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2022-09-21: Science of the James Webb Telescope Explained!

  • 04:11: ... light has now been traveling to us for most of cosmic history, and the expanding universe has stretched the light by more than a factor of ...

2022-08-17: What If Dark Energy is a New Quantum Field?

  • 01:41: ... because negative pressure is an inward pulling pressure. But in an expanding universe negative pressure actually energizes the ...

2022-06-01: What If Physics IS NOT Describing Reality?

  • 16:52: ... Instead we see the gigantic mammoths the type predicted by the expanding universe ...

2022-05-25: The Evolution of the Modern Milky Way Galaxy

  • 16:41: ... have led to miscalculations of the bombardment rate. OK, on to the expanding universe ...
  • 17:21: ... together from matter that was initially   moving apart in the expanding universe, and  that kinetic energy affects that final form   of the ...

2022-05-04: Space DOES NOT Expand Everywhere

  • 04:26: ... a classic classroom representation of the expanding universe that’s actually pretty useful here. Glue galaxies to a balloon and ...
  • 08:21: ... there is no constant tug of war between the expanding universe and the gravitationally bound systems it contains. That tug of war did ...

2022-02-23: Are Cosmic Strings Cracks in the Universe?

  • 08:50: ... event   and the completion of vacuum decay and then the  expanding universe stretched them up to the size   of the observable universe. We ...

2022-02-10: The Nature of Space and Time AMA

  • 00:03: ... means for space to expand or to stretch for example reference to the expanding universe asks whether there's a difference between the notions of expansion ...

2022-01-27: How Does Gravity Escape A Black Hole?

  • 15:39: ... Galaxy, Robert Herd asks the following: how can it be that in an expanding universe, where all the galaxies are rushing away from us, that we could be on ...

2021-12-20: What Happens If A Black Hole Hits Earth?

  • 01:23: ... so gravity had no strongly preferred direction to collapse towards. The expanding universe then thinned out this matter to more sensible levels, and those little ...

2021-04-21: The NEW Warp Drive Possibilities

  • 03:07: Or beyond the cosmic horizon, the expanding universe is carrying galaxies away from us faster than light.

2021-03-16: The NEW Crisis in Cosmology

  • 01:16: ... - when a distant galaxy’s light travels to   us through the expanding universe it gets  stretched out - its wavelength increases.   If ...
  • 11:57: ... to measure the Hubble constant. These waves get stretched by the expanding universe, just like   light does. But unlike light, they also ...

2021-01-26: Is Dark Matter Made of Particles?

  • 11:02: But its possible some particles may not have been able to find an antiparticle counterpart before the expanding universe pulled them too far apart.

2020-10-27: How The Penrose Singularity Theorem Predicts The End of Space Time

  • 10:36: ... to the   universe - that geodesics traced backwards in an expanding universe had to truly meet - to   form a singularity, which meant they ...

2020-05-04: How We Know The Universe is Ancient

  • 03:09: ... new picture was far more dynamic. We live in an evolving, expanding universe. The recession of the galaxies makes perfect sense in the context of ...

2020-04-28: Space Time Livestream: Ask Matt Anything

  • 00:00: ... schools of thoughts on this regarding energy not being conserved in an expanding universe so school thought number one is that the loss of the energy of those ...

2019-09-30: How Many Universes Are There?

  • 01:42: Within each bubble we get a new Big Bang that kicks off a more slowly expanding universe.

2019-08-19: What Happened Before the Big Bang?

  • 10:51: ... Slifer's observations of receding galaxies could be explained by an expanding universe and solved Einstein's equations to show ...
  • 11:07: ... were to Slifer's galaxies and so we couldn't properly test this expanding universe ...

2019-07-18: Did Time Start at the Big Bang?

  • 09:52: ... because it postulates the infinite future boundary of an eternally expanding universe Looks like the Big Bang of a new universe Mathematically so our heat ...

2019-06-20: The Quasar from The Beginning of Time

  • 02:06: ... out – redshifted – by traveling many billions of years through our expanding universe. The quasar appeared to be more distant than any we had ever seen. But ...
  • 05:12: ... traveling through the expanding universe sapped energy and stretched the wavelength of that light so that it was ...

2019-05-16: The Cosmic Dark Ages

  • 05:45: ... The absorbed wavelength has now been stretched – redshifted – by the expanding universe. The amount of that redshift tells us the when the very first stars ...

2019-03-20: Is Dark Energy Getting Stronger?

  • 01:38: They were measuring the distances to supernovae to track the changing size of the expanding universe.
  • 10:25: ... which is how much the quasar’s light got stretched as it traveled the expanding universe. ...

2019-02-20: Secrets of the Cosmic Microwave Background

  • 07:42: ... curvature due to its positive gravitational effect On the other hand an expanding universe with no energy would have negative curvature So a flat universe must ...

2019-02-07: Sound Waves from the Beginning of Time

  • 08:54: Redshift is just the amount by which a galaxy's light has been stretched as it travelled through the expanding universe.

2019-01-24: The Crisis in Cosmology

  • 03:09: ...which was stretched as it travels to us through an expanding universe.
  • 07:26: ...through an expanding universe.

2018-05-16: Noether's Theorem and The Symmetries of Reality

  • 04:49: That's the case with the expanding universe.

2018-02-14: What is Energy?

  • 10:29: What if the universe as a whole is not time symmetric, for example, in the case of an expanding universe?

2017-11-02: The Vacuum Catastrophe

  • 05:18: An energy of space itself should cause exponential expansion, at least in the case of an already expanding universe.

2017-10-25: The Missing Mass Mystery

  • 11:39: And rather differently to regular matter, vacuum energy doesn't dilute in an expanding universe.

2017-02-15: Telescopes of Tomorrow

  • 02:36: Light from these earliest of galaxies has been traveling through our expanding universe since near the beginning of time.

2017-01-25: Why Quasars are so Awesome

  • 03:05: For one thing, its spectrum was redshifted, the wavelength of its light stretched out as those photons traveled through the expanding universe.

2016-12-21: Have They Seen Us?

  • 07:49: But if such radio waves travel to us from the earliest of times, then they become stretched out as they travel through an expanding universe.

2016-11-09: Did Dark Energy Just Disappear?

  • 09:27: In a relatively empty, expanding universe as is represented by this part of the graph, space would not be flat.

2016-05-25: Is an Ice Age Coming?

  • 13:50: Eugene Khutoransky points out that the idea that energy is not conserved in an expanding universe is still pretty speculative.
  • 14:23: Described in general relativity, you can still come up with conserved quantities-- energy analogies that are invariant in, say, an expanding universe.

2016-05-18: Anti-gravity and the True Nature of Dark Energy

  • 11:29: See, the law of conservation of energy no longer applies in an expanding universe.

2016-04-27: What Does Dark Energy Really Do?

  • 01:43: ... we also know how long a given photon was traveling through that expanding universe, then its redshift tells us the total amount of expansion that happened ...

2016-04-20: Why the Universe Needs Dark Energy

  • 04:51: An underdense, infinitely expanding universe should be hyperbolic.
  • 06:13: This is totally inconsistent with the level of positive curvature we'd expect from an infinitely expanding universe.

2016-03-23: How Cosmic Inflation Flattened the Universe

  • 03:12: An expanding universe doesn't tend to stay flat, even if it starts that way.

2016-03-09: Cosmic Microwave Background Challenge

  • 01:58: ... years to reach this patch of space because it was traveling through an expanding universe. ...
  • 02:28: So first question-- what physical distance did that light from the CMB travel through an expanding universe to reach us today?

2016-03-02: What’s Wrong With the Big Bang Theory?

  • 11:04: So you can have regions of non-expanding space embedded in a globally expanding universe.

2016-02-24: Why the Big Bang Definitely Happened

  • 04:27: Having been stretched into microwaves as it traveled through an expanding universe, it's the cosmic microwave background.

2015-09-30: What Happens At The Edge Of The Universe?

  • 01:37: ... or galaxy clusters that blob evolved into, racing away from us with the expanding universe, as it ...

2015-03-11: What Will Destroy Planet Earth?

  • 04:53: ... about anyway just because of the sheer awesomeness factor-- death by expanding universe. ...
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