Recent content by derekmcd

The only difference between a black hole and any other object with mass is its density. If the Earth became a black hole with a radius of 9mm, our satellites would continue to orbit as if nothing happened (minus any measureable changes in frame dragging). The gravitation 'pull' of black holes...

Whenever I use the balloon analogy, I always add the caveat, prior to questions about what's inside/outside the balloon, that the inside represents the past with the center being t=0, the surface is the present and "outside" the balloon is the future. Get them to focus on the inside/outside of...

I don't thinks it is a matter of unit conversion. In their more detailed (.3733v1), they show that their cluster catalog extends out to z \leq .3. In the paper (.3734v1) they state on page 6: (any typos are mine) "Our results indicate a statistically significant bulk-flow component in the...

Where do you get 1.4Gly from? I see the survey extended out to redshift of .3 or a bit over 3Gly. Still not close to the aforementioned 6Gly. I reread the paper to see if I missed something, but found nothing. They did mention in the 'Future prospect' section that they desire to extend the...

I understand what they were trying to convey, they just did a lousy job of doing it. It's not really an easy concept to explain in one paragraph. Each sentence, taken individually, are factually correct. However, combining them leads to an ambiguous conclusion. With that said, I still see...

Somewhat relevant to the OP and the title of the thread is somewhat fitting. If a MOD feels this should be a new thread, by all means split it. "[URL http://www.space.com/scienceastronomy/080923-dark-flows.html "Mysterious New 'Dark Flow' Discovered in Space" As if the mysteries of...

I just got through reading: http://www.hcs.harvard.edu/~jus/0302/song.pdf" by Jun S. Song (Song.pdf) It was recommended in a couple other threads here. Pages five and six explained at a level clear enough, even I could understand it. Excellent paper. In reference to the...

Thank you for your responses and reaffirming my intuition is leading me in the right direction. Is it related to the Aharonov-Bohm effect and Berry phase? I've read a few papers on each and on the Anomolous Hall effect. Sadly, some (all) of the pdfs are a bit (way out) of my league...

I'm currently involved in a debate elsewhere with an EU proponent involving magnetic reconnection. The debate shifted from astrophysical events to events in Tokamaks. Right now, the debate is focusing on Priests usage of the term "monopole" here...

I might be approaching my search for an answer the wrong way... http://en.wikipedia.org/wiki/Proton "a diameter of about 1.65×10−15". In the discussion section: "It's a bit hard to say what "proton diameter" means. Most experiments seem focused on determining the "proton...

I don't believe there is any evidence for the Milky Way, or any other galaxy in the local group, being influenced by another external, central, supermassive black hole. What you are asking, if I'm not mistaken, is that the universe has a preferred direction and that the matter within the...

If I haven't already made it obvious... I have no formal education in nuclear physics. I just like to try to figure stuff out and came across 2 completely different radii for the proton. I'm just trying to understand the distinction between the two. The reason this question came up was from...

Ok. I think I finally have it figured out. If someone were to ask, "what is the radius of a proton", I would cite 1.2 fm. Would I be correct in stating the charge radius is the exchange force range between two protons? In other words, when they reach a distance of around .875 fm, the...

If I understand your question correctly, you are correct. Tachyons actually need additional energy to decelerate. For the same reason Special Relativity doesn't allow us to accelerate particles to C, a tachyons cannot decelerate to C.

CERN's Here's a pdf of CERN's most recent report: http://cern.ch/lsag/LSAG-Report.pdf