Scientists uncover a signal sent out by the first stars in the universe


For millions of years after the Big Bang, the universe was a cold place filled with hydrogen and helium created at the dawn of the universe. 

And then, suddenly, there was light.

For the first time, a team of astronomers think they’ve detected a signal from some of the first stars that formed less than 180 million years after the Big Bang. 

Two new studies published in the journal Nature this week detail new evidence about when those stars formed after the Big Bang. 

The new work also opens up questions about those early eons after the universe came to be, and may even reveal cracks in our understanding of physics. 

The researchers behind the new work didn’t directly see those first stars bursting into being, but they did detect a faint signal showing hydrogen gas interacting with those first stars, effectively allowing the gas to be seen at various radio frequencies. 

A timeline of the universe.

A timeline of the universe.

Image: N.R.Fuller, National Science Foundation

“Finding this miniscule signal has opened a new window on the early universe,” astronomer Judd Bowman of the University of Arizona, and lead author of one of the new studies said in a statement.

“Telescopes cannot see far enough to directly image such ancient stars, but we’ve seen when they turned on in radio waves arriving from space,” he said.

How they did it

Bowman and his team made these measurements thanks to a small radio antenna in Australia, called EDGES, which was able to detect the faint signals from the first stars because of its remote location, far from radio signals created by humans. 

What Bowman and his colleagues saw in the data appeared to confirm that those first stars formed just 180 million years after the Big Bang. 

The appearance of the radio waves also seems to match the way that signal is expected to look, according to theoretical models, the study says. 

“The signature of this absorption feature is uniquely associated with the first stars,” Haystack Observatory director Colin Lonsdale, who is not an author of the study but does work on instrumentation that enabled it, said in a statement. 

“Those stars are the most plausible source of radiation that would produce this signal.”

The research team initially looked for the signal in a different radio wavelength, and when it wasn’t found, they moved to another wavelength, where they did find that tell-tale signal created by hydrogen. 

Breaking physics as we know it

The new research could also have some bearing on how we understand dark matter — the mysterious form of matter that hasn’t been directly observed but seems to dominate 85 percent of our universe. 

In theory, dark matter shouldn’t interact with regular matter, but the new study shows evidence that the hydrogen that dominated the early universe was actually much colder than expected, possibly implying that dark matter could have interacted with that early gas. 

In short, the new dark matter conclusions — detailed by Tel Aviv University astronomer Rennan Barkana in a separate study — could break physics as we understand it, if validated.

“So far we detected dark matter only through its gravitational effect on visible matter (stars and gas). The existence of some other coupling would indicate new physics and help decipher the enigmatic nature of dark matter,” Harvard-Smithsonian Center for Astrophysics astrophysicist Avi Loeb said via email. 

“It is possible, for example, that some fraction of the dark matter has a slight electric charge, so small that we would never detect it in environments other than the cosmic dawn,” Loeb, who wasn’t associated with the study, added. 

What’s next?

That said, this work is far from over. 

Scientists will have a long future in front of them filled with astrophysics experiments that will hopefully help figure out exactly what’s going on with this data. 

EDGES ground-based radio spectrometer, CSIRO’s Murchison Radio-astronomy Observatory in Western Australia.

EDGES ground-based radio spectrometer, CSIRO’s Murchison Radio-astronomy Observatory in Western Australia.

“Extraordinary claims require extraordinary evidence,” Loeb said. 

“The key for future research on this exciting frontier of the cosmic dawn would be to test the Bowman et al. result with other independent experiments.”

Those new experiments should be coming online in the coming years as well. 

While the new studies effectively detail the results from looking at this hydrogen signal in one dimension, other observatories like the Square Kilometre Array will be able to look at that signal in 3D, according to Loeb, hopefully illuminating exactly what was going on in that early epoch of the universe. 

“We should be guided by additional experiments. With future observations we will not only test the reality of the Bowman et al. signal but also be able to map the hydrogen in three dimensions…” Loeb said. 

“The details of future data will reveal whether there is excess cooling and if so whether it originates from the coupling between dark matter and hydrogen.”

from Mashable!

Obama calls out Facebook and Google and says it’s hard to know how long democracy can survive the current political climate


barack obama

  • Former President Barack Obama last week lamented the state of political discourse in the US, saying social-media platforms like Facebook and Google were "shaping our culture in powerful ways."
  • Obama made the off-the-record comments at an MIT conference on Friday.
  • The former president is the highest-profile figure known to have challenged tech giants to take more responsibility for their effects on the social fabric.

Former President Barack Obama made some revealing comments about the state of political discourse in the US, suggesting last week that tech giants like Facebook and Google were compounding problems.

His remarks were captured in an off-the-record speech at a sports conference at MIT. Audio from the presentation was first reported by Reason, a libertarian-leaning publication.

Obama spoke on numerous topics at the conference, at one point riffing on how news coverage diverged sharply among competing media outlets — often to the point that the lines between fact and opinion are blurred as coverage seems governed by ideology rather than the public good.

And he said it’s not just about Russian bots and fake news.

"This is Fox News versus The New York Times’ editorial page," Obama said. "If you look at these different sources of information, they do not describe the same thing. In some cases, they do not even talk about the same thing."

Indeed, different news outlets have, at times, taken vastly different approaches to big political stories, perhaps most notably on developments in the Russia investigations.

While commentators on left-leaning media outlets have spent considerable time dissecting the federal investigation of Russia’s meddling in the 2016 US election, Fox News and other right-leaning publications have leaned toward casting doubt on the investigators themselves.

Obama said social-media platforms like Facebook and Google were exacerbating the problem. Regarding the power that the tech giants wield over the distribution of online content, Obama said those outlets could better acknowledge their effect on "shaping our culture in powerful ways."

He called the platforms a "hugely powerful potential force for good" but added that "what’s also true is that our social-media platforms are just a tool."

"ISIS can use that tool," he said. "Neo-Nazis can use that tool."

Obama said the tech giants "have to have a conversation about their business model that recognizes they are a public good as well as a commercial enterprise."

In the case of Facebook, that particular comment hits at the heart of one of the social-media giant’s most controversial arguments: that it isn’t a media company and that it relies on its algorithms and isn’t making editorial decisions about what types of content gets seen on its platform.

Facebook has taken heavy criticism for helping propagate conspiracy theories and intentionally false stories disguised as news, which were amplified in part by the algorithm that Facebook insists establishes the company’s neutrality. Some of those algorithms have frequently promoted questionable content more prominently than news from reputable sources.

"It is very difficult to figure out how democracy works over the long term in those circumstances," Obama said.

Listen to the full audio of Obama’s speech here »

SEE ALSO: Facebook is under fire after one of its execs railed against the Russia coverage in a tweet that Trump cited

Join the conversation about this story »

NOW WATCH: Henry Blodget: Will arming teachers with guns help stop school shootings?

from SAI

The moon’s getting a mobile data network


Think of the roaming charges: The moon (yes, our orbital natural satellite) is getting a mobile network. Said network will make it possible to stream HD video live back to earth from the moon’s surface, since I guess space streaming is all the rage following Elon Musk’s Starman stunt.

The network will be put together by a group that includes carrier Vodafone Germany, hardware maker Nokia and, perhaps most unexpectedly, automaker Audi, Reuters reports. The project was announced at this year’s Mobile World Congress in Barcelona, and the target launch for the network hardware required to make it work is 2019, with SpaceX acting as launch provider.

The companies involved are working with PTScientists, a Berlin-based group of volunteer scientists who work on special projects in collaboration.

Despite the seemingly futuristic goal of putting a mobile network on the moon, this project will deploy 4G connectivity, not the next generation 5G standard currently in the early stages of a global rollout. The project’s creators opted to use the slightly older tech on purpose, however, since it’s more reliable at present and easier to engineer for use in the rigours of space .


from TechCrunch

The Best Advice for Reducing Food Waste & Saving Money — Kitchn


Food waste is something I think about a lot. I just hate throwing food away that has gone bad, whether it’s leftovers no one’s eaten or something that wilted before we got to it. Even when I look at the bits and bobs in my compost bin, I wonder if I shouldn’t be doing more with them.

Beyond just being wasteful, food waste can be a budget issue, too — if you’re throwing away food, you’re throwing away money that could have been better spent. So we reached out to our readers to hear their best tips for reducing food waste. Here are 11 of the best suggestions we got.

1. Plan your meals.

“I believe in meal planning, which includes planning to eat the leftovers for lunch the next day. Every item I buy has a plan for when and how it’s going to be used, unless I’m stocking up on sale items for the freezer.”David Lindsay

“Menu planning! Kale on sale? Plan two recipes that week that use kale and make kale chips with the leftovers. Buying chicken breast in a bulk packaging? Cook it all and use it twice that week and freeze the rest for a future soup or casserole.” Carrie Hill

“Make sure that things that might normally spoil or be partially used in a single recipe are consumed in multiple recipes/dishes throughout the week. Kale salad, kale in a soup, kale sautéed as a side… etc.” Dorothy Hunt

2. Shop more frequently.

“Plan for an extra trip to the store over an overly ambitious meal plan. If I shop for seven days worth of meals, we will always end up forgetting about something until it’s gone bad. I usually only plan for three meals and we hardly waste anything.” Erin DiNorscia Edelman

“Shopping for just three days allows for a spur of the moment meal out.” Kate McWhirter

“Buy less, but more often. When I try to plan a week always something comes up and we have to change or miss a meal, food goes rotten.” Tammy Heggerud

“I used to do a big grocery run on Sundays, but plans would always change and a lot of food ended up going to waste. Now I shop for household stuff and staples (like milk, snacks, etc.) on Sunday and during the week, dinners are planned on a day by day basis. Just stop at the store on my lunch hour or after work to pick up meat or fish and fresh produce.” Ann MacIntosh Baker

3. Buy only what you need.

“When I need fresh ingredients that I know I’m not going to eat beyond the one meal, I hit the salad bar. If I’m never going to eat a whole green pepper and need just a few carrots, and the salad bar has it!” Lisa Ku

“Don’t buy what you don’t need. Sales and bargains are great but you can only eat so much before you get sick of it or it goes bad. Buy only what you know will be consumed.”Carmine Leanza

“Buy less. Be realistic about the amount of time I have to cook and what plans for eating out I already have lined up for the week.” Tricia Bateman

“Smaller dinner amounts and smaller portions leave little to no leftovers, so there’s nothing to throw out three days later.” Dennis San Vicente

4. Buy less fresh produce that will go bad.

“Embrace canned and frozen foods….” Pam Barone

“Don’t impulse buy fruits and vegetables just because they’re on sale.” Teresa Simmons Dutton

5. Include leftovers in the meal plan.

“At least one night a week I feed my kids mac and cheese, and my husband I eat leftovers.” Grace Kelly

“Monday is ‘leftover Monday’ — that’s when everything that will go out of date is eaten. This week we had leek and potato soup for lunch and a biryani packed full of left over veg for dinner.” Carol Smith

6. Or turn those leftovers into something new and exciting.

“Learn to repurpose leftovers, especially if your family doesn’t love them. Leftover meatloaf can become shepherd’s pie, spaghetti sauce can become become chili with a few spices and some beans. Almost any leftovers can become soup or pot pie. You can also toss most meat or veggies with some cheese and add to a pie crust with eggs for quiche.” Laura Summers

“Make pasta or fried rice with all of the leftover bits. And a chopped salad of everything you can’t/don’t want to heat. If you always have a can of beans, a bag of frozen mixed veggies, and an egg on hand you can make a meal out of anything.” Erin DiNorscia Edelman

“If we have leftovers I can’t freeze, I make a quesadilla out of them: tortilla + leftovers + cheese, or I smash them into breakfast potatoes in the skillet and top with an egg for brunch.” Marianne Nt

7. Preserve things before they go bad.

“Freezing! That one leftover bowl of chili. That handful of mixed berries. Herbs. Everything comes back to life in the near future whether it is via soup, smoothies, or that night you are on your own for dinner but don’t want to cook.” Talei Hoblitzell Mistron

“I use my dehydrator to dry items like lemons going soft, nut pulp from nut milk, leftover herbs, etc. I can make teas from the herbs/fruits.” Leta Rozzie

“I save jars of pickle juice for the celery, cukes, and carrots I can’t use in time. Drop the veggies in there and let them pickle for a few days, they’re delicious!” — Rowan Roth

8. Be less picky.

“Even when the food looks like it’s going bad, most of the time, you can peel back layers or cut spots off to get to the good. Tomatoes that are starting to turn can still be made into sauce. (It’s how tabasco and ketchup are made.) Condense jars/bottles of the same item when one gets low. Add a little milk or water to a sauce or dressing to get the dregs out for a serving” Deborah Dryden Walls

9. Collect scraps for future dishes like omelets, smoothies, and soups.

“When I have small bits of bell peppers, onions, mushrooms, snap peas, broccoli, etc, I dice them and add them to the ‘omelette veggie’ bag in the freezer. Then when I want a quiche or omelette I use those frozen veggies.” Jen Sieve Hicks

“I freeze fruits and vegetables that are going bad or leftover in plastic bags and then grab them to put in the blender for smoothies and soups.” — Mary Ann Ungerson

“Save the bones from chicken and all the ends and pieces from mushrooms, carrots, onion and celery in a bag in the freezer. When you have enough, make soup stock to can or freeze.” Laura Summers

“I save the bits and bobs of leftovers and either make omelets or quiches out of them or freeze them and make ‘Refrigerator Soup’ out of it later. Always delicious!” Tawna Sue Morris

“I save veggie scraps I’m not using for broth. Carrot tops and peels, onion peels, the stems of kale, potato peels, the green tops of leeks & onions, etc. I save it all in a gallon-sized bag in the freezer and once the bag is full, just add water and spices to taste. It makes for very flavorful and vitamin-rich broth!” Dana Owens

“Saving peels and scraps for broth!!! It’s a delicious and economical way to use bits that often get tossed as ‘trash.'” Alexa Browning

10. Or feed your scraps to the compost bin, worms, chickens, or dogs.

“Get a worm farm…. all left over scraps can be turned into amazing compost to grow even more amazing food.” Joene Els

“Compost any fruit and veg for the garden.” Christine Hamilton

“Any leftover stuff that just didn’t make it goes into the compost, so at least it isn’t in the trash and my soil benefits.” Christy Shiferdek

“Keep chickens. Mine love scraps and leftovers and I get fresh, healthy eggs in return!” April Doiron

“Get a dog!” Bonnie Young

11. Practice mindfulness and gratitude.

“Think of the people who don’t have food. When you shop and do not use all of the food you buy, you are hurting a person who could not afford to buy it!” Jayshree Rai

How are you being less wasteful?

from Apartment Therapy

How Much Money You Should Have Saved By Certain Ages In Your Life? Here Are Some Guidelines


How Much Money Saved Certain Ages


Ever wonder if you are saving enough money so you’re not broke in retirement? Unless you’re a cryptocurrency millionaire my guess is that you have. I also am guessing that a lot of you reading this (a) have no idea how much you should have saved by now, (b) have not invested or saved nearly enough, and (c) will never be a cryptocurrency millionaire (unless you get all of Steven Seagal’s virtual money, then you’re golden).

So? How much money should you have saved toward retirement at certain ages in your life? Knowing that amount is half* the battle. (A totally arbitrary number, unlike the figures I will be presenting below.)

According to the fine financial folk over at Investopedia, who should know, here are some guidelines to follow…

1. Retirement Income: the 80% Rule

Most experts say your retirement income should be about 80% of your final pre-retirement salary. That means if you are making $100,000 annually at retirement, you will need income of at least $80,000 per year to have a comfortable lifestyle after leaving the workforce.

How’s that working out for you so far?

2. Total Savings: The 4% Rule

To determine the amount you will need to have saved to generate the retirement income you want, one easy-to-use formula calls for dividing your desired annual retirement income by 4%. To generate the $80,000 cited above, for example, you would need a nest egg at retirement of about $2 million.

So much math, right? That’s why financial advisors exist.

3. Multiples of Your Salary

Fidelity suggests you should have 50% of your annual salary in accumulated savings by age 30. This requires saving 15% of your gross salary beginning at age 25 and investing at least 50% in stocks.

To accomplish this, you need to have started saving 15% of your gross salary beginning at age 25 and investing at least 50% in stocks. By age 40, you should have saved twice the value of your annual salary. By age 60, you should have saved six times your annual salary. And so on.

How Much Money Saved By Certain Ages


4. Another Multiple Formula

Another formula (like the one proposed by Fidelity) holds that you should save 25% of your gross salary each year, starting in your 20s. The 25% savings figure may sound daunting, but it includes a combination of 401(k) withholdings, employer match, cash savings and even debt repayment.

Using this formula, you should have three times your annual salary saved by age 40, six times your annual salary by age 55, and eight times your annual salary by the time you are 65-years-old.

5. How Much Can You Save?

Based on figures provided by the Bureau of Labor Statistics (BLS) in its 2015 “Consumer Expenditures Survey,” the percentage of income left over (and available for savings) for workers between the ages of 25 and 74 averages 19.8% on a pretax basis.

So based on this figure you the average person has somewhere between the the two formulas that use 15% and 25% as a benchmark for how much of your gross salary should be going into savings.

As Investopedia points out, all of these numbers are not hard and fast rules. Life sometimes throws you a curve and you can’t invest as much you’d like in any given period of time. The important thing is to do your best to try to meet your savings goals you have set for each stage of your life.

Check out the full breadth of Investopedia’s retirement advice here and here and here.


The best photos taken of planet Earth last year will transform the way you see the world


1st Max Rive 8396

The natural world is a stunning place.

Every year, the best landscape photography shows off Earth’s beauty. The following photos are some of the winners from the 2017 International Landscape Photographer of the Year contest.

They highlight powerful mountains, scenes of isolation, worlds of color and light, and the abstract loveliness found in landscapes all over the world. Winning photos were shot in the wilds of Patagonia, the mountains of Iceland, and in the desert-surrounded lakes of Brazil.

They show the world in ways that will make you want to get up, pack a bag, and go exploring.

SEE ALSO: A remarkable picture of a single glowing atom just won a photography prize — here are the most eye-catching images from the competition

Cristiano Xavier of Brazil won the aerial photography award with this stunner from the Lençóis Maranhenses in northeastern Brazil.

Brazilian photographer Marcio Cabral won the long-exposure award for this galaxy-revealing shot from Veadeiros National Park in Brazil.

Huibo Hou, who’s based in San Diego, won third in the "Photographer of the Year" competition. Here, she shows the otherworldly Bisti Wilderness Area of New Mexico.

See the rest of the story at Business Insider

from SAI

How to Compress Time Into One Photo


Throughout the history of photography, many photographers have blended multiple exposures into one final image. Obviously, they didn’t shoot the exposures at the same time, but at some interval to achieve something.

One really common purpose is to remove people by shooting several photos and making sure that all areas are covered without any people and then blend all the images into one image. Another purpose of shooting multiple images is bracketing for HDR. Yet a different purpose is to compress a long time into one photo.

Italy Manarola Day to Night

In this article, you will learn how to make an image that compresses a long time-span into one image. It is a bit like a time-lapse movie sequence, but instead of making a movie you create one final image.

Like in time-lapse photography you will shoot several photos shot over a period of preferably several hours to see a change in the scenery. To make it more interesting, you shoot the photos during a change of light, like from daylight to nighttime. When you put such photos together, you get something really fascinating.

Required Gear

To be able to make such a photo you must have a camera and a tripod or similar device. While you shoot, you need to avoid touching the camera more than you have to. Therefore a cable release or remote trigger is recommended.

You will be standing still for several hours and the temperature will most likely change quite a bit. Remember to bring clothes for a change of temperature.

Australia Sydney Harbor View Time Compressed

Where to Shoot

In theory, you can shoot these kinds of photos anywhere and of anything. But since you are putting a lot of time into one single image, it is recommended that you have an excellent composition of an interesting scene.

When to shoot

You should shoot when the light changes the most, which is from daytime to nighttime or the other way around. It is this change that will make it into a remarkable photo. If you just shoot for four hours around midday, you will get a midday photo.

How to Shoot

When you shoot photos that you intend to blend into one final image, it is essential that you make sure to have an almost identical composition in each frame. You can do that by stabilizing your camera, typically on a tripod. Minor pixel shift differences can be handled later in the post-processing phase, but big differences in the composition will be really hard, if not impossible to blend.

You can either use a remote control to trigger the camera for each shot or put the camera into a time-lapse mode. The advantage of triggering the shutter release remotely yourself is that you can time your shots if something interesting happens.

As the light changes, you will need to change the camera settings.

During the daytime put your camera in Aperture Priority mode at ISO 100 and set the aperture around f/8. This mode makes sure that the images have the same depth of field and therefore are identical, except for the change of light. Do a couple of trial shots to make sure you don’t blow out the highlights or the shadows. If the image is too bright or dark, use the exposure compensation to adjust.

As it gets darker, the camera will make longer exposures and when you hit the 30-second mark, you will need to increase the ISO. You will typically end up at ISO 800 or 1600.

Sweden A Mountain Sunset in Sweden

You most likely want to switch off autofocus before it gets dark. It depends on the scenery. City photos often offer good low light autofocus points, while the contrast disappears in landscape photos and makes autofocus impossible. Alternatively, you can use Back Button Focus.

How many photos do you need?

You need at least two different photos, but any number larger than one will work. For my photo of Sydney, I used a couple of night shots. For the morning part, I only used two.

If you shoot the “many people” variation, you will need photos with interesting people in all those areas you want to be populated with people. For the photo of Manarola, Italy I used approximately 60 photos from a batch of around 200.

Switzerland Montreux Compressed Time

How to handle high dynamic range?

Some situations are hard or impossible to capture in one exposure because the dynamic range gets too high. Typically this happens in nighttime city photos or if the sun enters the frame. The difference between the strong light source and the shadows is too great to capture in one single exposure.

In these situations, you must either switch to Auto Exposure Bracketing (AEB) or do some manual exposure compensation.

How to blend the photos

You can use any layer-based photo editing tool to blend the photos together. I will demonstrate using Photoshop, but Photo Affinity, GIMP or any other similar photo editing tools can do the same.

UK Lake District Time Compressed

The overall process is to pick one of the good photos from the shoot as the base photo. Then you handpick a set of other photos that you want to blend into the base image.

The technique you are going to use to blend is called “Layer Masking”.

Step 1

Put all the photos you have picked into an empty folder on your computer. JPEGs are fine, but you can also use RAW files.

Step 1 image folder with images - How to Compress Time Into One Photo

Step 2

Pick your base photo and open that in Photoshop.

Step 3

Pick another photo with different light. Load that in into Photoshop by dragging the file onto the base image. Position the photo and press enter.

Notice that you now only see the top layer.

Step 3 image drag layer into place - How to Compress Time Into One Photo

Step 4

Add a mask to the top image, by selecting the top layer and clicking Layer > Layer Mask > Hide All. You have now added a Black Mask. Notice that you can now see the lower image layer again.

Step 4 image The black layer mask - How to Compress Time Into One Photo

Step 5

Select the layer mask by clicking on the black mask and then select the brush tool. Select white as your brush color and set the opacity to around 50% and hardness to 0%. You want to work with a BIG soft brush for most stuff. When you need to do more detailed work, increase hardness to around 50%.

Step 5 image Select a brush - How to Compress Time Into One Photo

Step 6

Start painting in some areas and see how the image changes. Each time you click the mouse and paint in an area, the more the top image becomes visible. Play around until you see something you find interesting.

Step 7

Add more photos by dragging them into Photoshop one at a time and make sure the new layer is the top one. You can drag it to the top of the stack if it is not. Then repeat steps 4-6 again.

The final image

In the end, you will end up with several layers containing photos from which you have used bits and pieces, to create your own unique and quite fascinating image. In the image of the idyllic alp town of Hallstatt in Austria, I used 18 photos to create my image.

Tutorial image 3 An example of layers

Austria Hallstatt Day To Night

Additional things to consider

8-bit or 16-bit?

Normally you should never use 8-bit mode for image editing, but if you are blending 20+ photos, you will run into serious performance issues at 16-bit, even with a high-performance computer. One workaround is to use 8-bit at the cost of image quality. You can change the mode by going to Image > Mode > 8-bit/Channel. The downside of using 8-bit is that you may end up having banding which is when you can see the colors transition from one to the other (they do not graduate smoothly).


You have probably had to adjust the camera while shooting and most likely you will find that the images are slightly misaligned. It may not be more than a pixel or two.

Tutorial image 1 Move tool

You use the Move Layer tool to micro adjust the misaligned layer using the arrow keys.

Addition tip – try to make more than one final image from the same photos, by switching around the night and day photos.

The post How to Compress Time Into One Photo by Jacob Surland appeared first on Digital Photography School.

from Digital Photography School