1

Physiology & Medicine / How safe is the "Brain-Zap?

« on: 07/08/2020 13:14:48 »

https://www.usnews.com/news/health-news/articles/2020-04-07/magnetic-brain-zap-shows-promise-against-severe-depression

Some time ago I posted about a friend who was seriously suicidal.  He’s still with us, and is now considering trying the “Brain-Zap”.  Better than suicide, I guess.
 
It’s 20 years since I left MH work, and I believe this sort of treatment has progressed considerably in that time, but in the back of my mind there is still the lurking image of the post ECT “zombies” I’ve worked with.
 
Does anyone have any information about this?

2

General Science / Is this the future?

« on: 13/07/2020 19:01:03 »

https://www.laboratoryequipment.com/566170-Robot-Scientist-Quickly-Discovers-New-Catalyst/ 

Robot Scientist Quickly Discovers New Catalyst

This is not just another machine in the lab: it’s a new superpowered team member

And no sexual/racial prejudice.  Oh wait; it might be programmed in.

3

Just Chat! / Who really wrote the papar?

« on: 07/07/2020 14:30:26 »

https://www.sciencemag.org/news/2016/08/cat-co-authored-influential-physics-paper#

In 1975, Jack Hetherington and F.D.C. Willard published a paper together in Physical Review Letters. The paper is an influential view into atomic behavior and has been cited multiple times, but only one of its authors is human—F.D.C. Willard is a cat, Atlas Obscura writes. His owner, Hetherington, added the feline (not pictured) as a co-author when he realized that although he was the sole author, he used the plural “we” and “our.” Instead of retyping his entire paper, he simply tacked on his cat Chester, sneakily calling him “F.D.C. Willard” after his species name, Felix domesticus, his actual name, Chester, and the name of the cat’s father, Willard. When the cat was out of the bag, Chester was invited to join the university’s physics department full-time.

My money’s on the cat.

4

Physics, Astronomy & Cosmology / Can an object be confined to a region smaller than its Compton wavelength?

« on: 25/06/2020 21:00:59 »

If there were a physical singularity at the centre of a BH, would this not involve confining a particle to a region smaller than its Compton wavelength?

Are there any circumstances in which this could occur?

5

Just Chat! / When have religious gatherings been illegal?

« on: 19/06/2020 19:05:09 »

Has there been any time between the Reformation and the enactment of The Health Protection (Coronavirus, Restrictions) (England) Regulations 2020, when religious gatherings were prohibited by Law in England?

6

Geology, Palaeontology & Archaeology / Are private or national interests impeding progress in geology?

« on: 14/05/2020 14:51:39 »

https://www.nature.com/articles/d41586-020-01366-w?WT.ec_id=NATURE-20200514&utm_source=nature_etoc&utm_medium=email&utm_campaign=20200514&sap-outbound-id=56B42D71ED7789053A927BA3D1C596A6925F1DD8

This seems to suggest that we may be wasting opportunities at a time when new fossil discoveries are particularly exciting.

7

Physics, Astronomy & Cosmology / Does GR predict a singularity?

« on: 21/04/2020 20:25:56 »

It is not unusual to meet the idea that GR says that all matter/energy in a black hole is crushed into a singularity with zero volume, but is that right?

Would it be more accurate to say that GR predicts the black hole; but trying to identify a spacetime object at its centre would be extrapolating beyond the limits of GR?. 

8

Physics, Astronomy & Cosmology / What difference does this make to our understanding of infinity?

« on: 07/04/2020 23:42:46 »

https://www.quantamagazine.org/mathematicians-measure-infinities-find-theyre-equal-20170912/

Someone posted this link (thanks).  I’ve lost track of it, but wanted to comment.
My question is: If p = t, does this mean that all infinities, countable and uncountable, are the same size?

9

Physics, Astronomy & Cosmology / How is Itzhak Bars progressing with his 4+2D theory?

« on: 15/12/2019 11:47:42 »

https://en.wikipedia.org/wiki/Itzhak_Bars

In 2006, Bars presented the theory that time does not have only one dimension (past/future), but has two separate dimensions instead.

I seem unable to find any information of more recent date.  Does anyone know if/what progress there might have been?   

10

Just Chat! / Quis est homo?

« on: 10/09/2019 17:33:46 »

Ad mortem, Britanniae Popularis Regiminis

Quis est homo qui non fleret,
“Führer” Boris dum videret,
In tanto impreio?

Foris coge opponentes!
Sumi vires inflectentes;
Silente quem praeterio!

Recommendation: avoid google translate.

11

The Environment / Are Humans the most stupid, self-destructive creatures ever?

« on: 29/08/2019 18:56:43 »

Wildfires 2019
https://fires.globalforestwatch.org/map/#activeLayers=viirsFires%2CactiveFires&activeBasemap=topo&activeImagery=&planetCategory=PLANET-MONTHLY&planetPeriod=null&x=-129.638672&y=34.513058&z=2

It seems that every continent, except Antarctica, is on fire.

We have the weapons to reduce this planet to a nuclear desert, but we lack the equipment necessary to stop these fires from destroying the forests that are vital for so much of our oxygen. 

What are World Governments thinking of?

No problem answering that for the British Government.  Various neo-Nazis and latter-day Fascists are seriously threatening to rob us of the last vestiges of our tattered Democracy, while the World burns. 

Come back Nero, all is forgiven! 

12

Just Chat! / How far back can PMs be traced?

« on: 22/08/2019 13:17:09 »

I've just looked at my PMs, and they seem to go back only to 07.18.  am I doing something wrong/missing something?

13

Physics, Astronomy & Cosmology / Is uniqueness conserved?

« on: 21/07/2019 22:32:48 »

Here’s another one from the past.

https://www.thenakedscientists.com/forum/index.php?topic=52973.msg444979#msg444979

A spacetime event must be unique and immutable; so, how can something that is unique and immutable appear to be so different in different frames of reference?

The event has a specific set of spacetime coordinates, that's true. However its relationship between other events depends on the observer. That's what relativity is all about.

For clarity; I'm not disagreeing with Pete; just trying to clarify my thoughts.

    The glib answer to the question: “…how can something that is unique and immutable appear to be so different in different frames of reference?” is that an event has a specific set of spacetime coordinates, which are unique, but its relationship to other events depends on the observer.  “That's what relativity is all about”.

    For most practical purposes, this answer is all we need.  Never-the-less, the fact that discussions about what one might observe in relation to a person, or object, approaching, or crossing, an event horizon are so commonplace, does suggest that it leaves some aspects unclarified in the minds of hitch-hikers and, to some extent, experts.

    One question might be.  If a spacetime event is unique, but its relationship to other events is observer dependent, does this mean that it is unique only in its own reference frame?  If so; is “uniqueness” relative, and what on Earth might that mean? 

    Consider a scenario in which a specific spacetime event (X) occurs in RF1.  Observer A is in the same RF and is, therefore, stationary relative to X.  Observer B is in RF2 which is in motion, relative to RF1.   

    Observer A sees X occurring at location L and at time t.  These coordinates are unique and immutable.

    Observer B sees X occurring at location Lʹ and at tʹ.  These coordinates are unique and immutable.  Under SR, both are to be considered valid.  L ≠ Lʹ and t ≠ tʹ, but there is only one original event, which is “unique”.  Observer B’s “reality” is valid, and also unique.

Should we conclude that place, time and uniqueness are all observer dependent, and therefor relative, and that “in translation”, uniqueness is conserved?

14

Physics, Astronomy & Cosmology / Why negative gravitational energy?

« on: 07/04/2019 19:15:05 »

https://en.wikipedia.org/wiki/Negative_energy 

“The strength of the gravitational attraction between two objects represents the amount of gravitational energy in the field which attracts them towards each other. When they are infinitely far apart, the gravitational attraction and hence energy approach zero. As two such massive objects move towards each other, the motion accelerates under gravity causing an increase in the positive kinetic energy of the system. At the same time, the gravitational attraction - and hence energy - also increase in magnitude, but the law of energy conservation requires that the net energy of the system not change. This issue can only be resolved if the change in gravitational energy is negative, thus cancelling out the positive change in kinetic energy. Since the gravitational energy is getting stronger, this decrease can only mean that it is negative.”

Why is gravitational energy, rather than kinetic energy, seen as being negative?

15

Physiology & Medicine / How naïve can one be?

« on: 03/04/2019 18:47:34 »

https://www.laboratoryequipment.com/article/2019/04/usda-ends-controversial-cat-research?et_cid=6655502&et_rid=517749120&et_cid=6655502&et_rid=517749120&linkid=Mobius_Link

Agricultural Research Service (ARS)     

Did someone not think that one through?

Oh, wait!  There’s Department of Agriculture (DOA), as well!

Oh, God! He's back!     I had to say that before someone else does.

16

Physics, Astronomy & Cosmology / Is there an angular equivalent to Planck length?

« on: 21/03/2019 23:34:32 »

Is there a point at which no further division of an angle is practically possible?  In the case of angular measurement, one might be tempted to suggest that a limit would be reached when the segment of a circle subtended by the angle in question became so small that it reached the Planck length.  Obviously, this would not work, as, by the simple expedient of lengthening the radius of the circle, the length of the segment would be increased without any change in the angle.  My feeling is that quantization of an angle might not be meaningful, but I’m open to correction.

17

Physics, Astronomy & Cosmology / Do we go round in circles?

« on: 10/03/2019 12:25:20 »

There’s a chance I may not continue posting, and there are a few things I would still like to clarify, just in case.  Please have patience if I dig up some “oldies”.

Looking back at past exchanges, I find myself thinking that there are areas in which we tend to go round in circles.  This may be because some of us “hitch-hikers” are slow to catch on. It may also be because experts often answer the question they think should have been asked, rather than the one that was actually asked.  Then there are crossed wires……

One point that needs to be cleared up arises from:  Can we lay nothing to rest? https://www.thenakedscientists.com/forum/index.php?topic=53002.msg445560#msg445560  Where Pete says:

But you haven't been appreciative enough to take my advice and read what I suggested. I feel as if you're being disrespectful to me when the fact is that I'm being as respectful to you as I possibly can by doing a lot of work trying to help you understand this and all you do is skirt around my one single suggestion which will help you

It saddens me that, in asking a question about something that an expert has said, I might give the impression that I am disrespecting that person’s expertise.  Such is not the case, but I will never pretend that I understand something, if I don’t. Therefore, I ask questions.

I did read the information Pete attached, it certainly improved my understanding of mathematical infinities; thanks Pete.  However, there still remain a few unanswered questions.  This may be, in part because, before we can say anything meaningful about a concept, we have to be quite clear about the context in which a question is being asked, and an answer given.

Before even attempting to go any further, I should check, and possibly improve, my understanding of the mathematical concept of infinity.  Hopefully I will post my thoughts soon.

18

Physics, Astronomy & Cosmology / Is all motion relative?

« on: 17/02/2019 18:38:17 »

I’ve lost track of recent threads, so, although this might fit into one of them; I’m starting a new one just to test my thoughts.   

A and B are in relative non-accelerated motion. Each knows that one of them is moving, because their relative positions are changing, but neither can say which is moving, and which, if either is stationary.  No experiment carried out in either RF will determine which is moving; other than that, each can say there is relative motion between the two.

A accelerates. An accelerometer in A’s RF will establish that A is accelerating. A knows that she is the one accelerating,and, therefore, moving.
B’s accelerometer does not register acceleration, so B also knows that it is A who is accelerating, and is therefore moving.

Observers in non-uniform motion can establish that they are moving; but motion must be motion relative to something; or does that apply only to uniform motion?

If A and B are the only objects in an empty universe, the motion of each/either must be motion relative to the other.  Unlike the case of uniform motion, both can know which is in accelerated motion.

If B is removed from this imaginary universe, A has nothing relative to which she can measure non-accelerated motion.  Uniform motion becomes meaningless; she has no way of knowing if she is moving, in any sense.

If A accelerates, she can measure this acceleration, thus, she knows she is moving; although there is nothing relative to which she can be said to be moving.  This begins to look like “absolute” motion; but can have little, or no, real meaning.

Consider that, in this “empty universe” scenario, A starts with a possible velocity (v1), which is effectively meaningless; accelerates, then returns to uniform motion, (v2).  By the above reasoning, v2 is also meaningless.  However, A has accelerated, which implies a change of velocity; So v1 and v2 must differ from each other.
If that is right, what actual difference could there be?   

19

Just Chat! / That’s just not “cricket”, is it?

« on: 08/01/2019 17:27:41 »

“Mystery ‘Sonic Attack’ on U.S. Diplomats in Cuba Was Really Crickets”

https://www.laboratoryequipment.com/news/2019/01/mystery-sonic-attack-us-diplomats-cuba-was-really-crickets?et_cid=6571441&et_rid=517749120&et_cid=6571441&et_rid=517749120&linkid=Mobius_Link

20

Physics, Astronomy & Cosmology / How remiss is our attitude towards entropy?

« on: 07/01/2019 15:23:33 »

Entropy is just a natural outcome of statistics. The fact that it is increasing only means that the universe started in a highly ordered state, and is still much more ordered than it ultimately will (can) be.

Re: Does time stand still in the quantum world? #13.

There are a few points I would like to clarify from this post, let's start with this one. This has echoes of Sean Carroll’s assertion that a “Past Hypothesis”, demanding a low entropy boundary condition, is necessary in order to justify an expanding universe theory.

Moving away from the idea of entropy as a measure of disorder, and thinking of it as the number of accessible energy eigenstates, how reasonable is it to think of the first instant of the Universe as having low entropy.

If all the matter and energy in the Universe today were “packed” into an infinitesimally small “speck”; surely, the number of accessible energy eigenstates would have been zero, or as near to that as uncertainty permits.