1

Just Chat! / Re: a suitable pseudonym

« on: Yesterday at 01:22:45 »

I had assumed it was HAL from the space odyssey books, but version c  - so not trying to kill everyone.

So much for not trying to leave an impression. It's short for Halcyon.

NOAX   would have been hard to work out.  No-one would have known it was Non-Oxide Adhesive eXperimental,  or a pop singer.   Best guess -    "No Axe to grind".

Last one was closer.
If you remember my answer to one of your other threads about who we are, I put out an answer about identifying biases (a post which was copied by a spammer bot). To do that, one has to hold a minimum set of base assumptions, so it means no axioms.
So I'm way beyond 'cogito ergo sum' since that statement seems to beg at least two such biases.

2

Just Chat! / Re: a suitable pseudonym

« on: Yesterday at 00:13:46 »

Consider the abbreviations
People often tend to shorten names online, which I leant by experience.

That they do, which is why I pick a name short enough that it's not likely to happen. Besides, I often need to refer to myself in the 3rd person, and a long name just means a lot of typing.

However, your name is what you start with and why make people start with an impression that is miles away from where you are?

My name here is just a shortened word and not meant to leave an impression. I could have used 'Noax', which isn't meaningful on first impression, but that name does mean something, even if it isn't quite 'wearing your heart on your sleeve'.

3

Physiology & Medicine / Re: why is my skin so sensitive when I have a fever?

« on: 19/05/2022 16:14:22 »

Is this a known effect?

Very much so, especially for flu. It is similar to heightened sensitivity to sound and light, especially when feverish.

Is there a known (or likely) mechanism?
Is there anything I can do to limit it while recovering?

Apparently staying hydrated is a good way to limit it. Ibuprofen helps reduce inflamatory related symptoms, including the skin sensitivity. I found that acetaminophen does a nice job on headaches and fever, but not so helpful with the inflamation.

Benefit of covid: Our altered social practices have seemingly prevented about two years of all the common stuff I/we usually contract each year. Sorry this hasn't been entirely true for you.

4

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

« on: 17/05/2022 17:37:39 »

Mention a different alternative to "always existed".

This would require one to drop one or more naive bias.

"Always existed" is a phrase only meaningful to objects (a house, galaxy, the weather, etc.) contained by time. So if the universe is not reduced to an object contained by time, but is rather a structure that contains time, then it just exists. This is standard realism, a view held by Einstein and by probably the majority of physics that understand Einstein. If the universe is not a structure that contains time, then all of relativity theory is wrong, and there's not really an alternative thoery that has done its own generalization. So for instance, there's the neo-Lorentian interpretation, which says absurdly that all the equations that Einstein derived in relativity theory can be used to make any prediction, despite the fact that they're all based on premises that are wrong (such as the frame independent constant speed of light). But that's a view (used by nobody that actually has to work with physics) that posits the universe as an object contained by time, and thus is in need of being 'started'.

Dropping the bias of 'universe as an object in time' is not difficult, but if it is for you, then dropping the others will be out of reach, so I'll not go into other alternatives that require more out-of-the-box thinking. This is a science forum. Science is concerned with making empirical predictions, and none of the explanations of the existence of the universe make any empirical predictions, so they're not science.

It's like the question you asked about life elsewhere: If it's beyond the event horizon (which is currently just outside the Hubble radius and well inside the radius of the visible universe), then it cannot be measured by us and by any definition of existence that involves measurability, doesn't exist. That's a very different answer than the mathematical "any nonzero probability multiplied arbitrarily high results in a certainty".

5

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

« on: 14/05/2022 06:52:40 »

Would you mind posting a few words from your thoughts

For the most part, you seem to have gotten completely off track. None of your recent posts have been about multiple bangs or related theory. To be honest, I have little idea what you're currently proposing. You're just blogging random and mostly unrelated thoughts.

about how unique life is in the universe, given an infinity of time and space.

If life is of any probability greater than zero for any given star system, then given unlimited star systems, there must be life on an unlimited number of stars. Any other possibility is mathematically inconsistent.
This assumes infinite space (and thus infinite star systems), but not infinite time, since any given type of life is only good for a finite region of time: Too soon and there's too much violence and not time to develop stable life. Too late and entropy takes over and there's no energy left to support life. As it is, life has been on Earth about 4-5 billion years and all but the simplest life will be gone here in another billion. The planet will not support eukaryotic life soon, and that includes anything multicellular.

[Spoiler:]

6

Just Chat! / Re: A Short puzzle with dogs.

« on: 12/05/2022 15:01:04 »

Another physical solution:

Spoiler: show

Replace the river 'rod' with a mirror and shine a laser (a surveyors laser that leaves a line on the ground) from the dog to the reflection of the house

[Spoiler:]

7

Just Chat! / Re: A Short puzzle with dogs.

« on: 12/05/2022 14:52:34 »

I'm still working on the circle problem, but have had almost no time to do so. It's coming.

Maybe the dog can shorten the effort by jumping on a board floating on the river, saving steps. I presume such complications are not part of the problem.
This problem has a physical solution:

Spoiler: show

Just put pegs in a board where the house and dog are, and a rod representing the river. Tie a string to the dog and the house looped around the rod and pull it tight. It will move to the shortest path, which momentarily touches the river 4/7th of the way, or ~43 m west of the house.

8

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

« on: 18/04/2022 20:11:54 »

Many of us recognize the graphic of the birth of the universe, with the pinpoint beginning from a single "primordial atom" (per Georges Lamaitre), that is expanding outward into any imaginable future we want to entertain.

While I've seen may graphics, I can find none that were authored by Lemaitre himself. He certainly didn't posit the universe beginning from a small state. The visible universe perhaps, but that never grew to infinite size in any finite time. So I think you're misrepresenting the general big bang concept.
I don't see how a graphic can depict an infinite thing and a finite thing in the same picture.

The graphic depicting the universe growing from a single primordial atom to an infinite expanding universe doesn't seem to be right to me, but it seems to be the current consensus.

That's a common naive misconception. It is certainly not any kind of consensus. You said you don't want to learn any actual physics, so I can not really help you. Your blog is already 800 posts and still asking the most basic questions.

I prefer an "always existing" universe, where Big Bangs naturally occur; they occur in any patch of space containing enough matter and energy to allow gravity to form a Big Crunch/Bang

Well that's the problem with this model. Any collection of matter/energy (let alone what we see in our visible universe) squeezed into a small existing space like that would constitute a black hole (and a violation of energy conservation), and it would be in a crunched state before it could ever bang. It couldn't happen once, let alone multiple times.  The Milne model works something like that, but only because it is a zero energy solution, so no black holes form.

I think you agree that the universe is infinite. Correct me if not.

I think this question was directed to me, despite lack of mention of me in the post.
The size of the universe is unknown, and also coordinate system dependent and also dependent on the direction the measurement is taken. So for instance, in the approximate inertial frame of Earth, the universe is physically bounded and under 28 BLY across. The visible universe is often quoted as being larger than that, so the often quoted figure doesn't use inertial coordinates for the measurement.

9

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

« on: 17/04/2022 18:16:17 »

We are talking "Bogie Logic" here, lol.

Yea, I noticed.

Go in a straight line into space forever and tell me when you run into the wall, crash wham!!!

First of all, spatially, you can go in a straight line forever and not even reach stuff that you can see in front of you, regardless of speed. That part is known.That's hardly any kind of evidence of the universe being spatially infinite or not.
Secondly, finite space does not imply it has an edge. Space on the surface of Earth is finite, yet there's nowhere where you can go in a straight line and wham into the end of it. So much for "Bogie Logic".

Thirdly, you can draw a straight line in the temporal direction and you will very much 'bang into a wall'. There may or may not be meaningful 'universe' on the other side of that wall, but the wall is very much there, which seems to be how you define a boundary according to your logic.

Just a brief example:
Let's assume that you are a jet eng. designer.
You had been asked to design a jet engine for an airplane.
However, you have no clue about the size and the total requested load of this airplane.
Can you do it successfully?
Don't you agree that a get engine for 100Kg should be different from a jet for 1,000,000,000 Tons?
Maybe for that kind of load a jet engine is not good enough.
So how could it be that we have any sort of theory for a universe without any knowledge about its total size?

Example is inapplicable unless you can name one engineering project (or any empirical observation for that matter) that depends on whether or not the universe has finite spatial extent or not.

[Spoiler:]

10

Just Chat! / Re: A Short puzzle with dogs.

« on: 15/04/2022 14:34:32 »

To get this straight, the nasty dog is restricted to the circular path and always moves at 4x your speed in the direction that takes it closer to the point on the circle to which you are nearest.

Seems pretty simple.

Spoiler: show

Run away from the dog. As it picks a direction, you change course and follow a circular path as well. This works fine as long as you're within a quarter of the distance from the center to the edge. So you are capable of keeping the dog at max distance until this point.  Starting at that point, you break for the edge, and angle your path in a 1-4 ratio from the dog's motion, just to buy a little more space.

Is this enough?  Circle of radius 1 and the dog needs to travel 3.14.  I am at 0.25 and need to travel 0.75.  No problem. I don't even need to do the angle bit.

I think a curved path might be optimal and it would seem an interesting problem to determine the max speed that the dog could run before you could not escape the circle. I suspect it's over 5x, but didn't work it out.

11

Just Chat! / Re: There's a section with "similar topics" appearing.

« on: 13/04/2022 18:24:36 »

It's been there forever, and it seems to be a simple best-match on what it sees as keywords.

    The Similar topics suggested included:
a)   "Can I Use Washing Up Liquid To Wash Hands And Hand Soap To Wash Plates?"
b)   "How long must a prism-shaped corridor be to render a light-source invisible?"

The first one obviously matched 'plates', but no clue why it thought b) should be on the list.

12

Just Chat! / Re: A Short puzzle with dogs.

« on: 12/04/2022 19:23:44 »

The calculus appears pretty complicated, but the picture shows some trivial facts.
First, to answer a prior question, I assume everything is a point, the problem otherwise not really being fully defined.

You've approximately shown nearly half the distance traveled. At the actual point (har!) the distances between them have been halved, the answer is simply twice the distance already traveled.

The remaining distance is a square still, but rotated something like 30 degrees or so. Each time the distance is halved, the square gets rotated by that amount, so the dogs are going to circle each other an infinite number of times before the collision after a total path length.

My attempt: The problem can be broke into tiny pieces, so let's say a dog moves a trivial distance x, almost a straight line. It will curve just a little bit, but for sufficiently small x, a straight line, bringing it exactly x closer to the next dog. This leaves the same initial condition, but rotated and a little closer. Therefore the path length of each dog is exactly 1 by symmetry since each movement of x reduces the distance between them by x.

13

Physics, Astronomy & Cosmology / Re: How does a red-shift affect a black body spectrum?

« on: 05/04/2022 03:49:43 »

I think I agree with Origin's statement about the shape, but is the T2 shape of a stationary object just a shifted version of an object with a different temperature?  If not, then a shifted (as seen by a moving observer) object at T2 would not be the same shape as a stationary object with a 'proper temperature' (if there is such a term) of T2. I don't know my black body radiation enough to say one way or the other.

In the rest frame of the observer, is the radiation they receive from the black body still going to have the right distribution to be consistent with a Black body spectrum but just with a different temperature T2?

As for the statement above, the temp T2 is dependent not just on the frame, but the position of the observer in that frame.  So if the black body is moving at v in the +x direction, the observer (stationary in that frame) might see a red or blue shift depending on his position in that frame.
You know this, but the OP didn't make that clear. Maybe he's off to the side and the thing is going by him without any Doppler shift, at least for a moment, just like an ambulance going by momentarily has an unshifted pitch to its siren.

14

Plant Sciences, Zoology & Evolution / Re: Can A Cuttlefish Act As A Video display ?

« on: 02/04/2022 16:03:26 »

I think he already is one. Like his squiddity relatives, he can put on a video of his background for camouflage, put on a scary show for what's considering him for lunch, or maybe a sexy vid to get the ladies (like he needs that... already cute enough to want anybody to cuddle a cuttlefish). Only trick left is to pick up the wifi so he can stream netflix or something.

15

Just Chat! / Re: What is your main area of interest or expertise?

« on: 31/03/2022 17:25:53 »

I'm going to give the award of the "best answer" in a couple of days.  If you want a chance to win this greatly coveted award then get your replies in soon.

This topic is more of a survey and not a question where there are answers more correct than others, so I'm not sure of the meaning of one of them being the best. Is one person's interest/expertise better than another?

Secondly, I suspect you overestimate the level at which that 'best answer' status is coveted. Saying thanks to all replyers is often more appropriate, and something where the 'score' is kept as well.

Best regards

16

Just Chat! / Re: What is your main area of interest or expertise?

« on: 30/03/2022 13:25:25 »

My main interests are identification of irrational biases, things people take for granted without ever really justifying them. I tend to discuss such things elsewhere as this is a science site.

My limited expertise seems to be in relativity, quantum interpretations, and logical reasoning, as such expertise is required in the pursuit of the above, but I'm by no means an actual expert in any of it. My knowledge is weak in electromagnetism, and I avoid answering questions there. I am here mostly to answer questions coming from the rare poster that actually seems interested in learning.

You (ES) have probably already figured out most of that, except probably the bit about the biases.

17

Question of the Week / Re: QOTW 22.03.21 Does relativity make rocks on the moon older than Earth rocks?

« on: 27/03/2022 13:32:53 »

If I recall correctly, proximity to the sun is sufficient to put the planets in the right order of time dilation that would apply on their surface from Mercury to Pluto - their own individual mass, radius, rotation and orbit speed makes just a small contribution.

Rotation speed is completely insignificant compared to orbital speed, and even that makes terribly little difference compared to the varying potentials.

Sorted by slowest to fastest clocks on the surface of each planet, the list is:
Mercury, Jupiter, Venus, Earth, Saturn, Mars, Neptune, Uranus, Pluto

The standard reference for this data, including many of the moons, is Randall Munroe who yes, did all the mathematics for xkcd

18

New Theories / Re: Could the Hubble constant be related to the proton radius?

« on: 19/03/2022 15:53:00 »

Now, if you read the preprint, you will notice that all physical values are referred to as constants, including the proton radius.

Despite its name as 'the Hubble constant', it isn't a constant. For a zero energy solution of the universe, H would be exactly 1/t where t is time. The value has the same units as 1/t.

So, your conclusion about my idea is unjustified.

What conclusion exactly was that? I don't remember making one about your idea.

I looked at the paper a bit.
The first 'constant' is this M_min which lacks a reference. The H value (references given in introduction) is given to far more precision than is justified by the range of values in the references.  Looking at really distant galaxies doesn't count since they're way in the past when the value of H was considerably different.

I'm just saying that you're not justifying the sort of precision that the paper claims.

Origin is right, you're substituting variables of different units into equations, rendering them meaningless. You're using the energy formula for a photon and applying it to something that isn't a photon.

19

New Theories / Re: Could the Hubble constant be related to the proton radius?

« on: 18/03/2022 20:15:54 »

The value of M_min corresponds to the Wesson’s mass (m_E ≈ 2 × 10 ⁶⁸ kg), i.e., the quantum of mass calculated by Pr. Wesson [10] in 2003 using the constants c, h and Λ (the cosmological constant).

Yes, it seems Wesson attempted to determine a quanta of mass.

In the last century, Paul Dirac popularized this β ratio in a cosmological context [8] [9]. It still gets attention because of its high value (β ≈ 2.268 66 × 1039). The gravitational force is tiny compared to other forces.

You're giving refereces 8 & 9 which don't correspond to any bibliography.

You are obviously copying directly from the works of others without giving credit. This plagiarism violates site rules.
Please edit your posts with credits properly given.

The decreasing value of the Hubble constant is indeed suggested by the conformal model ΛCDM.

That very model suggests that H will actually settle down to a constant value of around 57 km/sec/mpc, which is straight exponential expansion.

20

General Science / Re: evolution

« on: 23/02/2022 12:16:27 »

I can come as beards being a hangover from an indication of testerone etc levels in attracting a mate.

Agree, so long as you remember that the testosterone level is not there to attract a mate, but rather it is the female that is bred to be attracted to the testosterone level.

As food gathering, and rearing young there are numerous spieces where gender cooperate in this.

Yes there are, but you wouldn't know it to read the paragraph I quoted Morgan who says "I don't know of any other species where males obtain food to share with females and young". You name several of the examples that also came immediately to mind to me.

The aquatic ape theory I heard 40 years ago and seems no closer to verification.

Well, the aquatic part is certainly obvious. One has to be blind not to see that. But all the details about hair distribution, social roles, the loss of estrus, etc. remain speculation.