Free planetarium

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by Watsisname
19 Sep 2017 18:16
Forum: Space Journeys
Topic: Image Dump
Replies: 1059
Views: 59121

Image Dump

Awesome images, DoctorOfSpace.
by Watsisname
18 Sep 2017 05:00
Forum: Science and Astronomy Discussions
Topic: Science and Astronomy Videos
Replies: 241
Views: 11457

Science and Astronomy Videos

Just so.  For example, on some level we don't know what stars are.  They're just lights in the sky that "behave nicely" in the sense that our knowledge of other phenomena (gravity, thermodynamics, nuclear physics, etc) happen to make sensible, testable models about how they appear and on ...
by Watsisname
17 Sep 2017 23:09
Forum: Science and Astronomy Discussions
Topic: Total Solar Eclipse 2017
Replies: 309
Views: 7588

Total Solar Eclipse 2017

midtskogen wrote:
Qr Bbpost EDIT: I'm not allowed to post too soon after a post in another thread?

There shouldn't be any limitation for that.  It's just discouraged to have several posts in a row in the same thread.
by Watsisname
17 Sep 2017 22:23
Forum: Science and Astronomy Discussions
Topic: Science and Astronomy Videos
Replies: 241
Views: 11457

Science and Astronomy Videos

13666 If events are not absolute, then doesn't that make time travel to the past possible even with just one timeline? No.  Events are absolute in the sense that one, and only one, event specifies a location in space-time.  (In other words, a particular point of space-time is  that event).  What I ...
by Watsisname
17 Sep 2017 19:32
Forum: Science and Astronomy Discussions
Topic: Science and Astronomy News
Replies: 303
Views: 12909

Science and Astronomy News

Ok A-L-E-X , I'm sorry to do this, but I did give you a strict warning, and after both Doc and I had given several gentle warnings.  4 posts in the same thread in rapid succession is not   acceptable; I'm giving you 4 days off for it.  You must  figure out a way to avoid doing multi-posts. You can r...
by Watsisname
17 Sep 2017 18:15
Forum: Science and Astronomy Discussions
Topic: Total Solar Eclipse 2017
Replies: 309
Views: 7588

Total Solar Eclipse 2017

Another image.  This time I combined several frames from the GoPro with some close-up shots to get an HDRish wide-angle view.  I love the way the colors turned out. ^_^

Image
by Watsisname
16 Sep 2017 18:15
Forum: Science and Astronomy Discussions
Topic: Science and Astronomy Videos
Replies: 241
Views: 11457

Science and Astronomy Videos

DoctorOfSpace , no, I'm telling you that you are right. :)  All events that make up your life from birth to death exist as a world line in space-time.  Your eating something in 10 years is an event which is unambiguously in your future. The point I'm making is that past and future are not always un...
by Watsisname
16 Sep 2017 17:36
Forum: Science and Astronomy Discussions
Topic: Science and Astronomy Questions
Replies: 665
Views: 26316

Science and Astronomy Questions

13598 Yes I know what is aerobraking and have done this in Orbiter spaceflight simulator multiple times. I thought it might be different from Mars(or any other terrestrial world with atmosphere) on gas giants since they have fast rotation, which causes large planetary scale storms.  Ah, yes, it sti...
by Watsisname
16 Sep 2017 11:54
Forum: Science and Astronomy Discussions
Topic: Science and Astronomy Videos
Replies: 241
Views: 11457

Science and Astronomy Videos

It exists, but different observers may disagree whether one event precedes or follows another event, if they are separated more in space than in time.  Time is not a fixed landscape that we pass through in an absolute sense.  The slice of "now" that separates past from future depends on ho...
by Watsisname
16 Sep 2017 11:10
Forum: Science and Astronomy Discussions
Topic: Science and Astronomy News
Replies: 303
Views: 12909

Science and Astronomy News

FastFourierTransform, great analysis!  The Plutonium indeed gets diluted to ridiculously small concentrations very quickly.  Even if much of it survives the atmospheric entry, it will sink into the lower layers and be vaporized and mixed into the core anyway. :)
by Watsisname
16 Sep 2017 11:06
Forum: Science and Astronomy Discussions
Topic: Science and Astronomy Questions
Replies: 665
Views: 26316

Science and Astronomy Questions

It's also a super fun thing to do in Kerbal Space Program or Orbiter. :)
by Watsisname
16 Sep 2017 08:55
Forum: Science and Astronomy Discussions
Topic: Science and Astronomy Videos
Replies: 241
Views: 11457

Science and Astronomy Videos

13557 Basically, the past, present and future all coexist as if on a landscape of time and we journey through it, unaware that time is just like the other three dimensions we know about. Relativity raises trouble with this idea though, because what events are in the past and what are in the future ...
by Watsisname
16 Sep 2017 08:51
Forum: Space Journeys
Topic: Image Dump
Replies: 1059
Views: 59121

Image Dump

Wow, I like that one a lot. :)
by Watsisname
15 Sep 2017 05:21
Forum: Science and Astronomy Discussions
Topic: Science and Astronomy Videos
Replies: 241
Views: 11457

Science and Astronomy Videos

As the video caption says, it is weirder than you think. :)   Quantum mechanical effects being apparent to our senses is cool but not in itself weird or even rare.  The colors of fireworks and neon signs are determined by the quantum mechanical behavior of electron transitions.  One of my favorite e...
by Watsisname
14 Sep 2017 19:49
Forum: Science and Astronomy Discussions
Topic: Science and Astronomy Videos
Replies: 241
Views: 11457

Science and Astronomy Videos

Yeah, Cassini will be turned into vapor far above the cloud tops.  Its entry speed will be over 30km/s (4 times as fast as return from Low Earth orbit and 3 times as fast as return from the Moon), and it has no shielding.  To survive very far into a gas giant's atmosphere would require some serious ...
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