energy conditions in physics (so it probably can't exist).  It is also likely that even if it can exist, it may be impossible to actually get it into the required configuration.  A common argument (though I have yet to see it demonstrated rigorously) is that, similarly to trying to build a wormhole, Hawking radiation would amplify as you approach the conditions necessary for the horizons and FTL behavior, and the thing destroys itself.  Which kind of brings us full circle -- your initial suspicion that there is a problem with having the ship generate this field around itself from scratch is probably correct, but for less obvious reasons.

Who is online

Users browsing this forum: No registered users and 1 guest