1

Geek Speak / Re: Should you secure erase an SSD before giving it away, like you should an HDD?

« on: Yesterday at 18:33:16 »

But because I've used it at the hospital and for clinical work, while there should be no personal data there, I wanted to erase it with a data over-write to be absolutely certain.

There's a duty on you to take reasonable care to delete the data.
The consensus here (and I agree with it too) is that overwriting once should be enough.

I think that would meet the legal definition of "reasonable".

2

New Theories / Re: Biblical Flood

« on: 01/02/2023 19:00:35 »

Object B at close proximity to object A has a strong charge polarization and is pushed towards object A more strongly than is pushed away from object A. Object C at longer distance from object A has a weak charge polarization and is pushed away from object A more strongly than pushed towards object A, accounting for the attractive force of gravity at shorter and repulsive force of gravity at longer astronomical distances.

https://twitter.com/Yaniv_Stern/status/1620730118980395012/photo/1

Bollocks.

3

Technology / Re: Is solar energy the same as light energy?

« on: 27/01/2023 00:00:13 »

but at the heart of every photon is a magnon

You should stop posting this bull.

4

New Theories / Re: Biblical Flood

« on: 23/01/2023 13:07:38 »

https://onlinephilosophyclub.com/forums/viewtopic.php?f=12&t=15652
That page just shows that you are consistent, not that you are right.
I note he has removed the post....

I did not remove my post. Who removed my post ?

Probably somebody who realised it was pointless obfuscation.

http://www.rationalskepticism.org/pseudoscience/experiment-to-test-w-mg-t55108.html

I think the rules have something to say about posting here to drive traffic to other sites.
If you think you made a valid point at some other forum, just make the same point here.
We don't need to look through dozens of people telling you why you are wrong.
We already know that.

5

Technology / Re: Electricity Generation via treadmill. Can one person generate enough?

« on: 19/01/2023 23:23:33 »

Simple answer: No.

Complicated answer; Still no.

6

Physics, Astronomy & Cosmology / Re: Has the speed of light been tested in a vacuum?

« on: 08/01/2023 10:26:07 »

Hey...  Does anyone have any comments on my back-of-the-envelope calculation of air being 99.85% vacuum?

Especially the part where I try to derive the refractive index of air from the refractive index of liquid nitrogen
- The method I used for that calculation used a lot of hand-waving
- What would be a better method of calculating it?

While your calculation isn't precise, it's a whole lot better than lots of the ideas put forward in this thread.
Ignoring the oxygen is not a serious problem because the refractive indices of O2 and N2 are pretty similar.


It's possible to measure the speed of light in a gas at varying pressures and then plot a graph and extrapolate to zero pressure, which will give you the speed of light in a vacuum.

7

Physics, Astronomy & Cosmology / Re: Has the speed of light been tested in a vacuum?

« on: 06/01/2023 18:23:48 »

I say again: space is a vacuum. The universe is mostly space, plus some matter. Do not confuse "universe" and "space"- this is a science forum, not a bunch of bad journalists torturing the language.

I say again , but space is't devode of all matter

Nothing is devoid of all matter.
There is no true vacuum.
All you can hope for is a partial vacuum and, on a big scale, the universe is a pretty good partial vacuum.

8

Physics, Astronomy & Cosmology / Re: Has the speed of light been tested in a vacuum?

« on: 06/01/2023 17:36:49 »

If space is a vacuum it isn't a very good vacuum because I can see lot of matter

You can only see the matter because there's a vacuum between you and it.


BTW, you keep refusing to answer this.

Do you understand that a vacuum is impossible?

9

Physics, Astronomy & Cosmology / Re: Has the speed of light been tested in a vacuum?

« on: 05/01/2023 16:26:15 »

There is no such thing as a perfect vacuum.
But the space between the stars + planets is a much better approximation to a vacuum than any ever produced by man.

10

New Theories / Re: Is there a better way to explain light?

« on: 01/01/2023 15:49:42 »

Go and look up what the words mean.

Does a silver mirror transparent, as per your definition?

Does it what?
Or did you use the wrong word?

Is the silver mirror transparent?

No.
In principle it does not absorb light.

11

New Theories / Re: Is there a better way to explain light?

« on: 29/12/2022 09:48:23 »

How should the question be stated according to your understanding?

How am I meant to guess what you want t know if you can't write it down?

12

New Theories / Re: "New" theory of human movement as described by Tesla

« on: 22/12/2022 21:27:40 »

If so should we hold a press conference

That would depend on what the external influence "wants".

13

Physics, Astronomy & Cosmology / Re: Is there an experiment that shows the oscillation in the E field of light?

« on: 20/12/2022 18:42:48 »

I understand what Hamdani is alluding to and it is something I have often thought about-permeability and permittivity are macroscopic properties derived fundamentally from the presence of charges in said material. Do they have a meaning at the atomic level?

You can calculate a refractive index from the relative permeability and permittivity.
That's a measure of how much light slows down as it passes through the material.
But light doesn't actually slow down,  simplistically, it gets "stuck" to the particles
So, on the microscopic level, a refractive index isn't well defined and thus nor is the permeability or permittivity.

On the other hand, I can say the plastic they make thin spectacle lenses from has a high refractive index because it's full of sulphur compounds and the sulphur is big and polarisable- the nuclei don't keep a very tight grip on the electrons so, a passing ray of light interacts strongly with the electrons and thus with the plastic.
That's a good enough model down to the atomic level or thereabouts

It's not a clear cut issue.

14

New Theories / Re: Is there a better way to explain light?

« on: 18/12/2022 15:04:45 »

Which dimensional analysis are you talking about?

Two things can not be the same if they have different dimensions.
For example, a speed can never be the same as a distance.

And you can not measure mass in seconds.

So a current which has units of charge divided by time can not be a charge.
So a coulomb is not, and can not be, a current.

If you find that your maths shows that they are, you should go back and find the error in your maths- because you can be absolutely certain that there is one.

So, yes, you are human and will make mistakes.
Please check for them before wasting the site's bandwidth.

Also, when someone points them out, please correct them rather than trying to pretend that you are right.

15

Physics, Astronomy & Cosmology / Re: Is there an experiment that shows the oscillation in the E field of light?

« on: 17/12/2022 17:44:25 »

Hi.

That energy is transferred when a force moves through a distance.

   That's a result from mechanics, especially Newtonian mechanics.   Not all energy is transferred in a way that can be identified as some force moved through some physical distance.

   For the transfer of heat between two bodies, there doesn't need to be some force identified and some distance over which it was applied.   For example, a hot body does not push a colder body away, it just transfers heat.  (You can try to look microscopically and consider particles being agitated or accelerated by some force but if you look again with different glasses on then there are no particles, just waves.  Alternatively you just need to recognise something you ( @Bored chemist )  said in a different thread about temperature - temperature can be a measure of all sorts of internal energy in a substance and not just translational, rotational or vibrational motion of particles).

   The transfer of energy by waves is, of course, another example.   A water wave is a wave in something,  you could imagine that a superposition of two waves into a bigger wave (which is then a bigger lump of energy) happens because the water is being pushed up by some force from the other wave.  For an e-m wave, it does not have to be a wave in any material like "the aether".  Somehow the two waves just do combine and there is a big wave BUT there may not be any material or any force acting on that material that can be identified.   You obtain a bigger amount of energy in the final e-m wave but there was no material where mechanical forces had been applied over some physical distance.

   Getting directly to the situation being discussed:  For an atom and photon interaction,  the energy is transferred in some way that is not like some sort of mechanical force applied over some physical distance.   For example, you can't have two small forces that would sum up to the sufficient force (such as two low energy photons striking the electron).   You must have one photon of the right energy all in one go.   There is also no way you could use a smaller force but allow it to act over a larger physical distance   (I don't even know what that could mean or look like - the photon just interacts and there was no "distance" over which that force was applied).

Best Wishes.

The latent image in a photograph is composed of "out of place" electrons.
There's not many explanations for that which don't involve electromagnetic forces.

16

New Theories / Re: Is there a better way to explain light?

« on: 17/12/2022 00:54:33 »

If the ball is replaced by a cylinder, what will be shown on the screen?
What if it's replaced by a box?

You have two options.
Do the experiment to find out, or look at the results from the  17th, 18th and 19th century researchers who did make the observations, and, on whose observations the likes of Huygens and Maxwell constructed their models.

17

Just Chat! / Re: was the Manahan project a faliure

« on: 11/12/2022 22:08:30 »

$2billion in nineteens forty money was spent but other than teaching the USSR how to make nuclear bombs had little effect on the war.
the decision to separate  u235 by diffusion and electromagnetic  means instead of centrifuges meant that bombs were not available till Japan was defeated .     

Imagine that the project had started a little later.
Imagine that the war was over, but the bomb wasn't quite ready yet.
Do you think they wouldn't have finished making and testing it?

If you think that they probably would have carried on with it and checked if it worked (maybe saying it's "for next time" or something) then the (very debatable) question of Japan's defeat is irrelevant.
They were building it "to see if they could".
And, on that basis, it was a success.

18

Physics, Astronomy & Cosmology / Re: Why does "aether" still haunt alt science?

« on: 11/12/2022 13:17:09 »

You can't call yourself a reasonable person if you can't explain the reasons for your decisions.

You failed to supply a reason for your decision to post that.

My reason is to stop someone from being unreasonable for long.

OK, Now you have posted a "reason".
But it makes no sense.
Origin's comment was perfectly sensible.
Your reply was... unreasonable.

19

New Theories / Re: Is there a better way to explain light?

« on: 08/12/2022 08:30:03 »

. I've shown non-diffractive edge in experiments using total internal reflection in visible light. I 've also shown using a metal plate and microwave.

Can you post a link?

20

Technology / Re: Are electric cars responsible for natural gas demand?

« on: 04/12/2022 10:50:42 »

A horsy may be environmentally neutral

It isn't.