What's all the buzz about? [OT particle physics]

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Lynne Leichtfuss

Trad climber

Will know soon

Apr 27, 2011 - 01:54am PT

Reading about particle physics just now on line so I'd know what up with this Thread. Interesting. I like the pictures.....two beams of gold atoms colliding. I am still wading thru the rest.

I know there's so much in the invisible world that we have not tapped into...think it holds the answers for much of this worlds needs. Yet we remain in the dark ages for energy and more.

Hi Ed, thanks for your time and energy in bringing this to a level that interests my little brain. :DD

cleo

Social climber

Berkeley, CA

Apr 28, 2011 - 09:26pm PT

From PhD Comics, TODAY... all about Dark Matter (so cool!)

http://vimeo.com/22956103

howlostami

Trad climber

Southern Tier, NY

May 10, 2011 - 10:32am PT

Physics is Phun bump:

http://www.livescience.com/14080-nasa-gravity-probe-einstein-theory-relativity.html

Would anyone (Ed?) care to comment on all the gravity probe news? Do we have teleporters, anti-gravity or warp drives yet? :)

My guess is that the biggest ramification of this news is the reinforcement of parts of the standard model. That helps in the design of future experiments as we dig deeper and deeper, but will this discovery in and of itself lead to any real world impacts?

Ed Hartouni

Trad climber

Livermore, CA

Topic Author's Reply - May 10, 2011 - 11:04am PT

Gravity Probe B was designed (over 40 years ago) to test a prediction of General Relativity [GR]. That prediction has to do with the "curved space-time" that is induced by the Earth's gravity, and the changes of that space-time predicted by GR for a spinning mass.

http://einstein.stanford.edu/

GR is notoriously difficult to perform precise experimental tests on, the effects of gravity are very very small. This experiment is a "tour de force" in precision technique.

Part of doing physics is not just making up theories about the universe, those theories have to be challenged by experimental observation... in this case, Einstein's theory is found to be consistent with experimental observation. Amazing this theory was published in 1915 and remains our best understanding of gravity.

I am looking forward to the 2015 centennial celebration of GR... 100 years is a long time in physics!

MH2

climber

May 10, 2011 - 11:28am PT

Very good. Spherical gyroscopes? Sounds a little like the idea that let Cavendish weigh the Earth.

100 years a long time in physics?

About 59,000,000,000,000 miles I think.

howlostami

Trad climber

Southern Tier, NY

May 10, 2011 - 11:41am PT

Awesome, thanks for the thoughts. I read a few more articles and saw that although the results were consistent with expectations they weren't as precise as originally anticipated, it's still heartening to know they were able to derive relevant results. I also found it amazing that some other researchers had been able to mimic the experiment using other satellites originally intended for other purposes, and achieved similar overall results. I wonder if they would have ever thought to do that if this experiment wasn't underway. I got the impression this was sort of the end of the road for this line of experimentation, is there much left from GR that is left to be experimentally tested?

howlostami

Trad climber

Southern Tier, NY

May 10, 2011 - 12:23pm PT

Thanks del_cross, that led to some interesting reading.

Karl Baba

Trad climber

Yosemite, Ca

May 10, 2011 - 12:51pm PT

The Superconducting Super Collider, SSC, was to be built in Waxahachie, TX, and managed to dig a tunnel but did not survive the Congressional battle for funding. There was a lack of confidence in the management team's ability to bring the project in on time and on budget, the 1987 cost estimate was $4.4B and by 1993 the cost estimates were $12B.

Research into the nature of physical reality, along with the health and welfare of Seniors and the poor, must simply be marginalized so the noblest among us, the elite wealthy, aren't subjected to the torturous injustice of returning to paying a few percent more in taxes,

Plus, it's critical that we maintain lots of soldiers and bombing so the military budget (doubled since 2001) isn't reduced by any significant amount. Would you want to admit to having advocated the reduction of money going to our beloved troops (and defense contractors) once the Islamic hoards are marching down the street of Washington DC, implementing Sharia Law?

I thought not

rrrADAM

Trad climber

LBMF

May 10, 2011 - 04:51pm PT

DC... Thing is, (as Ed stated) tring to get finer detail in the measuments isn't easy.

As an analogy, think CMB...

First, Penzias and Wilson discovered what was predicted, but it took a LONG time (many decades) just to do that. Then COBE was launched to get better detail. While good, it wasn't fine enough, so we launched WMAP. While better, it still can be refined.

The differences in the CMB are WAY(^100) easier to detect than the deltas we are searching for concerning GR. (E.g., Omega, gravity waves, etc)

Ed Hartouni

Trad climber

Livermore, CA

Topic Author's Reply - May 10, 2011 - 05:46pm PT

procrastinating to do an experiment is an age old technique most physicists are very much aware of, first off it's easier to talk about doing an experiment than doing one, secondly you might get lucky and be able to take advantage of technologies to make your task a lot easier...

...fact of the matter is that doing experimental GR is not high on most scientific agendas, it's hard...

...so I applaud any and all such experiments.

The fact that GP-B didn't reach its design precision is for a lot of interesting details that could not have been anticipated before doing the experiment. The next generation of such experiments will benefit from the lessons learned. And the fact that there are two independent measurements of the same GR effect is a good thing.

Gravitational waves are the biggest thing to see as it is a dynamical test of GR, but large things have to move at high speed in an "unbalanced" manner, so far we haven't been able to make a source of gravitational waves, and we don't think we can... so we have to observe what nature gives us... it is rather daunting, and so far, nothing...

see the LIGO detectors...

http://en.wikipedia.org/wiki/LIGO