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  1. Naked Science Forum
  2. Profile of Colin2B
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Messages - Colin2B

Pages: [1] 2 3 ... 248
1
The Environment / Re: Why in spring are the day and night temperatures so different
« on: Today at 09:22:09 »
Just to add to what Alan is saying - same thing but different words
There are 2 factors that will affect this:
Ground heat capacity. During winter/spring the sun is lower in sky and doesn’t heat the ground as much as in summer when sun is higher in sky. This heat is radiated back out at night.
Water vapour. Summer has more water vapour in air. This absorbs heat during the day and not only acts as a thermal blanket at night, but also traps the reradiated heat from the ground. This is also why deserts get so cold at night.

2
Chemistry / Re: How are the wheat flakes in Weetabix stuck together?
« on: Yesterday at 22:52:25 »
Good guess. I would also suspect gluten.

3
Just Chat! / Re: Are you looking for Marketing, Media & Communications Jobs?
« on: Yesterday at 08:02:48 »
Quote from: zandrabhernandez on Yesterday at 04:58:31
Is it easy to find a job in New Zealand  after completing a BSc degree in food science? Or do I need more qualifications for that?
Don’t know.
But I do know it’s a lot easier to post here if you don’t try to spam us.

4
Physics, Astronomy & Cosmology / Re: Why Didn't Einstein FULLY Address Simultaneity-at-a-Distance?
« on: 15/04/2021 08:06:09 »
Quote from: charles1948 on 15/04/2021 00:21:52
Suppose  Marconi had been told, as he probably was, that meter-readings of radio-waves conclusively proved that the waves always travel in straight lines.
I’m quite sure someone did tell him this, but experiment proved otherwise.
However, this is still posting your alternative theory in a post on a different subject, in the main section.
Please take note of my warning, the choice is yours.

5
New Theories / Re: What is safety conditioning?
« on: 14/04/2021 23:52:33 »
Quote from: smart on 14/04/2021 23:30:08
Moreover its very unfortunate that this forum is being condemned
Please show evidence of anyone condemning this forum for questioning your claims - other than yourself.

6
Physics, Astronomy & Cosmology / Re: Why Didn't Einstein FULLY Address Simultaneity-at-a-Distance?
« on: 14/04/2021 23:48:34 »
Quote from: charles1948 on 14/04/2021 23:05:10
So I wouldn't waste time trying to take a picture of it.
How about you stop wasting our time by posting your nonsense in the main part of the forum.
Feel free to post your ‘theories’ in the appropriate section rather than here, otherwise you might find your ability to post in the main sections limited.

If it were left to you Hertz would have been told to ignore the meter reading and forget that radio waves might be discovered.

7
Physics, Astronomy & Cosmology / Re: Why Didn't Einstein FULLY Address Simultaneity-at-a-Distance?
« on: 14/04/2021 18:40:51 »
Quote from: charles1948 on 14/04/2021 17:00:16
All it means, is that we can't see two events happening at the same time.
No it doesn’t. It’s not due to the time taken for light to travel, that is a separate effect.

8
COVID-19 / Re: Side effect of COVID vaccines
« on: 14/04/2021 15:34:44 »
Quote from: alancalverd on 14/04/2021 00:24:48
........but I think it would be worth warning folk that it can impair your performance a bit.
Thanks for the warning

9
New Theories / Re: Is There Any Alternative to Special Relativity?
« on: 14/04/2021 10:10:11 »
Quote from: CrazyScientist on 14/04/2021 03:11:18
Your analysis is wrong because you keep using the same geometrical center of light emission A for both frames and I keep telling you, that it won't work - you need to have 2 different points of emission A1 and A2 for both frames:

And if you want to know all the details here they are:
https://en.wikipedia.org/wiki/Galilean_transformation
Galilean relativity treats any event as being the same event in all frames, it doesn't postulate 2 different events. So your starting point is not Galilean Relativity.
I must commend you on the degree of thinking you've put into this, but as others have pointed out there are inconsistencies which are nothing to do with SRT.
Have a look at emission theory which should turn up in any search. It has some of the ideas you are chasing and you can see why it was rejected.

It's important to remember that Einstein started his theory due to anomalies in the behaviour of moving electric and magnetic fields. You theory has to also explain these anomalies, some of which rely on length contraction in the wire. See https://phys.libretexts.org/Bookshelves/Modern_Physics/Book%3A_Spiral_Modern_Physics_(D%27Alessandris)/1%3A_The_Special_Theory_of_Relativity_-_Kinematics/1.8%3A_Length_Contraction_and_the_Magnetic_Force__(Project)

Keep thinking :)

10
Physics, Astronomy & Cosmology / Re: Is there a difference between visual and actual location in space?
« on: 13/04/2021 11:41:32 »
Very good question and the answer is far from obvious.

Changes to a gravitational field (caused by a moving mass) propagate at the speed of light, but in a somewhat surprising way that means the force experienced by a test mass will always point to the current position of the moving mass rather than it’s position x light seconds ago. Below is a popsci article that explains what happens and below that I’ve compared it with a similar effect due to a moving charge.

https://medium.com/starts-with-a-bang/what-is-the-speed-of-gravity-8ada2eb08430

There are similarities between em radiation and gravity and comparisons can be made which help us to understand them better.
Let’s start with the field surrounding an electron. A test +ve charge will be attracted to the electrons position. We know that the electric field propagates at light speed, but if the electron is moving the test charge will move towards the current position of the electron, not where it was. In this way the field behaves in a similar way to gravity.
What is less well known is that if the electron changes velocity the test charge will move towards the position the electron would have been at had it not accelerated, until such time as the change in the field propagates to the test charge’s position. How does the test charge know where the electron will be? I can offer an analogy that shows that this behaviour of fields is not so mysterious.
Imagine a boat crossing a lake, the bow wave propagates away from the boat, but even at some distance from the boat the crests point to the boat’s current position (almost,  because waves in water don’t propagate exactly as do em waves). If the boat changes direction it will take time for the change to propagate to the observer, and until it does the bow wave will point to the predicted position of the boat had it not changed course.
In the case of the accelerating electron we know the speed at which the change propagates, because the change causes a discontinuity in the field which we detect as em radiation - light, radio etc (and if we have a quantum detector we can say we detected a photon).  We can describe the electron field at any point as being dependent on the history of both the position and derivative of position (velocity) of the electron.
A similar effect occurs with gravity. The force felt by the moon is directed to the current position of the earth rather than it’s historical position. This led early researcher to conclude that the speed of gravity was either instantaneous or extremely fast whereas it does not need to be for similar reasons as I have described for the electron.
It’s worth pointing out that the gravity situation is slightly more complex because there is a higher order effect which allows the masses to ‘point’ towards each other’s current positions despite both being in non-linear motion around a common centre of mass. This higher order effect is also why em waves are dipole and gravitational waves are quadrupole. The gravitational waves that have been detected (which are analogous to the em radiation of the electron) show that the speed of propagation, and hence the speed at which gravity changes propagate, is as close to light speed as can be measured.

11
Technology / Re: Why do wind turbines shut down?
« on: 12/04/2021 23:08:35 »
Quote from: charles1948 on 12/04/2021 20:55:47
But still, I don't like seeing windmills!  There's something about them that smacks of defeatism and retrogression into the past.
Well, they aren’t grinding wheat are they.
There is nothing wrong in reusing technology and ideas; even nuclear power stations create  steam to drive turbines - how retro is that?

12
Technology / Re: Why do wind turbines shut down?
« on: 11/04/2021 07:58:19 »
Quote from: Petrochemicals on 11/04/2021 07:44:07
As in the big white things that are becoming quite common, why do they shut down? If its maintenance that is not very good.
Many of the inland ones were badly placed, not enough wind to keep them going all the time.
They will also shut down if wind speed is too high to prevent damage. Otherwise, I assume maintenance.

13
Just Chat! / Re: Where is Administration thenakedscientists.com?
« on: 10/04/2021 23:22:19 »
Quote from: Halc on 10/04/2021 17:52:02
I pitch about 5 of these a day into the recycle bin.
I do same when I spot them

14
Just Chat! / Re: Where is Administration thenakedscientists.com?
« on: 10/04/2021 17:17:41 »
Quote from: Origin on 10/04/2021 14:49:33
Bottom of the page says "contact us".  Try that.
It is some sort of trolling. No matter what replies you give they don’t follow up. All posts have same format.

15
Just Chat! / Re: Do you want to "talk" about American Politics?
« on: 10/04/2021 08:29:46 »
Quote from: Pseudoscience-is-malarkey on 10/04/2021 03:39:09
John Cleese ...... in a self-imposed exile because of ........ the rising influence of British evangelical organizations such as World Alive.
LOL He’s pulling your plonker  ;D

Had to look up ‘World Alive’ and it is a Christian organisation which runs annual events, apparently attracting 4000 guests at exotic locations such as Pwllheli in North Wales and the Pontins site, Prestatyn! Not exactly a mover shaker in the grand order of things.
To be honest, he could have complained about the growing influence of Glastonbury with 200,000 attendees.

Cleese has long been a critic of double standards in religious belief and recently engaged with evangelical Trump supporters. But seriously, you can’t believe a minor religious group - almost unknown outside their own circles - is responsible for him moving from the UK. He’s having a laugh at your expense; he is after all a comedian.

16
General Science / Re: Buy Spam Online for Sale USA
« on: 08/04/2021 13:30:22 »
Quote from: gem on 07/04/2021 23:47:06
Spam fritters for everybody.
wonder if they do a mars bar version ?
Wow, takes me back to childhood, spam fritters for lunch.
Not sure about tinned Mars bar though  😱

17
General Science / Re: Buy Spam Online for Sale USA
« on: 07/04/2021 14:36:31 »
Quote from: ElsaDell on 07/04/2021 12:50:37
boppity boppity time.
Is that a medical term?

Great stuff this spam. So, do you eat it or just smear it all over??

18
Cells, Microbes & Viruses / Re: Affordable microscope?
« on: 06/04/2021 23:45:22 »
Quote from: colarris on 06/04/2021 11:19:40
I also see a lot of cheap microscopes that are aimed at children on Amazon etc. Would they be good enough?
I’m afraid it’s a case of you get what you pay for. That said, there are some cheap microscopes which are surprisingly good quality at lower magnification - up to 200x which is plenty for your application. Often resolution is best at centre of field with some colour fringing at the edges, but you can usually improve that by using a blue or green filter to make monochrome light.

Worth noting that most cheap usb microscopes are little more than close focussing webcams. Often the magnification quoted is for digital zoom, which mean poor quality at high mag. Still ok around your working requirement.

I do know of one model which focusses, I’ll send you a link.

19
Just Chat! / Re: Do most men believe their penis is most important?
« on: 06/04/2021 23:41:46 »
Quote from: Zer0 on 06/04/2021 13:20:32
Sorry, i Misunderstood the image and made a Silly Defaming post about it being your own Self - Image.
☹️
Shame, you beat me to congratulating him on being first to post his own photo. 😱

20
Cells, Microbes & Viruses / Re: Affordable microscope?
« on: 05/04/2021 23:30:06 »
Tardigrades are quite big, from a microscope point of view. You will need between 20x and 50x magnification and direct top lighting rather than the through lighting that you see in a traditional microscope.
The type @evan_au mentions should be adequate, but make sure you have really good lighting eg led desk lamp.
If you really get into it and want a ‘proper’ microscope I would recommend a secondhand dissecting microscope

This was taken with iphone + adapter but many usb ones are just as good and real cheap.


* 4B5EDF7C-09EA-4978-91E7-EA3055B026BB.png (100.72 kB . 306x298 - viewed 334 times)

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