Could weaponized lasers be defeated by simple mirrors?

Ajent0ranje · 10 days

For certain lasers, the power density in a pulse can be high enough to cause multiphoton processes which create such interesting effects as metals becoming transparent for short periods at certain wavelengths (making the reflectivity negligible).

http://www.nature.com/nphys/journal/v5/n9/abs/nphys1341.html

ConfoundedThoughts · 10 days

If I can use "light" in the sense of electromagnetic waves, then a beam of hard X-rays directed at the optic chiasm should do it. Even from the side, while completely avoiding the eyelids.

optoomal2 · 12 days

NO NO NO

IamDieing · 19 days

Also, radiotherapy can shrink arterioveinous malformations inside 2 years.

SebastianMIchaeliz · 19 days

Also, hardly female. Moar boobz required.

ragault · 25 days

You are right in one respect, but this argument requires that the electron can be considered as a wave, which is extended in space and has an amplitude and a phase. You can take a snapshot in time and define a "wavefront" (or line of equal phase) which passes through multiple separated points at the same time. Points at higher or lower phase values in this snapshot represent places that the wave got to earlier or later.

There is also a defined region of space through which this wave can travel, determined by the amount of time between the emission of the electron at A and its detection at B. Outside that region of space, the amplitude of the wave is negligible or zero, meaning the electron couldn't have been detected there.

CrimsonCrossfire · 27 days

It's a beautiful ring!

hairyfro · 1 month

JWST is "only" a successor to the HST in the infrared, not in the vis and UV. That being said, to see further, we have to look at longer wavelengths due to the redshift in the light emitted by objects due to their motion away from us (... not being a space telescope guy myself, I am sure there are many redditors here that can add detail if necessary). But, if I read correctly the Hubble is past use-by date on a number of technical levels rather than just being superseded and put out to pasture. There seems to be limited opportunities for upgrades and equipment replacements. There is a write up about the future post-Hubble in the wiki article under "Successors".

hairyfro · 1 month

The price tag of the James Webb Space Telescope project is estimated at about half of that (estimated 8.7B in 2011). This will be a successor to Hubble, and will mostly see in the infrared looking for information about the formation of galaxies and stars/planets.

Breokz · 1 month

At the moment the barrier to this is the resolution vs the field of view.

To make an image at cellular level requires about micrometer resolution. For example a human red blood cell is about 6 microns wide. A passport photograph has a field of view of, say, 50x50cm. To express that field of view in micron-sized pixels, such that you could zoom into an arbitrary point with no change of scale into the micron level, the whole image would be a 250,000 megapixel image - or about 0.25 to 1.0 terabytes of data depending on the bit-depth of each pixel.

Each pixel in an image represents a spatial average over the area of the pixel, and unfortunately, digital zoom-enhance after the fact, à la CSI, doesn't work because we can't create data where there is none.

A preferable way to image this would be to do exactly like the zoom function on a microscope does, and only zoom in onto the area of interest, which is identified at lower resolution from a larger field of view scan. This way you get the high resolution information where you need it, without wasting a lot of time and storage space to scan unimportant or uninteresting regions at high res.

woahification · 1 month

I would think that the reason is mostly scattering of the light. You do see some of the light intensity coming through the tissues, but this is very diffuse and has been scattered many times. Therefore, what you see is not a shadow because the light is not travelling in a straight line from the source to your eyes.

This contrasts with hard X-rays which can travel in an almost straight line through the tissues. In that case, when you measure the transmitted X-rays with a film or X-ray detector, the projection image is a clear shadow of the materials in the beam path (with a little blurring due to the size of the source).

ftang777 · 1 month

There is a range of drugs called nootropics which are also referred to as smart drugs or cognitive enhancers. People report that they help to extend memory, concentration, attention span, etc.

Some of them have been studied for a long time, e.g., Piracetam.

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

splarkpug · 1 month

Over the years many amateur astronomers have discovered things which have remained unnoticed by "professionals".

Erotey · 2 months

Already patented: http://www.patentlysilly.com/patent.php?patID=7122000

lee_jihoon · 3 months

An average piece of human hair is about 0.05 to 0.08 mm in width. We can see much smaller things than that, especially isolated things. Resolving very small things that are very close together, such as a lines on a grating or a mesh, or pits on a CD (0.0005 - 0.003 mm), becomes difficult because they approach the wavelength of visible light, and begin to diffract it causing you to see rainbow colors instead of a true image of the object.

cerpintaxt33 · 3 months

You're right. You can even buy little stick-on mirrors that have a convex shape, allowing you to see the presence of something in the blind spot. But that doesn't sell cars. Telling people that they have a radar that keeps their family safe does.

JoesephSchmoeseph · 3 months

In terms of creating images, broadly speaking, the "resolution limit" usually depends on the wavelength of the probe you are using, and aberrations in the focusing optics used to form the probe or resolve the final image. So with visible light it's very difficult, without certain tricks such as used in STED microscopy, to make images of objects smaller than about 380 nanometers, the wavelength of blue light. Light with shorter wavelengths than this, in the UV and X-ray spectrum, can be used to make images of correspondingly smaller things, currently down to about 5 or 10 nanometers. The limitation is really in the optics at this point: hard X-rays have wavelengths in the 0.1 nm range and so far the best optics in the world can focus to about 100x that wavelength.

Electrons also have a (deBroglie) wavelength, which is much shorter than this and is dependent on their energy, so that's why a beam of high energy electrons (200-300 keV, wavelength about 0.5 picometers) in a transmission electron microscope can be used to make images with about 50 picometers resolution, today. Again the limitation is the electron optics.

50 picometers is still fifty million times longer than the attometer length scales you mentioned. At 1 TeV, an electron would be moving about 99.99997% light speed and have a deBroglie wavelength of 1 attometer... with the right optics maybe it could be said to be capable of probing matter at that resolution? What the images would look like, nobody knows. As colcechristensen said, it's a different world down there.

economad · 3 months

In optics terms... ideally it should be some kind of ellipsoidal shape, where one of the foci is at the average location of the urine source, and the other focus is near the plughole... this way any stream hitting the urinal coming from the source should be roughly reflected toward the plughole. The failure comes from the different locations (height and position) of the source compared to the design, and the differences in force of the reflected stream resulting in a multiple reflection.

man_in_the_mirra · 3 months

Probably still enough for 80% of computer users today.

McStrauss · 4 months

By being able to see "far" in space, I guess that you mean zoom in on very small details, making them fill the screen? In that case the angular resolution of the telescope is the main factor, and it depends on the wavelength of the radiation the optics are sensitive to, and the diameter of the lens (numerical aperture). For very short wavelengths such as hard X-rays it becomes difficult to produce lenses (or mirrors) which are optically perfect -- that is, which do not introduce aberrations that spoil the resolution -- in very large sizes, limiting the achievable aperture.

anonymuscles · 4 months

The title bitch does not apply to all women, but all women have a little bitch in 'em -- Ice-T

1od1 · 5 months

That is an excellent tip. I have heard the same from many sources and it seems a shopping vacation is in order!

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