Sorry, can't do that--Einstein's thought experiment specifically stated a closed box, no view. That way you don't know where you are--on Earth or in space. And think of complementary case of being in an elevator (not one of those cool ones in hotels, where you can look out) and someone cuts the cable: you free fall and feel weightless. So are you falling in a gravitational field, or are you out in space, away from any objects that would give you weight?
Also, our personal human time scale versus the time scale of geologic and solar events are quite different. I read one geologist a few years back saying that the big California Northridge earthquake of 1994 could be considered, if you step back, as mostly an aftershock of the San Francisco quake of 1906. He had a good point there!
Good point about problem of assessing solar output. It's naive and irresponsible, IMO, to think the Sun's output has been constant over the years--yet that's what most models assume. Further, any historical data on Sun's output that is more than 40-50 years old is useless. So if someone asks about sun's output 100 years ago, the honest answer is "can't really say." And for more-recent output, honest answer is "not really sure."
@Bill: ...not knowing if I sense my weight due to me standing on Earth's surface, versus being in a closed box accelerating through space at 9.8 m/sec2, bothers me!
Open the nearest door and look outside -- if you get sucked out by explosive decompression, then you are (or at least, were) in a box accelerating through space -- otherwise, relax and take another bite of your apple :-)
In the global warming debate, we have experts saying one thing and complete non-experts saying the opposite. Yes, it is wise to be a bit skeptical about expert opinion. A bit. It is utterly insane to not be at all skeptical about inexpert opinion.
In the case of the Emperor's New Clothes and a geo-centric universe, the "experts" in question were nothing of the sort. In the case of climate science, the experts in question really are, just like they are in every other branch of science. If you dismiss that expertise, you may as well dismiss every other form of scienctific or technical expertise.
I am an expert in VHDL. And in OFDM. Surely you would agree that the chances of John Doe climate scientist finding fault in that expertise is basically zero. You must be expert in something, too. Surely you wouldn't expect John Doe climate scientist to be capable of finding fault in that expertise either?
I had been working for Motorola for about a year when I was transferred to the Product Research labs of the Comm division. My first assignment was to look at how to improve the small-signal sensitivity of VHF receivers. As I had at that point not only a couple of EE degerees, but also had been building radio receivers since I was about 10 (as a ham radio operator) I thought I knew what to look into. Improved noise figure, and minimizing losses in the front-end band-pass filter wre the things to look at. My mentor/supervisor explained to me that may be the theoretical approach, but in the "real world" the problem was the crowded VHF spectrum leads to intermodulation products that masked the desired signal. Thus the real assignment was to come up with a mixer design that would be used with NO RF amplifier in front of it that had much lower IM distortion than the current state of the art. This was in 1968, and to this day I remember to ALWAYS consider the REAL WORLD aspects of any engineering problem before trying to solve it!
The title of this column is "What if Gravitational Constant G Isn't?" -- but what if it doesn't actually exist at all.
The whole concept of G comes from Newtonian mechanics, which turned out to be an approximation of Einsteinian general relativity (which itself may or may not be 100% true as per my review of Reinventing Gravity).
As per Einstein, gravity isn't an "attraction" between two masses -- but rather the masses distort the space time continuum around them and these distortions interact to produce the effect of gravity ... having said that, as far as i know, we still don;t have much of a clue as to what gravity actually is -- we waffle on about things like "gravitons" as the gravitational force carrier and people make comparisons to the Higgs Boson and the Higgs Field (which doesn't help me at all).
Drones are, in essence, flying autonomous vehicles. Pros and cons surrounding drones today might well foreshadow the debate over the development of self-driving cars. In the context of a strongly regulated aviation industry, "self-flying" drones pose a fresh challenge. How safe is it to fly drones in different environments? Should drones be required for visual line of sight – as are piloted airplanes? Join EE Times' Junko Yoshida as she moderates a panel of drone experts.