Everything & Nothing  - Page 1
Forum section: electronics / general

author: Sionyn
author_rank: Frequent Contributor
timestamp: March 29, 2011, 08:37:25 pm
content: no doubt some of you like this enjoyEpisode 1Episode 2fixed indeed it was wrong

author: saturation
author_rank: Super Contributor
timestamp: March 30, 2011, 11:55:30 am
content: Great shows, again. Thanks for the links. We don't get these in the USA, and when we do BBC sometimes reworks with Discovery Channel to reedit them for US audiences. Several BBC nature shows with Attenborough were redone using Oprah Winfrey [ horrible] and Sigourney Weaver [ not bad] as narrators and new US made music, but either pales beside Attenborough and the BBC team. They should just leave BBC productions alone.

author: TheEENerd
author_rank: Contributor
timestamp: March 30, 2011, 12:08:32 pm
content: Very nice vid. I'm a big fan of BBC docus. They r porns for nerds.

author: FreeThinker
author_rank: Frequent Contributor
timestamp: March 30, 2011, 03:02:08 pm
content: BHAAPH! Everyone Knows that the answer to Everything in the universe is 42, WHERE HAVE THESE PEOPLE BEEN?

author: FreeThinker
author_rank: Frequent Contributor
timestamp: March 30, 2011, 06:01:08 pm
content: OK serious questionIf the galaxy's at the edge of the universe are so faraway that the light from them has not reached us yet and all matter originated from the same point in space due to the big bang how did the matter (which cannot travel faster than light) get so far away that it's light cannot travel fast enough to reach us?I seem to remember that (in another program) it was calculated that the furthest stars were further out than the time to the big bang ... so how did they get there. Now my head is hurting, going for a lay down in a dark room

author: Sionyn
author_rank: Frequent Contributor
timestamp: March 31, 2011, 03:36:50 pm
content: indeed plus with the expansion of space bend the light changing its wave lengthalso strange is that on average i can't walk through wallsbut quantum mechanics gives ever a slight chance todoesn't mean that i going to try it.But still my mind begins to wonder what is really reality and what is this strange stuff that light doesn't interact with it

author: Simon
author_rank: Unknown
timestamp: March 31, 2011, 05:00:32 pm
content: Quote from: FreeThinker on March 30, 2011, 06:01:08 pmwell the stars did not form instantly so having the "matter" got so far they would need time to congregate into a star ?I always imagined the universe as finite with others next to it but at that point my mind boggles

author: Sionyn
author_rank: Frequent Contributor
timestamp: March 31, 2011, 05:11:23 pm
content: maybe dave knows or has a funny take on it

author: saturation
author_rank: Super Contributor
timestamp: March 31, 2011, 06:30:22 pm
content: As I understand beyond 42, the universe is expanding faster than the speed of light. Also, as as another pointed out, the formation of the various stars can occur anywhere, so what was just gas Y years ago, could be a star today.There are 2 parts to the universe as we know it, the observable universe, that is within the limits of our tools and ideas, and the 'theoretical' edge, based on the physics of the cosmic background radiation.http://en.wikipedia.org/wiki/Observable_universeQuote from: FreeThinker on March 30, 2011, 06:01:08 pm

author: FreeThinker
author_rank: Frequent Contributor
timestamp: April 01, 2011, 07:25:29 am
content: As I understand it nothing can travel faster than light and therefore matter no mater how small must always travel at sub light speed. The only exception to this is the theory that some unknown as yet particle (I think they are named tachyons) have always travelled faster than light but cannot slow below it. I don't pretend to understand it, but something that has always puzzled me is does light have mass? if it does how does it travel at the speed of light? If it doesn't how can it react with particles etc?.......feel my bad head coming on again

author: deephaven
author_rank: Frequent Contributor
timestamp: April 01, 2011, 08:09:03 am
content: Quote from: FreeThinker on April 01, 2011, 07:25:29 amThere doesn't have to be something with a mass travelling with the speed of light, it's just the 'message' does. It's just like turning on a light, when the current starts to flow, the electrons haven't physically moved down the piece of wire at close to the speed of light, just the message has. Think of a 1 metre long rod and push on one end so that it moves forward by 1 cm, the other end moves forward by 1cm very soon afterwards, but you haven't traversed that 1 metre in that short space of time.

author: EEVblog
author_rank: Unknown
timestamp: April 01, 2011, 11:18:17 am
content: Quote from: FreeThinker on April 01, 2011, 07:25:29 amI believe the answer is both yes and no (mostly no), depending on how and under what circumstances you look at it.Light has energy (E=hf), and of course because of "EMC" (Young Einstein joke) it therefore should have a (tiny) mass as well, in theory.But then it starts to get messy and that's when your head can explode.Dave.apj4QSN8XQY

author: FreeThinker
author_rank: Frequent Contributor
timestamp: April 01, 2011, 02:02:16 pm
content: Quote from: saturation on March 31, 2011, 06:30:22 pmWow! Thanks for that link now I really understand....not.Going back to my original theory of 42, don't understand that either but at least it is consistent. (runs away laughing madly)http://searchcio-midmarket.techtarget.com/definition/42

author: Neganur
author_rank: Unknown
timestamp: April 01, 2011, 03:53:20 pm
content: I had to take a break at around 8:20 of the second part of the documentary, since I completely lost focus after hearing how the evidence that settled a bitter debate was a powerful hooker telescope.

author: Simon
author_rank: Unknown
timestamp: April 01, 2011, 04:06:14 pm
content: err, is there a part 2 ? for me it is the same as part one

author: FreeThinker
author_rank: Frequent Contributor
timestamp: April 01, 2011, 04:53:09 pm
content: Quote from: Simon on April 01, 2011, 04:06:14 pmCheck out youtube, part 2 is there.

author: saturation
author_rank: Super Contributor
timestamp: April 01, 2011, 05:36:08 pm
content: Yes, it is postulated special phenomena can exceed the speed of light, since dark matter & energy have properties to suggest it:http://en.wikipedia.org/wiki/Faster-than-light#Space-time_distortionFor other things beyond tachyons, see the other links Wikipedia.Although 42 has been given a lot of meaning since Hitchhicker's Guide made it be, I think its core meaning is its simply absurd. Since attempts to explain meaning and the universe are subject to exceedingly verbose explanations that still are hard to justify, saying something inert as a number or a symbol gives an answer without an answer.If you follow this linkhttp://en.wikipedia.org/wiki/Answer_to_Life,_the_Universe,_and_Everything#Answer_to_the_Ultimate_Question_of_Life.2C_the_Universe_and_Everything_.2842.29You can type in the meaning of life as an "easter" egg in some products and the answer is 42!The show is 2 parts in one, #1 is Everything and #2 is nothing, for the 1st and 2nd hour. Some pirate sites carry the full 720p version.Quote from: FreeThinker on April 01, 2011, 02:02:16 pm

author: Sionyn
author_rank: Frequent Contributor
timestamp: April 01, 2011, 06:33:06 pm
content: the irony is if you are massless like photons you have to travel at the speed of light

author: Sionyn
author_rank: Frequent Contributor
timestamp: April 01, 2011, 06:52:00 pm
content: before i forget this might answer your questions on how light interacts with matter

author: ShiftPlusOne
author_rank: Regular Contributor
timestamp: April 01, 2011, 07:44:31 pm
content: since light is affected by gravity, does that not imply mass?

author: Zero999
author_rank: Super Contributor
timestamp: April 01, 2011, 08:27:10 pm
content: Quote from: ShiftPlusOne on April 01, 2011, 07:44:31 pmWell light is a form of energy and E = mc2so that would make sense.Quote from: Sionyn on April 01, 2011, 06:52:00 pmInteresting video.I admit i didn't understand it all. A magnet emits a photon WTF?Also if light is photons which are particles doesn't that mean the same is true for radio? I know about the particle/wave duality but how could radio waves be in discrete packets call photons? So how could I design a circuit to emit one photon at say 1GHz? Would sending a single electron up and down an antenna of the appropriate length work?

author: Simon
author_rank: Unknown
timestamp: April 01, 2011, 10:19:28 pm
content: I gave up with that video about light, the narrators voice was highly annoying and they were taking it a bit slow on somew concepts

author: jahonen
author_rank: Super Contributor
timestamp: April 02, 2011, 09:39:08 am
content: Quote from: ShiftPlusOne on April 01, 2011, 07:44:31 pmMy understanding of the relativity has been that light always travels straight path in the spacetime, but the spacetime is itself distorted by the gravity (black hole causes infinite distortion), so it appears that light bends around the mass (Einstein lense, for example).Regards,Janne

author: ShiftPlusOne
author_rank: Regular Contributor
timestamp: April 02, 2011, 10:17:31 am
content: Quote from: jahonen on April 02, 2011, 09:39:08 amYeah, that thought crossed my mind. I don't understand curved space-time too well, so I didn't want to say it. Does it not apply to mass the same way it applies to light? For example, orbits are the effect of curved space-time as well. Imagine a 2D friction-less plane made of a thin rubbery material, put a lead ball in the middle and that's sort of like the sun. Throw in another ball and let it 'orbit'... in reality the same happen to mass and energy, right?http://www.fourmilab.ch/gravitation/orbits/http://demonstrations.wolfram.com/GravitationVersusCurvedSpacetime/

author: ShiftPlusOne
author_rank: Regular Contributor
timestamp: April 02, 2011, 10:18:58 am
content: Ah, now I have confused myself by saying "the same happen to mass and energy" so then light does not have to have mass. >_<Edit: What the hell kind of nonsense did I just write in the previous post!? Obviously I wasn't trying to say that light orbits around the sun, but it came out that way. I guess my point was that sure light travels in a straight line around the space-time 'funnel', but so does mass.Edit 2: Wait, actually light CAN orbit an object (like a black hole).http://en.wikipedia.org/wiki/Photon_sphereWell, at least I wasn't completely crazy.But to answer my own question, no light does not have a mass.

author: Sionyn
author_rank: Frequent Contributor
timestamp: April 02, 2011, 04:59:32 pm
content: also bending light changes its wavelengthorder of chaos

author: Zero999
author_rank: Super Contributor
timestamp: April 02, 2011, 05:43:16 pm
content: Quote from: ShiftPlusOne on April 02, 2011, 10:18:58 amYour previous post made sense to me. Light dosesn't orbit the sun because the sun's mass isn't high enough. Light can orbit a black hole because it's mass is high enough. A black hole is so dense light can't escape it which is why its black.QuoteLight may not have mass but it can behave like it. It appears in discrete packets (photons) and is bent by gravity, just like a particle travelling through space.Energy also has apparent mass. As an object travels faster, it becomes denser, when a system looses a lot of energy it looses mass and matter can be directly converted to energy when it's annihilated with antimatter.

author: ShiftPlusOne
author_rank: Regular Contributor
timestamp: April 02, 2011, 05:55:45 pm
content: Yeah, I used Earth and the Sun as an example while thinking about a black hole and light, so... I was typing something different to what I was thinking.All interesting stuff either way. Might be time to re-read Hawkings' books. For some reason physicists look down on these books, documentaries and so on... they label them 'pop-sci'. It's not like we have time or patience to read textbooks and papers, geez.

author: Sionyn
author_rank: Frequent Contributor
timestamp: April 04, 2011, 12:40:53 pm
content: well maybe this is a better explanation of lightfrom the man him selfhttp://video.google.com/videoplay?docid=-5604842186235091737&hl=en&emb=1#