# Big Bang faster than light? **URL:** \ **Category:** Factual Questions\ **Created:** [November 5, 1999, 9:34pm UTC](https://boards.straightdope.com/t/big-bang-faster-than-light/4805 "1999-11-05T21:34:00Z")\ **Posts on this page:** 11\ **Page:** 4
**Author:** ![John\_Kentzel-Griffin](https://avatars.discourse-cdn.com/v4/letter/j/ccd318/32.png) [@John\_Kentzel-Griffin](https://boards.straightdope.com/u/John_Kentzel-Griffin)\ **Post date:** [November 13, 1999, 6:17am UTC](https://boards.straightdope.com/t/big-bang-faster-than-light/4805/61 "1999-11-13T06:17:00Z")
But seriously folks, Earlier I made the assertion that by Hubble’s law objects whose distance is greater than c/H would have recession velocity greater than that of light. I also figure there would be an event horizon at a distance of c/H making such objects undetectable (except for their mass, charge, and angular momentum). I think the only two assumptions I am making are the universe is infinite (or has diameter at least 2c/H) and that Hubble’s law applies at all distances. Am I justified here or am I off base? Thank you. ---
**Author:** ![torq](https://avatars.discourse-cdn.com/v4/letter/t/dfb087/32.png) [@torq](https://boards.straightdope.com/u/torq)\ **Post date:** [November 13, 1999, 6:39am UTC](https://boards.straightdope.com/t/big-bang-faster-than-light/4805/62 "1999-11-13T06:39:00Z")
I don’t think Hubble’s Law applies at all distances, at least not in the form you stated it. I would expect that something analogous to the Lorentz transformation would need to be applied in some way in order for it to be strictly true. However, I’m not an astrophysicist, so I could very well be wrong. It’s interesting you use the term “event horizon”, though. I recall reading many years ago, when black holes first began being mentioned in popular culture, that as black holes became more massive they also became less dense. The article I was reading said that the observable universe had an average density which was a sizable percentage (roughly 10% IIRC) of the expected density for a black hole of the same size. ---
**Author:** ![John\_Kentzel-Griffin](https://avatars.discourse-cdn.com/v4/letter/j/ccd318/32.png) [@John\_Kentzel-Griffin](https://boards.straightdope.com/u/John_Kentzel-Griffin)\ **Post date:** [November 12, 1999, 7:05pm UTC](https://boards.straightdope.com/t/big-bang-faster-than-light/4805/63 "1999-11-12T19:05:00Z")
**torq** I was wondering wheither there is some Lorentz-type correction. Thank you. I used the term event horizon because an event horizon is something such that nothing can cross from the other side to “us” without exceeding the speed of light. I admit this is a unique event horizon but I think it fits the definition. Of course if I am wrong about Hubble implying FTL then there might not be such an event horizon. * * * Virtually yours, DrMatrix ---
**Author:** ![John\_W.Kennedy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_w.kennedy/32/1031_2.png) [@John\_W.Kennedy](https://boards.straightdope.com/u/John_W.Kennedy)\ **Post date:** [November 16, 1999, 5:01pm UTC](https://boards.straightdope.com/t/big-bang-faster-than-light/4805/64 "1999-11-16T17:01:00Z")
The fallacy in the scissors-blade thing was pointed out decades ago. The actual limit is the speed of sound in the material the blades are made of. * * * John W. Kennedy “Compact is becoming contract; man only earns and pays.” – Charles Williams ---
**Author:** ![John\_W.Kennedy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_w.kennedy/32/1031_2.png) [@John\_W.Kennedy](https://boards.straightdope.com/u/John_W.Kennedy)\ **Post date:** [November 16, 1999, 5:12pm UTC](https://boards.straightdope.com/t/big-bang-faster-than-light/4805/65 "1999-11-16T17:12:00Z")
> [@](#): > > The second is defined by be the time it takes for an atom of some particular element (I forget which one) to vibrate 1.79 bazilion times. The speed of light is defined as one light sec per sec. A light second is defined as the distance light travels in one sec. A meter is defined as some fraction of a light second. From the National (USA) Institute of Standards and Technology [quote} The second is the duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom. [/quote] > [@](#): > > The meter is the length of the path travelled by light in vacuum during a time interval of 1/299 792 458 of a second. Note, however, that this definition _assumes_ the idea that the speed of light is invariant. If this were to be overturned, a new definition would be found. * * * John W. Kennedy “Compact is becoming contract; man only earns and pays.” – Charles Williams ---
**Author:** ![rubes](https://avatars.discourse-cdn.com/v4/letter/r/b782af/32.png) [@rubes](https://boards.straightdope.com/u/rubes)\ **Post date:** [November 17, 1999, 12:25am UTC](https://boards.straightdope.com/t/big-bang-faster-than-light/4805/66 "1999-11-17T00:25:00Z")
Does anyone have a timeline of these events? Big Bang Milky Way Forms Our Sun Our Solar System Earth Moon Life on Earth Slightly off topic, but I have been digging for info on this for an animation I want to create. email me directly if you do: [rubes@citilink.com](mailto:rubes@citilink.com) thanks ---
**Author:** ![John\_Kentzel-Griffin](https://avatars.discourse-cdn.com/v4/letter/j/ccd318/32.png) [@John\_Kentzel-Griffin](https://boards.straightdope.com/u/John_Kentzel-Griffin)\ **Post date:** [November 17, 1999, 7:23am UTC](https://boards.straightdope.com/t/big-bang-faster-than-light/4805/67 "1999-11-17T07:23:00Z")
**John W. Kennedy** said > [@](#): > > The fallacy in the scissors-blade thing was pointed out decades ago. If we position two rulers at a small enough angle and move them so that they approach each other, their point of intersection can be made to move as rapidly as we desire by decreasing the angle. The speed can reach infinity by making the angle zero. I would be interested in knowing how this involves a fallacy. > [@](#): > > Note, however, that this definition assumes the idea that the speed of light is invariant. If this were to be overturned, a new definition would be found. Well, yes… One of the assumptions of GR is that the speed of light (in a vacuum) is constant for all observers. The current definitions of our units of time and distance are based on this assumption. If this were to be overturned, more than just the definition of the meter would have to be reexamined. All of relativity would be affected. * * * Virtually yours, DrMatrix ---
**Author:** ![John\_W.Kennedy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_w.kennedy/32/1031_2.png) [@John\_W.Kennedy](https://boards.straightdope.com/u/John_W.Kennedy)\ **Post date:** [November 17, 1999, 3:16pm UTC](https://boards.straightdope.com/t/big-bang-faster-than-light/4805/68 "1999-11-17T15:16:00Z")
> [@](#): > > If we position two rulers at a small enough angle and move them so that they approach each other, their point of intersection can be made to move as rapidly as we desire by decreasing the angle. The speed can reach infinity by making the angle zero. I would be interested in knowing how this involves a fallacy. You’re making the unstated assumption that your two rulers are infinitely rigid. If infinitely rigid objects existed, you could transmit information faster than light much more easily just by pushing and pulling a long rod. * * * John W. Kennedy “Compact is becoming contract; man only earns and pays.” – Charles Williams ---
**Author:** ![John\_Kentzel-Griffin](https://avatars.discourse-cdn.com/v4/letter/j/ccd318/32.png) [@John\_Kentzel-Griffin](https://boards.straightdope.com/u/John_Kentzel-Griffin)\ **Post date:** [November 18, 1999, 6:05am UTC](https://boards.straightdope.com/t/big-bang-faster-than-light/4805/69 "1999-11-18T06:05:00Z")
Imagine a stationary ruler and a second parallel and approaching the first. When they meet the point of contact moves with infinite speed. If a second observer moves along the ruler fast enough for special relativity to be taken into account the points of contact will still have space-like separation and therefore be moving faster than light. The aparent direction of this movement will be in the opposite direction to the direction of the second observer’s motion. I would note that even though the point of contact moves faster than light, this cannot be used to transmit information faster than light. * * * Virtually yours, DrMatrix ---
**Author:** ![jab1](https://avatars.discourse-cdn.com/v4/letter/j/ee7513/32.png) [@jab1](https://boards.straightdope.com/u/jab1)\ **Post date:** [November 17, 1999, 7:31pm UTC](https://boards.straightdope.com/t/big-bang-faster-than-light/4805/70 "1999-11-17T19:31:00Z")
I think my head is spinning faster than light. Linda Blair’s got nothin’ on me! * * * Fighting my own ignorance since 1957. ---
**Author:** ![John\_W.Kennedy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_w.kennedy/32/1031_2.png) [@John\_W.Kennedy](https://boards.straightdope.com/u/John_W.Kennedy)\ **Post date:** [November 18, 1999, 5:56pm UTC](https://boards.straightdope.com/t/big-bang-faster-than-light/4805/71 "1999-11-18T17:56:00Z")
## If you assume one stationary ruler and one ruler that “was always spinning”, then, yes, you might get the point of “contact” moving faster than light, at which point, of course, there is no transfer of information. John W. Kennedy “Compact is becoming contract; man only earns and pays.” – Charles Williams [Previous page](https://boards.straightdope.com/t/big-bang-faster-than-light/4805.md?page=3)