swansont

16 minutes ago, Michael McMahon said:

One reason many Australians and Brazilians might not be too afraid of large spiders and snakes might be that the head-size of tarantulas are comparable to a snake head even though a snake would have a much longer body. This might help to counteract the mysteriousness of their minimal psyche even though I’m not too sure if most arachnophobes also have a fear of snakes. I was slightly creeped out looking at online photos of tarantulas yesterday only to have a dream of carrying a snake box last night as if to neutralise the initial fear of tarantula images. 

3 hours ago, externo said:

It is the part where it says "No twin paradox in an absolute frame of reference"

Saying this is not the same as “there is a paradox except in the case where we postulate a privileged reference frame” but at this point I’m not surprised that you don’t see this.

46 minutes ago, Photon Guy said:

Nope animals are just consumers, it's the plants that are the producers. 

Carnivores eat herbivores, and sometimes other carnivores.

This notion of producers and consumers seems overly simplistic. Like someone is applying a very rudimentary economic model to it.

2 hours ago, externo said:

 

Yet, Wikipedia says that there is a paradox except in the case where we postulate a privileged reference frame.

Is that the part where it says “Therefore, the twin paradox is not actually a paradox in the sense of a logical contradiction”?

2 hours ago, externo said:

 

I wrote "This is also how Einstein saw it, he thought that there was an ether which was stationary for everyone."

It is called the relativistic aether, but it is also a luminiferous ether, it is the Lorentz ether deprived of its state of motion.

Just saying this doesn’t make it so.

”It may be added that the whole change in the conception of the ether which the special theory of relativity brought about, consisted in taking away from the ether its last mechanical quality, namely, its immobility.”

doesn’t support that notion

neither does “We may assume the existence of an ether; only we must give up ascribing a definite state of motion to it”

28 minutes ago, externo said:

He later changed his mind.

Not really. He concluded that space has properties, but it’s not a medium that represents a preferred frame of reference, or is required for light. The aether he spoke of later is not the luminiferous aether of Lorentz theory.

Welcome to SFN

AFAIK a time crystal is predicated on no energy loss, so you’d destroy it by removing energy from it. Like taking energy out of a pendulum - it would stop ticking.

It certainly doesn’t generate any energy.

1 minute ago, avicenna said:

I am saying the potential difference between the ends of the wire, i.e. a long wire connected to a dc battery.

The latter part of my explanation applies to this. The current is uniform. There’s no way for it to vary.

1 hour ago, avicenna said:

If the voltage across a long wire is constant, is the current uniform throughout the wire length

If the voltage is constant (for a real wire) there would be no current. If there is a voltage drop, and thus a current, the current will be uniform even if the voltage drop is not (e.g. if there’s a resistor, or a series of different-valued resistors); there’s no way to vary it. Charge is conserved, so current flowing in to a point equals the current flowing out.

38 minutes ago, ImplicitDemands said:

Thank you for repeating that. 

If you repeat your errors I will repeat the corrections.

38 minutes ago, ImplicitDemands said:

Proteins are made out atoms which have electrons. So at the very most basic level what is happening is literally ionization from light in the dna composing the retina. Yes when you get to the cellular level things like photosynthesis seem more complex but it's all just light and electricity interacting with each other just like the computer. 

Red light lacks the energy to ionize, so that’s not what’s going on. I’ll leave it to others to correct the biology.

7 hours ago, ImplicitDemands said:

An LED is basically the reverse of photovoltaics, i.e. electroluminescence. 

Which is not the photoelectric effect. In an LED you excite electrons to a higher band in a semiconductor, and when they drop back down you get a photon. 

2 hours ago, ImplicitDemands said:

Photoelectric effect - As an electron returns to its normal state upon one photon entering and exiting a system, two photons are released.

Photoelectric effect is basically the same as photoionization of an atom, for a single photon. Photon in, electron out.

edit: an LED is not doing this

1 hour ago, MSC said:

Then what is your position?

On what, specifically?

18 minutes ago, MSC said:

Regimes rise and fall, Putin, Kim and Khamenei are all mortal men with an expiration date, opinions and policies change. You are old enough to know that the world does in fact change as you've lived through more of those changes than I have. 

But one thing you notice is that such leaders are always around. Before this it was Saddam Hussein, Kim Jong-il, Nicolae Ceaușescu, Pinochet, Idi Amin, Khaddafi, and more, and that’s only going back ~50 years

18 minutes ago, MSC said:

Same goes for @swansont and the arguments he's made, they just aren't very strong or convincing and that isn't on me but on you guys. I'm not the type to listen to what amounts to "because I said so.", I'm sorry but that's just not going to happen. 

I don’t think I was saying BISS, or really making an argument (or advocating a position) as much as I was poking holes in what you were presenting.

1 hour ago, Luc Turpin said:

Then this disqualifies me from participation in this forum.

Plenty of people without expertise participate here. The ones doing it successfully generally ask questions to fill in the gaps in their knowledge rather than pontificate in areas where their knowledge is deficient, and defer to those who know more.

1 hour ago, externo said:

Time is not physical, so you don't age?

Aging is a biological process. Time is time. Time passes at a different rate (i.e. frequency) in different reference frames

1 hour ago, externo said:

Why would the wavelength decrease?

Because that’s what happens in the Doppler effect. Red shift is shifted toward longer wavelengths and blue shift toward shorter. It’s observed to happen, so there’s no point in denying it.

2 hours ago, externo said:

It's simple: we synchronize the clocks according to Einstein's procedure so that the one-wat speed of light is measured constant. If this speed is physically constant, the synchronization must indicate the physical time.

Physical time? You keep using expressions like this, and they make no sense.

2 hours ago, externo said:

So, you see, his speed is not constant relative to the waves...

The speed of a wave is frequency*wavelength

The frequency increases by the same factor as the wavelength decreases. These terms cancel. The speed of the wave is the same.

2 hours ago, externo said:

I'm not saying that it doesn't happen as soon as they started moving toward earth, on the contrary, but for it to happen instantly

These are the same thing

2 hours ago, externo said:

they have to change speed in relation to the waves and therefore the speed of light cannot remain constant when they accelerate, therefore the postulate of the constancy of the speed of light cannot be true. That's all I'm saying.

--------------------------------

And you’re wrong. The speed of the wave is constant (it’s right there in the math) since both frequency and wavelength are changed.

2 minutes ago, Luc Turpin said:

Pop-science in not Michio Kaku, nor Star treck, but science studies that are made available for public viewing.

That’s not what pop-science is. At least that’s not what most people mean by it. You can get science studies on places like arxiv, but it’s not written for the general public. They are preprints of articles that end up in journals. Definitely not meant for the general public. pop-sci typically removes most of the math, and with it, a lot of the rigor and ability to actually do science with the information

2 minutes ago, Luc Turpin said:

This is not the interpretation of others. If I am reading the second sentence correctly, I am not implying anything; surely not that current subatomic models are getting it wrong.

If models aren’t getting it wrong, why do we need new ones?

1 hour ago, externo said:

If the speed of light is physically invariant by change of frame of reference then instead simultaneity must vary physically. If you play to modify the laws of kinematics you must assume the consequences.

I don’t know what you mean by “simultaneity must vary physically”

Things are simultaneous or not, and it’s a temporal effect. Events that are simultaneous in one frame are not simultaneous in other frames.

On 4/18/2024 at 4:39 AM, externo said:

When the traveling twin turns around to reach Earth, it observes a blueshift of the light emitted by Earth instantaneously, not after some time. This seems to suggest that the blueshift arises from the twin's own acceleration and therefore its own motion through ether, not from the apparent movement of Earth relative to it. 

The earth twin sends out a continuous signal at some frequency, with some wavelength. The space twin travels at some speed, and sees this signal as red-shifted - they get the crest of one wave, but have moved away before the next crest can reach them, so they measure the signal with a longer wavelength and lower frequency.

Then they turn around, and are now moving toward the source. They get the crest of one wave, but have moved closer before the next crest reaches them. Since the signal was sent continuously, this happens immediately - the light is already there to be detected. They measure the crests as being closer together and with a higher frequency. Blue-shifted.

I can’t fathom why you think this would not happen as soon as they started moving toward earth.

14 minutes ago, externo said:

It's simple reasoning. The theory imposes an ether naturally. The speed of light is constant relative to the ether. Now to remove this ether, we must postulate that the speed is invariant with respect to all frames of reference, but this requires that this invariance be physical,

I’m not sure what this even means. 

c being invariant has certain consequences, two of which are time dilation and length contraction

14 minutes ago, externo said:

otherwise it is only a mathematical construction,

Physics is chock full of mathematical constructs, so it’s not like this is a strike against physics.

14 minutes ago, externo said:

the speed of light still changes and there still exists an ether. It turns out that this hypothesis of physical invariance requires that the Earth ages suddenly, that's how it is. It's pure nonsence but it's not my theory.

It’s not relativity, either. It’s a straw man of relativity. You’re the only one here saying the earth ages suddenly, and you’re not a credible source on the topic.

46 minutes ago, Phi for All said:

It's not though. It's often exaggerated or implies things the actual scientists never implied. It's inherently biased regarding a methodology that strives to remove bias.

And when it’s a scientist it’s often slanted toward the views of individuals who make themselves available, but are commenting on topics outside their area of expertise, like Michio Kaku. 

46 minutes ago, Phi for All said:

Popular science articles are meant to interest the reader who isn't jazzed enough by the nuts and bolts of science. 

Or just don’t have the background to understand the nuance that’s involved. (which the author might lack. see e.g. any quantum teleportation piece that mentions Star Trek)

1 hour ago, Luc Turpin said:

Pop-science journalism is an extension of science and promulgating basically the conclusions of science. I persist in saying that there is a prevailing negative undertone in science. As if we are still hung up on what religion entailed for society as a whole in the past. As if the counter revolution never stopped. The mere mention of religion or god gets everyone riled up.

By and large pop-sci is journalists and not scientists, and the two groups don’t always get along.

1 hour ago, Luc Turpin said:

Science as in evidence versus the scientific community as in scientists interpreting the meaning of the evidence

Who else would interpret the meaning of the evidence?

When there’s some new result, we don’t necessarily know what it means. It takes time to figure that out. Until there’s a consensus it’s irresponsible to claim that we know what the evidence means. What you can do is make your argument, but the final decision has to wait for more evidence.

1 hour ago, Luc Turpin said:

Classical physics was replaced by quantum physics not because it was wrong, but because it was insufficient at describing the subatomic world.

IOW its description of subatomic behavior was wrong. What are current models getting wrong?

1 hour ago, MSC said:

if you are going to claim that they are similarly hazardous, you'll need to provide evidence to back up the claim. 

 

Given the numbers of each, conventional weapons don’t have to be as hazardous from a chemical standpoint to have a greater cumulative effect. 

TNT and RDX are toxic and possibly carcinogenic 

https://en.m.wikipedia.org/wiki/TNT

https://en.m.wikipedia.org/wiki/RDX

21 minutes ago, MigL said:

I'll give you an ounce of T-Nitro-Toluene and an ounce of radioactive Cesium

And this should be scaled to the amounts created for weapons

33 minutes ago, Luc Turpin said:

I am not talking about inheritance for now. I am talking about the prevalent mindset that we have no control over our lives because of our genes. "Doom and gloom" scenarios are prevalent in science and being percolated down to the public all the time.

I think you are mistaking pop-science journalism with science.

33 minutes ago, Luc Turpin said:

Science is shifting rapidly; the scientific community appears to not always be following the current.

Models need not be proven wrong to be replaced; better models need only to be found.

I can’t reconcile either of these statements 

Science is performed by the scientific community. Any shifting is from them. Not all surprising results pan out, so it’s not prudent to chase after them until they are confirmed, and one result might not be nearly enough to formulate a new model.

If a model is not wrong - it accurately predicts/matches results - then what constitutes a better model? There has to be some discrepancy between model and experiment for there to be improvement in the model. i.e. there has to be something that it gets wrong.

On 4/21/2024 at 10:03 AM, Luc Turpin said:

Talking about Dawkins “I don’t think the great majority of research biologists are any longer going down that path in the way in which he laid it out. I am sorry to say; I think the ground has shifted quite a long way”

“I don’t think that people like Richard yet know that; that things have really moved on rapidly”

I thought your position was that science doesn’t shift; these are quotes that imply that this is indeed happening.

If models need to be replaced, they have to be shown to be wrong. You haven’t shown that. 

I recently saw there were some interviews on “new physics” and one of the comments, from Chad Orzel, was "Will there be new physics? We’re not done with the old physics yet".  i.e. we know where the holes are in physics and where new physics is needed, but there’s a lot of science to be done in the established areas of physics. I think the same applies to biology.

42 minutes ago, MSC said:

Is it? I hear about much more concern these days over fossil fuel use than nuclear waste, but again the concern is largely ignored by governments. Will respond better later, working. This is a good conversation though! Thanks for having it with me. 

There hasn’t been much nuclear plant construction in the US in the last 30 years, at least in part because of public opinion, so not much to actively protest on that front.

10 hours ago, MSC said:

As for your question about depleted uranium; Does making bullets or firebombs produce nuclear waste? Which if not handled or stored properly does its own damage to ecosystems without any requirement for a weapon to be fired or detonated at all. Enriching plutonium and uranium does. Reprocessing nuclear weapons does. Making bullets, grenades, napalm and other conventional weapons does not (unless the manufacturing facilities are powered by nuclear energy of course).

My point is why the focus on nuclear waste? It’s similar with energy generation - the phobia about radiation when burning coal causes lots of disease and death, but somehow we’re sorta OK with it; the pushback on coal is minuscule when compared to nuclear. 

Unused conventional weapons are eventually discarded, and this does cause issues. Many countries banned the practice of dumping them in the ocean because of the problems, like the toxicity of TNT and RDX.

https://www.sciencedirect.com/science/article/pii/S014111362030862X

The existence of nuclear power means there will be nuclear waste, so getting rid of the weapons doesn’t eliminate the problem