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Comment Sail Problems (Score 1) 170

The cover article in the March 2017 issue of Scientific American was about using multiple light sails and miniature sensors to visit Alpha Centauri, with a large array of lasers -- either earth-based or space-based -- as the primary accelerant. The use of light sails, however, can be problematical.

First of all, consider solar wind, the stream of gases and particles emitted by the sun. If solar wind is faster than the sails, it will accelerate them beyond the force of the proposed laser array. If the solar wind is slower than the sails, however, the sails will decelerate. In either case, the solar wind and the sun's gravity can alter the trajectory of the sails.

The Oort cloud also requires consideration. If the sails are not punctured by the particles in the Oort cloud, impacts of those particles on the sails will decelerate them. If the sails are punctured, they will become useless in decelerating the sensors when the target star is approached.

Then there is the fact that space is not a perfect vacuum. Without dark matter, space still contains gas and dust, which can decelerate the sails. If dark matter does indeed pervade space, the deceleration might be sufficient to prevent the sails and their sensors from ever reaching their target stars.

This does not make the concept of light sails impossible. Before such a project is launched, however, more knowledge is needed about the solar wind, the Oort cloud, and what exists in space between here and any target star.

Comment Use a Local Not a Remot Passwords Manager (Score 5, Insightful) 415

Some password managers rely on remote servers or the cloud to store your password. That is risky for two reasons. (1) A service holding passwords for many users is a more likely target for hackers than your own individual computer. (2) If the server or cloud service goes down even temporarily, you are stuck without your passwords.

You should choose a password manager application that is installed within your computer and does not rely on you having an Internet connection. The application should use a master password -- actually a master pass-phrase -- to encrypt the individual passwords. That master pass-phrase itself is not stored anywhere. Instead, if it is entered incorrectly, it fails to decrypt any passwords. By "pass-phrase", I mean a longer expression containing blanks, punctuation, etc.

Note that Mozilla-based applications have internal password managers that reflect my second paragraph above.

Comment Name "Internet Health Report" Already in Use (Score 1) 69

There already is a Web page called "Internet Health Report" at http://internetpulse.keynote.c.... It has been reporting the status of the U.S. backbone providers since possibly 1993 (23+ years). At least, that was when the domain keynote.com was first registered.

It reports latency in msec, percent availability, and percent of packets lost. The page is copyrighted. The terms of service indicate there might be a trademark on the name "Internet Health Report".

Comment Theorized in the Early 1960s (Score 1) 90

This was presented more than 50 years ago by Gordan J. F. MacDonald, at that time professor of geophysics at UCLA's Institute of Geophysics and Planetary Physics. His paper "Origin of the Moon: Dynamical Considerations" appeared in Annals of the New York Academy of Sciences on 7 May 1965. As one of his computer programmers, I did the calculations for that paper. I think, however, that I might have done those calculations a few years earlier and that MacDonald published the same theory earlier than 1965.

Comment Blanket Warrant (Score 4, Insightful) 203

The basic issue is not about bitcoin. It is about the scope of warrants, summonses, and subpoenas. The Fourth Amendment to the U.S. Constitution states:
> The right of the people to be secure in their persons, houses,
> papers, and effects, against unreasonable searches and seizures,
> shall not be violated, and no Warrants shall issue, but upon probable
> cause, supported by Oath or affirmation, and particularly describing
> the place to be searched, and the persons or things to be seized.

I doubt there is "probable cause" that tax evasion has indeed been committed by Coinbase's users. Such a broad summons fails to describe which persons' accounts are to be examined. Since the summons was served on Coinbase, which has not been suspected of a crime, a challenge of the summons to appeals courts or the US Supreme Court might be very successful.

Comment Small Sample Size (Score 4, Informative) 228

Only 19 persons were tested. All were from the same religion. There was no control set of non-religious individuals tested to see if the MRI scans were indeed representative of "religious and spiritual experience".

Most important, the Slashdot headline "Religious Experiences Have Similar Effect On Brain As Taking Drugs, Study Finds " differs from the title of the original study report. In the original report, the title is "Reward, salience, and attentional networks are activated by religious experience in devout Mormons", clearly limiting the scope of the study to one religion.

Comment Re:Cost? (Score 1) 228

I too wonder about the efficiency. Relative to the amount of electricity that can be obtained by burning the ethanol, how much electricity is required to run the conversion? How much can be obtained relative to the amount electricity needed to dissolve CO2 in water?

Comment Disabiling Checks for Malware and Phishing Sites (Score 1) 67

I do not know about Chrome. However, there are two preferences that control the checks for malware and phishing sites in Mozilla-based browsers (e.g., Firefox, SeaMonkey).

For SeaMonkey:

1. Select [Edit > Preferences] on the menu bar.

2. On the Preferences window, select Privacy & Security.

3. On the Privacy & Security pane, there are two checkboxes, one for malware Web sites and one for phishing sites. Unchecking a checkbox disables the corresponding check.

For Firefox, I am not sure if there is a user interface. However, the preference variable browser.safebrowsing.enabled controls the check for phishing Web sites; and the preference variable browser.safebrowsing.malware.enabled controls the check for mailware sites. Setting one of these to False via about:config disables the corresponding check. I have the PrefBar extension installed for SeaMonkey. In it, I created buttons to enable and disable each of these checks.

Comment Some Lessons Are NEVER Learned (Score 1) 239

In the summer of 2003, the Great North-East Blackout hit New England and other areas in the U.S. and parts of Canada. My wife were in Montreal at the time. When we tried to fly home non-stop to California from Trudeau International Airport (called Dorval International Airport at that time) via Air Canada on an early morning flight, we instead found ourselves flying in the late afternoon to Dulles in Washington, DC, changing planes, and then flying home. We arrived at our house more than 12 hours late.

No, Montreal and the rest of the province of Quebec were not affected by the blackout. Air Canada's computers, however, were in Toronto. Toronto and much of the province of Ontario were indeed blacked-out. While other airlines continued normal operations out of Montreal, Air Canada could not confirm reservations or issue boarding passes. Air Canada had no remote backup facilities.

Apparently, Delta Air Lines learned no lesson from Air Canada's experience 13 years ago.

Comment Re:Screw Them (Score 1) 46

I consider myself an expert in modern technology. For 40+ years, I was a software specialist. For 30+ of those years, I tested software used by the military to operate their earth-orbiting space satellites. I do not have a cell phone, not because I do not understand them but because I have no need for one.

However, the big deal is that cell phone text messages are very insecure. The Social Security Administration's form of two-factor authentication will not enhance users' security. Wait until some Social Security recipient -- relying on the asserted but false enhanced security of the SSA's two-factor authentication -- discovers that a hacker has redirected the direct deposit of his monthly benefit payment into a hacker's back account.

Submission + - US Social Security Web Access Requires Two-Factor Authentication 1

DERoss writes: Effective 1 August, the U.S. Social Security Administration (SSA) requires users who want to access their SSA accounts to use two-factor authentication. This involves receiving a "security" code via a cell phone text message.

This creates two problems. First of all, many seniors who depend on the Social Security benefits to pay their living costs do not have cell phones. In order to manage their SSA accounts, they will now have to buy a cell phone and pay monthly subscription fees; but the SSA will not be increasing benefits to pay those costs. Many seniors who do have cell phones use them only as phones and are not knowledgeable about texting.

More important, cell phone texting is NOT secure. Text messages can be hacked, intercepted, and spoofed. Seniors' accounts might easily be less secure now than they were before 1 August. For example, seniors might find the direct deposits of their benefits being redirected to hackers' bank accounts.

This is not because of any law passed by Congress. This is a regulatory decision made by top administrators at SSA.

Comment Test More Than Once (Score 3, Interesting) 104

Visit the test Web site more than once. If subsequent visits indicate that you remain unique -- that you are the only one out of all visits including your own prior visits -- then you are somewhat safe from tracking. Even better is when it reports inconsistent results from several visits within a short period of time. I did that, and the report was that I was unique twice relative to HTTP_ACCEPT Headers. Also, the Monitor Contrast Level was not the same for two consecutive visits.

I get this result by installing the Secret Agent extension from https://www.dephormation.org.u.... Panopticlick has similar problems characterizing my browser. And various Web sites that attempt geolocation have me all over the globe.

Comment Current Version is GIMP 2.8.18 (Score 4, Informative) 117

The current end-user version of GIMP is 2.8.18. Per the GIMP Web site home page, version 2.9.4 is a development version and not an end-user, stable version. The next end-user, stable version will be 2.10. Use 2.9.4 at your own risk.

Go to http://www.gimp.org/downloads/ and scroll down about 2/3 to "Development snapshots".

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