All your science in here


#361

Brain unable to process all the concepts at play here…:exploding_head::exploding_head::exploding_head:


#362

Neutron stars are the smallest, densest stars known to exist: about 12 miles wide, with a teaspoon of neutron star material having a mass of about a billion tons. The core is a soup of pure neutrons, while the crust is smooth, solid and 10 billion times stronger than steel.

This is the sort of thing that does my head in…


#363

Never mind the details. It’s a way of making gold out of … well … other stuff. How long before Trump wants to know why government science labs haven’t built him one ?

VB


#364

This bit just makes my mind boggle:

Initially separated by 200 miles, they circled each other 30 times a second. As they whirled inwards, accelerating to 2,000 orbits each second, the signal rose in pitch like a slide whistle.

That is two stars, each having greater mass than our sun, orbiting each other at 2000 orbits per second.

:exploding_head: (again)


#365

I’m pretty sure this will require a long answer. Why can’t we make gold out of other stuff? Not alchemy but proper sciency type manufacturing. We make lots of molecules all the time from elements.


#366

Scratch that, I just though it through :see_no_evil:


#367

What does my noggin in is that Einstein was able to predict all (or certainly the majority) of this using effectively just pen and paper.


#368

Using his mind

The pen and paper just recorded it


#369

I love pointing that out to students when discussing work that is 35 - 40 years old. No access to Maple or the like to do your maths for you.


#370

Who ever wrote that has to be on a wind up, nothing so small can weigh that much.


#371

Exactly!!!


#372

True, but the fact is he was also very good at writing his work up. The staggering thing about him is just how many bits of physics he worked on. If you say Einstein the man in the street might come back with Relativity and E=mc2. But in 1905 he published four ground-breaking papers - one on the photoelectric effect, one on Brownian motion and two on aspects of special relativity. When he eventually got the Nobel prize the citation notes that one of these subjects was particularly impressive and it’s not relativity but the photoelectric effect !

In a previous life I was a laser scientist. Laser stands for Light Amplification by Stimulated Emission of Radiation. The idea of stimulated emission was first proposed by Einstein and I eventually got round to reading his original paper on the subject. It’s really, really well written - clear, beautifully structured, economical (there isn’t a wasted word) and contains the simple, perfect solution to what had been an intractible problem. It’s one of the very best papers I’ve ever read.

VB


#373

Truth is stranger than fiction. Atoms are almost empty. Practically all the mass is concentrated in a dot in the middle (the nucleus). In neutron star material all that empty space has been squeezed out and the resulting stuff is unimaginably dense.

VB


#374

The point I was making was that he only had a pen and paper to put his ideas down with, these days scientists have supercomputers to model their ideas and prove their theories.

Einstein did all of his modelling and theories by hand.


#375

I realised that


#376

#377

Someone’s had a try though. A billion tonnes in a tea spoon pffft.


#378

The spoon would bend, I reckon. So how do you prove it?


#379

So presumably all the heavy elements have less space and more stuff then?


#380

I’ve read that. It is absolutely beautiful. If you leave aside the technical elegance of the work, the prose is magnificent. I shudder to think how many times the work was rewritten (by hand again) before it was ready to be submitted for publication.

In my field we use Brownian motion in general, and Brownian Bridges in particular, in developing the asymptotic theory used to describe the properties of estimators. Others in closely related fields use Brownian motion as a model for movements in asset prices, which I find unappealing as prices become very discontinuous (ok discrete) just when you need the model the most (e.g. 2007/2008).