1

Physics, Astronomy & Cosmology / Re: How does light move in a vacuum?

« on: 01/12/2020 13:20:35 »

- Since nothing can go faster than c, if c=0 then you have an immobile universe which cannot sustain life

Or possibly a universe composed of tachyons, and whatever might evolve from that.  Might be good for sci-fi.

  Due to the E=mc2 , if c=∞, it takes an infinite amount of energy to create mass, so there can only be massless particles traveling infinitely fast, and no matter.

If we are postulating that c could be infinite, we could also have an infinite cosmos, with infinite energy available, so an infinite amount of matter would be inevitable. 

Another comment from that video: c is actually the speed of causality. if c=∞, then we would be potentially affected by everything else going on in the universe, and it would be hard to tell what event causes other events(ie the concept of time would be very different).

Come back David Bohm, all is forgiven!

2

Geology, Palaeontology & Archaeology / Re: What is this stone that looks like it's been attacked by woodworm?

« on: 12/11/2020 21:18:31 »

Rough guess.  The holes were there first, in the form of borings possibly with a CaCO3 coating. The flint nodule was precipitated around them from a solution rich in silica.   

3

Geology, Palaeontology & Archaeology / Re: What is this round-shaped pebble with a conical end?

« on: 08/11/2020 11:41:26 »

I would guess at Echinocorys Sp. but it's a long time since I dabbled in that sort of thing.

4

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

« on: 08/08/2020 15:43:53 »

By "Brain Zap", do you mean this:
https://en.wikipedia.org/wiki/Transcranial_magnetic_stimulation

More specifically; this device.

 https://www.newscientist.com/article/2221743-europes-first-home-brain-zap-device-for-depression-launched-in-uk/

5

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

« on: 08/08/2020 15:33:56 »

If pushed, I'd prefer ECT to medication,

 

My comment should not be taken to suggest that I do not accept that ECT has its successes, or that I consider it “better” or “worse” than other forms of treatment.  Providing psychiatric liaison in a busy A & E Dept. I was much more likely to be in contact with the failures of treatment, of all types, than with the successes.  The successes being less likely to attempt suicide.     
 
The “Psychotropic Revolution” produced its plethora of mumble-worded, shuffle-footed victims; but these tended to be kept out of sight until “Care In The Community” liberated them; often to squats and shop doorways.  When I transferred to working in the “grey area” between the Criminal Justice System an MH provision, it was, again, the failures of the care provision who were most commonly referred in our direction.  Perhaps this leads to a jaundiced view. 

However, it was information/opinions about a specific device I was looking for, rather than any sort of critique of NHS provision, fascinating as that might be

6

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?

7

General Science / Re: What caused the whistling sounds of bombs?

« on: 03/08/2020 13:03:38 »

Fortunately I have no memory of either.

Nor I; but one of my earliest memories is of a large chunk of chimney pot landing in the hearth, having been hit by a passing incendiary.  I guess, if it had been a few feet lower, I might not be posting this now. 

8

Physiology & Medicine / Re: Do Nightmares Affect The Quality Of Sleep ?

« on: 01/08/2020 15:20:12 »

https://www.sleepfoundation.org/articles/do-dreams-affect-how-well-you-sleep

Possibly worth a look.

9

Physics, Astronomy & Cosmology / Re: If I Was Able To Stop Time, What Would The Temperature Be ?

« on: 01/08/2020 15:11:25 »

The assumption of causal symmetry is one of the vanities of philosophy, which is anathema.

That’s why I needed to check, before trying to move on.

Time being what separates sequential events, it is the dependent quantity.

OK, so far.

Change is not dependent on what we measure, but what we measure depends on change.

That makes sense, as well, but, the OP was looking at the possibility of stopping time.  #7 is probably all the indication you need that I’m very sceptical about this “possibility”. 

 However, it does link to Neilip’s question about time coming into existence.  If there were no time, wouldn’t the concept of change be meaningless?  Presumably, in the absence of time, everything would be somewhat meaningless, but it is particularly the time/change aspect that I'm interested in, here. 

10

Physics, Astronomy & Cosmology / Re: Do planets rule our destiny?

« on: 01/08/2020 14:46:42 »

Are we likely to find that this situation is related to human relationships?

As far as we know, we live in a finite Universe.

There is an obvious cyclicity. Therefore, it would seem reasonable to assume that there is a finite number of possible cycles.

There is a finite number of people who can populate a finite Universe.

People have different personalities and characteristics.  There must be a finite number of these.

If everything else is cyclic, the distribution of these characteristics may also be cyclic.

Astrologers may have spotted this duel cyclicity and attempted to link the two in a causative way. Cum hoc, ergo propter hoc.

Marks for imagination, rather than science, please.

11

Physics, Astronomy & Cosmology / Re: If I Was Able To Stop Time, What Would The Temperature Be ?

« on: 31/07/2020 19:54:05 »

Stopping time is an idea beloved of Sci Fi authors, but trying to translate it into the physical world provokes three questions.

1. If you cross a bulldog with a shih tzu, what do you call the resulting “breed”?
2. What is the chance that future generations will breed true?
3. Is this off topic?

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Physics, Astronomy & Cosmology / Re: If I Was Able To Stop Time, What Would The Temperature Be ?

« on: 31/07/2020 17:40:26 »

Time is the space between sequential events.  If you stop time, there will be no sequential events

Agreed.

In the absence of anything else there can be no change, so time is meaningless

Agreed. 

This looks like saying that in the absence of change, time is meaningless, and in the absence of time, change is meaningless. 
Need to check that I’m not misinterpreting.

13

Physics, Astronomy & Cosmology / Re: Does the speed of an object change its mass?

« on: 30/07/2020 13:45:36 »

Perhaps, thinking in terms of inertia would help.

This problem was well known to the people involved in the transport of goods by horse drawn canal barges.  A lot of energy was needed to overcome the inertia of a stationary, loaded barge, but once an optimum speed had been reached much less energy was required to maintain that motion.  However, should the person in charge of the barge decide to try to increase the speed, he found that a very significant amount of energy was needed to achieve only a small amount of acceleration.  Most of the additional energy seemed to go into producing a larger bow wave.  In other words, the faster the horse tried to pull the barge, the more weight the unfortunate animal had to pull along.  Or, expressed in different terms, the more inertia it had to overcome. 

Much the same thing happens when we try to accelerate an object close to the speed of light.  In this case, though, the weight does not come from picking up pre-existing mass, such as the water in the canal, it comes, or so books of popular science generally tell us, directly from the conversion of energy to matter, according to E=mc².

I suspect this is just the tip of the iceberg.  The next question must be; in whose RF which effect occurs.

14

Physics, Astronomy & Cosmology / Re: How Did Time Come Into Existence ?

« on: 29/07/2020 12:08:02 »

time starts

Nice one, ML, that takes us right back to the OP. 

What starts time; in the middle of what?  We know that time "emerges" in response to sequential events.  Do we assume that these events have always been happening (a touch of the eternal, there); or are we to think of these events as starting at some point?

15

Physics, Astronomy & Cosmology / Re: How Did Time Come Into Existence ?

« on: 28/07/2020 21:16:57 »

There is no pre-exist,

If this says that everything is eternal, I would not argue with that.  I just wonder if it would leave Neilep feeling he had a woolly answer to the OP; but I'll not bleat about that.

16

Physics, Astronomy & Cosmology / Re: How Did Time Come Into Existence ?

« on: 28/07/2020 19:40:44 »

The beauty of this theory is that as the sum of mass is zero, you don't need anything to preexist the BB,

I know we’ve been here before, but I still lack resolution.  The sum of the mass is zero; no problem, but would the masses not have to “pre-exist” in order to sum to zero?

The only way we could infer the presence of an unreal particle is if two real particles spontaneously move apart due to the presence of an unreal particle between them. Which is just what we observe in the expanding universe.

Like it.  Think “Bill Ockham” would approve.  Need to give it some thought.

17

Physics, Astronomy & Cosmology / Re: Why is ‘NOW’ Not The Same Everywhere ?

« on: 28/07/2020 18:03:19 »

The fact that there is or there is not a now everywhere, linking all particles together at a speed faster than light, is a matter of belief, for now..

If there is such a “now”, and if it links all particles together, then “a speed faster than light”, or any speed, could not be involved.  The “now” would have to be static, eternally. The particles would be permanently “here” and “now”.

18

Physics, Astronomy & Cosmology / Re: How are particles monitored for position and velocity in the LHC?

« on: 28/07/2020 13:33:01 »

  but Bell's theorem proved that both cannot be true, so no interpretation asserts both.

This seems to add a bit to Bell’s theorem.

https://www.scientificamerican.com/article/quantum-tunneling-is-not-instantaneous-physicists-show/?utm_source=Nature+Briefing&utm_campaign=de91845aee-briefing-wk-20200724&utm_medium=email&utm_term=0_c9dfd39373-de91845aee-42120079

19

Physics, Astronomy & Cosmology / Re: Why Can Photons And Other Subatomic Particles Be In Two Places At Once ?

« on: 28/07/2020 13:17:44 »

A realist (counterfactual) interpretation (like Bohm) would say that the particle (photon, electron, cat) at a given time is in fact at single location X and state S and since there's been no measurement, that location and state is simply unknown to the observer.

Only with respect to the "Explicate Order".   

20

Physics, Astronomy & Cosmology / Re: How Did Time Come Into Existence ?

« on: 26/07/2020 19:59:14 »

'Happened' is a verb tense that simply suggests that it occurred prior to some reference event,

That doesn’t remove the “action” from the verb.  “it occurred” suggests that there was an element of change involved, rather than stating that it was an eternally “existing”, unchanging entity. 

So how could the BB have preceded this post? 

I don’t understand the question.  I would certainly not suggest that this was posted prior to the BB. 

How can the big bang happen?  Things 'happen' in the course of the flow of time, so it implies such a flow, and thus is a problem I suppose for those that suggest such a flow.

We’ve visited “tensed” and “tensless” time before.  There’s a fairly recent one at:

https://www.thenakedscientists.com/forum/index.php?topic=73398.msg545390#msg545390

Neither removes the problems that are relevant to the OP

Coming of anything into existence requires time, so it is contradictory for time to come into existence. It exists or it doesn't, but 'coming into existence' is 'becoming', which is a process, and process requires time

Perhaps there are some things we should accept that we agree on, so we can clear them out of the way before, possibly, addressing the “basics”?

Lots more things to consider in this thread, but duty calls.