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Old 2022-03-30, 13:02   #2993
Dr Sardonicus
 
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See FTL Photons by John G. Cramer

Alternate View Column AV-43
Keywords: Casimir effect, vacuum fluctuations, virtual particles, FTL, superluminal
Published in the Mid-December-1990 issue of Analog Science Fiction & Fact Magazine;
This column was written and submitted 6/1/90 and is copyrighted ©1990, John G. Cramer.
All rights reserved. No part may be reproduced in any form without the explicit permission of the author.

It explains things well IMO.

It appears the formula for the speed of light between the plates is misstated. Either v/c should be c/v, or the minus sign should be a plus sign. I'm too lazy to track it down.

BTW I first read this column in the Mid-December 1990 ANALOG (which is how I knew to look for it online). The original column had a cartoon with a speed limit sign something like

SPEED LIMIT

670,616,629 MPH

So strictly enforced you can't imagine!

Next to the sign is an open-mouthed, eyes-bugging-out traffic cop watching a photon (a grinning, round white blob wearing shades) going by in excess of the speed limit...

Last fiddled with by Dr Sardonicus on 2022-03-30 at 13:11 Reason: xingif posty
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Old 2022-04-01, 09:43   #2994
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Quote:
Originally Posted by xilman View Post
So?

The Casimir effect violates the null energy condition. That has been known since the Casimir effect was detected in 1997 - at least.
In the early '90's when I was at UBC as a mature student, Prof. W. Unruh was gracious enough to answer a few questions for me in this regard..zero-point energy..that sort of thing. There are many "effects"..Hall effect, Coanda effect...and I've been keenly interested in all of them.
Although I don't like using Wiki articles, this one: https://en.wikipedia.org/wiki/Energy_condition near the bottom with the sub-title "Attempts at falsifying the energy conditions" gives a decent explanation for your "So?"
One of my all-time favourite papers is this one: https://www.jstor.org/stable/2689486 and I have a decent reference collection on this and associated effects. I followed the initial "warp drive" posting down that rabbit hole to see how "whatever I came up with" coincided with my prior inquiries on this subject. Since I only have my imagination to work with, communications, navigation, safety (not getting pockmarked by micro-meteorites..), motive power..etc. are relevant considerations; mathematical physics first and the Drake equation second..it would be nice to meet beings smarter than humans as a whole despite Hawking's misgivings.

I'm adding this note, using the keywords: entanglement, spacetime, factorization in a search engine you'll come upon a typical link like this one: https://journals.aps.org/pra/abstrac...evA.103.022213
I joined this forum because it is a great resource for integer factorization tools, methods and results. Factorization, in a general sense, seems to have far more utility than simple number theoretic excursions. In 2001, when I first noticed the RSA Challenge (..then the Certicom Challenge..) I never thought my inquiries would lead to fundamental mathematical notions
nor abstract notions about the conception of the universe but they have. Both the forum and the subject of factorization (in its widest interpretation) have choppy water from time to time.

Last fiddled with by jwaltos on 2022-04-01 at 10:06
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Old 2022-04-07, 14:26   #2995
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YOUR BRAIN PROCESSES SMELLS LIKE PAINTINGS AND SYMPHONIES

Birds Make Better Bipedal Bots Than Humans Do

Scientists develop a recyclable pollen-based paper for repeated printing and ‘unprinting’

This Startup Made a Functioning 'Invisibility Shield'. Here's How It Works

The SAT Isn’t What’s Unfair

Satellites Reveal Slow Shift of the Entire Boreal Biome

Ask Ethan: Is there a better way to measure cosmic time?

Father-Son Team Solves Geometry Problem With Infinite Folds

Hubble Telescope Spots the Most Distant Star Ever Detected in Outer Space

Researchers generate the first complete, gapless sequence of a human genome

SQUID SKIN INSPIRES MATERIAL THAT KEEPS STUFF HOT (OR COOL)

Scientists Translated a Spiderweb Into Music, And It's Utterly Captivating

Brain Implants Allow Paralyzed Man to Communicate Using His Thoughts

What a Math Party Game Tells Us About Graph Theory

Supermassive Black Holes Could Have Formed Directly in the Early Universe

You’ve probably never heard of terahertz waves, but they could change your life

Large Hadron Collider ATLAS and CMS Collaborations Chase the Invisible With the Higgs Boson

Scientists Discover Specific Neurons Involved in Making Memories

Astronomers See a Bizarre Space Circle in Unprecedented Detail

Math’s ‘Oldest Problem Ever’ Gets a New Answer

Utah Captures and Collars First Wolverine in State History

The Evolving Quest for a Grand Unified Theory of Mathematics

Burst of animal evolution altered chemical make-up of Earth's mantle


Dennis Sullivan, Uniter of Topology and Chaos, Wins the Abel Prize

Scientists See What People Picture in Their Mind’s Eye
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Old 2022-04-08, 06:31   #2996
LaurV
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Quote:
Geothermal energy has become the forgotten renewable. With solar and wind increasingly dominating the market of green energy, efforts to tap the vast reservoir of heat deep beneath our feet remain stubbornly well behind. It's not hard to understand why. Despite being a perfectly good choice of clean, uninterrupted, limitless power, there are very few places where hot rocks suitable for geothermal energy extraction sit conveniently close to the surface.
Well, they forgot to mention the heavy patenting. For example, unless you talk about injecting water into the lava pool (through pipes) and getting steam outside to power a turbine on the other side, the "clean" way, using thermocouples, is mainly forbidden. Thermocouples produce ~0.6V and you can not cascade them, putting a sandwich of (for example) aluminium and chrome foils one over the other, still produce 0.6V, even if you put other metals in between (like copper wires), so you can only get more energy if you take their "cold side" away (lots of wires and pipes from the hole to the surface and back) or if you enlarge their contact surface, in which case you get billions of amperes, but still 0.6 volts. There is a whole branch of power electronics and tricks that work at such low voltages but they are so heavy patented, they are pain in the butt to work with (trust me here, I know what I am talking about, this is work-related).

Last fiddled with by LaurV on 2022-04-08 at 06:38
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Old 2022-04-08, 15:16   #2997
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Quote:
Originally Posted by LaurV View Post
Well, they forgot to mention the heavy patenting. For example, unless you talk about injecting water into the lava pool (through pipes) and getting steam outside to power a turbine on the other side, the "clean" way, using thermocouples, is mainly forbidden.
The article says temps at the bottom of the borehole would be around 500 degrees centigrade. According to this University of Arizona geology lecture,
Quote:
From the surface to the transition zone - lower mantle boundary (670 km depth) we can estimate the pressure by the simple rule of thumb that each 30 km depth change is close to 1 GPa pressure change.
The borehole article proposes burning down to a depth of 20 km. So, I estimate a pressure of 2/3 of a GPa, which converts to over 96,600 psi. My guess is, at such temperatures and pressures, the engineering problems of keeping the borehole open and maintaining water/steam pipes would be non-trivial.
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Old 2022-04-12, 01:12   #2998
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https://www.allaboutcircuits.com/new...tum-computing/
https://www.allaboutcircuits.com/new...ement-forging/
Below is a link to the paper listed in the above article:
https://journals.aps.org/prxquantum/...antum.3.010309

Last fiddled with by jwaltos on 2022-04-12 at 01:29
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Old 2022-04-25, 19:52   #2999
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Scientists at CERN restarted the Large Hadron Collider this last weekend after a 3 year
period of doing maintenance and adding upgrades.

https://www.space.com/large-hadron-c...restarts-run-3
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Old 2022-04-29, 15:02   #3000
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How the James Webb Space Telescope Will Search for Extraterrestrial Life

New Links Found Between Musical Training and Cognitive Ability

Microplastics are in our bodies. How much do they harm us?

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Artificial intelligence is creating a new colonial world orderhttps://www.technologyreview.com/202...e-colonialism/

Prehistoric people created art by firelight, new research reveals

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Engineers introduce the Oreometer

SUPERMASSIVE BLACK HOLE ANCESTOR WAS HIDING IN PLAIN SIGHT

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Fungi Could Make Soil From Asteroids and Homes on Mars

This subatomic particle’s surprising heft has weighty consequences

Deep Learning Poised to ‘Blow Up’ Famed Fluid Equations
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Old 2022-05-19, 15:02   #3001
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Canadian Telescope Delivers Deepest-Ever Radio View of Cosmic Web

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Descending into one of the deepest caves on Earth

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Last fiddled with by Uncwilly on 2022-05-20 at 19:23 Reason: Tracking codes begone, and then fixed a munged description, and grouped them
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Old 2022-06-03, 15:34   #3003
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What the simple mathematical abilities of animals can tell us about ourselves

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