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Science and Astronomy Videos

Posted: 30 Nov 2017 07:46
by Watsisname
Neat!  Cody's Lab did something I've long wished to try but couldn't get it to work this nicely: using an infrared camera to observe the heat released by the phase change of supercooled water freezing:

[youtube]YyHogH2bFc8[/youtube]

Science and Astronomy Videos

Posted: 25 Dec 2017 11:23
by Watsisname
General relativistically accurate video of the view on an orbit around Sagittarius A*, with a model of its possible accretion flow:

[youtube]-7krHb9_d-E[/youtube]

And a video showing the trajectory of the camera, which explains why this may seem disorienting.  The orbit is very unlike those that we are used to, due to the strong curvature of the space-time.  In Newtonian gravity the time it takes to loop around once radius-wise and to loop around once angle-wise is the same, so that the orbit always retraces itself as an ellipse.  But in strong gravity the orbit hangs around longer at smaller radii, so it is no longer an ellipse.  The orbit is also dragged around by the spin of the black hole.


[youtube]tZ5fUTEhn30[/youtube]

Science and Astronomy Videos

Posted: 27 Dec 2017 03:21
by Watsisname
[youtube]U-KvBFT9rY8[/youtube]

Science and Astronomy Videos

Posted: 29 Dec 2017 01:23
by Salvo
General relativistically accurate video of the view on an orbit around Sagittarius A*
It reminds me a dream I had a few weeks ago   :)


What do you think about this video? It's quite interesting.

[youtube]yArprk0q9eE[/youtube]

Science and Astronomy Videos

Posted: 30 Dec 2017 01:40
by Watsisname
What do you think about this video? It's quite interesting.
Aye, it's a fun subject.  In an earlier science questions thread discussion, I pointed out CP violations as an example of when a presumed law of nature was found to be incorrect.  Sometimes in physics we encounter a behavior that appears so highly systematic, or so theoretically sensible or aesthetic, that "It must be a law!"... and later find that there are exceptions. :)


In other news, Cody did a pretty interesting video that he had been hinting at for a while.  Isolation of uranium metal!

[youtube]bl3NamzoFrM[/youtube]

Science and Astronomy Videos

Posted: 04 Jan 2018 07:29
by midtskogen
Cody did a pretty interesting video that he had been hinting at for a while.  Isolation of uranium metal!
That was a lot of work to get a small piece of metal!  Interesting, but I'm left a bit undecided whether he extracted a nice piece of metal or destroyed a nice piece of ore and created a lot of toxic waste...

Science and Astronomy Videos

Posted: 04 Jan 2018 09:40
by FastFourierTransform
This guy built a Radio Telescope with a TV dish, a 3D printer and some wood sticks. The apparatus is capable of showing the radio emmision of the geostationary satellites ring around Earth:

[youtube]aeah3fFYlnA[/youtube]

The same guy then built an antenna and started receiving data and images from many satellites. Downloading images of Earth directly from space in real time without any permission (not needed just a joke).

[youtube]cjClTnZ4Xh4[/youtube]
[youtube]L3ftfGag7D8[/youtube]


And this guy went to the parking of a mall at night to receive with his antenna an image directly transmitted from the ISS
[youtube]7to9uX1sWC4[/youtube]

Science and Astronomy Videos

Posted: 04 Jan 2018 10:54
by Watsisname
Interesting, but I'm left a bit undecided whether he extracted a nice piece of metal or destroyed a nice piece of ore and created a lot of toxic waste...
Same.  The ore itself and the geology behind it is interesting, while the process for refining it into solid uranium metal is also interesting (particularly all the chemistry involved and the different ionization states the uranium shows).  I was fairly concerned with how he would manage with the various safety issues, but it looks like he knows what he's doing and did a good job recovering the waste with plans for how to recover it further or condense it down to a safer form.  I would not trust most edutainment youtubers with this kind of activity!

Science and Astronomy Videos

Posted: 04 Jan 2018 12:45
by midtskogen
His safety precautions may have been sufficient for this one experiment, but if this refinement were his daily job, I would be somewhat concerned.  In particular about the various fumes.

Science and Astronomy Videos

Posted: 17 Jan 2018 18:23
by Watsisname
PBS Space Time is going into depth on Hawking Radiation and the nature of the vacuum near event horizons, with more to come in this new mini-series of videos. :)

[youtube]bG-xu5H6plk[/youtube]

Science and Astronomy Videos

Posted: 17 Jan 2018 20:10
by DoctorOfSpace
[youtube]bxdBRKmPhe4[/youtube]

[youtube]rpA-Bd0d6kw[/youtube]
[youtube]XLTb0V1BGNw[/youtube]

Science and Astronomy Videos

Posted: 27 Jan 2018 00:12
by Watsisname
There was some discussion of rheoscopic fluids (which visualize turbulence in fluid flow) on the SE Discord earlier, and while looking at various videos of it on youtube, I stumbled on this little gem.  This is the convection pattern set up on a plate of canola oil + mica after being removed from heat.  This is a very good visualization for the granulation pattern on star surfaces. :)


[youtube]4JC1ijzmH3U[/youtube]

Science and Astronomy Videos

Posted: 27 Jan 2018 15:05
by A-L-E-X
Science being a social construct is an interesting idea though.  I've has this discussion on here and other forums, talking about the differences between science and nature.  Nature= what IS (whether we know it or not) vs Science (our modeling of nature, which will always be to some degree imperfect.)

I dont pay much attention to Tyson, he's a blowhard in many respects.

Science and Astronomy Videos

Posted: 27 Jan 2018 15:08
by A-L-E-X
PBS Space Time is going into depth on Hawking Radiation and the nature of the vacuum near event horizons, with more to come in this new mini-series of videos. :)

[youtube]bG-xu5H6plk[/youtube]
I hope they talk about closed timelike curves :D  Thanks for all these amazing videos!

Science and Astronomy Videos

Posted: 31 Jan 2018 19:14
by DoctorOfSpace
SpaceEngine and Isaac Arthur in PBS Spacetime

[youtube]9-SxVSpSoek[/youtube]