Astronomy Lecture

TEST lecture

Category:

Howto & Style

Tags:

• astronomy
• lecture

[TheSupatrader]

the reason people in their majority are certain "we" went to the moon and back is because they are being told, matterfactly, that it is a fact - just like this guy in the beginning of the lecture. however, any ORP who looks into it will conclude that it is impossible to fly a man to the moon and back "in one piece" with the current state of technological affairs, if only due to the existence of VanAllen belts.

[doctordave]

@TheSupatrader "Conspiracy Theory" is the antithesis of scientific thinking - where the ABSENCE of evidence is what counts as evidence. The thinking of conspiracy theorists is logically backwards and constructed in such a way that makes intelligent argument impossible. Why don't you go off and play with the Holocaust deniers and the "US blew up the World Trade Center" loonies.

[doctordave]

A few people have commented on this - I try to always say "all the DISTANT galaxies are all red-shifted" rather than "all the galaxies" . The distinction is necessary because within any gravitationally-bound system, space actually DOES NOT expand. Andromeda and the MIlky Way are part of a gravitationally bound system of galaxies called the Local Group, and these nearby galaxies are not moving away, they are just all orbiting the center of mass of the system.

[19RedLineR74]

Colour and Temp. When I heat steels with a welding torch, they all go cherry red and orange and yellow etc. But I haven't seen aluminium do it or lead? Do I just need more heat, or is it something else?

[doctordave]

@19RedLineR74 Not sure about LEAD, but if you check out a table of specific heats, AL is about TWICE that of steel... which means it takes twice as much "heating" to get aluminum to the same TEMPERATURE as steel. So my guess is, the blow torch isn't heating it fast enough relative to the rate that it cools in air.

[InvaderTaizic]

I wanna go back to school...

[navidsonpuzzle]

Thank you for putting these up! Where are these lectures from? I wish more astronomy lectures were online and freely available, similar to all the other subjects available from fx. MIT. <3

[TheSenuseret]

@TheSupatrader You know how WE are certain that we went to the moon ? that the USA put a man on the moon ? Because our big rival, the URSS gave us the credits and and said in public they recognized the feat. They knew they were defeated. That's enough for me. So next time, don't be so low mind person.

[StrikaAmaru]

@TheSupatrader A quasar IS a supermassive black hole, located in the center of a galaxy; the difference between a quasar and what's sitting 60,000 light-years from us is that ours has long stopped feeding on surrounding gas.

Fun tidbit: quasar = QUASi-stellAR object. Just FYI.

[StrikaAmaru]

Video starts at 1:30.

[jameywcll]

attn drdave: i heard your guitar and it was not bad i love your lectures and probably because

of you i have a new interest in becoming a richard dawkins kind of guy.

what would i do to become a person that would explain things of this sort to ordinary people. is the dna of chemosynthesis related to photosynthesis btw.

i have searched on this and not found a good reply.

is this a profession? also check out my pickin its all ad lib like what you seem to be doing search jameywcll

humility first

[glowingdarkmatter25]

I don't use the microwave for food, but for experiments. :0)

[iz2sicc]

@TheSupatrader Reading this comment just made me dumber :/