Metabunk

May
22
by Mick West at 8:10 AM
(63,964 Views / 1 Likes)
17 Comments
Level Plane Title Metabunk.

Youtuber Darryle Marble, a believer in the "Flat Earth" theory, recently took a spirit level on a plane to attempt to demonstrate that the world was flat by showing the pilot never had to angle the plane down to compensate for the curve. Somehow the story went viral and the internet reacted as you would expect, with incredulity and mockery.

Unfortunately most of the reaction seemed to boil down to "what an idiot, of course the world isn't flat", when really the situation arouse from a series of misconceptions and misunderstandings of flight and physics that might be shared by many people. Very few people really think much about things like gravity, acceleration, or the curvature of the earth. Despite getting everything wrong, Marble is at least doing an experiment, so I think...
May
21
by Mick West at 2:52 PM
(22,032 Views / 7 Likes)
78 Comments
One problem I have in telling people that contrails can actually persist, and can even spread out to cover the sky, is that people tend to be suspicious of random people on the internet. So I decided to simply let 70 years of books on clouds speak for themselves.



Result: Every single book on clouds that I could find for the last 70 years says that contrails can persist for hours.

So next time some random guy on the internet tells you contrails can't persist and spread, then ask them why 70 years of books on clouds say the opposite.

My cloud book collection:
[​IMG]

Selected References:

1991: National Audubon Society Field Guide to North American Weather
https://www.flickr.com/photos/metabunk/sets/72157644020551293/
[​IMG]

1988: Exploring the Sky By Day,...
May
19
by Mick West at 8:00 PM
(928 Views / 15 Likes)
7 Comments
DSCN5041-aw.

This was a very lucky shot. I did not know the plane was there and it was only in front of the sun for about six seconds. Note also the two sunspots above and below the trail.

P900 @ 2000mm
Date Time Original: May 19, 2017, 7:47:19 PM (PDT, so 02:47AM May 20th UTC)
Approximate photo location: 38.63°, -121°

It presents an interesting geolocation opportunity for identifying the plane, due to the precisely known location the the sun at any time.
May
12
by Henk001 at 1:09 AM
(1,685 Views / 1 Likes)
6 Comments
South of the equator when you are looking south at the southern night sky you always see the same point in the sky: the south celestial pole. Therefore the lines of sight must be parallel.
Three examples
Sydney, Australia (notice the Sydney Opera House on the left)
20120618_startrails-1024.
Image Source: http://www.rc.au.net/blog/2012/06/26/kirribilli-sydney-harbour-trails/
From Reúnion
upload_2016-3-4_10-5-45.
From ESO, Chili
upload_2016-3-4_10-6-21.
So, instead of this
upload_2016-3-4_10-8-15.
We must assume this

upload_2016-3-4_10-9-51.
May
09
by Mick West at 12:13 PM
(5,337 Views / 4 Likes)
26 Comments
HD Full Disk Satellite Images Metabunk.

There are several satellites that take photos of the full disk of the earth on a regular basis, but the most impressive are the three above. The first two (Himawari-8 and GOES-16) are geostationary satellites taking photos from 22,236 miles above the Earth's equator. The third, DSCOVR is located in an orbit between the Earth and the Sun, about one million miles away. All three take several photos a day.

Quick Links To Full Disk Satellite Feeds
May
08
by Mick West at 9:53 AM
(791 Views / 2 Likes)
1 Comments
ground truth, n.
1. A fundamental truth. Also: the real or underlying facts; information that has been checked or facts that have been collected at source.
2. a. In remote sensing: information obtained by direct measurement at ground level, rather than by interpretation of remotely obtained data (as aerial or satellite images, etc.), esp. as used to verify or calibrate remotely obtained data.
2. b. Information obtained by direct observation of a real system, as opposed to a model or simulation; a set of data that is considered to be accurate and reliable, and is used to calibrate a model, algorithm, procedure, etc.

The modern scientist's understanding of the universe is built largely on trust. They trust that the reference books and the scientific literature are largely correct. They trust that the mathematical models of gravity,...
May
07
by Mick West at 6:21 PM
(2,597 Views / 5 Likes)
4 Comments
20170507-181006-wrhy8.

https://www.metabunk.org/flat/

I wrote a flat vs. globe route simulator over the weekend. It shows the shortest route between two points on a globe, a flat earth, and an standard map. The lengths of each route are calculated for the globe and the flat earth.

(Note: does not work on mobile devices, works best with Chrome)
Apr
28
by Mick West at 1:32 PM
(2,943 Views / 5 Likes)
22 Comments
solar system verify.
From past the orbit of Mars, the solar system looks a bit like the above. Earth is just a speck, not even visible here (at the end of the blue line). The sun is much larger than the earth, yet still seems small and far away. Its light shines equally in all directions.

Can we actually verify this? Can we prove the sun is not actually a spotlight shining on only half of a flat earth, like some people claim to believe?

Yes, we can do this in various ways but I like practical science experiments that are (relatively) easy to perform, so I'm going to focus on a few here, things that you can do yourself. We shall demonstrate:
  1. The size of the sun is the sky remains almost exactly the same all day long, meaning the relative change in distance is very small, so it's very far away.
  2. The Sun looks circular from every direction, so...
Apr
27
by Mick West at 10:16 AM
(3,448 Views / 4 Likes)
11 Comments
20170427-094930-2xbri.

The conspiracy-oriented group Architects and Engineers for 9/11 Truth claims there is lots of evidence the the World Trade Center towers were brought down by a complex sequence of pre-planned demolition charges using a silent yet powerful classified explosive substance capable of precisely cutting steel beams in half and then throwing them hundreds of feet in the air. They call this "nanothermite".

An obvious problem with this theory is the huge fires that burned for an hour before the buildings collapsed. Why didn't the fires set off the nanothermite?

AE911 attempts to answer this in their FAQ, mentioning the ignition of nanothermite in the detailed answer to FAQ #2:
Apr
20
by Mick West at 1:09 PM
(4,428 Views / 2 Likes)
82 Comments
DIY Theodolite.

A theodolite is a relatively simple instrument for measuring vertical and horizontal angles. It's commonly used for surveying, but you can also use one to get a rough estimate of the curvature of the Earth by measuring how far the horizon falls below eye level from different altitudes.

Modern theodolites are now often digital and expensive, but the classic theodolite still works quite well for this purpose. A classic theodolite, like the Würdemann model seen above, consists of an adjustable base that you set to level with adjustment screws and spirit levels. You then use a telescope with a crosshair to sight the distant object (the horizon in our case) and then read off the angle of the telescope for the circular scale.

You can then measure the dip of the ocean horizon from various altitudes. While...