Measurement of Elenin's light curve by amateur astronomers appear to show that Comet Elenin is undergoing disintegration (see graph below), and thus will no longer be a potential naked eye comet later this year. This is also confirmed with optical images which appear to show the disintegration (see animation below).
Details are found here
As spaceweather.com puts it "So
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JonnyMcA
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Laboratory
From here
QuoteSo why hasn't WASP-18b already gone "poof"? Hellier's team figures that the solar-type star (spectral type F6) is about a billion years old. Yet tidal theory argues that the big planet will edge close enough to be torn apart in well under a million years. As theorist Douglas Hamilton notes in an accompanying perspective, the odds of finding WASP-18b just bef
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JonnyMcA
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Alternative Geometry and Numerology
if you read other articles on the subject it gives more details. The second moon would have been created at teh same time as our our remaining one, but the collision would have occurred about 100 million years after formation. Thus it is more like billions of years ago, and not millions. It is likely no indigenous earth life was around at the time to witness it.
Jonny
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JonnyMcA
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Laboratory
Hi Sansahansan
A few comments on your post (one of which is rather long winded, so go boil the kettle and make yourself a cuppa before sitting down to read.
QuoteFirst off, I hadn't known there was controversy over the maximum speed of light - although I don't necessarily believe in such.
Its not really a controversial issue, but rather a testing of the foundations of theory, w
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JonnyMcA
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Laboratory
Many thanks (to all) for the information. One further question, what evidence (archaeological), if any, exists to corroborate the founding date of 753 (or 748/747) BC for Rome. Are these dates pasted down from lost texts, or just stated by teh authors because thats what they heard. Is there any archaeological evidence backing up the claims for these dates of founding?
Jonny
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JonnyMcA
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Ancient History
Quoteand there's no reason why anything on Earth should be affected by stars that are a hundred million miles away.
Oh I dont know about that. The sun is a star and is only about 93 million miles away, and if it stopped shining or exploded, it would sure have some effect upon the earth
Jonny
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JonnyMcA
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Apocalypse
In case people are thinking that some scientists are wasting money on such research endeavours, it is useful to bear in mind the purpose and nature of this journal. from here <;
QuoteFocus and Scope
This is an undergraduate journal for year 4 (MPhys) students in the Department of Physics and Astronomy at the University of Leicester. The journal accepts brief articles on topics original t
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JonnyMcA
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Laboratory
Have you ever been kept up at night wondering exactly how fast you could write with a ball point pen? How much energy the Death Star needed to destroy Alderan? How many Hamsters it would take to power the UK for a year?
Well look no further to cure your insomnia, you may find the answers to all your ponderings here....Journal of Physics Special Topics.
There is even a paper dedicated to th
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JonnyMcA
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Laboratory
Just enough to charge their mobile phones and ipods then
Jonny
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JonnyMcA
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Ancient Egypt
I posted this question on GHMB, but I would be interested in this forums views on the matter. Please excuse the copy and paste.
When reading through stuff on the Romans (thanks to the dodecahedron post), I came across Plutarchs account of the life of Romulus and the founding of Rome.
What I was struck by was the mythological templates imposed upon the account, such as the "virgin birt
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JonnyMcA
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Ancient History
Hi Charlie,
In a sort of way yes. Light does, because it is redshifted. This can be thought of in many ways. The most accurate way is this. The expansion of space can be thought of as a river (indeed, it is often refereed to as the Hubble Flow). Regardless of of which direction light travels, it is always going against the current because expansion is in all directions. Therefore it lose
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JonnyMcA
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Laboratory
You may be interested in these two articles printed a couple of years ago in PhysicsWorld, which discuss replacement of pi with tau.
Constant failure
Shifty Constants
Personally I think substitution of tau for pi makes physical sense, but I think it is really superfluous, as those doing the science or maths will still be using the same numerical value regardless what one calls it or defi
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JonnyMcA
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Coffee Shop
he only reference that I see with regards midnight is this
QuoteNote that the date September 6, 3114 B.C. began at midnight of the previous day, J.D. 584283.5; at noon on that date, it was J.D. 584284, and at midnight, J.D. 584284.5
Which appears to be referring to our calendar system, in which we denote a day being from midnight to midnight. As you can see the Julian date system (which as
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JonnyMcA
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Apocalypse
QuotePersonally, I always feel that I can cope with cosmic cataclysms that much more easily if I've had my morning coffee first.
I dont think that should be a problem. If the mayans were anything like modern astronomers, then a new day does not begin and end on consecutive midnights, but rather at midday, i.e. the time period between two successive returns of the sun to the local meridia
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JonnyMcA
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Apocalypse
Hi Charlie
The redshift value tells us essentially how much smaller the universe was at the time the light was emitted. The formula is d(then)/d(now) = 1/(1+z), where d is the size of the universe at the time the light was emitted, and its size now as we detect it. Therefore for z = 7.085, the light was emitted when the universe was about 12.4% its present size. For z = 8.2 and 8.6 the value
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JonnyMcA
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Laboratory
Hi Charlie
For z = 8.2, we are talking about 633 million years after time zero (i.e. the big bang), and for z = 8.6, about 594 million years. (calculated using approximately the same parameters as in the paper). Because of the nature of redshift, the difference between times at high redshift is much less than the difference at lower redshift (see diagram below)
Caption: Look-back time a
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JonnyMcA
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Laboratory
Hi Charlie
Its not the oldest/furthest object, as other objects with a larger redshift (z value) have been observed. This is the oldest/furthest quasar (z = 7.085), but there are observations of a galaxy (z = 8.2) and a gamma ray burst (z = 8.6) further than this new quasar.
More can be read here and a version of the original nature paper can be read here A luminous quasar at a redshift
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JonnyMcA
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Laboratory
The sister experiment of CDF, namely D0, fails to reproduce the "bump" reported above. Science in action
Full story here
Jonny
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JonnyMcA
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Laboratory
When it comes to Physics, if you are not confused, you are doing it wrong
Jonny
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JonnyMcA
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Laboratory
To tell the truth, I have become rather confused over what's going on with all these announcements of lumps, bumps and humps.
In this case, all I can say is that the Punzi (who presented this data) does not state that it is the Higgs, nor does he state it is not. I have looked at the presentation slides (not that i could understand much of it), and the peak occurs at 147 +/- 5 GeV. This
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JonnyMcA
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Laboratory
more on this.
QuoteTwo months ago, in early April, the particle-physics community was rife with speculation and excitement over a “bump” — a possible new particle — in the data that Fermilab’s CDF experiment was looking at. On Monday 30 May, Giovanni Punzi, a CDF collaborator presented an update on what is now referred to the “ W-jj” bump, as a part of his talk at the “23rd Rencontres de
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JonnyMcA
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Laboratory
Fermilab CDF collaboration member adds credence to Higgs discovery rumors
QuoteOver the weekend, at a physics conference in France, Fermilab CDF collaboration member, Giovanni Punzi, gave a presentation where he showed some slides that appeared to back up the rumors that cropped up a month ago on the Internet, suggesting the team had found some evidence that might hint at the existence of a pr
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JonnyMcA
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Laboratory
An article from physicsWorld giving a bit more details of the study
Jonny
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JonnyMcA
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Laboratory
Interesting stuff
Quotebefore the M9 earthquake, the total electron content of the ionosphere increased dramatically over the epicentre, reaching a maximum three days before the quake struck.
At the same time, satellite observations showed a big increase in infrared emissions from above the epicentre, which peaked in the hours before the quake. In other words, the atmosphere was heating
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JonnyMcA
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Laboratory
Hi martin,
Truth be told it was not immediately obvious to me either, since there were numerous articles about the LHC and Fermilab/Tevatron finding particles, forces, bumps and humps, among other things all coming out around the same time. Especially when they use the lab names CDF, ATLAS, D0 etc for the different internal labs and detectors. I get lost in it all myself, and have to check u
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JonnyMcA
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Laboratory
Quote"Hysterics" being an analogy for "degeneracy pressure", presumably ...
Indeed this is the case. The more you try to force fermions into the same states, the more they resist it. Degeneracy pressure (for electrons which are fermions) is described by this equation
ignore everything but the Big P on the left of the equal sign, and the Greek rho on the top line of
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JonnyMcA
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Laboratory
Bosons and Fermions are terms physicists like to throw around a lot. I always liked to think of them as like men and women. Fermions are quite obviously female, and will refuse to go to a party if another lady is wearing exactly the same outfit as themselves, and will go into hysterics if you try to force her. Bosons are like men at teh same party. they dont care if they are all wearing the s
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JonnyMcA
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Laboratory
I am not so sure we should write its obituary yet. There are still plenty of room to search in the energy spectrum for it. The problem is, the Standard Model does not predict what its mass should be, only a range of mass it could have, as well as an upper limit. While the Standard model has its problems (it is quite ugly looking), it still works extremely well, and has been very successful in
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JonnyMcA
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Laboratory
Hi Martin,
I posted some information about that here <; along with an interesting interpretation here <;
Jonny
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JonnyMcA
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Laboratory
Its just as well homoeopathy doesnt work then, otherwise you would have all sorts of problems fabricating semiconductor junctions.
jonny
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JonnyMcA
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Laboratory