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Physics, Astronomy & Cosmology / when balls bounce from trains, do they speed?

« on: 10/01/2019 17:00:46 »

This one is fun.

" Imagine standing on a train platform, and throwing a ball at 30 km/h toward a train approaching at 50 km/h. The driver of the train sees the ball approaching at 80 km/h and then departing at 80 km/h after the ball bounces elastically off the front of the train. Because of the train's motion, however, that departure is at 130 km/h relative to the train platform; the ball has added twice the train's velocity to its own.  "
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Is it right, or wrong?

2

Physics, Astronomy & Cosmology / Negative Energy is here? There? Where???

« on: 10/01/2019 16:42:22 »

Hope you like this one.

" Astrophysicists Alexei Filippenko at the University of California, Berkeley and Jay Pasachoff at Williams College explain gravity's negative energy by way of example in their essay, "A Universe From Nothing": "If you drop a ball from rest (defined to be a state of zero energy), it gains energy of motion (kinetic energy) as it falls. But this gain is exactly balanced by a larger negative gravitational energy as it comes closer to Earth’s center, so the sum of the two energies remains zero." "

Aha, 'zero'

At the center of a perfect sphere of a perfectly distributed density too?
what do you think?

( There the ball will be weightless as far as I get, so how does this work? :)

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Physics, Astronomy & Cosmology / how do objects heat up in a vacuum? aka black holes

« on: 09/01/2019 12:02:50 »

Read this " http://curious.astro.cornell.edu/disclaimer/86-the-universe/black-holes-and-quasars/general-questions/436-what-type-of-energy-does-a-black-hole-have-intermediate " where it is stated that "  These objects can gain energy from the black hole, as they fall into the potential well they heat up and radiate (often in the X-ray region of the spectrum). " ?

that they do it falling from space here on Earth is due to friction, but a mass following a geodesic in a vacuum?
Why would they 'heat up'?
Tidal forces?

Can't  be the Unruh effect

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Physics, Astronomy & Cosmology / Why doesn't a duck's quack echo?

« on: 05/11/2018 17:56:56 »

Saw it on the telly today, given as a fun fact?

(waiting for the doctor:)

Is it true? If so, why?

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Physics, Astronomy & Cosmology / how would you define ' Falsifiability ' in physics?

« on: 16/07/2018 11:21:33 »

To me it is a term that contradict itself,

A falsifiable TOE is one where you by simple logic prove it to be wrong if I get the idea correctly. If it in any sense can be proven to be wrong, how can a TOE ever exist?

And if one demand of any physical theory is that it must be proven to be falsifiable to be true, then?

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Physics, Astronomy & Cosmology / Does the universe lose energy as it expands?

« on: 07/04/2017 08:49:01 »

Geometrically I mean :)

Per inch, cm, whatever you prefer.

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Just Chat! / Some things I wonder about

« on: 17/02/2017 17:53:15 »

Make it a statement if you too wonder.

1. why don't we use the Internet to vote, and make our votes at a regular time, meaning at what you're interested in. We could create a system without 'politicians', but we don't?

2. Why do people think that making it unbearable for those needing a car, for work, or just to make the day, will stop the pollution we have?

2.a As a suggestion to the last, make public services 'smart' at any time of the day, and cheap instead.

(and I think we all know the real answer, it's a cheap way to increase incomes without increasing taxes Also 'stating' that you 'do something'.)



I do have some more, but I hope you too have thoughts on what makes you wonder.

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Physics, Astronomy & Cosmology / If an elephant jumps while aboard an aeroplane, does the plane get lighter?

« on: 11/02/2017 16:55:27 »

We have a aircraft,  in it a elephant jumps, as it do so does it count to the aircraft's mass?
Just argue, don't need to be perfect :)

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Just Chat! / What is life?

« on: 02/02/2017 14:39:39 »

Ok, I'm 'coming of age' as Tolkien would have had it.
And I'm at that point where I start to look back.

So?

What is it all about?

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Just Chat! / What irritates me with our new website

« on: 02/02/2017 05:40:29 »

1. Getting flooded in my mail by 'subscriptions' to threads I once wrote in, finding no way to turn it of in here?
It should be my choice if I want to 'subscribe'.

2. Finding no 'global' way of turning of those yellow fat moons (smileys) I just don't like them. I'm not into Facebook, twitter, etc and I don't think that everything I write need to be commented upon there, and the same goes for what you write :) btw.

In conclusion, the look of our new web site is nice and clean, but I'm missing global settings that we should be able to set, as well as I don't see what Facebook etc has to do with TNS?
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3. Okay, a third one. I used to be able to set a time for staying logged in. That seems gone now, and suddenly I find myself logged out without knowing. It may have to do with my choice of browser (Firefox), but in the first instances of this new version I still could set a time as I remember.

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Just Chat! / Kissing butt?

« on: 25/04/2015 16:27:46 »

Since Mathew and JP disappeared from this site it seems it's going downward. Don't know why? You're introducing bullying and gang behavior, which I, as I said before, find distasteful? Furthermore you don't seem to know the physics I present No big deal for me, but the former is. ah well, have fun following the decline.

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Physics, Astronomy & Cosmology / Anyone want to make a new theorem?

« on: 16/04/2015 17:36:02 »

Thinking of the brains structure, and the lungs

So?

Think of a towel, as the hitchhikers. How can you 'shrink' it topologically?
How close can it be?

Planck scale?

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Just Chat! / Why 0h why?

« on: 19/02/2015 21:32:18 »

keep getting

"The following error or errors occurred while posting this message:
Your session timed out while posting. Please try to re-submit your message."

Doesn't help if I allow all of the new scripts IP number and all, using FF clone and 'no script'. Restarting (Pale moon Version: 12.2.1) doesn't help

either. Seems that with each new 'upgrade' this site loses some functionality.

Let's see if I'm 'allowed' to post this then?
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Nope, restarted the dam* machine now and have allowed everything, including google analytics & apis, just to be sure. Also I'm wondering about this 'new'

IP number (81.201.132.39) that has shown up after the server change, disregarding that I already allowed TNS itself?
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I don't believe it.

Can't even log out it seems?

"An Error Has Occurred!
Session verification failed. Please try logging out and back in again, and then try again."

Ahh, and that came as I was trying to log out?

Ah well
=
Last try, succeeded in logging out and then in again..
Fingers crossed.

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Physics, Astronomy & Cosmology / If you magnify, would a pointlike particle also become magnified?

« on: 19/12/2014 19:16:40 »

It's about shapes, actually. Started to wonder about the way we used to look at atoms, etc, as some spherical objects. then thinking of those 'electrons' photoed at Lunds university. Then thinking of that electron as consisting of a 'probability cloud'.  Then thinking that if I use magnifying as some standard for what is 'real', would it all dissolve?
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and yes, what is the most probable shape we will see, assuming we 'back up' from that dissolving reality.

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That CAN'T be true! / What do you think? Beahaviorism as the answer to life?

« on: 04/11/2014 20:01:04 »

What do you think?

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Physics, Astronomy & Cosmology / Do you like Levitating Houses?

« on: 22/10/2014 10:25:28 »

Have a look at http://www.forbes.com/sites/aarontilley/2014/10/21/hendo-hoverboard/

the key seem to be "He explained the technology as having a primary magnetic field, then creating a second magnetic field in the conductive surface."

And the difference between it and a mag lev?

I'm not sure, somewhere I saw it defined as a magnetic field directed downward 'pushing on itself' though?
Any one have an idea what differ its 'Magnetic Field Architecture' from the one used for a maglev train?

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Physics, Astronomy & Cosmology / What is your view on weak experiments, and how would you prove it to yourself?

« on: 20/09/2014 10:17:46 »

The reason I'm wondering is because I'm of two minds, again. It would be nice if one could define it such as it works, or works not. But, the more I wonder about it the more it seems to connect to how you view physics. As for example the Copenhagen definition. And it should be important. Maybe one can't decide it, but it would be nice to see the arguments for both views as clearly presented as possible.

The only way I can see it work, is if you can guarantee that there is no communication of any kind between what you want to know about, and what you measure on. But then we have the problem of defining that 'system', because when you measure you should need boundaries, defining a 'system'. Even though you don't measure directly, you then can be said to have disturbed this 'system' you use. So there seems several ways, and pitfalls, defining it. So? From which view would one define it as my measurement should have no impact, on those variables (stuff) I do not want to disturb?
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Experiment in Physics.

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Physics, Astronomy & Cosmology / does light 'bend' to a magnetic field?

« on: 10/09/2014 20:56:19 »

have a read.

http://www.news.cornell.edu/stories/2014/09/defying-physics-engineers-prove-magnetic-field-light

Then tell me what they mean

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The Environment / How close are IPPC reports fit to climate?

« on: 21/07/2014 00:42:04 »

This is the new IPCC Fifth Assessment Report. https://www.ipcc.ch/report/ar5/wg3/

This is what the Guardian has to say about it. http://www.theguardian.com/environment/earth-insight/2014/may/15/ipcc-un-climate-reports-diluted-protect-fossil-fuel-interests

It's tricky isn't it? I mean, political pressures, and economic interest groups lobbying, is a way of life it seems. The more clout you have the more people listen to you. Assuming it is correct, where is the threshold for direct lying?

http://www.robertstavinsblog.org/2014/04/25/is-the-ipcc-government-approval-process-broken-2/

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Just Chat! / Books

« on: 22/01/2014 11:52:20 »

If you've, as me, been searching without finding for a while.

Try Nick Harkaway. 'The Gone-Away World'. It's different.