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## Supermassive Black Holes Not So Big After All153

An anonymous reader writes "Supermassive black holes are between 2 and 10 times less massive than previously thought, according to new calculations published by German astrophysicists (abstract)."
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## Supermassive Black Holes Not So Big After All

• #### Math? (Score:3, Insightful)

on Thursday February 17, 2011 @11:28AM (#35232312) Homepage

How can something be X-times less massive than something else? I can understand half as massive, or 1/10 as massive, but two to ten times less massive doesn't make any mathematical sense for a result that must be a positive number.

• #### Re:Math? (Score:3, Insightful)

on Thursday February 17, 2011 @11:33AM (#35232378) Journal

How can something be X-times less massive than something else? I can understand half as massive, or 1/10 as massive, but two to ten times less massive doesn't make any mathematical sense for a result that must be a positive number.

I agree. That pet peeve ranks right up there with "I could care less".

Like nails on a chalkboard.

• #### Re:Math? (Score:4, Insightful)

on Thursday February 17, 2011 @11:33AM (#35232382)

How can something be X-times less massive than something else? I can understand half as massive, or 1/10 as massive, but two to ten times less massive doesn't make any mathematical sense for a result that must be a positive number.

Don't worry, it's only you. Everybody else understood perfectly that they are now estimated to be between 10% and 50% of the former estimate. Or can you imagine any other reasonable interpretation for that?

• #### Re:Math? (Score:5, Insightful)

on Thursday February 17, 2011 @11:38AM (#35232438)
two times less massive: 1/2 * m
ten times less massive: 1/10 * m

Really, if you want to make it in the world out there, you've gotta get off of your high pedestal, and accept that the scientific world is only a small percentage of the "regular folk" out there. Theoretically, you're right, but practically, noone cares about theory so you're screwed.
• #### Re:Just as I thought... (Score:5, Insightful)

on Thursday February 17, 2011 @11:48AM (#35232562)
Certainty in a position gives people a stronger reason not to believe competing ideas. It's basic cognitive dissonance. Let's say I prepared for aliens to visit and destroy the world on a certain day [wikipedia.org]. When that doesn't happen, I can either admit I was wrong or I am uncertain about whether these aliens even exist, or I can confidently believe that the aliens spared us because of our faith. It's easier to confidently believe that AGW is a big hoax than to admit the possibility that we're causing the climate to change. It's easier to believe that evolution is not real if it causes me to question my faith in the existence of God. People will do all kinds of mental gymnastics rather than admit a truth they find emotionally disturbing. Even the lamest excuse will do. The latest is the old "the science isn't settled" when there's the least little bit of uncertainty.
• #### Re:Math? (Score:5, Insightful)

on Thursday February 17, 2011 @11:53AM (#35232660)

Welcome to the English language, you will notice that it is not actually a branch of Mathematics.

• #### Re:Math? (Score:5, Insightful)

<delirium-slashdot@NOsPam.hackish.org> on Thursday February 17, 2011 @11:57AM (#35232708)

It's not even uncommon language in science, though maybe you'd be more precise when writing a paper. In this context, "times" is understood as colloquial shorthand for "by a factor of", and factors can be either multiplied or divided, depending on whether it's "greater" or "less" by that factor.

The translation from "two times less massive" to "less massive by a factor of two" is pretty straightforward and easily understood...

• #### Re:Math? (Score:4, Insightful)

on Thursday February 17, 2011 @12:18PM (#35232998)

The 'ambiguity' is a standard phrasing that has been part of the language for more than 100 years. Language is not math, language is not 100% logical. This argument is equivelent to yelling at someone for saying that they're "as hungry as a horse" because they are incapable of eating as much as a typical horse. It's a stupid and pedantic argument that tries to apply strict logic and mathematical rules to a system (language) that does not follow them.

• #### Re:Math? (Score:0, Insightful)

by Anonymous Coward on Thursday February 17, 2011 @01:24PM (#35233894)
Actually, "as hungry as a horse" only implies that the intensity of the hunger is equal, not the capability to eat a given amount of food.
• #### Re:When will we ever learn (Score:4, Insightful)

on Thursday February 17, 2011 @01:38PM (#35234124)

Scientists would do everyone a favor if they dropped the formula "we used to think, but now we know".

Kinda hard to drop something that's never been used.

I could have dismissed this as the reporting being at fault, but the abstract ends with "Knowing the rotational velocities, we can derive the central black-hole masses more accurately; they are two to ten times smaller than has been estimated previously."

Emphasis added. Hope that helps with your parsing problem.

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