Starship Asterisk*

by **cherlin** » Wed Aug 12, 2009 8:28 pm

Aha! Even better.

Firefogg is an addon for the free software browser Firefox that can encode Theora videos on the fly, as it uploads them to a website.

http://firefogg.org/

by **cherlin** » Wed Aug 12, 2009 7:31 pm

RJN wrote:
>I do not have the software myself to put these lectures in a format playable only through a web browser.

There is Free Software to do the job, available for Linux, Mac, and Windows. Those of us in the Free Software community prefer to use formats that are publicly defined and not under patent. In this case, Ogg Theora format would be the best. You can get the ffmpeg2theora conversion utility

http://en.flossmanuals.net/ffmpeg2theora
"You can send live video from a video camera across the internet, capture video from a DV camera, convert other formats to Ogg Theora, change the size of video files, add extra audio tracks etc etc etc."

with a GUI frontend.

http://www.softpedia.com/downloadTag/theora+converter

Free Manuals at http://en.flossmanuals.net/
including

VIDEO EDITING
Kino
Avidemux
Ogg Theora
GTranscode
ffmpeg2theora
Handbrake

If you need technical assistance, ask me offline. (mailto:echerlin@gmail.com) I will put you on to one of my friends in the Video business.

(Disclosure: I am an anti-Microsoft, pro-Free Software "bigot", and a writer and editor for FM, including How to Bypass Internet Security and Introduction to the Gnu/Linux Command Line. I also work on astronomy and other course material for the Sugar software from the One Laptop Per Child project: laptop.org, sugarlabs.org, earthtreasury.org)

What would you say to letting us translate your lectures to the languages of countries in the One Laptop Per Child program, and either dub or subtitle your videos? With corrections?

http://translate.sugarlabs.org/
http://www.earthtreasury.net/worknet/?p ... gTextbooks

by **adrianxw** » Mon Jan 19, 2009 9:06 am

I see, okay.

(Sorry for the delay. Your reply is dated the same day as my sudden and rather unexpected entry into hospital.)

by **rigelan** » Thu Nov 27, 2008 12:56 am

Technically.

Thanksgiving is Thursday. Secondary schools typically have class on Monday, Tuesday, Wednesday. Then take a break on Thursday, Friday.

Private (not public) colleges can have breaks whenever they want, but publicly funded colleges tend to take all Thanksgiving week off. Michigan is a public state college. I guess its probably easier to schedule. I know my college (Iowa State) took all week off for thanksgiving. We still get the recommended number of classtime hours for the semester by making sure we start early enough in August.

This is what I've experienced living in the Middle of the US. But I suppose there are always exceptions.

by **adrianxw** » Wed Nov 26, 2008 8:16 pm

Hmmm, I thought "Thanksgiving" was a single day.

by **rigelan** » Wed Nov 26, 2008 7:51 pm

Thanksgiving week. American Holiday. School's out for a week.

by **adrianxw** » Wed Nov 26, 2008 7:32 pm

No lectures this week?

by **jose palacios** » Sun Oct 12, 2008 5:46 pm

I became addict to APOD about two years ago, and the classes I just found make a fantastic use out of it. I want to thank prof Nemiroff for the great idea, and for the great classes, too.

In fact, I would like to try something similar from my microbiology classes (the other end of the size scale). how difficult it is to convert the classes into the podcast? Could it be enough with QuickTime software or I need much more support?

Thanks again,

jose

by **Chris Peterson** » Fri Oct 10, 2008 7:43 pm

BMAONE23 wrote:If the mass of Jupiter were suddenly removed the objects most affected would be the Trojans at the lagrange points since their cohesion was dependant on the mass of Jupiter for stability. The lagrange points would disappear and they would need to seek stable solar orbits which could lead to many interctions.

The Trojans are in stable orbits. The thing that is special about the Lagrange points is that they are the only stable points in Jupiter's orbit. If Jupiter disappeared, the Trojans could spread out to fill more of the orbit. Of course, over time, with so many bodies in the same orbit, there would be interactions and collisions. But for the most part, the Trojans would carry on just fine if Jupiter disappeared. In the absence of interactions with each other, or with Saturn, they wouldn't "seek" new orbits.

by **BMAONE23** » Fri Oct 10, 2008 7:30 pm

If the mass of Jupiter were suddenly removed the objects most affected would be the Trojans at the lagrange points since their cohesion was dependant on the mass of Jupiter for stability. The lagrange points would disappear and they would need to seek stable solar orbits which could lead to many interctions.

by **Chris Peterson** » Fri Oct 10, 2008 7:20 pm

emc wrote:<<"Now, here is the really neat part: all objects accelerate to the Earth at exactly the same rate given the same distance from the Earths center. In other words, even the Moon is accelerating towards the Earth at a rate that is appropriate for its distance from the Earth's center! If another object, say with the mass of this desktop computer, were to be placed in the moon's orbit it would circle the Earth at exactly the same speed as the moon.

BTW, we don't need to keep this hypothetical. There are small bodies in the same orbit as larger ones. There are satellites orbiting the Sun in Jupiter's orbit, ahead of or behind the planet. These trojan satellites are, of course, much smaller than Jupiter.

by **emc** » Fri Oct 10, 2008 7:06 pm

Chris Peterson wrote:
emc wrote:I was thinking that since the moons are traveling at Jupiter's velocity around the sun that they would tend to move away from the sun's gravity due to their lower mass reaching relative escape velocity.
When the mass of the orbiting body is much less than the mass of the central body, mass can be ignored. If Jupiter disappeared, its satellites would still be moving mainly in the same orbit as Jupiter. Each would find itself moving slightly faster or slower as its own orbital velocity component around Jupiter was added to its much larger solar orbit velocity. This would result in a slight spread of the satellites inward or outward, depending on where each was in its Jupiter orbit when the planet disappeared.

Thanks Chris, I feel like a student who hasn't been paying attention in class.

I found this article on the subject of Earth's mass which touches on orbital mechanics which also helps...

physlink.com online Q&A
<<"Now, here is the really neat part: all objects accelerate to the Earth at exactly the same rate given the same distance from the Earths center. In other words, even the Moon is accelerating towards the Earth at a rate that is appropriate for its distance from the Earth's center! If another object, say with the mass of this desktop computer, were to be placed in the moon's orbit it would circle the Earth at exactly the same speed as the moon. Why? Because both objects are accelerating towards the Earth and all objects, regardless of their mass, accelerate towards the Earth at exactly the same rate.">>

So the above quote also applies to what you, BMAONE23, and Dr. Nemiroff are saying... the moons of Jupiter would follow their same solar orbit even after their adjustment to loosing the gravity of Jupiter because they share the same relationship to the sun's gravity as Jupiter did.

I was complicating/confusing the loss of Jupiter's gravity as a "release" relative to the moons allowing them to move away from the sun kind of like how acceleration allows our spacecraft to exit Earth's gravity. I see I was wrong.

Thanks again!

by **v13** » Fri Oct 10, 2008 4:04 pm

adrianxw wrote:
There is a problem with this website's security certificate.

The security certificate presented by this website was not issued by a trusted certificate authority.

I get that when going to the URL for the lectures. Clicking continue to site seems to do so though.

This is because the certificate is not signed by a well-know Certificate Authority. If you want to get rid of this message you must either accept it permanently or get the CA certificate from here: http://hydra.it.teithe.gr/ca/.

I'm sorry but the server is used for sharing files some of which are password protected and thus we need to have encrypted communications. Since there is no easy way to differentiate between protected and non-protected areas, it isn't possible to provide a non-https URL for now.

by **adrianxw** » Fri Oct 10, 2008 3:07 pm

There is a problem with this website's security certificate.

The security certificate presented by this website was not issued by a trusted certificate authority.

Security certificate problems may indicate an attempt to fool you or intercept any data you send to the server.
We recommend that you close this webpage and do not continue to this website.
Click here to close this webpage.
Continue to this website (not recommended).
More information

If you arrived at this page by clicking a link, check the website address in the address bar to be sure that it is the address you were expecting.
When going to a website with an address such as https://example.com, try adding the 'www' to the address, https://www.example.com.
If you choose to ignore this error and continue, do not enter private information into the website.

For more information, see "Certificate Errors" in Internet Explorer Help.

I get that when going to the URL for the lectures. Clicking continue to site seems to do so though.

by **Chris Peterson** » Thu Oct 09, 2008 9:44 pm

emc wrote:I was thinking that since the moons are traveling at Jupiter's velocity around the sun that they would tend to move away from the sun's gravity due to their lower mass reaching relative escape velocity.

When the mass of the orbiting body is much less than the mass of the central body, mass can be ignored. If Jupiter disappeared, its satellites would still be moving mainly in the same orbit as Jupiter. Each would find itself moving slightly faster or slower as its own orbital velocity component around Jupiter was added to its much larger solar orbit velocity. This would result in a slight spread of the satellites inward or outward, depending on where each was in its Jupiter orbit when the planet disappeared.

by **Indigo_Sunrise** » Thu Oct 09, 2008 6:12 pm

Thank you, v13! I hadn't had a chance to view past the first two, so many, many thanks!!!

8)

by **emc** » Thu Oct 09, 2008 1:40 pm

BMAONE23 wrote:I would imagine that, like the Jovian Trojans, They would find equilibrium with the Solar Gravity and become part of an enlarged asteroid belt. Though some of the interactions with the older belt asteroids could prove disasterous over time

Thanks BMAONE23, You're telling me that Jupiter's moons would drift into similar to existing orbits. I expect you are correct as I know little to nothing of astrophysics/orbital mechanics. And that is what Professor Nemiroff said too... it just threw me for a loop.

I was thinking that since the moons are traveling at Jupiter's velocity around the sun that they would tend to move away from the sun's gravity due to their lower mass reaching relative escape velocity.

v13 wrote:
RJN wrote:Yes. You have my permission to post my lectures to your website and post the URL here for others to use. This applies to anyone who wants to do this. Please abide by all laws when doing so. I thank you for your efforts here.
Here it is: https://titanas.it.teithe.gr/shared/v13/astronomy/

I'll try to keep it up-to-date but it won't hurt to contact me if you (or anyone else) notices that there are missing videos.

Keep up the good work!

Thank you v13!

by **v13** » Thu Oct 09, 2008 12:55 pm

RJN wrote:Yes. You have my permission to post my lectures to your website and post the URL here for others to use. This applies to anyone who wants to do this. Please abide by all laws when doing so. I thank you for your efforts here.

Here it is: https://titanas.it.teithe.gr/shared/v13/astronomy/

I'll try to keep it up-to-date but it won't hurt to contact me if you (or anyone else) notices that there are missing videos.

Keep up the good work!

by **BMAONE23** » Wed Oct 08, 2008 5:04 pm

I would imagine that, like the Jovian Trojans, They would find equilibrium with the Solar Gravity and become part of an enlarged asteroid belt. Though some of the interactions with the older belt asteroids could prove disasterous over time

by **emc** » Wed Oct 08, 2008 1:30 pm

In your tenth lecture you mentioned that if Jupiter disappeared the remaining Jovian moons would maintain their solar orbit. I was thinking that they would not because of the mass to orbital velocity relationship, right? Wouldn't the moons drift further from the sun or is my lack of understanding showing?

by **RJN** » Wed Oct 08, 2008 1:05 pm

Yes. You have my permission to post my lectures to your website and post the URL here for others to use. This applies to anyone who wants to do this. Please abide by all laws when doing so. I thank you for your efforts here.

- RJN

by **v13** » Thu Oct 02, 2008 9:11 pm

I'm using Linux here and I wasn't able to view your videos after the direct links were removed from learnoutloud. So I'm now using a vmware machine running windows and iTunes to download them. I'll be glad to store them online and post the URL here but I need (a public) authorization for such an action. This will hopefully allow everyone out there without iTunes to watch the videos.

So, do you RJN allow me to make available your videos online?
There will be no advertising etc. Just a directory with the videos.

by **porcupine** » Wed Oct 01, 2008 5:04 pm

I'm watching your podcasts and LOVING your presentations. My eyes usually glaze over where anything encompassing science and/or numbers is concerned, but you've made it fun and interesting. Thank you so much for sharing your knowledge in such a witty and accessible way! I'm hooked!
Regards
Sue

by **g-banjo** » Mon Sep 29, 2008 9:49 am

Oh yes please!

by **v13** » Sun Sep 28, 2008 9:41 pm

Case wrote:If Michigan Tech doesn't have the capacity to host these files for all to download, then it must be hard to find an additional host elsewhere. I know my ISP would remove/block the files if the downloads were too many from my personal webspace.

As I said in a previous post, I'm willing to host them at a University in Greece with 1Gbps internet connection and no traffic restrictions.

If you (RJN) can store them somewhere (not public) I can automate the mirroring procedure. I can also perform format and quality conversions if needed.

Feel free to contact me at v13 - at - it.teithe.gr (I don't read the forum every day)

Starship Asterisk*

Free Astronomy Course Taught Online by an APOD Editor

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course on astronomy for a microbiologist

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With thanks!