Comment

Comment by Jaume on January 14, 2011 at 5:54pm

I'm not the one who chose to equate 'at rest' with 'not accelerating'. 'At rest' doesn't actually mean anything in Special Relativity, where everything moves relative to something else. since SR rejects the principle of an universal frame of reference.

But if you assume that 'at rest' and 'not accelerating' mean the same thing, as the article does (and why not? It's only a definition), then it follows that any inertial frame of reference is at rest. And that includes (unaccelerated) photons.

Then, from (1), you have to conclude that photons move through time;

And from (2), that they don't.

Contradiction.

 

Obviously the article uses a non-standard definition of acceleration since it also also equates traveling/moving with accelerating. I have the impression the author uses 'accelerating' for 'moving' (whether the motion is inertial or not), and 'not accelerating' for 'at rest relative to an universal frame of reference'. And that would be enough to make Einstein rock and roll in his grave.

Comment by Jaume on January 14, 2011 at 5:03pm

I disagree:

 

(1) But, when you’re at rest (not accelerating) all of your head’s movement is through time, none of it is traveling (accelerating) through space.

(2) Since light waves use all of their motion to travel through space at Light Speed, they have absolutely no motion through Time.

 

Since light waves (photons) are technically at rest (not accelerating), we have an obvious contradiction here.

Comment by Jaume on January 14, 2011 at 3:55pm

Funny. I've made the same hypothesis about photons being unaffected by time somewhere on this site, but it's the first time I see someone else trying to make that point. Anyway there seems to be a good bit of confusion between speed and acceleration here. Photons move at constant speed, i.e. they don't "accelerate", so this reasoning would not apply to them.

Comment by Jaume on January 10, 2011 at 7:41pm

Smallest exoplanet found so far, orbiting Kepler-10

Astronomers have discovered the smallest planet outside our solar system, and the first that is undoubtedly rocky like Earth.

Measurements of unprecedented precision have shown that the planet, Kepler 10b, has a diameter slightly lower than Earth's, and a mass 4.6 times higher. [more]

 

(Actually, given that iron is the most stable element and that Earth's core is all iron and nickel, there's no way a rocky planet smaller than Earth could be 4.6 times as massive. See here for the most accurate data there is on the Kepler mission.)

Comment by Jesus_Was_A_Man_Or_Myth_Or_Both on December 1, 2010 at 5:52pm

The Estimated Number of Stars in the Universe Just Tripled

A study by Yale astronomer Pieter van Dokkum just took the estimated number of stars in the universe—100,000,000,000,000,000,000,000, or 100 sextillion—and tripled it. And you thought nothing good ever happens on Wednesdays.
Van Dokkum’s study in the journal Nature focuses on red dwarfs, a class of small, cool stars. They’re so small and cool, in fact, that up to now astronomers haven’t been able to spot them in galaxies outside our own. That’s a serious holdup when you’re trying to account for all the stars there are.
As a consequence, when estimating how much of a galaxy’s mass stars account for – important to understanding a galaxy’s life history – astronomers basically had to assume that the relative abundance of red-dwarf stars found in the Milky Way held true throughout the universe for every galaxy type and at every epoch of the universe’s evolution, Dr. van Dokkum says. “We always knew that was sort of a stretch, but it was the only thing we had. Until you see evidence to the contrary you kind of go with that assumption,” he says. [Christian Science Monitor]

Comment by Sydni Moser on November 18, 2010 at 2:39pm

Michel, thanks for your input on Kaku's take on UFOs - I had no idea why he would make such a comment, I had given him much more credit than that. Live and learn...

Comment by Sydni Moser on November 17, 2010 at 12:31am

vimanaboy | August 23, 2010

Theoretical physicist Dr. Michio Kaku discusses Leslie Kean's new book, "UFOs: Generals, Pilots and Government Officials Go on the Record."

Air date: Monday August 23, 2010

http://www.ufosontherecord.com
http://www.mkaku.org

Comment by Sydni Moser on October 12, 2010 at 12:07am

New evidence that Mars may have once had an Earthlike atmosphere

Mars's thin atmosphere is now about 95% carbon dioxide, but when the planet's atmosphere is only 1/200th the size of Earth's, that doesn't mean very much. Now deeply buried minerals reveal Mars once had nearly Earth-like levels of carbon dioxide.

One of the best ways to reconstruct Mars's ancient atmosphere is to examine the mineral composition of the planet's interior miles below the surface. The types of minerals buried down below can reveal the gases that were abundant on the surface when they first formed eons ago, and lots of carbonate minerals are evidence of extensive carbon dioxide.

Obviously, we can't yet mine the Martian interior to bring up mineral samples, but impact craters bring up these deeply buried minerals, and we're able to inspect what's there using probes and satellites. The Leighton crater, near Mars's Syrtis Major volcano, has turned up the biggest deposit yet of carbonate minerals. All previous findings had been relatively small, but this is the best find yet to demonstrate that Mars was once rich in carbon dioxide on a scale far greater than what the planet is today. For more, you can check out the original paper over at Nature.

[Nature Geoscience]

http://io9.com/5661250/new-evidence-that-mars-may-have-once-had-an-...

Comment by Zack on October 1, 2010 at 3:05am

http://en.wikipedia.org/wiki/Gliese_581_c

Comment by Bill on September 12, 2010 at 11:28pm

Michel, don't I know it!

An astronomer I talked to told me that a fixation with an infinite universe borders on religion, all evidence points to the contrary, but that I shouldn't worry, because cosmologists set the bar very high for insanity.

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