# imatfaal

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## Posts posted by imatfaal

### Typesetting equations with LaTeX: updated

51 minutes ago, Doctordick said:

y=f(x)dx

[LaTeX] y = \int f(x) dx [/LaTeX]

\] y = \int f(x) dx \]

How do I get latex to work???

$$equation in line$$
$equation in block$

checking $$F=ma_{centripetal}=mr \omega^2$$

$\omega^2=\frac{a_{centripetal}}{r}$

### Typesetting equations with LaTeX: updated

inline $$y=x^2$$  check $$y=ax^2+bx+c$$

display $x= \frac{-b\ \pm \sqrt{b^2-4ac}}{2a}$

$y = \int f(x) dx$

FFS - How many people in a football team? If I make the question simpler do you understand the idea?

So still simplified How many people in the White House Science Office?"

Maybe Trump has a point - argue about the phrasing of a question rather than debate the substance - give me strength.

The United States has had more Nobel Laureates in history than any other country (more than top five other countries combined)* - so bearing in mind that incredible heritage ...

Question: How many people in the White House Science Office (technically The science division of the White House's Office of Science and Technology Policy (OSTP) ) as of Friday close of business?

None at all.

*including Peace prize and Organizations - I couldn't be bothered to find a list of just real person Science prize winners.

### Bullet fired from a gun and a bullet dropped descend simultaneously

If you fired a highly polished and reflective spherical pellet through an evacuated track, to a very tiny degree it should look like an oblate spheroid to the rest frame, right?

Could you not aim various lasers from various angles at a point in the track where the pellet will cross, and judge by the landing spots of the reflections, on screens very far from the pellet, for leverage, the oblateness?

In principle yes (although I have no idea what this has to do with the subject). And this is confirmed by experiments in particle accelerators.

I am not convinced you and Tar are right there.

The sphere is length contracted but very odd things happen when you "look" at it - light (very fast as it is) still has a finite transfer time, and when you are "looking" at something which is moving at a sizeable fraction of the speed of light one must not think of transmission as instantaneous. If I have remembered correctly a sphere being observed will appear to be a sphere rotating (the direction of rotation is as if it is rolling along a floor and we are looking through the floor).

The phenomenon is called Penrose-Terrell rotation. NB this is just what the sphere looks like to an observer - it is actually flattened

### Understanding Reality

I did. I just figured out the full numbering convention, and it uses the version of the quote that has "word" instead of the second name.

So, for the record: "What's in a name? That which we call a rose by any other word would smell as sweet."

Brilliant! A plus one on both your Houses Posts. I thought the more prosaic version with word instead of name fitted better.

### The Allais Effect Solved

http://science27.com appears to be a crackpot site (Elastic Universe????).

I think it is the OP's own website - and yes, I agree with your characterisation

### Today I Learned

Today I learned that the Toyota symbol represents the end of a needle and a string passing through the opening.

And the Hyundai represents the seller and the buyer shaking hands.

At least for Toyota that might be difficult

http://www.toyota-global.com/showroom/emblem/passion/

The old one was really impressive (flying kanji for toyoda)

### Understanding Reality

Just a guess, is it the "weird sisters" from Macbeth?

- nope but I can see the logic

It's not this, but I think the OP would strongly approve of

When we are born, we cry, that we are come

To this great stage of fools.

not that - but again can see the thinking

### Understanding Reality

Oddly, it just happened to be the one speech which we had to memorize (other than the obligatory "quality of mercy"). It would be even more difficult to recite on topic....

6455, 46766, 3455, ......

An on-topic Shakespeare would have to be

23812019,914,1,141135,208120,238938,235,311212,1,1815195,225,11425,15208518,2315184,231521124,191351212,119,19235520

There is a green plus one from me for anyone who can work it out...

### Viruses, ransoms, trojans, spys and other malware into corporations...

I was just saying in another thread that I think we are reaching peak-online. Not that amount online will fade - but we have reached a situation where it is asked "is it worth putting this online" rather than "can we put this online". The novelty and the thrill of sharing information is wearing off - in situations in which there is a gain to be had then we can go online very easily now and thus there is no advertising premium for being online just for the sake of it. I remember signing up for stuff purely because I thought it was cool to do this or that online. Now, as with smart-phones, computers in general, portable vs "in situ" and many other things, we have matured as a society and grown used to these technologies - we no longer feel the need to do them just because we can

### what is a virtual particle?

There is not much that is forbidden for a virtual particle

Here is the good Doctor Matt Strassler

They are "off-shell" and do not have to obey many of the laws that real particles do.

Note that Noether's theorem is the mathematical treatment of conservation laws / invariance under transformation

### [solved... sort of] Trigonometry Problem

..

(Did you see that recent question here as to why everything needs to be online?)

No I missed that - but I can imagine. I am no old fogey - but I do think that a fashion in teaching allied to insidious cost cutting has led to a real decline in the methodology of examination. I do not hold with the "everything is getting easier" mantra that is so easy for those of us with pockets full of exams to trot out every August - I think children, young adults, and students in further/higher education work harder (and with less financial) support than I ever did.

I think we are at peak-online; we are realising that whilst online access can be world-changing somethings are just better off-line.

Once it is no longer a challenge to get stuff online it stops being an end in and of itself, and going to an online scenario is chosen because of a positive cost-benefit analysis rather than an online-good ideology.

### Fossils - Finds, purchases, collections

I was struggling yesterday from my phone.... I sent them to my laptop and it was way easier from there.

I'd LOVE to get an MRI scan of that Hadrosaur fetus. If anyone one has access, thinks it would be cool and is willing to run the scan then please do let me know!

Yea - I have started putting stuff into boxes and adding pics and notes... I think it displays the fossils nicer.

MRI tends to work on the Hydrogen in water and fats within the body. I have no idea whether it would work on stone - it is possible that the variation in stone which we can easily see in fossils is not great enough to create a variation in the nuclear spin transition and relaxation which is picked up in an NMRI scan; on the other hand maybe it does work. Just in case someone approaches you with a chance to do a scan at a cost I would contact your local university's palaeontology dept. first. If you have already done this I would be fascinated to hear response. I know NMRI can be used on other nuclear spin models - but I thought they were specially made machines

Here is a link to a lecture I attended at the Royal Society - it is a few years ago and it all the info seem to have fled my head

https://royalsociety.org/science-events-and-lectures/2014/magnetic-resonance/

### [solved... sort of] Trigonometry Problem

Yes I saw this morning when I opened your spoiler that you had reached the 3D conclusion before I did.

I don't know if this was obvious in the textbook (for instance a chapter on 3D trig).

Also this question demonstrates the need for proper labelling of diagrams.

If the pretty picture was a scan from the textbook I would take proper labelling over beauty any time.

I think the authors were unduly lazy.

Agree completely - I remember watching examiners attempt an ad hoc rationalization of similarly poorly written question; it was all intended to help draw out/highlight proper understanding of the subject etc. Then someone piped up - Was the fact that there was no section c, there were three spelling mistakes, and the diagram was wrongly labelled all part of the same teaching strategy; at that point the staff admitted that everyone thought someone else was checking the questions for basic quality control.

Did you see the news piece around 6 months ago about errors in exam revision texts? Some O'level and A'level science and maths primers had enormous error ratios in the self-test answers.

http://www.bbc.co.uk/news/uk-wales-38721478

### Virtual particles and fields

Gravity is interesting because it is not properly understood by science, there are many theories around, so for anyone to claim they personally understand gravity demonstrates a lack of understanding of gravity or arrogance. I started the discussion but will step out, good luck with understanding gravity.

I would suggest getting a consistent understanding of the graviton might be your starting point for discussion. I did post a link from Wikipedia which was reasonably concise ref the graviton but seems to have been not suitable for your level of understanding. Various differing ideas ref the graviton have been posted, the link would have answered your questions.

https://phys.org/news/2017-03-team-dark.html#nRlv

https://phys.org/news/2017-06-ditch-dark-energy-relativity.html?utm_source=nwletter&utm_medium=email&utm_campaign=daily-nwletter

TTFU is a joke, that normal folk find amusing ROFL.

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