1

Physics, Astronomy & Cosmology / Do we know the identity of Dark Matter?

« on: 03/04/2013 18:00:43 »

The long awaited and trailed announcement from the AMS Collaboration is here

 SPECIAL CERN-EP Seminar on Wednesday 3rd of April 2013
 "Recent results from the AMS experiment"
 by Prof. Samuel TING (Massachusetts Inst. Of Technology (US))
https://indico.cern....y?confId=244334

NASA TV BRIEFING DISCUSSES ALPHA MAGNETIC SPECTROMETER RESULTS
 NASA will hold a news conference at 1:30 p.m. EDT on Wednesday, April 3, to discuss the first results of the Alpha Magnetic Spectrometer (AMS) experiment.

 For NASA TV streaming video, scheduling and downlink information, visit:
http://www.nasa.gov/ntv

AMS Draft Press Announcement (cannot find final version) http://ams.nasa.gov/AmsScientificPublications.html
 
BBC - http://www.bbc.co.uk/news/science-environment-22016504

Nature http://www.nature.com/news/space-station-experiment-deepens-antimatter-enigma-1.12718

Space,com http://www.space.com/20488-nasa-astrophysics-discovery-ams.html  (although can you trust an astro site that cannot convert EDT to GMT???)

Science Magazine http://news.sciencemag.org/sciencenow/2013/04/two-billion-dollar-cosmic-ray-de.html



The know-nothing bozzo version is a little disappointing.  What the AMS Colab are announcing is at present confirmation of the previously hinted at positron excess - more positrons (anti matter electrons) than would be expected in open space.  This is not new but previous evidence was compromised and unconvincing.  The AMS detects from the whole sky (so rules out a localized source), was designed to tell positrons from electrons (so does not suffer from the possible problem of using deflecting by earths magnetic field to distinguish), and can accurately tell that these are the light positrons rather than much heavier protons.  From my early reading this confirmation of (lower energy) positron excess is well documented and evidence by the AMS data and is accurate to a high significance. 



The more interesting bit is that the theory suggested that the level of positron excess should fall with measured energy - but it clearly shows a dip and rise.  There is something which is annihilating or decaying to positrons which is outside of current theory.  The idea is that this unknown is dark matter.

 

Even more speculative is the fact that after a rise - at around 250-300 GeV - the curve starts to flatten off.  It would make sense that you cannot get dark matter particles to produce positrons of a higher energy than the parent particle - is this flattening off the sign of the energy of a dark matter particle?

2

General Science / Where should I look to see 2012 DA14?

« on: 15/02/2013 12:41:10 »

I am struggling to find consistent information about where to look in the sky this evening for a chance to see the Neo (I am in outer London on northeast).  Between Leo and the Plough seems the most regular advice from 8pm - but that's a big space and an uncertain time.  I have tried pasting the orbital elements into fourmilab yoursky without success

 

Any clues - preferable a sky map with a nice line drawn on it?  :-)

3

General Science / What is this fish?

« on: 09/10/2012 16:17:45 »

Hello Everyone

Took a few pictures a couple of days ago of a fish swimming around the harbour just beside the taverna I was seeking refreshment from.  It was a strange looking thing and I wondered if anyone knew what it was - it might be frightfully common, but I thought it was a just a bit odd!

Any ideas?

 [ Invalid Attachment ]

4

Physics, Astronomy & Cosmology / Did a broken cable produce apparently faster-than-light neutrinos?

« on: 23/02/2012 09:51:16 »

Preliminary news leaking out on the possibility that a dodgy cable connection was to blame for the anomalous readings

Initial news article here

5

New Theories / Mike's side topic on the photon and time

« on: 19/01/2012 10:19:52 »

Mike - please stop with "light travels instantaneously ... in its own reference frame" - this is not accepted science.  It is an extension of SR (to an impossible inertial light speed frame) that is completely against the postulates of SR itself.  It is quite acceptable in its own thread (and it is fascinating) - but as an answer to another's question in the main forum it is not ok

6

Just Chat! / The Life Scientific

« on: 12/10/2011 13:46:46 »

For those that can use bbc iplayer or are able to listen live there is a new series on BBC Radio 4 "The Life Scientific" in which Prof Jim al-Khalili talks to prominent scientists. The first episode was Sir Paul Nurse and a very good listen indeed

http://www.bbc.co.uk/iplayer/episode/b015n3b7/The_Life_Scientific_Paul_Nurse/

Their work is changing the world we live in, but what do we really know about their lives beyond the lab?

Each week on The Life Scientific, Jim Al-Khalili, Professor of Physics at Surrey University, invites a leading scientist to tell us about their life and work. He wants to get under their skin and into their minds; to find out what first inspired them towards their field of research and what motivates them to keep going when the evidence seems to be stacking up against their theories. And he'll ask what their ideas and discoveries will do for us.

He'll talk to Nobel laureates as well as the next generation of beautiful minds, finding out what inspired them to do science in the first place and what motivates them to keep going. The programme will also feature short drop-ins from fellow scientists. Some will comment on our guest's early career, the implications of their discoveries, or offer alternative perspectives.

7

Guest Book / Woo Hoo

« on: 11/10/2011 13:36:44 »

Just heard our own Helen Scales on BBC radio 4  - and with a comedy hero John Lloyd.  Way to go Helen - great show.

http://www.bbc.co.uk/iplayer/episode/b015mzzd/The_Museum_of_Curiosity_Series_4_Linehan_Sutherland_Scales/

8

Just Chat! / Rambling discussion split from "neutron star compressing heliosphere right now"

« on: 23/08/2011 10:58:22 »

Modnote - please put copied text in quotes, I know you provided a link but it wasn't clear that the second paragraph wasn't your own.  either use old fashioned type ones (ie the things above the 2 on a keyboard - " ) or go to preview, highlight the copied text and hit the quote button (which is the second button from the right just above the emoticons, it's three lines in a speech bubble.


On your comments - do you have a link to the experiment?  Energy/Mass warping space-time is the basis of einstein's general relativity and has been very well proved, we can see it through the orbit of mercury and a huge number of other effects.

9

Technology / How would you damp a camera?

« on: 17/08/2011 17:10:49 »

I am thinking of making a knock-off / el-cheapo steadicam and curious what amount of damping to aim for?  Any suggestions? 

I already have a very basic handmade steadicam (uj and semicircular weighted bit) - but fancy adding a bit of damping for the vertical movement of walking.  I presume that I should aim for critical damping - but any ideas/knowledge would be greatly appreciated. 

10

Geek Speak / Splashtop browser?

« on: 27/07/2011 17:27:55 »

Hi Guys

Anyone ever used splashtop browser?  My new laptop can use it with out booting windos, and first impressions are brlisteringly fast.  Any security concerns that you have heard of

11

Just Chat! / Could you use free access to Cambridge Journals for 6 weeks?

« on: 15/07/2011 12:17:41 »

In order to reach out to new readers, who may not enjoy access to high quality scientific and academic research, all 2009 and 2010 content on Cambridge Journals Online (CJO) will be made free to access between 15th July and 30th August 2011.

Follow this http://journals.cambridge.org/action/displaySpecialPage?pageId=2964.

h/t to ajb in another place

edited - cos I forgot to put a title  [:I]

12

Just Chat! / Mad Google Earth Aerial photo

« on: 13/07/2011 16:00:37 »

My brother noticed this great aerial picture when trying to find out where to go in Bloombury

http://maps.google.co.uk/maps?q=russell+square&um=1&ie=UTF-8&sa=N&hl=en&tab=wl

Zoom into the Northern corner of Russell Square and make sure you have satellite photo rather than just map!

13

New Theories / Shell Theorem problem (split from What is Mass)

« on: 11/07/2011 11:01:16 »

To coin an analogy from football, some of those bosons look more like plays than players.

Great line! - I am gonna steal that. 

Phract - you could try the videos of Leonard Susskinds - the theoretical minimum.  They are all available on line and range from introduction to einsteins relativity to qcd and particle models.  Good stuff - not too easy, but not too hard

14

Geek Speak / Charting Application - Any Ideas

« on: 30/06/2011 23:44:22 »

Anyone got a hint for a charting ap or add-on to excel?  I would like to be able to create a chart that works like, but not the same as a histogram - ie the width of each block corresponds to the duration of measurement and the height corresponds to the rate for that particular period and thus the area corresponds to the number of instances during the period.

I would love to know if there is an excel addon or a nice cludge for this.   I could do it with a graphics program but I would like to be able to generate the chart quickly.  Any ideas?

Thanks Matthew

15

Geek Speak / Any recommendations for good Malware/Spyware blitzer

« on: 23/03/2011 15:45:22 »

Hello Everyone

Could anyone recommend a good anti-malware/-spyware programme?  I must have picked something up I shouldn't and I am a bit worried about possibility of key logger etcs. Done malwarebytes (no hits) and zonealarm superdeepscan (also no hits); so it's either very sophisticated or someone got my gmail details through another source (which is probably the most worrying).

16

General Science / From 2D to 3D. Can you tell what it is yet?

« on: 10/03/2011 19:24:46 »

A Challenge to the NSRers

To explain, the net of a polyhedron is a plane diagram which shows the edges of a polyhedron which could be folded to create the polyhedron.  As shown below the cube has eleven nets

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Now I see no reason that curved shapes should not have nets too - patterns on a piece of paper that when cut out and the edges are stuck together a three dimensional shape is formed. 

The challenge is - what does the below piece of paper become when taped together.  To be clear (it doesnt show in photo) the paper crosses over itself - ie one section goes under the other where is crosses.  I guarantee it can be put together with no cutting or cheating - just quite a few bits of sellotape; and it makes a proper 3d object that encloses a distinct volume

 [ Invalid Attachment ]

And as a hint - "it's all Geezer's fault"

17

General Science / How Did Ancient Pipe Organs Work?

« on: 04/03/2011 14:10:41 »

I had the immense honour of hearing Widor's Toccata last night at St Paul's Cathedral in London - and a question occurred to me.  The organ in St Paul's was constructed at the same time as the building- it was contracted for in 1694 - and I presume completed at the point when Parliament declared St Paul's completed almost exactly 300 years ago.  The very largest pipes produce a sound that one feels as much as hears (even in 1694 a 16 foot pitch pipe was included) and I would guess a fair volume of air needs to be pushed around. 

My question is - what power source and air storage devices would such a machine need?  This was before even the steam engine was in use - so the power would have to be either man/animal or water/wind? It couldn't just be one bloke with a foot pump, or could it? 

18

Just Chat! / Who doesn't believe in Santa now?

« on: 24/12/2010 11:00:49 »

To all you, oh so rational scientists, who stopped believing in Santa Claus before you could walk; I bring you confirmation that Santa does exist and that he is helped in his task by NORAD

http://www.nasa.gov/centers/goddard/news/topstory/2008/norad_santa.html

Please note this is a Nasa / Goddard Space Centre website - indisputable proof!   [:I]

19

Just Chat! / Where is Sheepy?

« on: 18/11/2010 17:11:10 »

Beginning to get worried that the latest round of scrapie might have laid our resident Sheepy low!  Hoping everything is ok and if it isn't that we could help in some way. 

20

General Science / Can a paper plane survive in space?

« on: 11/11/2010 17:30:10 »

For those of you that have been following the Registers PARIS mission - updates galore here.

PARIS page  Congrats to all involved.