Lec 15 | MIT 8.03 Vibrations and Waves, Fall 2004

[articlescholar]

I want this video on my C11 phone.

[juliantrevin38]

This video went viral on Egypt

[mdgreg]

Would you Expect that Mass Will Be Converted to a Form Which Emits Less Gravitational Field?

[angel13061987]

Nice lecture! Thanks.

I think there is a mistake in the way he derives the age of the universe at about 56:50. He is uses the relation d=ut where d is the distance the galaxies have travelled i.e. the distance from what was then the center of the universe. He then substitutes u=Hd by the Humble law.After that he simplifies the d on the left with the d from Humble law which is the distance from EARTH.So not the same d.

Am i getting something wrong?

[treven314]

at 24:20 if we wanted to see if the gravitational constant was different in the past perhaps we could find (m1 + m2) some other way and use that equation to get a reading of G in the past?

[maxwellsdaemon7]

I have a question. An often quoted analogy to describe the expansion of the universe is that of an expanding balloon, with points on the balloon representing galaxies. As the balloon expands, the points recede from each other, but doesn't the 'unit' of distance also expand with the balloon, so that the 'distance' between points remain the same? Can anyone care to enlighten me?

[luzzie9]

@maxwellsdaemon7 The general yardstick, the 'unit' is the distance light travels in a year. This distance does not depend on the radius of the universe, and thus it does not expand with the univderse.

[balli049]

can u please post polarization video

[sematic1]

thank you!