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Comment: Momentum of tachyon traveling at infinite speed (Score 1) 142

by Josh-Levin (#48685645) Attached to: New Paper Claims Neutrino Is Likely a Faster-Than-Light Particle

One of the strange things about a tachyon is that it can be traveling in one direction for some real inertial reference frame, and be traveling in another direction for some other inertial reference frame. For yet another reference frame intermediate between those two, the tachyon is traveling at infinite speed, yet has zero dynamic mass and a finite momentum of +/- i mc, where i is the square root of -1, m is the imaginary rest mass of the tachyon, and c is the speed of light.

The direction of the momentum vector is ambiguous.

Since this is a total contradiction, I assume that tachyons cannot exist.

Comment: Guaranteed d\funding source for NASA (Score 1) 156

by Josh-Levin (#48653211) Attached to: Can Rep. John Culberson Save NASA's Space Exploration Program?
I have an idea -- add a small excise (sales) tax on electronics and other high-tech good, with that money dedicated to NASA and a few similar agencies, such as NOAA and NIST. Then there would be a guaranteed source of funding for the very important research these agencies do.

Comment: I use NoScript; I also have a weak connection (Score 1) 230

by Josh-Levin (#47864967) Attached to: Comcast Using JavaScript Injection To Serve Ads On Public Wi-Fi Hotspots
I use NoScript, and only allow Javascripts that I trust.
I am also a Comcast customer. The cable connection is through an old, weak cable that goes through the apartment downstairs, and it slows down my connection a bit, but that is tolerable. To fix it, they would have to rip apart the walls in a bedroom occupied by an eight-year-old girl, and I don't want to put any child through that trauma. If I allow Comcast to share my cable connection, then I might be slowed down to an unacceptable level.
Also, their new cable modems DO NOT come with a battery backup -- they make you buy the battery from them.
They say that nobody can take advantage of you without your permission. Well, I'm paying enough in cable bills, and I'm not going to let them. Unfortunately, FiOS is not available in my apartment complex, so Comcast has a monopoly.

Comment: Re:Oblig. SMBC (Score 1) 157

by Josh-Levin (#45654317) Attached to: Google Doodle Remembers Computing Pioneer Grace Hopper
I understand that she handed out "light-nanoseconds", copper wires 11.8" long. Actually, 11.8" is how fast light travels in a vacuum. Electrical signals travel slower than that in copper, a little bit slower in unshielded wire, and 2/3c in coaxial cable (see

Comment: How about a tax to support Scientific Research? (Score 1) 434

by Josh-Levin (#43247705) Attached to: Internet Sales Tax Vote This Week In US Senate
Since the internet was an outgrowth of US-government-supported research, how about a flat sales tax (say 5%) on internet sales, not otherwise subject to state sales tax, that would go to fund scientific research of all sorts, including both basic and applied research. The government can take the difference from what it now spends on research, and give it to the states to compensate for lost revenue.

This way, scientists can be assured of a consistent source of funding. This will make America smarter, and more competitive.

+ - Ask Slashdot: Should there be a National Tax to Subsidize Scientific Research? 3

Submitted by
Josh-Levin writes "Scientific research in the US is hurting. Now there is talk of shutting the Relativistic Heavy Ion Collider (RHIC) at Brookhaven. I know that the Federal Government is short of money, but cutting back on scientific research is eating our seed corn.

Since basic research has been fundamental to all those hi-tech device we all enjoy, I think there should be a fixed Federal excise tax on hi-tech devices, the proceeds to go to scientific research. There shall be safeguards to prevent this tax money from being used for anything but scientific research.

I hope that Slashdot members who respond to this posting will flesh out this idea. How much money is needed, and how big is the hi-tech market? What should the tax rate be? (If it were 10%, it could be termed a "Techo-Tithe".) Who should be exempt? Should it be used only for terrestrial research, or should it include the space program? For products that are partially hi-tech, such as automobiles, should there be a reduced rate based on the hi-tech content of the product?

Ideally, the tax would be paid by the consumer, so that it is visible. Every time you by a computer, a smart phone, or a digital camera, you will know that your tax will subsidize the research behind the next generation of devices, which may be spintronic or optical rather than electronic.

I hope that this discussion will result in a "We the People" petition to the White House (see to ask that such a tax be implemented. We need 150 signatures to make such a petition visible, and 100,000 signatures to make sure the President sees it. Please, readers, do not initiate such a petition on your own, until the Slashdot discussion has reached some sort of consensus. We will want to do it right the first time."

Comment: God's Grown Children (Score 1) 528

by Josh-Levin (#42819411) Attached to: Ask Dr. Robert Bakker About Dinosaurs and Merging Science and Religion
IMHO, Mankind is evolving to be closer to God, more Godlike, even though we will never reach God's Level.

I have summed this up as four principles:

God is a loving Parent to all humankind - and Who made the universe such that we could live in it.

God is Unique and is One, each human being is unique and different, and so humankind is diverse.

God is Perfect, we are imperfect - therefore God has made us diverse, so that, in our diversity, we can approach, but never reach, Perfection.

God has given us free will, and wants us to grow in understanding - to grow towards, even if we never reach, His Wisdom.


In a sense, ancient texts, including the Bible, are little-children's books that God inspired His Prophets to write for us, so that things will be explained to us. Even though the Biblical accounts of the Creation of the Universe are not scientific, they do contain moral lessons which we should still heed.

Comment: StarTram: An Electromagnetic Space-Launch Gun (Score 1) 131

by Josh-Levin (#42571881) Attached to: The Science Behind Building a Space Gun
Dr. James Powell, co-inventor of superconducting Magnetic Levitation (MagLev), is also a co-inventor of a system called StarTram, that uses similar electromagnetic technology to launch manned and unmanned vehicles into space.


This is also described in the book "The Fight for Maglev"; see

Comment: Re:Boo Hoo (Score 1) 366

by Josh-Levin (#39525215) Attached to: Firefox: In With the New, Out With the Compatibility
I use the NoScript add-on the block JavaScript, and I have no such problems.

I also find that previous version of FF would slow down after a while, especially if they were chewing up a lot of Gigs (I have 8 GB RAM on this computer), and I had to restart. Fortunately, I always got my tabs back, and there must be a couple of hundred of them.

FF 11 does not seem to have that problem anymore. I guess I'll stop referring to it as Firefux!

Comment: Here's another way . . . (Score 1) 357

by Josh-Levin (#38173346) Attached to: Rethinking Rail Travel: Boarding a Moving Train
I thought of something along very similar lines about a decade ago, and rejected the concept because of overriding safety concerns. Besides which, how do you transfer yourself and all your luggage in the short period of time allowed before the vehicles undock? Instead, I propose a system of modular cars that can travel on regular roads for local travel, and high-speed MagLev rail for longer travel. The vehicles are stationary when transferred from one mode to another, avoiding most all the safety problems. The same rail network can also be used for freight. Please, please, check out for more details.

Comment: Class Action (Score 2) 1040

by Josh-Levin (#37027284) Attached to: S&P's $2 Trillion Math Mistake
Anyone in for a Class-Action lawsuit against S&P? The plaintiffs will be just about all US citizens, with certain obvious exceptions like guys who work for S&P, judges, and twelve randomly-chosen people to be the jury. We'll sue them for $14 trillion, or about $40,000 for each plaintiff. I could use an extra $40,000.

In seeking the unattainable, simplicity only gets in the way. -- Epigrams in Programming, ACM SIGPLAN Sept. 1982