Shakes cane, "when I was a boy", etc....
In Dutch, this has become the thing people do now as well. Being a Germanic sister language of German, Dutch also does/should not use the apostrophe in this sense, but people do it anyway. Then again, a language is a living thing, and in the end, it is what people speak and write. I can live with this.
Yes, and no. Yes, if you work off the model where there is a universal "now", and light just happens to travel at some high speed. In that model, the explosion happened, and we are now just waiting for the light to finally arrive. However, the problem with that model is that there is no universal "now".
So no: The speed of light is not related to light. Light travels at that speed, but there is nothing about the properties of light that somehow determines that speed; other things, such as gravitational interactions, travel at that speed as well. That speed is not just some arbitrary speed limit, but rather the speed of causality, full stop. There is nothing at point A that can even influence point B in less time. This is what determines our past light cone, or rather, our past causality cone.
And to be clear: this star's bright light-up is not in our past light cone, and so, for us, it did not yet happen.
I think that is outdated, at least for some brands. I have a Thinkpad Carbon X1 and a Dell Inspiron - both get very good battery lifetimes in Linux (8-12hr). A lot of this comes down to the BIOS and firmware.
What a wonderful little anecdote! That was Brian, all right.
Phil Karn, KA9Q
ABSOLUTELY! The first thing I do with any new OS is to map the caps lock key to the control key.
I can actually think of a practical use for this, if it could be made really lightweight.
I work with groups that fly small, long-duration stratospheric balloons with ham radio beacons. The payload weight budget is too small (15 grams) for batteries, and even with them the extremely low temperatures would be a problem. Supercaps work well at low temperatures, but energy densities are too poor to store enough energy for an entire night. So the payload only operates during the daytime from two thin-film solar cells.
I've been wracking my brain trying to think of another source of ambient energy (besides sunlight) that could be harvested. Even a few milliwatts could be useful, accumulated in a supercap until there's enough energy for one GPS fix and radio transmission cycle. Harvesting broadcast radio stations is one idea, but that only works near population centers. I'd thought of some sort of heat engine working between the warm earth below and the cold sky above, but did not know if it was at all practical. Maybe it still isn't, but it's an interesting idea.
Part of the introduction is missing:
After "Plenty of cat owners will happily tell you their felines are capable of responding to their own names"
it should read "...they just choose not to."
There, fixed that for ya.
Ah, so *THIS* is how the Talosians kept Captain Pike from bouncing off the walls of his cage. I always wondered about that.
I don't think it would be as hard as you might think PROVIDED you really understood it yourself. Of course, this applies to anything you wish to teach to anyone.
The problem with relativity is that it is so counter intuitive to everyday experience and to the classical physics you've been taught that you have to unlearn much of it first. That may make it easier for younger people to understand -- they don't have as much to overcome as they would later.
Like most EEs, I was taught classical electromagnetism, first in high school, then in lower level undergraduate physics, and finally in much more detail in junior level EE school classes. We were also taught relativity, but as a separate topic within physics. Had I been taught relativity first, and then been taught electromagnetism in the relativistic way I think it would have actually have been easier and more satisfying. I would have learned that there really isn't such a thing as "magnetism"; what we see as magnetism is really just the electrostatic force as affected by special relativity (and some quantum mechanics). I would have readily understood why there are no magnetic monopoles, for example. And it would have shown me how every field in physics is related to every other, in fact that there really is only one "physics".
Actually no, it's not a straightforward calculation. That's why they want to conduct the test.
It's not a simple collision like we learned about in physics class, with the change in the asteroid's momentum coming entirely from the impactor. The impactor will hit at extremely high velocity (by earth standards), meaning that it will carry a lot of kinetic energy (one half mass times velocity squared) in a small volume. This kinetic energy will vaporize and blow off part of the asteroid, which because of the asteroid's small size, will completely escape.
The mass of the ejecta will greatly exceed the mass of the impactor, so even though it may move much more slowly than the impactor it will carry away considerably more momentum (mass times velocity). The momentum of this ejecta will have most of the effect on the asteroid's trajectory.
But it's unknown exactly how much momentum will be carried away by the ejecta as this depends on the makeup of the asteroid, its density, porosity, how quickly the impactor stops and releases its energy, etc. So that's why they want to try it.
A similar effect was at play in the JFK assassination that helped cause the counter-intuitive "back and to the right" motion of his head that had so many people incorrectly thinking there was a second shooter.
... that is a given. The comet is a nice addition though.
The largest estimate for the size of Psyche is 253 km across. Mars is about 6800 km in diameter, enormously larger.
In 1914, the first crossword puzzle was printed in a newspaper. The creator received $4000 down ... and $3000 across.
