1

New Theories / Re: Where does quantization of energy of electromagnetic radiation come from?

« on: 05/06/2023 08:54:27 »

Hamdani, the biot-savart equation is the counterpart to coulomb, describing the magnetostatic.

2

Just Chat! / Re: Latest Forum Updates and Upgrades

« on: 17/05/2023 17:28:54 »

SERVER MIGRATION UPDATE - May 2023

Hello everyone. I wanted to bring you up to speed on what's been happening in the background recently.

After 17 years, the company that had hosted us through most of this site's lifetime were taken over by a new kid on the tech block. The "new broom" decided to make a clean sweep of existing relationships like the one we had and asked us to pay ?25,000 per year for our webservers, or pack up and go. I attempted to negotiate a bit, having pointed out that they'd had 120M+ brand impressions through us just on our podcast, but to no avail. Their best offer was still stupid amounts of money for what amounted to an annual electricity bill (the servers were already set up and running and had cost nothing in maintenance for a decade).

Unsurprisingly, I decided to exit and set up our own hosting from Naked Scientists Towers. This has involved quite a bit of behind the scenes work to migrate everything across and make it work stably; I was especially worried about this forum because it's notoriously fickle and doesn't like to budge from its home.

It looks like it's moved across okay, and I hope the user experience is tolerable. I'm still doing a lot of optimisations behind the scenes now to make things work better. There is always a bedding in phase with new setups where one strives to find the config "sweet spot" for the stack that's running. We're just at the start of this process at the moment, so it will hopefully continue to improve from hereon in.

My plans for this year are to upgrade this forum to newer iterations of the software, which should make it run more slickly, grow our user base more, and upgrade the theme to a more contemporary look. Suggestions, though, for the latter in particular, would be most welcome. And any coders and web gurus out there who would be willing to help, do please drop me a line.

Meanwhile, thanks for your energy and contributions, especially to the moderators!

Chris

3

Famous Scientists, Doctors and Inventors / Re: Are some scientists unique and only they could have made the discovery?

« on: 16/05/2023 10:12:59 »

I believe that luck plays an important part in major discoveries. One could apply a top notch researcher to a particular area of science( where no breakthrough is possible ) and waste their career down a cul de sac. A less accomplished researcher might pick an alternate topic and strike a goldmine.

4

Famous Scientists, Doctors and Inventors / Re: Are some scientists unique and only they could have made the discovery?

« on: 16/05/2023 05:27:21 »

I think Einstein himself admitted that the time was ripe for his theory, and he just got there first. Not to downplay the work, since so much was predicted and not verified until ages later, but it would have been done by others, even if not all by one person. He certainly had help himself.

I thought about it for a while, and the best candidates (without naming any) seem to be in the field of mathematics, discoveries that if not made, may not have been made for a long time or ever.

I can't think of a single similar feat in the area of physical sciences.

5

Physics, Astronomy & Cosmology / Re: Can Light Experience 'Time'

« on: 15/05/2023 21:04:00 »

I must say I was really impressed with ES and the "lateral" view of the question ie the red shift. Appealing to an engineering brain. Oh dear, I just crashed ES's latest post.

6

Just Chat! / Re: Where is the "Spiel Chicken"?

« on: 14/05/2023 23:09:08 »

I donno what the Problems seem to be, i am Not facing Any issues whatsoever.
(Android Mobile)


The Various input options seem to be in place...


Screenshot_2023-05-15-03-20-25-152_com.android.chrome.jpg (388.91 kB . 1080x2156 - viewed 306 times)


I never kinda Noticed any Spell Checker before...


Screenshot_2023-05-15-03-20-43-381_com.android.chrome.jpg (247.58 kB . 1080x2156 - viewed 307 times)


Thou, one Specific observation...


Screenshot_2023-05-15-03-19-20-445_com.android.chrome.jpg (414.84 kB . 1080x2156 - viewed 306 times)

I have NEVER seen the " Most Online Today " values less than 300, 500 or 700+
For some ODD reason, it's showing up as 7(only)


LaTeX Code(Copy & Paste)
Android mobile.




My Bad!
I just double checked, the OP is Korreckt!
(Spell Checker was before, gone away now)


Screenshot_2021-10-28-22-22-29-585_com.android.chrome.jpg (300.91 kB . 1080x2156 - viewed 304 times)


Patience is quite Bitter,
but it's Fruits, mostly Sweet.
&
You shouldn't even Try...
When you're Bad at sayin Goodbye!

7

Just Chat! / Re: Can someone assist me with some scientific terms?

« on: 14/05/2023 17:22:04 »

But how would the world look if F = GMm/r2.1?

Absent.
Only an inverse square law provides a stable orbit.

8

Physics, Astronomy & Cosmology / Re: Can Light Experience 'Time'

« on: 13/05/2023 17:56:25 »

Light travels well fast that at it's top speed it does not perceive time.....weird eh ?

Well, besides the point that subatomic things don't have 'experience', but that's probably not what's being asked.

If you were to slow light down, would the photons then experience time?

Only a time-like worldline defines a meaningful frame in which it has a temporal length. That means that a clock following that time-like line will log a certain amount of time. This is independent of any chosen frame.
This cannot happen for a space-like wordline nor a light-like worldline, which is what is followed by all things lacking proper mass.

All that jarjgon aside, if you slowed a photon down, it wouldn't be a photon, but the path taken by this slowed-down not-photon thing would indeed have a frame-independent temporal length, so in that sense, yes, it would experience time.

For instance, while light slows down in glass or some other medium with a refractive index, a photon does not. A photon at best can be said to be absorbed by the glass, briefly exciting some atom which in very short order emits a new photon in the same direction as the old one. It isn't the same photon, and it is a mistake to give a photon classic properties like that when it is a quantum thing, not a classical thing.
But bottom line is that you can have say a pipe in a square U shape with fast water running through it. You shine a light pulse from the side and it goes through the straight bottom part of the pipe to the other side. If the water flows fast enough, the light pulse will slow effectively to a stop relative to the pipe and will 'experience' as much time as does the pipe.

9

Physiology & Medicine / Re: What usually causes chemo to fail?

« on: 09/05/2023 20:19:45 »

Chemotherapy refers to the use of chemical substances to treat disease- under this definition taking an aspirin is a form of chemotherapy. I presume you are enquiring about cancer chemotherapy. The substances normally called "chemo"  such as nitrogen mustard, vinca alkaloids and anthracyclines are blunt weapons which cause widespread damage to most cells but most importantly have the greatest effect on rapidly dividing cells. Since most cancer cells divide very rapidly they suffer disproportionately. Because of the collateral damage these agents induce dosage limits may result in a failed elimination of the neoplasm. There are now numerous targeted therapies that reduce this collateral damage. 

10

Just Chat! / Re: TNS - Must Read B4 shift+delete!

« on: 07/05/2023 17:26:02 »

Hi everybody. I'm one of the new members, and what I am looking for is a place where scientific matters can be discussed at a good, preferably expert level. Because what I see on facebook or twitter groups is mainly advertising. There are lots of pictures and videos that are completely science-unrelated. But on the other hand, I've been trying to add a picture to my second post and have failed. I know about links in the first posts, but what about pictures? I think it would be good to point the newbies to some faq covering such issues.

11

Physics, Astronomy & Cosmology / Re: Talking about Physics

« on: 06/05/2023 11:42:59 »

WAG= wild ass guess, a term introduced on another thread by Kryptid, as far as I remember. I must apologise, yet again, for using acronyms that may not be understood.

12

Physics, Astronomy & Cosmology / Re: Talking about Physics

« on: 02/05/2023 09:25:12 »

Interesting that the Wikipedia article, when discussing sequential S-G  systems, talks about "measuring" when a particle passes through a nonhomogeneous magnetic field. When we use magnetic fields to select regions for analysis by spin resonance (e.g. MRI) we talk about polarising or forcing, not measuring*.  Wikipedia partially redeems itself with

Given that the input to the second S-G apparatus consisted only of z+, it can be inferred that a S-G apparatus must be altering the states of the particles that pass through it.

(my italics)

which is much more reasonable, and also makes sense if applied to the 45 degree optical polariser.

I may be a bit pedantic in distinguishing between segregating (black sheep to the left, white  to the right) and measuring (counting the sheep in each pen after segregation) but that's the residual chemist in me: qualitative and quantitative analysis are not the same thing. The "triple S-G" experiment simply selects white sheep then arbitrarily paints them red or blue.


*the measurement phase of MRI comes later: we listen to the radiofrequency emission as the selected spins relax and realign to the primary field.

13

New Theories / Re: A hypothesis: Time interval between a force and its reaction

« on: 01/05/2023 20:54:38 »

Hi ES, I read through that Feynman lecture and found it fascinating but hard going for my ageing brain. Many thanks.

14

Physics, Astronomy & Cosmology / Re: Acceleration of light?

« on: 24/04/2023 01:23:07 »

When a photon is ejected from an electron going to a lower energy level, what acceleration does the photon have?

From what I have read  a photon (in a vacuum) does not accelerate and only moves at the one speed(c)

15

Just Chat! / Re: Quantum puzzle

« on: 20/04/2023 11:54:31 »

Hi ES, this discussion is WAY over my head as merely being a nuts'n'bolts, matter of fact retired engineer. However as this is just "chat", I thought I would stick my head above the parapet  I feel there is a degree of incongruity in the question in that you are asking does a quantum phenomenon produce a macroscopic classical effect( pressure ). You yourself have alluded to a multiplicity of quantum "events" being necessary to produce a macro effect.  I now await a hail of spoiled fruit and rotten eggs etc, coming my direction!!

16

Just Chat! / Re: Quantum puzzle

« on: 18/04/2023 20:06:59 »

We don't know anything about ideal gases, because there aren't any!

So... that's one thing we know about them.
I think we know other stuff about them too.
They are colourless. (If they interacted with photons they would interact with those emitted by the walls of the container (and one-another) and that's forbidden by their definition.)

Arguably, we know everything about them for the same reason that Tolkien knew everything about Hobbits.

17

Just Chat! / Re: Quantum puzzle

« on: 18/04/2023 20:02:28 »

Interestingly, if you consider this

 

You run into a different conundrum.
In the first excited state- labelled C- your particle has zero chance of being in the middle of the box.
But it has a 50% chance of being one either side.
So, how does it get from left to right without ever  being in the middle?
You can pretend it doesn't matter- it's actually really on one side of the box and, unless it's kicked into a higher state, it remains there.
 But it's worse than that.
The observable universe can be treated as a huge box with very high walls.
Because the box is big, the energy level separation is tiny.
So any particle you see will actually be in a very high excited state.
It will be passing through a massive number of the "zeroes" of probability density every second.
How does any particle travel past the bits where its probability is zero?

18

Just Chat! / Re: Quantum puzzle

« on: 18/04/2023 09:36:12 »

How do you reconcile that with what we know about ideal gases?

We don't know anything about ideal gases, because there aren't any! The classical ideal gas consists of particles with mass but no radius, so it is infinitely compressible.

19

Just Chat! / Re: Quantum puzzle

« on: 17/04/2023 03:29:25 »

There is a well known model in Quantum mechanics called "the particle in a box" (also "a particle in an infinite square well").   Considering that model, does the particle exert pressure on the walls of the box?

I had to look up exactly what these words meant. "Box" and "Infinite square well" sort of imply a large container, where in fact they're talking about a very small one in a deep potential well from which escape (by tunneling say) isn't possible.

Without reading any bit about pressure, I'd say yes, it would since it could occupy a lower energy state if it had more room for a longer wavelength. It can exist only in certain quantized energy states in there, and a wider box allows a lower energy one. So it applies pressure the same way that water would since water could occupy a lower energy state with more leg room.

20

Physics, Astronomy & Cosmology / Re: How many beams or spots emerge from Stern-Gerlach apparatus?

« on: 14/04/2023 08:53:24 »

You want a material which vapourises as single atoms (unlike nitrogen for example, which forms N₂ molecules).
I also think you want a material with just 1 electron outside the "closed shells" in order to simplify the orbitals
And that leaves you with the alkali metals (which are a PITA to work with) and the coinage metals, of which silver is most volatile.