BellGab.com Archive

Quote from: Philosopher on January 14, 2016, 08:04:21 AM
42


The Answer to the Ultimate Question of Life, The Universe, and Everything.

To paraphrase, "This guy gets it."

Quote from: zeebo on January 13, 2016, 01:19:04 AM
There are others who know alot more than me about this, but my squirrel brain's understanding is ... mass warps the fabric of spacetime, making a 'curvature' (in 4 dimensions) which other bodies 'feel' as gravity (in 3 dimensions).  So what seems like a force pulling us towards the earth, is actually a bending in spacetime caused by the earth's mass.

Colossal cosmic events like two black holes mixing it up would cause intense ripples that would travel through the continuum like a rogue wave through the ocean.  I believe the LIGO experiment would detect a shortening of a steady laser beam which shows that for that instant spacetime has warped/curved as the grav wave passes through it.

This is a good description. Gravitational waves are the analogue of electromagnetic waves, but instead of a field carrying the disturbance, space-time carries the wave. This means that gravitational waves change distances and times that observers would measure by a tiny amount that is in principle only measurable by interferometry which can be very precise and make measurements smaller than the scales of atoms. The difference between EM and gravitational waves is that the electric part of EM waves have polarization in only one direction - say, up and down - whereas gravitational waves are more complicated and oscillate in more than one direction. This is because EM waves are described mathematically by vectors, which have one index and gravitational waves are described by something called a tensor, which has two indices similar to a matrix. That also means gravitational waves can't be generated by dipoles like EM waves can, you need at least a quadrupole to do it, such as two masses spiralling in to one another that give up some portion of energy, radiated away in the form of ripples in space-time.

Quote from: Dr. MD MD on January 13, 2016, 02:20:40 AM
Thanks, zeebo. Do you know how far away/long ago the phenomena is?

You can get gravitational waves from anywhere in the universe and in fact we will be able to see more with gravitational waves than we can with electromagnetic in principle, even beyond the veil of the cosmic microwave background, the earliest radiation we know of after the big bang when space-time became transparent to electromagnetic radiation. Gravitational waves have no problem with such a boundary and can reach us directly from the origin of the universe itself which makes them useful for studying cosmology at early times. A few years ago the claim was made to have seen such relic gravitational waves in a set of observations made by an instrument called BICEP2, but these results have since been attributed to the action of galactic dust fouling the signal and are no longer taken as a serious claim.

I should also mention that gravitational waves have been seen indirectly before, the Hulse-Taylor binary pulsars show energy loss exactly what you'd expect from GR (https://en.wikipedia.org/wiki/PSR_B1913%2B16) and won it's discoverers the 1993 nobel prize.

I'm hearing rumblings that advanced LIGO (https://www.advancedligo.mit.edu/) may have detected the gravitational wave signal of two black holes merging. If this is the case it will be a revolution in astrophysics and open a new window to the universe, since gravitational waves have not been directly observed yet. Gravitational waves are considered the last prediction of general relativity not yet directly verified.

Will keep this thread posted

Quote from: onan on December 24, 2015, 12:32:40 PM
Because the force.

Ohhhh I see now

Quote from: onan on December 24, 2015, 12:32:40 PM
good to see you, man

You too! Happy holidays and all that stuff.

Saw the movie last night at the 10:30 pm showing to a mainly empty theatre! We had hoped to avoid the rush so the late show before Christmas Eve seemed like a good idea.

What's up with the map to Luke Skywalker? Why was part of it missing? Where did it come from, and who made it and why? And how long has he been on Scotland-2? Why do they need a map at all when coordinates of the end point would be enough? Or is it at the end of some complex series of hyperspace jumps that need to be made in sequence? Some explanation would  have been nice instead of feeling like a plot hole.

What is the situation with the government anyway? If the First Order are really just a neo-nazi like splinter group trying to resurrect the Empire, how did they build all of these new star destroyers and bankroll a superweapon*? Also why is the Resistance so small, are they separate from the Republic, the military arm of the Republic or just backed by the Republic? If thats the case why do they seem even less substantial than the rebellion? The Republic was mentioned in passing but I felt it was not really explained how they fit in at all. At the end of the movie it felt like nothing had really changed in galactic politics from the end of Return of the Jedi to The Force Awakens.

* I'll let it slide that a planet sized superweapon absorbed the mass of a Star without gravity collapsing said superweapon

Hey great show with Birnes, I really enjoyed it

https://youtu.be/eVWEqQnjT0M

Quote from: jazmunda on December 19, 2015, 11:05:21 PM
Thank you. Check out our other shows too including the latest episode where we interview Bill Birnes.

I've got them all on my tablet, looking forward to that one as well as your reaction show to Art hanging up the mic.

Just finished watching Twin Peaks: Fire Walk with Me. The wife and I watched both seasons of Twin Peaks over the summer. It was both our first viewing and we really enjoyed both the show and movie. I'm surprised at all the hate directed at the film. Looking forward to the re-visit coming soon.

https://youtu.be/SfPv57KBpJI

Hey, I listened to your first episode today, love the show and playing your favorite clips was also great. Jaz' story about hearing C2C for the first time and then trying to find a way to listen when he moved back home was interesting as well. Great show, looking forward to hearing more from both of you. Nice work

WHOA. Is this... real?

Quote from: zeebo on December 17, 2015, 03:31:16 AM
Good to see ya AO.  So much happening around here lately I almost forgot about the rest o' the cosmos.

Good to see you too! Whenever there's any kind of development with Art, the turbulence stirs this place up something fierce.

Quote from: Camazotz Automat on December 16, 2015, 08:23:07 AM
I'm picturing Agent: Orange stepping outside and discovering a revival tent-sized polybag containing an ENIAC has been delivered.

Ohhh man with a magazine about ENIAC stuck to it, that's amazing

Quote from: (Sandman) Logan-5 on December 16, 2015, 05:58:11 AM
It would be interesting to add about 40 of these as nodes to an existing system to see what you can get out of them. Cabling would be a mess though.  

Yeah, neat idea. You could build the cheapest beowulf cluster in existence, but the cabling and rack would cost more than the hardware itself!

Other than the crafting aspect of that project I'm guessing it would make more sense to go to CUDA and GPU processing for serous crunching. But the out-of-the-box solution seems like much less fun

Also released recently: The upgraded particle detector used by the LUX team to try to detect dark matter particles has a non-detection and ruled out even more low-mass WIMPs.
The next step is an even more sensitive detector LUX-ZEPLIN that will begin operations in 2016.
http://www.symmetrymagazine.org/article/lux-maps-where-dark-matter-isnt
http://luxdarkmatter.org/

I know I'm late to this party and it's probably already been discussed to death - but a $5 Raspberry Pi the size of a credit card?!
http://arstechnica.com/gadgets/2015/11/pi-zero-a-full-raspberry-pi-for-just-4/

This magazine even shipped with one stuck to the front cover!
https://www.raspberrypi.org/magpi/issues/40/

I remember picking up many issues of PC Gamer for the sole fact that they came with demo disks that would give a few weeks of fun... now instead of games and an AOL promotional coaster you get a whole computer in the polybag.

No doubt about it, it's the future alright...

Hints of a new boson were announced today at the LHC. Nothing concrete yet, and the statistics have to vastly improve before it can be considered a discovery. However the rumors start here and now, and a mob of hungry theorists have begun licking their chops.
This guy has an excellent blog on particle physics with a review up: http://resonaances.blogspot.ca/2015/12/a-new-boson-at-750-gev.html

For a more popular approach (and less technical reviews) here are articles from New Scientist and Nature:
https://www.newscientist.com/article/dn28674-physicists-struggle-to-squeeze-new-particles-from-the-lhc/
http://www.nature.com/news/lhc-sees-hint-of-boson-heavier-than-higgs-1.19036

If the existence of this boson is confirmed over 2016, it will be the first sign of physics beyond the standard model. Exciting times...

Quote from: wr250 on December 14, 2015, 06:01:56 PM
wb and post often. also might consider being on the bell philes.

Hey WR how are you?

I'm guessing the Bellphiles is a new podcast in the vein of the gabcast? I haven't heard any of it.

It was a productive year with lots of travel and a few conferences in far away lands. My work schedule is as usual insane. But now that Art is off the air, there's a renewed need to post here more than ever.

Press event for tomorrow (Tuesday Dec 15 2015) regarding the latest high energy run of the LHC
https://webcast.web.cern.ch/webcast/

Free Art Bell

On the way home from work I actually said "can't wait for open lines tonight"... :\
Maybe I jinxed us?

All the best Art. Great show. I regret not calling in.

Hey all

Just heard Art is off the air and decided to pop in tonight. Life has been really crazy for the past year or so. Hope you are all doing well.

Meantime I'll just leave this here...
https://www.quantamagazine.org/20150922-nima-arkani-hamed-collider-physics/

That went well

I like the line "It's midnight". A lot

Good job Ward!

Is Art getting questions from bellGab? or are we all on the same frequency here?

MITD is living up to expectations

An ad for a kickstarter? Damn... it's the future.