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Joshua
Joshua
2:17 AM
I have a plausibly interesting physics question that came out of analyzing a KSP physics bug. If I treat the physics as implemented as a set of physical laws then Noether's thereom doesn't hold but it's not clear if it should apply or not.
 
 
3 hours later…
Swarup
Swarup
4:51 AM
In the analysis of rotational kinematics, the location of an axis of rotation is given. However, suppose I hit a tennis ball with my finger on the side, it will still rotate. Where should I assume the axis of rotation is?
 
John Rennie
John Rennie
@Swarup you would normally work in the rest frame of the ball, and in this frame it is simply rotating about an axis through its centre.
 
Swarup
Swarup
So in the rest frame of the ball, the axis of rotation occurs at the center of mass? Why would the ball rotate about its center while it could rotate about any other position?
 
John Rennie
John Rennie
in the absence of any external forces the position of the centre of mass cannot move, so it must lie on the axis of rotation.
 
Swarup
Swarup
I see, thanks!
 
John Rennie
John Rennie
:-)
 
bolbteppa
bolbteppa
5:53 AM
> At first, Weinberg’s electroweak theory, described in a three-page 1967 paper titled “A Model of Leptons,” didn’t get much traction. But it predicted properties of several then-unobserved elementary particles, the W, Z and Higgs bosons, and predicted the existence of “neutral weak currents” as a means by which certain elementary particles interact. All of these predictions were later confirmed experimentally.

> By 1976, his paper had become the world’s most cited high-energy physics paper, a position it held for more than three decades.
The thing is 3 pages long
 
Slereah
Slereah
6:55 AM
Important papers can be short
IIRC De Broglie's thesis is shockingly short
Not that short, I suppose
 
 
1 hour later…
John Rennie
John Rennie
7:57 AM
There seems to be a trend of wealthy philanthropists giving prizes to scientists who are already very famous. I'm not sure how this helps the subject. Wouldn't it be better to encourage the up and coming young scientists?
 
Slereah
Slereah
Yes
Send me money plz
 
antimony
antimony
me too
 
ACuriousMind
ACuriousMind
@JohnRennie I think there's reporting bias in that prizes to famous people gather more attraction than funding or prizes for newcomers, which both makes you underestimate the amount of investment going into research "on the ground" and encourages these philathropists to skew towards giving to already famous people so they get attention for doing so
 
John Rennie
John Rennie
Yes, I'm sure that's true. And I'm equally sure Milner enjoys the publicity.
 
Slereah
Slereah
@ACuriousMind Having experienced the funding process, I'm gonna say it's not ideal
 
John Rennie
John Rennie
8:07 AM
I guess a few million from Milner is small beer compared to higher education budgets so it doesn't make that much diffrence in practice.
 
ACuriousMind
ACuriousMind
A local example: The Klaus Tschira foundation has given millions to the uni for building new physics labs and funding research groups, but these are usually footnotes in local reporting compared to when they do some symposium or award ceremony where a bunch of big names show up
@Slereah I'm not saying that it's ideal at all! Ideally we'd value science as a society enough that we wouldn't need philanthropists funding research or highly bureaucratic processes for securing minimal grants, but well...
 
Slereah
Slereah
I'd better shmooze up to some billionaire
Quick get Elon Musk in here
 
antimony
antimony
at least musk has a physics degree
 
ACuriousMind
ACuriousMind
@Slereah whatcha gonna do, build a wormhole drive for spaceX? :P
 
Slereah
Slereah
@ACuriousMind I can certainly promise it
 
bolbteppa
bolbteppa
8:12 AM
A nobel prize isn't enough
I should try to read most of the top 10 papers in that video
 
Slereah
Slereah
I dunno
Usually historic papers aren't a great read
Because the authors just found out about it
They tend not to have a clear idea of the thing they're describing
 
bolbteppa
bolbteppa
Ah in fairness I'd blame me the reader for not being able to get the paper :p
 
John Rennie
John Rennie
8:28 AM
I'm going to start a KickStarter to get a billionaire to fund my research into my unified field theory. I call it Rennie's Theory of General Cupidity.
A few million should be enough.
 
ACuriousMind
ACuriousMind
needs a catchier acronym
 
John Rennie
John Rennie
Unemployed physicist: will calculate for food.
5
 
bolbteppa
bolbteppa
Pretty good intro to be able to read some of the Weinberg paper at least
 
Slereah
Slereah
8:52 AM
@JohnRennie If you donate enough you get to name a particle
the muskon
 
 
2 hours later…
Physics Meta
Physics Meta
11:16 AM
-1
Q: Should we increase the reputation points for editing/ quality of edit?

BuraianSo, I read this thread and I'm personally on the side that we should try to see what the user is actually is trying to say instead of focusing over lenses on the grammar of the post. Now with that in mind, I've recently become contributing to this site by editing and fixing questions to uphold t...

discussion
 
Jim
Jim
11:37 AM
@JohnRennie If I saw a homeless guy with that sign, I'd donate
 
 
3 hours later…
ACuriousMind
ACuriousMind
2:37 PM
"I can't tell if this is true or just stupid" incidentally describes my reaction to a lot of things :P
 
Slereah
Slereah
@ACuriousMind Mad psychologist would be a lot scarier than mad metrologist!
 
Faded Giant
Faded Giant
 
ACuriousMind
ACuriousMind
@Slereah a mad metrologist would introduce slightly different units in each country that are called the same - just imagine how many buildings would collapse, etc...pretty scary ;)
 
Slereah
Slereah
2:52 PM
the mad psychologist hypnotizes you to do his sinister bidding
 
John Rennie
John Rennie
3:40 PM
The mad mathematician would ... erm ... do maths I guess.
 
ACuriousMind
ACuriousMind
math is just the sciences' toolbox :P
 
John Rennie
John Rennie
At Cambridge the maths courses for scientists were arranged and taught by the maths department, but they insisted the courses be called mathematical methods not mathematics. Presumably to make it clear to us peasants that we weren't really learning maths :-)
 
JMac
JMac
4:14 PM
Our school had an "engineering mathematics" department that ran all our math courses; presumably it also helped keep the real math pure and untainted by our dirty application of it.
 
ACuriousMind
ACuriousMind
we had a choice between taking the "real" math courses and the "math for natural scientists", which was essentially for physicists and computer scientists because the biologists and chemists had their own "mathematical methods" course
 
Faded Giant
Faded Giant
4:34 PM
"engineering mathematics"? You don't want to know how engineers do mathematics in the real world.
2
 
JMac
JMac
Pretty much all the math I've done since my degree has involved money or is just like counting things.
 
ABC
ABC
5:29 PM
I know that in general with any surface I have this equation: $E_2-E_1=\frac{\sigma}{\epsilon}$ where I only consider Magnitude of fields. The equation talk about The discontinuity of Electric Field.

My problem is: If my surface is a plane, My intuition say that I have no discontinuity but the same value! Yes I know that I have a change of direction but the magnitude in my opinion is the same. What's my mistake?

Thanks!
 

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