1

New Theories / Re: What are they saying about Quantum Gravity?

« on: Yesterday at 16:54:20 »

I just wanted to stick my toe back in the water here and refresh my memory of posts on this thread and see if it seems right to restart posting

Origin seems right. All evidence suggests that your sole purpose in posting is to watch the count of the number of google bots that note each post. You seem to live for the number and nothing else. It is an obsession to the point of being compelled to put the number at the bottom of each post to track its progress.

As for the title of this topic, I didn't read it all, but I didn't actually find anywhere that attempted to convey what 'they' are saying about quantum gravity.

2

Physics, Astronomy & Cosmology / Re: Are there any philosophical or other implications to the underlying randomness

« on: 07/06/2023 03:17:20 »

I also  assumed that randomness  was the only interpretation of QM  that  was accepted .

There is no interpretation called 'randomness'. I think you mean the category of non-determinstic.
Of the 13 basic types of interpretations listed in wiki, 2 are agnostic, 7 non-deterministic, and 4 of them deterministic, meaning no randomness, no 'god rolling dice'. I would include relational interpretation as a 5th one there because it also has no randomness, but wiki lists it as non-deterministic.

So the decay of the nucleus is only of significance when it is measured (to my mind) and  this "measurement" is a synonym with "interaction"

Good point. For one, 'measurement' and 'interaction' are essentially the same thing in QM (with a couple exceptions). You seem to take the non-realist approach that says the decay doesn't exist until measured. I agree with that, but keep in mind that it's a choice, not something known.

Do you stand by your explanation that some occurrences (eg nuclear decay)  take place on their own and without a "partner" in the physical  environment (the wider system they are part of)?

There are valid counterfactual interpretations that say the decay happens even if not measured. Either way, the decay isn't 'caused' by anything, so whether it takes an interaction or not, it's still an uncaused and empirically random occurrence. Given the realist interpretation, it doesn't take two for the decay to occur, so no partner required. A partner is only needed for it to be measured. A tree falling in the forest makes no noise if there's nothing to measure the event. That makes no sense at the classical level since it is impossible for any part of the forest (or of Earth) to not measure the tree falling in it.

More generally,perhaps are not all systems ,large or small interconnected?

Well that's what the Schrodinger's box thought experiment illustrates. The box represents the isolation of a system from the outside, a severance of that connection. This has been demonstrated in the lab for 'large' things (something big enough to see without aid), which were isolated enough to be placed in superposition of state for a time. The procedure to isolate it would not be survived by a cat. Anyway, it constitutes a real situation where two systems were not interconnected for a time. It gets much easier with distance. A planet currently 20 BLY away is permanently not interconnected with Earth today, so there's an example of systems forever not connected, at least per a local interpretation. Given a non-local interpretation, one can influence the other faster than light. Maybe they share entangled particles or something.

3

New Theories / Re: If there was one Big Bang event, why not multiple big bangs?

« on: 29/05/2023 23:16:11 »

Why is Space temperature stuck at -270?C ?

It isn't. It's still falling, but being so close to zero already, it hasn't much further to go.

So why can't it go extremely low?

It's already extremely low.

is ' intesimally ' even a valid word?)

Interesting word, sort of combining 'infinitesimal' and 'intensely'.

Was the temp of the Observable universe ever between 21?C to 24?C?

1, it's the entire universe, not just the observable part. Yes, it was all those other temperatures along the way to where it is now.

Are Measurements lower than -273?C possible?

Zero K is as low as it gets. There are articles that claim some sort of negative energy and express it as lower than zero temperature, so you'd probably be able to google something that claims otherwise.

Ya i know, it's Absolute Zero, but i wanna know if We have instrumental capabilities to Measure lower temps or not?

Any instrument can display a negative number, but if nothing is actually colder than zero, it wouldn't be a measure of anything's temperature.

next im gonna inquire about BH temps, so be prepared.

See no-hair theorem. It says that BH has mass, charge, and angular momentum, and no other properties. Temperature isn't one of those.

4

New Theories / Re: If there was one Big Bang event, why not multiple big bangs?

« on: 23/05/2023 00:39:57 »

When We say the Universe is expanding, rather at an accelerated rate...
That's what We are currently Observing at the Edge of the observable Universe, Right..

Not right. You have to look more nearby to notice the acceleration since it is a more recent thing. The further away you look, the further in the past you see. So we notice things nearby expanding at a proportional rate greater than those currently further away. That's the acceleration, but it started about 6 billion years ago when the constant density dark energy became a greater density than the gravitational energy of all the mass, which became less dense as things moved further apart. So at that point, dark energy more than cancelled the gravity, and acceleration of expansion began. It was deceleration before then, so if you look as far as you can, the most distant galaxies, they're receding at a proportional rate that indicates that there had been a deceleration of expansion going on for over half the current life of the universe.

So, should We say it " is " expanding, or say it " was " expanding?

It is expanding and always has been expanding. If it ever started contracting (it won't), then matter would have won, and it would eventually end with a big crunch. But the expansion rate is currently accelerating, but used to be decelerating.

There used to not be event horizons, but continuous acceleration forms them, so there is our event horizon now about 16 BLY away. Light currently emitted beyond there will never reach our local galaxy group ever. That doesn't mean we can't see galaxies further away than that. It's just that the light emitted from those galaxies was from when those galaxies were much closer by.

5

New Theories / Re: If there was one Big Bang event, why not multiple big bangs?

« on: 20/05/2023 23:24:54 »

1) Is the Pioneer Anomaly resolved?

Yes, it was. Turns out that residual heat from the plutonium power source radiated heat preferentially in the direction it is moving, related to the way they spin. The lack of spin explains why most other craft (Voyager) don't exhibit this.

2) Infinity has no end point, but does it have a starting point?

Mathemtically, a line is infinite in length in both directions, but a ray is only in one direction and is bounded on the other. So it works either way.
For instance, the there's not a finite quantity of whole numbers, but they have a starting point. The integers do not.

6

Physiology & Medicine / Re: Can taking a pint of blood off the body reduce your blood pressure?

« on: 20/05/2023 16:30:32 »

As a supplemental question, is it beneficial (to the doner) to donate a pint of blood  ?

There are definitely some benefits.

It appears that regular donation reduces thickness of blood, lowering the pressure needed to maintain an adequate flow. This lowers stress to the heart.

You can burn 600-some calories without doing a workout. This is reduced by the free sugary snacks they give you afterwards, which itself might be a benefit to some. Don't skip the snacks. I almost passed out once long ago from dropped blood sugar and was 'revived' via a small bottle of coke syrup and breathing into a small paper bag.

You get a free medical screening, including pressure, iron levels, etc.

I've heard that regular donation reduces chance of certain cancers (lung, throat, stomach). Don't know why.

Finally, on the thinking that nobody will come to your funeral if you don't go to theirs, the biggest benefit is that it sets an example for everybody, which benefits everybody when the need arises.

7

New Theories / Re: If there was one Big Bang event, why not multiple big bangs?

« on: 19/05/2023 20:51:28 »

I have a pacemaker and the manufacturer sent a representative to observe the  procedure just in case (in case of what I don't know), and apparently they didn't see any tumors or peculiarities. Maybe they thought my dental work would heat up too much or something.

The dental work doesn't heat up, but the magnets pull the fillings and make your mouth vocalize stuff that you'd rather keep secret (account numbers and such). The pacemaker representative was there to record what your dental work made you say.

You heard it here first folks.   

8

New Theories / Re: If there was one Big Bang event, why not multiple big bangs?

« on: 19/05/2023 02:56:23 »

I did get to experience an MRI

Stands for 'Minimal Room Inside"

But hey, glad it was nothing. Take care

9

New Theories / Re: Solving the puzzle (problem) of Quantum Gravity and Theory of Everything, TOE

« on: 17/05/2023 21:51:48 »

This is a science site. Kindly post your theological musing on a theology forum. There's plenty out there.

Topic closed since no scientific idea is being discussed.

10

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.

11

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

« on: 15/05/2023 12:35:51 »

Hypothetically,  if ewe or I could travel at the speed of light armed with our sentience (yes it's impossible to travel at c).....and we travelled from the Sun to Earth....at the speed of c it would take 8 minutes yes ?, however, what would our perception of the time be ? instantaneous ?

Let's say we wanted to visit Andromeda (2.5 million LY away). If we accelerated enough in that direction, the trip would take not 2.5 million years of our time, but as little time as you want, like say 47^3/4 seconds. It can be even less time if you accelerate even more.
Thing is, even in that frame, you will be stationary and light will be going by you at c still, and Andromeda will be coming at you (from only 47^3/4 light-seconds away) at pretty much light speed.

So since the trip can be made in as little subjective time as you like, our perception of time approaches zero, which is pretty much a 'yes' to your question.

PS and @chris
I don't see your sheepy insideout signature photo anymore. I see it, but it's blank.
Also, the special characters appear in my edit window but turn into question marks when I save my post. Things are not all working anymore.

12

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.

13

New Theories / Re: If there was one Big Bang event, why not multiple big bangs?

« on: 08/05/2023 23:37:49 »

To propose a beginning tends to make me think it also requires the Supernatural.

A supernatural cause is not a beginning, so to propose a beginning tends to preclude a supernatural cause, unless that supernatural thing itself has a beginning. There seem to be contradictions to the usual assumptions no matter how this is phrased.

this is really one of life's imponderables.

You seem to be pondering an awful lot for it being an imponderable.

a recurring sequence of events that might be playing out over and over, here and there, across infinite and eternal space and time.

I think Olber's paradox is relevant here

Olbers's paradox, also known as the dark night sky paradox, is an argument in astrophysics and physical cosmology that says that the darkness of the night sky conflicts with the assumption of an infinite and eternal static universe.

I had read, in the Beginning, there were Equal amounts of Matter-Antimatter.
Any Assumptions available as to Why/How that Symmetry broke?

Kind of an unsolved problem There seems to be no conservation law since black holes violate the conservation of baryon number, so an imbalance isn't any kind of violation, but that's not an explanation.

the Universe isn't just Expanding, rather going thru a phase of Accelerated expansion.

The acceleration commenced about 6 billion years ago when matter density (and associated gravity) dropped below the constant dark energy density (the cosmological constant). It will now forever accelerate, eventually settling on an exponential expansion of about 57 km/sec/mpc.

It must have always been expanding

It was, but it doesn't have to. Had matter density been enough, it would never have dropped below the dark energy threshold and expansion would have stopped, with an eventual big crunch to follow. That isn't our fate.

Last but not the least, Inflation!
Any Imaginations...
Why/How did it Start all of a sudden?
& then Why/How all of a sudden, it Stopped?

Science doesn't answer how/why questions like that. But it started when the universe was about 10^-36 seconds old and lasted until the universe was about 3000 times older than that, which is still a really short time. Or at least the inflation here stopped then. In some models, it is still going on elsewhere.

14

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

« on: 07/05/2023 19:13:48 »

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.

There are some members here with good expertise in some fields, but not all. I for instance know relativity theory quite well but would not consider answering an electrical field question.

Because what I see on facebook or twitter groups is mainly advertising.

Those are not science sites, with no moderation for content. Quora similarly has wrong answers as much as correct ones. All the sites have problems with spammers, but facebook and twitter lack the resources to moderate the sort of volume they get.

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.

FAQ is here: https://www.thenakedscientists.com/forum/index.php?topic=45718.0
Link brings you to reply 3, which covers the attachments, using the "Attachments and other options" link just below your edit window. I honestly forget what the policy is about attaching images as a newbie. What I need is a second account to experiment as a newbie.

When i Search online for ' Science Forums ' i get results for redit, qora, scinet, sciphorums.
thenakedscientists.com does Not show up.

That may be because TNS is primarily a website supporting a radio podcast program, and it just happens to have a forum, rather than actually being a forum as its primary purpose.

15

New Theories / Re: If there was one Big Bang event, why not multiple big bangs?

« on: 04/05/2023 00:06:21 »

If the BB is an After Effect

What is an after-effect as opposed to an effect? I mean, are there 'before effects'?

If the BB is an After Effect, is the existence of a Primordial Cause mandatory?

If it's an effect, it needs a cause by definition. That doesn't mandate a 'first cause', or 'initial state' or however you might want to word it.

16

New Theories / Re: If there was one Big Bang event, why not multiple big bangs?

« on: 27/04/2023 23:33:26 »

the popular version of Big Bang Theory, i.e. a Single big bang, ignores the preconditions that would have to exist scientifically in order for a single big bang to occur.

That's kind of like saying that theory of plate tectonics ignores tornado seasons. It's just not something covered by the theory. It's not that scientists ignore what you call these 'preconditions', but such speculation wouldn't be part of the BBT.
If you're claiming that all of the cosmology community ignores these things, you'd be quite wrong. There are books devoted to it.

Also, the premise of there being only a single Big Bang event

. . . depends on one's definition of 'there being'. What is included in the set of 'what is' as opposed to what is not?

And along with contemplating the idea of multiple big bangs, how can we not consider multiple infinities; infinities of space, time and energy?

Agree. I have no trouble with multiples of these things.

17

New Theories / Re: A Quandary about Accelerated Motion in Special Relativity

« on: 24/04/2023 00:19:57 »

In my original post, I said:

"The LCE seems to require that the two curves get closer together as time increases. Does the upper curve slowly get closer to the lower curve? Or does the lower curve approach the upper curve?"

The LCE applies to rigid objects. 'The distance between two things' is not a rigid object. Read my post above. Your chart is correct and the curves stay equally separated in that IRF.

I've realized that the bottom curve doesn't move upward, because it already has speeds that approach the speed of light "c", and so it's speeds can't be increased any.  So all of the decrease in their separation has to come from a lowering of the upper curve.

So I suppose that is enough information to allow the correct upper curve to be plotted ... just subtract the amount of length contraction (using the LCE) from each point of the upper curve.

You persist in using the mathematics of a rigid object. That's fine, but not the scenario depicted on your chart.
Suppose you had a long rigid object of length D, a rocket say, stretching the distance between the two points on your chart. The rear of it accelerates per the curve shown in the chart. Now the LCE comes into play as you describe here.  All of the contraction of the rocket has to come from, as you say, a lowering of the upper curve, but this also has a consequence of lower proper acceleration of the upper curve since the full proper acceleration is the not-lowered curve that your chart shows. Yes, that is enough information to allow the alternate upper curve to be plotted, albeit a somewhat complicated way to do so. The plot of the full proper acceleration curve remains unchanged as your chart correctly shows.
Anyway, it means that accelerometers at either end of a rocket read different values.

Do the two observers who are doing the accelerating agree that their separation is decreasing?

They'd be wrong if they decided that. In the rocket (with the front guy under less proper acceleration), they'd agree that the rigid rocket remains the same proper length at all times. In the identical proper acceleration case that your chart depicts (and the Bell's scenario discusses, and you still haven't read), they'd agree that their separation is increasing as evidenced by the string between them breaking.

(Inertial observers don't ever think the yardsticks between them contract, so maybe accelerating observers don't think the yardsticks between them contract either.)

That's right, so in the long rocket case, the rocket always remains a constant number of yardsticks in length. The marking are in fact painted along the length of the rigid rocket so it really isn't possible for them to measure a different length.

I've scanned the chart into a jpeg.  How do I post that?

A bit complicated. Apologies.
http://www.thenakedscientists.com/forum/index.php?topic=45718.msg397740#msg397740

It all works through the 'Attachments and other options' link just below the edit window

18

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.

19

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

« on: 13/04/2023 20:08:19 »

Recall that the z-component of the dipole moment is going to be just a scalar not a vector quantity.   The choice of p orbital and the choice of spin all contribute to just one scalar quantity.  There are 3 different p orbitals exactly as you stated and depending on which you choose, the contribution is +1, 0 or -1  (in Bohr magneton units).     The contribution from spin will be +½  or  -½.   The contributions from each thing are of very similar sizes and not well spread, so you do not get 6 different total dipole moments.

OK, that makes sense

There are probably practical reasons for not choosing a simpler atom.  For example,  Lithium would react violently and you just won't have pure Lithum in your experiment for long.

Ah yes, spitting acid (or in this case, a strong base) at a screen might not be the best option.

Fundamentally, a silver atom has an odd number of electrons.
So, when they try to pair up, there will always be one left over.

Well that is satisfied by half the elements then.

20

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

« on: 13/04/2023 17:51:37 »

Well this is uninformed me commenting on just your post without reading anything from a website. So hardly a position of authority I'm saying.

Obviously the Ag atom didn't have just one electron but it's the outermost lone electron that is usually in the 5s orbital which is important.

'Usually'. BC can probably comment better on this, but I presume by that wording that it is not always the case. The higher orbitals can only get 'full' if there are electrons in higher orbitals. The outer one can only hold 8. So I guess Ag is where you get this new lone guy in the outermost orbital, but I can also imagine an atom in an excited state that has more than one out there.

All the other electrons are assumed to form a reasonably complete cloud with enough symmetry that they contribute a net 0 magnetic moment.

Today I learned ...
But if in that excited state, some inner orbital suddenly loses its symmetry and the defection might be due to that instead of the outer electron(s).

Just to explain why they bothered with Ag atoms instead of using just a simple electron beam - they wanted an overall Neutral charged particle.

Any atom fits that bill. Surely there's something other than Ag that fits the bill of having a lone electron in the higher orbital. Lithium seems the obvious choice.

Now, just to check I've understood this experiment.   If, for some reason, the outer electron was not in the 5s orbital (corresponding to quantum numbers n=5, l=0) but instead it was in the 5p orbital  (quantum numbers n=5,  l=1),  would we get a different set of spots?

OK, that seems to be the excited state I mentioned. Not a lower electron joining in the 5s, but the lone one jumping to a higher energy state. The 5p orbitals are not spherically symmetric, so given three possible 5p orbitals and 2 spin states, perhaps that's 6 dots not including the two 5s dots. BC perhaps can correct me on this. It was a very naive answer.